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Home My WebLink About20221030.tiffPap �1 6.4.18 EXHIBIT R - Proof of Filing with County Clerk and Recorder An affidavit or receipt indicating the date on which the application was placed with the local County Clerk and Recorder for public review, pursuant to Subparagraph 1.6.2(1)(c). Proof of filing with the County Clerk, pursuant to Subparagraph 1.6.2(1)(c): Weld County Clerk to the Board 1150 O Street Greeley, Colorado 80632 Subject: Colorado Division of Reclamation Mining and Safety (DRMS), Office of Mined Land Reclamation (OMLR) Permit application for Varra Companies, Inc. — Two Rivers Sand, Gravel and Reservoir Project. Your signature below acknowledges receipt of the above referenced permit application. The application will be placed for public inspection and review by your Office. The information will be made available to the public until final agency action by the OMLR Board, as defined by C.R.S. 24-4-105(14). Date Received: Received By: RECEIVED Office of Weld County Clerk to the Board 1 PAGE OF DOCUMENT INCLUDED IN PAPER FILE. REMAINDER RETAINED ELECTRONICALLY IN TYLER. Po IOU Rview c -c-• P1CTP), Pwczrr'r!CH / �R / � c) 2022-1030 Ot-V / a a o� �oH r as STATE OF COLORADO DIVISION OF RECLAMATION, MINING AND SAFETY Department of Natural Resources 1313 Sherman St.. Room 215 Denver. Colorado 80203 Phone: (303) 866-3567 FAX: (303) 832-8106 CONSTRICTION MATERIALS REGULAR (112) OPERATION RECLAMATION PERMIT APPLICATION FORM COLORADO D 3 V E S t O N o f RECLAMATION MINING —&— SAFETY CHECK ONE: ❑ There is a File Number Already Assigned to this Operation Permit :a 41 - (Please reference the file number currently assigned to this operation) 1 New .Application (Rule 1.4.5) FL Amendment Application (Rule 1.10) ELConversion Application (Rule 1.11) Permit # NI - (provide for Amendments and Conversions of existing permits) The application for a Construction Materials Regular 1 1 2 Operation Reclamation Permit contains three major parts: (I) the application firm; (2) Exhibits A -S. Addendum 1. any sections of Exhibit 6.5 (Geoteehnical Stability Exhibit: and (3) the application fee. When you submit your application. be sure to include one (1) complete signed and notarized ORIGINAL and one ( I ) copy of the completed application form. two (2) copies of Exhibits A -S, Addendum I. appropriate sections of 6.5 (Geotechnical Stability Exhibit. and a check for the application tee described under Section (4) below. Exhibits should NOT be hound or in a 3 -ring hinder; maps should be fielded to 8 1/2'' X 1 1 " or 8 1'2" X 14" size. To expedite processing. please provide the information in the format and order described in this form. GENERAL OPERATION FNFORMATION ATION Type or print dearly, in the space provided, ALL information requested below. I Applicant/operator or company name (name to be used on permit): Varra Companies, Inc. Li Type of organization (corporation. partnership, etc.): Corporation Operation name (pit, mine or site name): Two Rivers Sand, Gravel and Reservoir Project Permitted acrcaae (new or existing site): 3.1 Change in acreage (-' ) 3.2 'i'otal acreage in Permit area 409.234 permitted acres acres acres 4. Fees: 4.1 New Application S2.696.00 application fee 4.2 New Quarry Application 53.342.00 quarry application 4.4 Amendment Fee 82.229.00 amendment fee 4.5 Conversion to 112 operation (set by statute) 82.696.00 conversion fee sand gravel earth products 5. Primate commodities) to be mined: .5.1 Incidental currnnoditie(s) to he mined: I. - 1hs/Tons/yr 3. lbs't ons yr 4. bs "Fnns'vr- 2. IbsiTOns: yr 5. lhs,Tons/Yr 5.2 Anticipated end use of primary comnloditie(s) to be mined: rural and urban infrastructure needs N/A 5.3 Anticipated end use of incidental commoditie(s) to be mined: 6. Name of owner of subsurface rights of affected land: Varra Companies, Inc. If 2 or more owners. "refer to Exhibit t)". 7. Name of owner of surface of affected land: Varra Companies, Inc. 8. Type of minim operation: Surface E underground 9. Location information: The center of the area where the majority of -mining will occur: COUNTY: Weld PRINCIPAL MERIDIAN (check one): 1 SECTION (write number): TOWNSHIP (write number and check direction): RANGE (write number and check direction): QUARTER SECTION (check one): QUARTER/QUARTER SECTION (check one): 6th (Colorado) 53 T4 10th (New Mexico) 66 NE NE r 7 North East NW r SE South 'A'est SW SW Ute GENERAL DESC'RIPT'ION: (the number of miles and direction from the nearest town and the approximate elevation): 10. Primary Mine Entrance Location (report in either Latitude/Longitude OR L'TM): Latitude `Longitude: Example: (N) 39° 44' 12.9r (W) 104' 59' ;.87" Latitude (N): deu> Longitude (W.): deg UR Lxample: (N) 39.73691' (W) - 104.98449 min Min Latitude (N) 40.348174 -104.776631 Longitude(W) OR Universal -I ram erse Mercator (UTM) Example: 201336.3 4 NAl)27 Zone 13 4398351.2 N sec (2 decimal places) see (2 decimal places) (5 decimal places) (5 decimal places) UTM Datum (specify NANAD83 or WGS 84) Nad 83 ' 3 Zone Eastina North I I. Correspondence Information: APPLIC 1\T,OPERATOR (name, address, and phone of name to be used on permit) Contact's Name: Garrett a Varra Title: President Company Name:Varra Companies, inc. Street P.t). Box: 8120 Gage Street P.O, Box: C'itG Frederick State: Colorado 7_ip Code: 80516 Telephone Number: (303 ) _ 666-6657 Fax Number: (303 } _ 666-6743 PERMITTING CONTACT (if different from applicant:operator above) Contact's Name Bradford Janes Tide: Liaison. Interdisciplinary Affairs Company. Name: Varra Companies, Inc. Street/P.O. Box: 8120 Gage Street P.O. Box: City: Frederick State: Colorado Zip Code: 80516 Telephone Number: { 303 • ] - 666-6657 Fax Number: (303 ) _ 666-6743 INSPECTION CONTACT Contact's Name: -Title: Company Name: Street`P.O. Box: P.O. Box: City: State: Zip Code: Telephone Number: ( ) - Fax Number: ( ) - C CC: STATE OR FEDERAL LANDOWNER (iranr) Agency: Street: City: State: Zip Code: Telephone Number: ( ) - CC: STAI'F.OR FEDERAL i..A\DOWNFR(tram) Agency: Street: City: State: Telephone Number: Zip Code: -4 12. Primaryfuture(Post-min inv.) land use (check one): } I Cropland(C'R) I Pasturelanci(PL) n Rangeland(RL.) IT Forestry(FR) Residential(RS) n Recreation(RC) _171 Developed Water Resources(WR) 13. Primary present land use (cheek on n �n General A.zriculture(GA) 11 ildli1e I labitat(WL) industrial/Commercial(IC) Solid Waste Disposal(WD) J Cropland(CR) •.. Pastureland(PL) - General Agriculture(GA) LI__R_ Rangeland(RL) _ Forestry(FR) Wildlife Habitat(WL) Residentia](RS} Recreatinn(RC ) IndustrialiCammercial(IC'} Developed V step Resources(WR) 14. Method of \lining: Brietly explain mining method (e.g. truck.: shovel): Surface extraction, processing, and transport of aggregate resources until bedrock establishment of final basins is complete. 15. On Site Processing: r Crush ing ' Screen i nor 13.1 Brief!explain minim method (e.g. truck'shovel): it p!yr;y exlr$;!: on pf lm[:p!1 So IH{alr!d Still aria ay„eyate 0/ eaCavaler:, dozers. scrapers. or bads hoes folio.rod by Ira n sportal,on by torlveyor or haul lrirck!a a procetisi-^5 location: whrri{r rnatpnol is crvsrlea. screened_ and ere;;arnrl and Slnr.icrr.Ief! fcif CnnlmorCial Sale and rP.!1 •.nvel freer yrspefly. Al! comeS:ea materials may he utilized fa+ ei[h or commercial purposes or on-s1!e rec lamdl!nn and develppmenl. List any designated chemicals or acid -producing materials to he used or stored within permit area: None 16. Description of Amendment or Conversion: If you are amending or converting an existing operation. provide a brief narratire describing the proposed change(s). N/A - S - Maps and E hibits: Two (2) complete, unbound application packages must be submitted_ One complete application package consists of a signed application form and the set of maps and exhibits referenced below as Exhibits A -S, Addendum 1. and the Geotechnical Stability Exhibit. Each exhibit within the application must be presented as a separate section. Begin each exhibit on a new page. Pages should be numbered consecutively for case of reference. 1f separate documents arc used as appendices. please reference these by name in the exhibit. With each of the two (2) signed application forms, you must submit a corresponding set of the maps and exhibits as described in the following references to Rule 6.4, 6.5. and 1.6.2(1)(b): EXHIBIT A EXHIBIT B I XIfIr�I'rC EXHIBIT D EXI IIBIT I EXHIBIT F EXHIBIT Cr EXHIBIT H EXHIBIT I EXHIBIT J EXHIBIT K EXHIBIT L EXHIBIT M EXHIBIT N EXHIBIT U EXHIBIT P EXHIBIT() EXHIBIT R EXHIBIT S Rule 1 .6.2(1 )(b) Rule 6.5 Legal Description Index Map Pre -Mining and Minion Plan Map(s) of Affected Lands Mining Plan Reclamation Plan Reclamation Plan Map V ater Information Wildlife Information Soils lnlisrniation 1•'ceetation Information Climate Information Reclamation Costs Other Permits and Licenses Source of Legal Right -To -Enter Owners of Record ofAffected Land (Surface Area) and Owners of Substance to be Mined Municipalities Within Two miles Proof of Mailing of Notices to County Commissioners and Conservation District Proof of Filing with County Clerk or Recorder Permanent Man -Made Structures ADDENDUM 1 - Notice Requirements (sample enclosed) Geotechnical Stability Exhibit any required sections) The instructions for preparing Exhibits A -S. Addendum 1. and Geotechnical Stability Exhibit are specified under Rule 6.4 and 6.5 and Rule I .6.2(I )(b) of the Rules and Regulations. If you have any questions on preparing the Exhibits or content of the intbrmation required, or would like to schedule a pre -application meeting VLILI may contact the Office at 303-366-3567. Responsibilities as a Permittee: Upon application approval and permit issuance, this application becomes a legally binding document. Therefore. there are a number of'important requirements which you. as a permittee. should fully understand. I hese requirements are listed below. Please read and initial each requirement. in the space provided. to acknowledge that you understand your obligations. I you do not understand these obligations then please contact this Office for a full explanation. �y • I . Your obligation to reclaim the site is not limited to the amount of the financial warranty. You assume legal liability for all reasonable expenses which the Board or the Office may incur to reclaim the affected lands associated with your mining operation in the event your permit is revoked and financial warranty is forfeited: -6- 2. The Board may suspend or revoke this permit. or assess a civil penalty, upon a finding that the permittee violated the terms or conditions of this permit, the Act. the Mineral Rules and Regulations. or that information contained in the application or your permit misrepresent important material facts; 3. f f' your mining and reclamation operations affect areas beyond the boundaries of an approved permit boundary. substantial civil penalties. to you as permittee can result: 4. Any modification to the approved mining and reclamation plan from those described in your approved application requires von to submit a permit modification and obtain approval from the Board or Office: 5. It is your responsibility to notify the Office of any changes in your address or phone number: 6. Upon permit issuance and prior to beginning on -site mining activity. you must post a sign at the entrance of the mine site. ~,which shall be clearly visible from the access road. with the following information (Rule 3.1.12): a. the name of the operator: b. a statement that a reclamation permit for the operation has been issued by the Colorado Mined Land Reclamation Board: and. c. the permit number. 7. The boundaries of the permit boundary area must be marked by monuments or other markers that are clearly visible and adequate to delineate such boundaries prior to site disturbance. 8. It is a provision of this permit that the operations will be conducted in accordance with the terms and conditions listed in your application. as well as with the provisions of the Act and the Construction Material Rules and Regulations in effect at the time the permit is issued. 9. Annually, on the anniversary date of permit issuance. You must submit an annual fee as specified by Statute. and an annual report which includes a map describing the acreage affected and the acreage reclaimed to date (if there are changes from the previous year). any monitoring required by the Reclamation Plan to be submitted annually, on the anniversary date ofthe permit approval. Annual fees are for the previous year a permit is held. For example, a permit \with the anniversary date ofJuly 1, 1995. the annual fee is for the period of July 1. 1994 through June 30, 1995. Failure to submit your annual fee and report by the permit anniversary date may result in a civil penalty, revocation of your permit, and forfeiture of Your financial warranty. It is your responsibility. as the permittee, to continue to pay your annual fee to the Office until the Board releases you from your total reclamation responsibility. 10. For joint venture/partnership operators: the signing representative is authorized to sign this document and a power of attorney (provided by the partner(s)) authorizing. the signature of the representative is attached to this application. -7_ NOTE TO COMMENTORS/OBJECTORS: It is likely there •ill be additions. changes. and deletions to this document prior to final decision by the Office. Therefore. if you have and comments or concerns you must contact the applicant or the Office prior to the decision date so that you will know what changes may have been made to the application document. The Office is not allowed to consider comments. unless they are written, and received prior to the end of the public comment period. You should contact the applicant for the final date of the public comment period. if you have questions about the Mined Land Reclamation Board and Office's review and decision or appeals process. you may contact the Office at (303) 866-3567. 8 Certification: As an authorized representative of the applicant. I hereby certify that the operation described has met the minimum requirements ol'the following terms and conditions: I . To the best of my knowledge. all significant, valuable and permanent inan-made structure(s) in existence at the time this application is filed. and located within 200 feet of the proposed affected area have been identified in this application (Section 34-32.5-115(40). C.K.S.). 2. No mining. operation will be located on lands where such operations are prohibited by law (Section 34-32.5-1'5(4)(f). C.R.S.: 3. As the applicant/operator. 1 do not have any e`tI'actionlexploration operations in the State of Colorado currently in violation of the provisions of the Colorado Land Reclamation Act for the Extraction of Construction Materials (Section 34-32.5-120. C.R.S.) as determined throuLth a Board finding. 4. I understand that statements in the application are being made under penalty of perjury and that false statements made herein are punishable as a Class I misdemeanor pursuant to Section 18-8-503. C.R.S. This form has been approved by the Mined Land Reclamation l3oerd pursuant to section 34-32.5-112,C:R. S., of the Colorful(' Land Reclamation Act the Extraction of Construction Materials. Any alteration or modification u/ this form shall result in voiding our permit issued on the altered or modified form and .subject the operator to cease and desist orders and civil penalties for operating without a permit pursuant to section 34-32.5-123, C.R.S. Signed and dated this 2- C day of� Applicant/Operator or Company. Name Signed: Title: Garrett C. Varra, President State of [ � � (i) rckdO County of 0,.S PICA I he forego tag instrument was acknowledged before me tl is 2 day of if Corporation Attest (Seal) Signed '` tiM Corporate Secretary or Equivalent Town/City/County Clerk } ) ss. 20 . h. C as Ps\d t -- JESSICA HOOVER NOTARY PUBLIC STATE OF COLORADO NOTARY ID 20044035571 MY COMMISSION EXPIRES OCTOBER 4, 2024 My Commission expires: I a / SFr '2 -4 - SIGNATURES MUST BE IN BLUE INK of Qaitra . L&'5 T•tAc_ You must post sufficient Notices at the location of the proposed mine site to clearly identify the site as the location of a proposed minim operation. The following is a sample of the Notice required for Rule ] .6.2( )(b) that you may wish to use. NOTICE `Ja-ra Conoanles, I•ir.. This site is the location of a proposed construction materials operation. (Name or the Applicant/0perator) &12Q Gage St.: Frede«ck, 3D3-G"c•E-GG5 �� Applicant/Operator) address and phone number is (Address and Phone Number of the Applicant/Operato):;C: has applied for a Reclamation Permit with the Colorado Mined land Reclamation Board. Anyone wishing to comment on the application ma! view the application at the (County Name) r'M1'a!d County C!crc .a the Board Couint\ Clerk and Recorder's Office. f Clerlk and Recorder's office Address) 1 150 0 Street, Greeley, CO 80632 and should send comments prior to the end of the public comment period to the Division of Reclamation. Mining. and Safety. 1313 Sherman St. Room 2 1 5. Denver. Colorado 80203. Certification: 1 Bradford Janes . hereby certifl•' that 1 posted a sign containing the above notice for the proposed r µ•L` lovers Sand. Gra•,ei :Ann Reservoir Project 31 March 2022 permit area known as the (Name of Operation) on (Date Posted} \ATIJR ,641fri r /A r /zte' DAT[ I r2 Pae 1 6.4.1 EXHIBIT A — Legal Description (1) The legal description must identify the affected land, specify affected areas and be adequate to field locate the property. Description shall be by (a), township, range, and section , to at least the nearest quarter -quarter section and (b), location of the main entrance to the site reported as latitude and longitude, or the Universal Transverse Mercator (UTM) Grid as determined from a USGS topographic map. A metes and bounds survey description is acceptable in lieu of township, range, and section. Where available, the street address or lot number(s) shall be given. This information may be available from the County Assessor's Office or U.S. Geological Survey (USGS) maps. (2) The main entrance to the mine site shall be located based on a USGS topographic map showing latitude and longitude or Universal Transverse Mercator (UTM). The operator will need to specify coordinates of latitude and longitude in degrees, minutes and seconds or in decimal degrees to an accuracy of at least five (5) decimal places (e.g., latitude 37.12345 N, longitude 104.45678 W). For UTM, the operator will need to specify North American Datum (NAD) 1927, NAD1983, or WGS 84, and the applicable zone, measured in meters. All lands located within the permit boundary which may be affected include those parcels located in parts of • SW/4, ; and S/2SE/4, ; all in North; Range 66 West; and, • W/2NE/4, and the E/2NE/4; ; and the W/2NW/4 and NE/4NW/4; ; all in North; Range 65 West; all in the 6th P.M.; Weld County, Colorado, and comprising 409.234± acres, more or less as determined by American West Land Surveyors, Brighton, CO. The mine entrance is identified on Exhibit C-2: Extraction Plan Map, and located as identified under NAD 83 Colorado State Plane North Zone: Lat/Long for ALL Fields: Central Field SW Entrance: Central Field N Entrance: Central Primary Entrance: NW Field S Entrance: NW Field E Entrance: NE Field SW Entrance: Latitude (N) 40.41540 Latitude (N) 40.34816 Latitude (N) 40.34174 Latitude (N) 40.34596 Latitude (N) 40.34954 Longitude (W) -104.64020 Longitude (W) -104.77656 Longitude (W) -104.77663 Longitude (W) -104.78363 Longitude (W) -104.77504 Internal from Central Field Town of Milliken is adjacent to a portion of the West Boundary Town of Evans is overlain across portions of the combined Parcels If MILLIKEN, CO 2016 EL X 0 z m m x z O TWO RIVERS SAND GRAVEL & RESERVOIR PROJECT U O D! SCALE: 1 NCH = 1 MILE VARRA COMPANIES, INC. 8120 GAGE STREET FREDERICK, COLORADO 80534 TELEPHONE: (303) 666-6657 DATE: 21 JUNE 2021 REVISION: PACE: OF 1 1J: PARCEL 4: PARCEL OWNER OF RECORD ADDRESS ADDRESS CITY STATE ZIP CODE SEE SRUCTURES/ROW/EASEMENTS, BELOW 1 105704000024 VARRA COMPANIES, INC. 8120 GAGE ST. FREDERICK CO 80534 PDC ENERGY INC. 2 105704000025 14822 HIGHWAY 396- EVANS PDC ENERGY INC. 3 105703000026 4 105703000027 5 095934300006 NOBLE ENERGY INC. 6 095933000007 14822 HIGHWAY 396- EVANS 7 105704000003 SHABLE HOMESTEAD LLC 12701 STATE HWY. 60 MILLIKEN CO 80543-9308 PDC ENERGY INC. 8 095933000023 JDLB FARM LLC 7251 W 20TH ST., BLDG LSTE 200 GREELEY CO 80634-4626 PDC ENERGY INC. NOBLE ENERGY PRODUCTION 9 095933000009 JOYCE.' ALLELY 17 DOS RIOS GREELEY CO 80634-9502 10 095933000008 11 095933400029 PDC ENERGY INC. 12 095933400030 13 095934400010 PDC ENERGY INC. 14 095934300001 TAMMY SUE CAMENISCH 14898 COUNTY ROAD 396 MILLIKEN CO 80543-9305 15 095934300005 14898 COUNTY ROAD 396 14898 COUNTY ROAD 396- EVANS MILLIKEN 16 095934400036 CITY OF AURORA CITY MANAGER 15151 E. ALAMEDA PKWY. AURORA CO 80012 17 095934400035 PDC ENERGY INC. 18 105703300004 NOBLE ENERGY INC. 19 105704400001 NOBLE ENERGY INC. 20 105704000023 21 105703100045 DIXIE WATER LLC. 400 POYDRAS ST., STE 2100 NEW ORLEANS LA 70130-3282 22 105703200041 ROBERT I LEMON 1675 BROADWAY, STE. 1275 DENVER CO 80202-4602 23 105703300007 1BS FIVE RIVERS CATTLE FEEDING LLC 4848 THOMPSON PKWY, STE. 410 JOHNSTOWN CO 80534-6511 24 105704300028 SW SPRUCE MOUNTAIN LLC 812 GRAVIER ST., STE 360 NEW ORLEANS LA 70112-1408 25 105704300030 AGGREGATOR LLC 812 GRAVIER ST., STE 360 14240 COUNTY ROAD 396- WELD NEW ORLEANS LA 70112-1408 C/O RUBY ALVAREZ 1J: OWNER: STRUCTURE - EASEMENT - ROW ADDRESS ADDRESS CITY STATE ZIP CODE TELEPHONE#: CITY OF EVANS ATTN: JIM BECKLENBERT, CITY MGR. 1100 37TH ST. EVANS CO 80620 970-475-1170 EVANS TOWN DITCH CITY OF EVANS PUBLIC WORKS 1100 37TH ST. EVANS CO 80620 970-475-1170 TOWN OF MILLIKEN ATTN: TIM SINGWALD, TOWN ADM. MILLIKEN TOWN HALL; 1101 BROAD ST. MILLIKEN CO 80543 970-587-4331 WELD COUNTY DEPT. OF PUBLIC WORKS JAY MCDONALD, DIRECTOR P.O. BOX 758 GREELEY CO 80632 970-4000-3750 X3750 CENTURY LINK ATTN: DAN ORTEGA, ENGINEER III 2505 1ST AVE. GREELEY CO 80631 855-891-4083 XCEL ENERGY ATTN: RIGHT OF WAY DEPT. 3737 WEST 10TH ST. GREELEY CO 80632 970-395-1239 CENTRAL WELD COUNTY WATER DISTRICT ATTN: RIGHT OF WAY DEPT. 2235 SECOND AVENUE GREELEY CO 80631 970-352-1284 LITTLE THOMPSON WATER DISTRICT ATTN: RIGHT OF WAY DEPT. 835 E. STATE HWY. 56 BERTHOUD CO 80513-9237 970-532-2096 SNYDER OIL CORPORATION ATTN: RIGHT OF WAY DEPT. 777 MAIN ST., STE 2500 FORT WORTH TX 76102 817-338-4043 1625 BRAODWAY, STE. 2200 DENVER CO 80202 303-592-8500 NOBLE ENERGY PRODUCTION, INC. ATTN: RIGHT OF WAY DEPT. 2115 117TH AVE. GREELEY CO 80631 970-304-5000 a.k.a., CHEVRON " 1001 NOBLE ENERGY WAY HOUSTON TX 77070 800-220-5824 DCP MIDSTREAM ATTN: RIGHT OF WAY DEPT. 3026 4TH AVE. GREELEY CO 80631 970-356-9700 NATURAL GAS ASSOCIATES ATTN: RIGHT OF WAY DEPT. 621 17TH ST., STE. 2010 DENVER CO 80293 303-623-0747 ANADARKO PETROLEUM ATTN: RIGHT OF WAY DEPT. 1201 Lake Robbins Dr. THE WOODLANDS TX 77380 832-636-1000 KERR-MCGEE OIL & GAS ONSHORE LP ATTN: RIGHT OF WAY DEPT. K.P. KAUFMAN COMPANY, INC. ATTN: RIGHT OF WAY DEPT. 1675 BROADWAY; 28TH FLOOR DENVER CO 80202 303-825-4822 PANHANDLE EASTERN PIPE LINE COMPANY ATTN: RIGHT OF WAY DEPT. 8111 WESTCHESTER DR., STE. 600 DALLAS TX 75225 800-275-7375 XCEL ENERGY ATTN: RIGHT OF WAY DEPT. 1500 6TH AVE. GREELEY CO 80631 970-395-1239 PDC ENERGY INC. ATTN: RIGHT OF WAY DEPT. 1775 SHERMAN ST.; STE.300 DENVER CO 80203 970-506-9272 POUDRE VALLEY REA ATTN: RIGHT OF WAY DEPT. 7649 REA Parkway FORT COLLINS CO 80528 800-432-1012 WESTERVELT ECOLOGICALSERVICESS ATTN: RIGHT OF WAY DEPT. 7348 S. ALTON WAY, STE9-D CENTENNIAL CO 80112 720-955-3029 "°"T Two Rivers Sand, Gravel and Reservoir Project NOTES SCALE 1 Inch = 400 feet """'": Exhibit C-1: Existing Conditions Map DATE 01 November 2021 REVISION 22 February 2022 1 OE PRO"a" Two Rivers Sand, Gravel and Reservoir Project N01''234.06±Acres Basins Total + 5.60±Acre Wash Pond R.0 RI & Easements not shown from Ex., C-1. Existing Conditions Map, are obsolete or vacated. SCALE1 loon = 200 feet °"A.'"R Exhibit C-2: Extraction Plan Map LEGEND DATE 22 February 2022 PENSION PAGE- OF I Page I 1 6.4.5 EXHIBIT D — Extraction Plan The mining plan shall supply the following information, correlated with the affected lands, map(s) and timetables: (a)description of the method(s) of mining to be employed in each stage of the operation as related to any surface disturbance on affected lands; (b)earthmoving; (c)all water diversions and impoundments; and (d)the size of area(s) to be worked at any one time. (e)An approximate timetable to describe the mining operation. The timetable is for the purpose of establishing the relationship between mining and reclamation during the different phases of a mining operation. An Operator/Applicant shall not be required to meet specific dates for initiation, or completion of mining in a phase as may be identified in the timetable. This does not exempt an Operator/Applicant from complying with the performance standards of Rule 3.1. If the operation is intended to be an intermittent operation as defined in Section 34- 32.5-103(11)(b), C.R.S., the Applicant should include in this exhibit a statement that conforms to the provisions of Section 34-32.5-103(11)(b), C.R.S. Such timetable should include: (i)an estimate of the periods of time which will be required for the various stages or phases of the operation; (ii)a description of the size and location of each area to be worked during each phase; and (iii)outlining the sequence in which each stage or phase of the operation will be carried out. (Timetables need not be separate and distinct from the mining plan, but may be incorporated therein.) (f)A map (in Exhibit C - Pre -Mining and Mining Plan Maps(s) of Affected Lands, Rule 6.4.3) may be used along with a narrative to present the following information: (i)nature, depth and thickness of the deposit to be mined and the thickness and type of overburden to be removed (may be marked "CONFIDENTIAL," pursuant to Rule 1.3(3)); and (ii)nature of the stratum immediately beneath the material to be mined in sedimentary deposits. (g)Identify the primary and secondary commodities to be mined/extracted and describe the intended use; and (h)name and describe the intended use of all expected incidental products to be mined/extracted by the proposed operation. (i)Specify if explosives will be used in conjunction with the mining (or reclamation). In consultation with the Office, the Applicant must demonstrate pursuant to Rule 6.5(4), Geotechnical Stability Exhibit, that off -site areas will not be adversely affected by blasting. (j) Specify the dimensions of any existing or proposed roads that will be used for the mining operation. Describe any improvements necessary on existing roads and the specifications to be used in the construction of new roads. New or improved roads must be included as part of the affected lands and permitted acreage. Affected land shall not include off -site roads which existed prior to the date on Page 12 6.4.5 EXHIBIT D — Extraction Plan which notice was given or permit application was made to the office and which were constructed for purposes unrelated to the proposed mining operation and which will not be substantially upgraded to support the mining operation. Describe any associated drainage and runoff conveyance structures to include sufficient information to evaluate structure sizing. Prologue: Extraction of natural resources for rock products is essential to the well-being of a community. The urban infrastructure served by development of construction materials is a local and transitional benefit. The more remote these resources are from the need, the greater the cost to the private and public community. Unlike fixed urban impacts to the landform and area ecosystems, reclamation and restoration of extracted lands allow for preservation of natural buffers, and complementary alteration of both natural and human systems. Commencing on the family farm in 1948, the Varra family combines nearly 73± years of operational experience that serves as testimony to a history of sound and thoughtfully executed operations of this kind. For the Two Rivers Sand Gravel and Reservoir Project, lands not otherwise occupied for Developed Water Resources will be improved to the highest possible end -use. Post Extraction Uses beyond the Primary Use of Developed Water Resources will likely comprise continuing and diverse general agricultural uses; as well as possible light residential, commercial, or industrial uses; as determined by right, or as otherwise authorized by the governing authority. The restoration of above ground lands to native grasses and attending large water bodies are a baseline asset to area wildlife terrestrials and avifauna. Beyond good will, there are continuing landowner philosophical and economic enticements to further benefit area wildlife populations and diversity to further the value and enjoyment of the modified and surrounding lands. These efforts laid down over time involve the considerable experience of the landowner, staff, and other resources, including periodic consultation with the Colorado Division of Wildlife, the U.S. Natural Resources and Conservation Service, Colorado State University Natural Resource Departments and Extension Service, and a multitude of other natural resource professionals; including those highly qualified organizations and professionals who have already contributed to the Exhibits included under this application. Setting: The project area lies along and within the flood plain of the South Platte and Big Thompson Rivers. The predominant location of extraction is proximal to the geological delta found near the existing confluence of the two Page 13 6.4.5 EXHIBIT D — Extraction Plan rivers (hence, the Two Rivers Sand Gravel and Reservoir Project (Two Rivers Project; or TRP); and overlies bedrock that varies in depths as shallow as 20± feet in some locations, and more commonly 30-45± feet in depth from the surface. The permit area is flanked on its immediate western boundary by agricultural operations. To the north, residential uses expand, as remnant agriculture clings to the rising ground. Unfettered agricultural and rangeland uses still thrive as they extend beyond the permit boundary east, west, and south of the permit boundary along the alluvial influences of the two rivers. To the immediate east of the TRP, riverine lands are under active transformation into a created wetland bank. It should be understood that agricultural practices will remain active over the project area until converted by resource recovery and reclamation. America's first Transcontinental Railroad was being discussed in the 1840's, and surveyed in the 1850's. The railroads began the transformation of the American West on 10 May 1869 at Promontory Point, Utah. Railroad routes were being planned for this location and surrounding lands likely soon after the end of America's Civil War. The lines planned over the Two Rivers parcels were never built. Other lines were built nearby, like the Union Pacific's Dent line, that runs parallel to this day along the south bank of the South Platte River; and below the TRP. With area railroads came increased settlement, and with population the nature of the landscape became modified to complement growing market economies of agriculture and commerce since the early 1870's. We estimate the lands hugging the two rivers were farmed and the topography gradually manipulated for agriculture following the early establishment of Greeley and LaSalle, Colorado; in 1869-70. Area crops are commonly in corn, but this has not always been the case. We postulate that near the onset of the Twentieth Century sugar beet farming began to feed the demand of area sugar beet mills, further evidenced by speculative railroad routes over and near the parcel, itself. So, the appearance of the land that we see today, is commonly different than what it appeared at the time of settlement. In order to improve the area and extent of tillable lands, even early agricultural practices included landform modification to aid the plow. Prior floodplain modification is evidenced today by the historical placement of utilitarian levees flanking the existing agricultural fields along the outer cottonwood tree lined escarpments of each river. The levees are maintained to this day, and form perimeter access to the rivers and tillable fields. Page 14 6.4.5 EXHIBIT D — Extraction Plan The later creation of farm to market County Road 396 eased access to the areas' agricultural fields, yet consequentially separates the fields at the TWP with its graveled surface, and subsequent rights -of -way and easements. The levees, public roads, cottonwood corridors and area tributaries are visible in the different map exhibit aerial images, and will not be impacted by planned extraction. All planned operations have conforming setbacks, and levee access will remain limited to wheeled vehicles during operations. Today, the upper terrace where extraction operations are planned, supports agricultural crops above the lower stream terrace formed further below and beyond the perimeter levees and cottonwood corridors that frame the adjacent active stream channels. The Fields designated for resource recovery (Central Field and North-West Field; as shown on Exhibit C - 2: Extraction Plan Map) lie over a nearly level upper terrace of the two rivers. The South Platte River borders the southern and eastern extent of planned extraction, and the Big Thompson River intersects the permit area north of the Fields. The stream terrace itself is a riparian area that supports on its flanking escarpment an uneven aged stand of Cottonwood trees. The uneven aged trees suggest this segment of the river has experienced some scouring in the past from periodic, yet commonly limited, flooding; which encourages natural regeneration of Cottonwoods. To determine the influence of past activities on groundwater, twelve (12) Piezometer Wells were located along and within the entire TRP boundary. Groundwater level information here, is based on 5.75 years of continuous monthly measurements at twelve (12) piezometer locations identified on the included Exhibit G: Water Information Map. Recorded groundwater depths vary in elevation below the surface, with a general (weighted) mean depth of 8.40± feet. Groundwater elevations are influenced by crop irrigation practices that run generally from April through September, and may occasionally lag into the middle of October. During this time groundwater depths may be skewed higher in elevation to the extreme North-eastern extents of Central Field, yet with few exceptions, groundwater elevations over the entire site remain significantly deeper than 5.11± feet from the surface, year over year, over the entire TRP area. Using the approximate surface elevation at the extreme eastern boundaries of North-West Field and Central Field, and noting that groundwater fluctuations will commonly meet at 8.40± feet below the surface, yet rarely rise more than Page 15 6.4.5 EXHIBIT D — Extraction Plan 5.11± feet from the surface, we determined the Static Water Level using the upper limit of 5.0± feet. The Cyan colored contour shown on Exhibit G: Water Information Map represents the Static Groundwater Elevation at 4675' at North-West Field, and 4673' at Central Field. Since completed reservoirs will be lined to meet State of Colorado Water Resources specifications and requirements, and since lined basins will ultimately equalize with the surrounding groundwater elevations, the Static Water Levels shown should reasonably reflect those of the both the lined or unlined state; and represent a proper reflection of the optimal surface area of the water over the finished basins. Varra Companies, Inc. has sufficient water to meet the circumstances and obligations of both the lined and unlined states; and as reflected under Exhibit G: Water Resources Information; until and unless the reservoirs have an approved liner, the Operator will dedicate sufficient waters to secure the reclamation of the resulting basins in the unlined state. Planned Field Activities: The 409.23± acre parcel boundary forms the permit boundary, as reflected on exhibit maps. All lands under its direct control within the 409.23± acre permit area, are affected lands under C.R.S. 34-32.5- 103(1), respective of this permit application. As a result, any changes required in the nature of planned extraction or reclamation will be made only through the Colorado Office of Mined Land Reclamation (OMLR), by Technical Revision only. If lands are needed beyond the designated permit boundary, those lands will be secured for the active OMLR permit by Amendment. Within the permit boundary, there are two* (2) identifiable areas designated for primary extraction, the description of which will help to explain the nature of planned extraction and reclamation. The Primary Areas of Extraction are as follows: 180.76± Acres = Primary Extraction (***) Central Field: 20-30± years (2022- '52)** 53.30± Acres = Primary Extraction North-West Field: 5-10± years (2047- '57)** 234.06± Acres = Total Primary Extraction * 175.17± Acres = Affected Lands beyond planned extraction limits 409.23± TOTAL (*) NOTE: The third area of secondary extraction is limited to apx. 5.60± Acres for a Plant Processing/Stockpile Area Pond, as further indicated, below; and is not included in this total. (**) NOTE: Final reclamation will add up to five (5.0±) years to the anticipated Life of the Mine, subsequent to completion of extraction and removal of all marketable materials. Life of Extraction is an approximation, and could lengthen or shorten the overall life of the mine depending upon market conditions. (***) NOTE: Of the 180.76± Acres of Primary Extraction, 4.22± Acres comprise an existing Farm Yard & Structures with residence. These facilities may be leased or Page 16 6.4.5 EXHIBIT D — Extraction Plan otherwise utilized as an Office and Support/Storage facilities for Operations, potable water and sanitation. Lands identified within a designated Extraction Limit may not be extracted, including the Farm Yard area, as circumstances warrant according to the discretion of the Operator. Of the outlying 175.17± Acres: 15.76± Acres = Plant Processing/Stockpile Area 5.60± Acres = Secondary Extraction - Plant Processing/Stockpile Area Wash Pond 21.35± TOTAL The remaining 153.82± acres of lands within the permitted limits may comprise planned or existing permanent access roads, levees, previously affected areas, and areas of minor to no disturbance (including public transportation corridors, right-of-way's, easements, permanent structures, river and stream terrace and cottonwood corridor buffer areas), or other farm land features or structures; or as otherwise determined from included maps and aerials. These lands may also include essential support operations, including: parked vehicles, equipment, plant site equipment and processing stockpiles, etc., not otherwise explicitly indicated or shown, but reasonably associated with operations of like kind, and may be varied in location and extent over time; or otherwise, field fit within the permit boundary as warranted. Wetland conditions appear confined within portions of the stream terrace and bank -full stage of the rivers, and along segments internal to the Evans Canal. Extraction will form a depression (basin) within the floodplain as shown in Exhibit C-2: Extraction Plan Map. Temporary above ground fill may occur within the floodplain, and as part of this permitted activity, provided the above ground volume does not exceed the below ground volume created by extraction. All product stockpiles and processing will occur within the city limits of Evans under this application, and North and outside of the floodplain boundary of the 100 -year floodplain of the Big Thompson River. The floodplain extent will be visually marked in the field to better assure the integrity of the floodplain. Material transport of raw materials from extraction locations to the plant site will occur via conveyor (see route on Exhibit C-2: Extraction Plan Map). This will in turn serve to minimize impacts to area transportation corridors. The actual location, extent, and nature of the conveyor systems not otherwise designated in this submittal will be provided as updates in the required OMLR Annual Reports. Known structures and landowners, including above and below ground utility owners, located on and within 200± ft. of the permit boundary, are shown on Exhibit C-1: Existing Conditions Map. Exhibit S: Stability Analysis - provides Page 17 6.4.5 EXHIBIT D — Extraction Plan certification from a registered professional engineer that these structures will not be harmed by planned extraction profiles and extents. Access to the Theater of Operations: Entry into the permitted areas is dependent upon the needs and necessary management of continued agricultural activities during operations, as well as essential management and mobility within the active areas of extraction, processing; and correlated need for transportation of human resources, equipment, and product. Human resources for operations, heavy equipment, and haul traffic will occur based upon the desired and dynamic activities necessitated by time and circumstance within the designated Fields. Access points for continued agricultural, extraction, and plant site operations are shown ;; on Exhibit C-2: Extraction Plan Map, as follows (NOTE: Access purpose and usage may change in time from that indicated here -in. Also, General Existing Dimensions and length of existing access roads are represented in the aerial images on the Exhibit Maps relative to the Access locations detailed, below. Modifications may occur as needed and will be reported in OMLR Annual Reports.): 0 * Entrance 1: Farmstead entrance. Limited Access. Note: Visitors will first access operations by checking in at an established plant scale -house, not here. Entrance 2: Primary Access to the lower boundary of Central Field. Entrance 3: Primary Western Access to the North-West Field. Entrance 4: Primary Eastern Access to the Wash Pond and designated Plant Site. Entrance 5: Adjacent Parcel Existing Access. Entrance 6: Oil & Gas Access into the Western Section of Central Field. Entrance 7: Primary Eastern Access to the North-West Field. Entrance 8: Primary Northern Access to Central Field. Entrance 9: Primary Northern Access into the designated Plant Site location. Entrance 10: Internal Access from Adjacent Lands. Entrance X — Agricultural/Mechanical Entrance WV — Agricultural/Mechanical — Westervelt R -O -W Access to adjacent Wetland Bank Existing roads outside of the permit boundary are shown on Exhibit C-1: Existing Conditions Map. Existing on -site internal access roads are also visible to scale in the aerial information provided under Exhibit C-2: Extraction Plan Map and other map exhibits included with this submittal. In general, Page 18 6.4.5 EXHIBIT D — Extraction Plan Operations will predominantly utilize unmodified existing agricultural field access roads (unless otherwise indicated), which will themselves be subsequently extracted in time where they fall within the extraction limits shown on Exhibit C-2: Extraction Plan Map. No other defined roads within the Extraction Limits will occur except for the temporary paths created by extraction equipment, or otherwise determined by subsequent Revision to the permit. All existing agricultural roads outside of the designated extraction limits will be retained according to the desires of the landowner. The same shall form part of the final end use of the reclaimed lands, unless otherwise indicated in this submittal or by subsequent permit revision. For purposes of this submittal, all lands within the indicated permit boundary will be considered affected lands, but only those locations between the existing access roads, and which otherwise remain above the anticipated static water level of the resulting basins, will be soiled (where soil is absent) and seeded to establish vegetation consistent with the approved reclamation plan. Area and Site Soils: Soil formation surrounding and within the project area varies according to diverse geologic, natural, and man -caused influences. The United States Soil Conservation Service, Soil Surveys, are the foundation source for understanding area soils as identified on Soil Survey Maps by their Soil Unit Number. Unit 3 Soil formations for Weld County are not easily typified or quantified as other soil units, for a reason; natural and man-made alteration and use of the land over time. Planned extraction limits will affect predominantly Unit 3 Soils. Extract from Exhibit I/J. Page 19 6.4.5 EXHIBIT D — Extraction Plan Unit 3 soils commonly form within floodplains. As a result, differing states of soil formation may exist within the soil unit designation; such as soils with little horizon development like Entisols and Inseptisols. Mollisols with deep well -developed horizons may exist in the minority and the near fringe of planned extraction. Refer to graphic above, and bleow. Enceptisol Inceptisol • :WSJ• _ - { Molisol tr Soil Morphology With over a century of agricultural manipulation of area agricultural fields, prior mixing or importation of soils for land leveling, or flood plain management in the creation of levees, may have dramatically altered the original native soil profiles and properties. The native A profile of the upland terrace found within the agricultural Fields at the TRP, is predominantly modified as a plow (Ap) layer of 6.0± to 8.0± inches. The historic practice of incorporating manure into the plow layer should have served to maintain the organic base and quality of the cropped soils and accelerated soil horizon formation and development where it was lagging. Since the cropped soils have been irrigated, care should be taken not to salvage soils greater than 12.0± inches in depth to avoid mixing of potential accumulated salts. Generally, total soil depth (including all soil horizons) over the property may vary from approximately zero inches to four [4.0±1 feet, yet predominantly having a shallow Ap plow layer of six to eight [6-8±1 inches, lacking a B profile and having the potential for a mixture of silt, clay, or gravel outcrops over random areas. Gravel depth may occur from the surface to the underlying Fox Hills Sandstone varying at approximately 30.0± to 45.0± feet over the entire property. Suitable soil in excess of that needed for reclamation will be made commercially available to meet area infrastructure and residential demand. Page 110 6.4.5 EXHIBIT D — Extraction Plan Soils found within the entire project area are described more thoroughly under Exhibit I - Soils Exhibit, and the attending Exhibit I/J - Soils and Vegetation Map, shown not to scale, above. Additional geologic considerations are also included under Exhibit S - Stability Analysis. Area and Site Geology: The area geology is typified by mixed alluvial and aeolian development, that is commonly alluvial in nature at lower elevations. As viewed in the Geologic Timeline and shown in Figure 1, below, the aggregate deposit is found between the Laramie and Fox Hills Sandstone formations, both formed during the Upper Cretaceous Period nearly 65 million years ago. The alluvium of the river valleys and aeolian sands that cap the hills formed of the Laramie formation north of the permit area are more geologically recent, developing during the Quaternary Period. ERA PERIOD EPOCH I O g 4 QLaLunary Hi..h i fiif'• klaulONSOF lig AIS AGO NOVO 0.1 fi.F4 a.8. 3.6 i.1 ! 1 ; !A A 1 3,; a 41 .1.51-u 61.0 #']k5 '4.1 199 Id(' 20.6 24.) 2a?4 Geologic Time - Livescience.com Page 111 Figure 1: Area Geology Map 6.4.5 EXHIBIT D — Extraction Plan /24 - , � Oa , j r" _-- 4f T5N R66W T 4 N ROW Ox, Nose The areas of extraction are in the alluvium whose general morphology, area and extent are better understood in Figure 1 above, and 2 and 3, below (Colorado Geological Survey). Figure 2: Area Geology 3D Oblique View Page 112 6.4.5 EXHIBIT D — Extraction Plan CORRELATION OF MAP UNITS StRFIC:L-U. DEPOSITS DEPOSITS LLJ L -L L:EFi: S_ IS of ag ❑ a. 4a, Oa Qa3 �rconfrn'itI 0g. Lr.conf rmity Of Ca:LA E 0 L L2.24 DEPO=T REPO ,ITS I I QT — ra_oze ne - -_=_iliacrne Figure 3: Surficial Deposits relative to areas shown in Figure 2, above. The aggregate deposits of Qal and Qa2 (Figure 3, above) form the bulk of the deposit planned for extraction. Depths vary by field from apx. 30 to 45 feet. Depths are shallower as the adjacent hillside rises to the north; while the deposit dips deeper toward the South -East of each designated Field. Soil Salvage: Resource recovery will commence by first removing the upper [A profile/plow layer] six to twelve inches of soil [six (6.0±) inches typical], combined with existing grass or crop stubble. Removal will utilize scrappers or excavators, aided by dozers where necessary, and hauled to the Northeast Section of Central Field. All extraction and surface related activities detailed in this application will occur under an approved Fugitive Dust Permit issued by the Colorado Department of Public Health and Environment (CDH). Until resoiling activity occurs, where harvested soils have been stockpiled and remain undisturbed for reclamation or sale, they will be seeded with the mixture specified under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. A stabilizing cover of native vegetation may take up to three years to fully establish the desired cover. In the event the native seed mixture fails, an optional mixture of predominantly introduced species will be used as a fall back to better assure a stabilizing cover of vegetation. Still, using the Page 113 6.4.5 EXHIBIT D — Extraction Plan preferred native seed mixture offers opportunity to gauge the potential performance of the selected species prior to utilizing it over larger areas requiring reclamation later in the life of the resource recovery operation. Once vegetation is established over the initial reclamation soil stockpiles, they will likely remain untouched for the life of the operation until final reclamation of remaining affected lands takes place. Where concurrent reclamation is possible, operations will utilize soil in an over the shoulder method when practical. In this manner, reclamation is expedited without increasing soil stockpile volumes while reducing expenditures related to labor, handling, and time. Dewatering: As extraction activity progresses into the aggregate profile, groundwater must generally be removed in advance through the use of pumps and subsequent discharge into area tributaries. A complete dewatering evaluation was performed by AWES in their report of 27 July 2020, as provided at the back of Exhibit G: Water Information. The report concludes that 'the results of analytical and numerical solutions indicate that the proposed mine dewatering activities will not adversely affect the regional groundwater hydrology.' The reader is further assured that all discharge of waters will be conducted under an approved CDH discharge permit. Initial dewatering of the property in preparation for extraction and resource recovery will occur by establishment of a dewatering pump and/or well in the Southern boundary near an existing agricultural pond. The point of discharge is on Exhibit G: Water Information Map. Other discharge locations may occur in time as needed and otherwise approved under the applicable CDH discharge permit requirements. Subsequent CDH approved discharge locations will be field fit and the location updated in the following OMLR Annual Report. Active Resource Recovery: Following soil salvage, the balance of the extractable deposit will be removed to the depth of the unconsolidated or weathered bedrock, transported by conveyor to the plant site pit run, and subsequently manipulated as desired by screening, crushing, washing, and other methods to size and properly dimension the earth product into diverse merchantable materials for sale. Resource recovery will commence radially North and East from a point near the existing pond and planned first discharge point shown near the Southern boundary of Central Field. There are no fixed sequences or phases scheduled as part of the extraction plan. Instead, Fields are used instead of Phases to describe the activities, since each Field can be accessed concurrently instead of sequentially with the Page 114 6.4.5 EXHIBIT D — Extraction Plan other; as reflected or otherwise updated as part of required OMLR Annual Reports. Under this method, extraction is 'pulsed.' As such, the rate of extraction and subsequent reclamation will slow or quicken according to influences of the markets, weather, and internal logistics. Flexibility in Operations encourages better outcomes when adapting to changing circumstance or unexpected field conditions, and may involve actively working different fields or different parts of the same field as necessary. Generally, flexibility aids integrity of operations and encourages optimizing operational activity and subsequent reclamation of affected lands. Therefore, any method that accelerates the extraction timeline will be utilized, and should be encouraged to better engage the unpredictable elements and variables that reasonably affect the capacities of the Operator. Exhibit C-2: Extraction Plan Map, shows the location and planned extraction limits, general direction of extraction, and related features described above; along with features made obvious in the included aerial image of the permit location and surrounding lands. Additional information is provided under Exhibit C-1: Existing Conditions Map; which shows all known current and active significant man-made structures located on or within 200 feet of the permit boundary detailed under including creeks, roads, buildings, oil and gas facilities [such as tanks, batteries, wells and lines], and power and communication lines and support structures, easements and rights -of -way; located over the permitted lands or within 200 feet of the same. A listing of the adjoining surface owner's names and addresses located within these areas are listed under Exhibit C Text, correlated with those shown in the afore -mentioned Exhibit C-1: Existing Conditions Map. The extraction limits assure through the use of setbacks that other interests are not affected by planned extraction. Extraction is set back uniformly at a minimum 10.0± feet from the edge of property lines; easements and rights -of - way; underground gas lines or other underground facilities, irrigation ditches and seep ditch, wells and other structures. Specific variations in the location of: stockpiles, boundaries of extraction, and related information relative to adjacent structures and easements; from that represented on Exhibit C-2: Extraction Plan Map. Extraction will not occur closer than 125± from the face of a residential structure; unless there is a written accommodation with the owner of the residential structure that allows extraction to occur within a closer stated limit. Extraction will occur no closer than 25± feet from well heads and related above ground facilities. Extraction around well heads will be concurrently backfilled to maintain a 100± foot buffer from the balance of extracted lands. At all Page 115 6.4.5 EXHIBIT D — Extraction Plan times, safety will take precedent and over -ride all other conditions in time with a matter of safety or emergency respective to any and all aspects of the approved permit. To minimize the potential of river capture, planned setbacks from the two rivers was evaluated by Flow Technologies (refer to report at the back of Exhibit G: Water Information - titled: 'Two Rivers Riverside Berm Failure Analysis and Flood Control Mitigation Plan' of 22 January 2020). The report finds: `... that head cutting/erosion will not progress through the full length of a 100 -ft riverside berms. It is important to note that should a flood occur that results in head cutting/erosion of a riverside berm, Varra Companies, Inc. will act diligently to restore the damaged areas to pre - flood conditions. As mentioned, this analysis is conservative and riverside head cutting/erosion is based on the 100-yr flood. There is a small probability that such a flood event could occur during extraction and when the pit is dewatered. During extraction, a predominantly vertical advancing pit wall (the extraction front) is not anticipated due to the use of excavators in the removal of the material deposits. Excavators provide a great deal of control over the extraction process. The maximum length of the extraction front will likely never exceed the length of one side of a quarter section of land, or 1,320± feet, or less; in any given direction. The advancing front will result in a moving face with a slope typically equal to or flatter than 1.25H:1V, and commonly not greater than 1.25H:1V along the perimeter of the extraction limits to depth. The exception to cut perimeter slopes is shown with a distinct Red Boundary on Exhibit C-2: Extraction Plan Map, where cut slopes will not exceed 2H:1V in order to maintain integrity and stability along that designated perimeter area (refer to the AWES Slope Stability Analyses of 23 December 2019, located at the back of this exhibit). Internal transport of extracted materials to conveyor systems or other internal transport; or otherwise by approved public roadways, will be used in the transportation of extracted materials to the designated plant/stockpile location, described in greater detail, below. Acreage to be affected during the first year of extraction activities include the establishment of the initial Wash Pond and attending Settling Pond(s), Plant Site, and Initial Areas of Extraction and attending means of transportation by ground haulage or conveyor. While the acreage required for the Plant Site and Wash Pond are not expected to change, the Initial Area of Extraction will Page 116 6.4.5 EXHIBIT D — Extraction Plan expand until concurrent reclamation follows as each location is exhausted of resource. Although initial extraction may otherwise result in temporary slopes up to I.25h:lv, all cut slopes will be backfilled with unconsolidated bedrock, overburden (on -site unmerchantable excess materials, or imported inert materials) and soil to advance the reclamation and completion of the desired basins. Final reclaimed slopes and grades will be concurrently established where practical to 3h:lv, or flatter, and at a minimum from 5± feet above to 10± below the expected water level of each location of extraction, and to the basin floor. Concurrent backfilling and grading of cut perimeter slopes, while desirable, may be obstructed in time and extent by the need to maintain keyways and basin discharge during extraction. Backfilling of slopes can only occur once enough of the floor is exposed to facilitate backfilling and finished grade of extracted basin slopes without interfering with basin discharge operations. This makes concurrent backfill difficult to accurately forecast. Regardless, any completed slope remediation will be indicated in any subsequent OMLR Annual Report. Cut slopes will cause direct precipitation to drain internally into the resulting basins and are not anticipated to result in any off -site impacts due to erosion or stormwater runoff. The gentle to near flat topography of the area landscape tends to aid in overall stability above the planned areas of extraction. While some erosion of resulting basin perimeter slopes will be evident subsequent to extraction, the advance of reclamation activity over affected lands will provide cover for both near and long-term stability of those lands remaining above water level of the finished basins. All completed slopes above the anticipated static groundwater elevation will be soiled, seeded and stabilized as provided for under Exhibit E - Reclamation Plan. Of the total 234.06± acres of potential extraction, the resulting basins will function as multiple -use reservoirs with a slightly fluctuating combined water surface area covering 218.44±. The remaining balance of 3 7.9± acres of land above the anticipated high-water mark of the reservoirs, and not otherwise committed to existing or planned structures or infrastructure over the parcel, will be stabilized with vegetation; including the anticipated 16.50± acres of basin slopes reflected in the total, and 32.3 acres requiring resoiling. NOTE: Shoreline irregularities and fill to establish and enhance the aesthetic and end -use functions of the resulting basins shown on Exhibit F: Reclamation Plan Map, are illustrative only, as this effect as to location and extent will be Page 117 6.4.5 EXHIBIT D — Extraction Plan field -fit where practical, and may substantively different from that portrayed under the application. The actual location and extent will be identified in subsequent OMLR Annual Reports, and absent there, at the time of any applicable release of a location in part or whole from the permit. Since representations cannot be accurately portrayed in advance, Exhibit F simply identifies the near maximum extent [typical] of the resulting basins or ponds and the potential for shallows during lining and finished grading. The estimated timetable for extraction, commencing approximately spring to winter 2021; is estimated to take 25-30± years combined, or longer, followed by an additional five years to complete reclamation; or a total estimated life of the mine of 30-35± years; ending approximately winter 2052 to 2057. This is a life of the mine operation and all timetables are estimates and may prove shorter or longer than stated. The final determination will occur five years after the deposit is exhausted and all marketable product has been removed and necessary infill completed at the location to the point of final reclamation as approved or modified under the terms of the permit is completed. This submittal is unable to fully forecast the maximum extent of affected land expected at any given point in time, beyond an annual basis. As operational extraction and reclamation efforts will vary annually, the timing of extraction, reclamation, and life of operation as forecasts must be based on an initial estimate [refer to Exhibit L - Reclamation Costs], then subsequently verified and adjusted as reasonably determined at the time of the required OMLR Annual Report. If justified by field conditions, a rider to the warranty would follow in due course to reflect current or forecast conditions where such conditions cannot be reasonably attenuated in a timely manner prior to the due date of the next year's Annual Report. This will serve to assure flexibility and confidence in continued operations until completion of the desired end use. Additional information on the reclamation and restoration of affected lands is identified under Exhibit E: Reclamation Plan. All reclamation will follow guidelines established under Exhibit E - Reclamation Plan and Exhibit I/J: Soils and Vegetation Information, until and unless otherwise revised. To the extent possible, pond bottoms will be left rough, with the possible introduction of logs or other non -putrescent inert material to aid in aquatic habitat and cover [Refer to Exhibit H - Wildlife Information]. Plant Site Development & Operations: Plant operations are generally comprised of portable equipment. A small wash pond will be established near the onset of extraction operations as shown in Exhibit C-2: Extraction Plan Map. Deposit materials are predominantly transported or conveyed from the Page 118 6.4.5 EXHIBIT D — Extraction Plan extraction areas to the plants or surrounding yard, where subsequently processed and scaled for sale. Pit -run (unprocessed materials) may also be loaded and transported directly from the extraction areas to area markets as needed and where appropriate. Plant Site operations may also receive and process materials, and utilize fresh water supply, sourced from locations outside of the permit area or planned areas of extraction. Provisions for a material processing plant may at some point be joined by complementary processing that may include periodic use of on -site recycling facilities. While recycling activities may occur within the approved plant site/stockpile location; concrete and/or asphalt batch plant facilities and locations are not presently determined or sought at the time of this submittal. Due to the extended life of the mine the Operator desires an essential flexibility to complement future area needs according to permit requirements and approvals applicable at the time should such facilities be sought. Any facility development of this kind will be determined at that time as identified in a later Technical Revision to the OMLR under the approved permit. These potential activities are mentioned here solely for purposes of transparency in establishing these activities as acceptable, normal, and necessary activities to meet and facilitate the delivery of essential construction material needs of the area which may occur over time during the life of the approved OMLR Construction Materials Permit Operations. Initial Plant Site Theater as seen in Exhibit C-2: Extraction Plan Map With the exception of the wash pond, whose margins follow existing surface elevations; all plant site processing activities will occur on upland areas outside of the existing 100 -year floodplain. These lands occur north and Page 119 6.4.5 EXHIBIT D — Extraction Plan north-west of the existing Evans Ditch as it courses winds north of the Big Thompson River. Plant activities will require a wash plant and attending wash pond to recycle wash water and receive discharge silts and other reject fines from the washed product. Plant and Wash Pond areas are identified on Exhibit C-2: Extraction Plan Map. The wash pond will function as recycling wash water and receiving basin for reject fines for the intended Plant/Processing activities. Since the basin functions in a closed system, it will not require dewatering. Once the wash pond is established, wet plant operations can be created and join any dry plant activities in progress. Dry Plant operations can be readily established since water is not integral to their operations. Once established, wash pond water will function as a closed system. Settled materials from wash Ponds will be utilized as product or for reclamation as desired. Plant equipment will include, but is not limited to, a crusher, screens, and conveyors, scale house and scale, and attending equipment. Resulting stockpiles of pit run and processed products may be temporarily stockpiled here with processed stockpiles, or combined as needed, until transported to market. Ultimately, once the wash plant activities near the completion of extracted deposit material, the closed system wash pond will fill with silt and be revegetated in a manner consistent with Exhibit E - Reclamation Plan. Interim clean out of the wash pond will occur until that point, returning the inert materials to the bottom of exhausted pits, or utilizing it in part or in whole as product, or for purposes as substitute soil, soil additive, or as subsoil for reclamation. Plant and material processing activity will divide materials into diverse and dynamic product stockpiles that will come and go with unpredictable variations in sale and production. To the extent possible, product material will surround plant activities to further lessen visual and noise impacts to surrounding properties. Plant placement will assure that plant noise is well below that of the nearby traffic. Relative to noise, traffic travelling on area roads at 55 mph or above is approximately 70.0± decibels within 100 feet from the centerline of the Highway. Noise at ground zero at a cone crusher, as measured by a hand- held meter, is at 80.0± decibels, dropping to 70.0± decibels at I00.0± feet from the center. The level drops an additional 5.0± decibels for every 100.0± feet from the center of the crusher and surrounding plant noise, achieving residential background levels at a total setback of 400± feet. Page 120 6.4.5 EXHIBIT D — Extraction Plan Backup sirens and heavy equipment averaged 60.0± to 75± decibels, with similar decreases in decibel readings from the source measured in a manner similar to that indicated for the crusher and plant equipment sources. Plant stockpiles will aid muting of plant sourced noise just as noise levels at areas of extraction are buffered with increasing depth of extraction. The location of the portable scale and scale house and correlated internal traffic at the plant site location will vary depending upon production levels and areas needed for product stockpiling. Regardless, the scale house will be located along internal paths for haul trucks, where finished material will be weighed and disembarked to help build the urban matrix of roads, highways, foundations, and desirable neighborhoods communities most desire. For a diverse list of products to be extracted and/or processed, and sold, they may include but are not limited to the more common products identified under Table DI - Earth Products, or other inert or commonly useful products used for diverse construction purposes, including, but not limited to: structural fill, concrete products, road construction products; and other products to aid the residential, commercial, industrial customer; and for any other infrastructure use. Explosives - will not be utilized. SAND & GRAVEL READY MIX CONCRETE 8120 Gage Street • Frederick, CO 80516 Bus.: (303) 666-6657 • Fax: (303) 666-6743 11/2" Washed Rock 3/4" Washed Rock 3/8 Pea Gravel Squeegee Concrete Sand Wicking Sand Silt Concrete Mix 3/8" Pea Gravel 5/16" Chips 1/4" Chips 11/2" Road Base 3/4" Road Base PRODUCT LIST Pit Run Unscreened Top Soil Screened Top Soil Fill Dirt Class 1 Structural Fill 1/4" Crusher Fines Salt & Sand Clay 3/4" Recycled Asphalt 3/4" Recycled Concrete 3/4-11/2" Recycled Concrete 11/2-3" Recycled Concrete 4-6" Recycled Concrete Asphalt Millings F.O.B. the Pit and Delivered prices quoted upon request. Call for availability Page I 1 6.4.5 EXHIBIT E - Reclamation Plan (1) In preparing the Reclamation Plan, the Operator/Applicant should be specific in terms of addressing such items as final grading (including drainage), seeding, fertilizing, revegetation (trees, shrubs, etc.), and topsoiling. Operators/Applicants are encouraged to allow flexibility in their plans by committing themselves to ranges of numbers (e.g., 6"-12" of topsoil) rather than specific figures. (2) The Reclamation Plan shall include provisions for, or satisfactory explanation of, all general requirements for the type of reclamation proposed to be implemented by the Operator/Applicant. Reclamation shall be required on all the affected land. The Reclamation Plans shall include: (a) A description of the type(s) of reclamation the Operator/Applicant proposes to achieve in the reclamation of the affected land, why each was chosen, the amount of acreage accorded to each, and a general discussion of methods of reclamation as related to the mechanics of earthmoving; (b) A comparison of the proposed post -mining land use to other land uses in the vicinity and to adopted state and local land use plans and programs. In those instances where the post -mining land use is for industrial, residential, or commercial purposes and such use is not reasonably assured, a plan for revegetation shall be submitted. Appropriate evidence supporting such reasonable assurance shall be submitted; (c) A description of how the Reclamation Plan will be implemented to meet each applicable requirement of Rule 3.1; (d) Where applicable, plans for topsoil segregation, preservation, and replacement; for stabilization, compaction, and grading of spoil; and for revegetation. The revegetation plan shall contain a list of the preferred species of grass, legumes, forbs, shrubs or trees to be planted, the method and rates of seeding and planting, the estimated availability of viable seeds in sufficient quantities of the species proposed to be used, and the proposed time of seeding and planting; (e) A plan or schedule indicating how and when reclamation will be implemented. Such plan or schedule shall not be tied to any specific date but shall be tied to implementation or completion of different stages of the mining operation as described in Rule 6.4.4(1)(e). The plan or schedule shall include: (i) An estimate of the periods of time which will be required for the various stages or phases of reclamation; Page 12 6.4.5 EXHIBIT E - Reclamation Plan (ii) A description of the size and location of each area to be reclaimed during each phase; and (iii) An outline of the sequence in which each stage or phase of reclamation will be carried out. (The schedule need not be separate and distinct from the Reclamation Plan, but may be incorporated therein.) (f) A description of each of the following: (i) Final grading - specify maximum anticipated slope gradient or expected ranges thereof; (ii) Seeding - specify types, mixtures, quantities, and expected time(s) of seeding and planting; (iii) Fertilization - if applicable, specify types, mixtures, quantities and time of application; (iv) Revegetation - specify types of trees, shrubs, etc., quantities, size and location; and (v) Topsoiling - specify anticipated minimum depth or range of depths for those areas where topsoil will be replaced. Acknowledged. Rule 6.4.5(1) is an advisory statement, the particulars of which are provided for, below. MISSION STATEMENT: Utilizing Resource Recovery of Sand and Gravel as a Method of Conservation to Establish DEVELOPED WATER RESOURCES; and to function as a Foundation for the implementation of other beneficial Multiple End -Uses over the Property. Reclamation and Development of the Property over Time. The majority of sand, gravel and other earth product demand, like water, is the consequence of market forces resulting from urbanization. The commercial, industrial, transportation, and other land use matrixes arise to support and sustain a growing residential population. Governments count the roof tops for they rely upon public and commercial revenue to sustain the roads, schools, water supply and infrastructure needed to secure it. With continued growth of human habitat and development in Colorado, the products that make possible the construction and maintenance of it all, comes from the ground. Page 13 6.4.5 EXHIBIT E - Reclamation Plan Unconsolidated aggregate deposits simply must be taken where they are formed. The aggregate resource must be recovered from undeveloped locations first, before those locations are overtaken by ever expanding urban development; or it is lost. Now is the time and this is the geologically determined and economically feasible location from which the proposed extraction activity must occur. Hence, the Two Rivers Sand Gravel and Reservoir Project. Underlying earth resources are too often squandered when human development occurs in advance of resource extraction and recovery. Extraction and resource recovery are required by Colorado law to occur in advance of development where sand and gravel deposits are present. The resource is 'recovered' to benefit inevitable and unrelenting human habitat and infrastructure expansion, while providing a more enduring indigenous buffer to the very impacts it serves. The extraction of aggregate resource is in fact resource conservation. Beyond that, it is an essential social asset. Without earth products, transportation maintenance costs increase as infrastructure begins to fall apart. Industries begin to shrink, along with correlated revenues for state and local governments. Impacts would likely spread downstream from there, degrading schools and everything else dependent upon government revenue, as taxes increase to make up the difference. Affected populations would likely begins to flee an ever-increasing tax burden, further depreciating home values while accelerating loss of revenues from ever diminished home valuations, loss of businesses, jobs, and ultimately the very infrastructure itself. Without earth products, the economic engine and quality of life for everyone, begins to unravel. The secondary and enduring benefit of mineral extraction is in the reclamation and restoration of extracted lands. Extraction of aggregate resources is comparatively temporary and transitional by its very nature. Reclamation at this location is geared to lay a foundation that will capture both short and long- term multiple -end use benefits that will complement the dynamic mix of surrounding land uses over time. While residential, commercial, and industrial development will eventually be inspired by economic forces over portions of the Two Rivers property; the primary end use will be the creation of essential Developed Water Resources. An understanding of the vital importance of aggregate resources to the people of Colorado is not new, but well established; and protected. It remains the stated duty of any governing body in Colorado to aid in the lawful recovery of these vital mineral resources under Title 34. Section 22-5-80 of Weld County's Code of Regulations is consistent with Colorado law, both of which require that this resource must be recovered prior to other development which would otherwise impede access to it. Municipalities are obligated for the sake of their citizens to assert the same. Page 14 6.4.5 EXHIBIT E - Reclamation Plan The subsequent development of a diverse multiple land use potential at this location, when complemented with sound environmental parameters, as advanced under this application and the attending OMLR permit exhibits, is in keeping with the spirit and intent of the policies and goals of the State of Colorado, Weld County, and the Towns of Evans and Milliken. Approval of the application will allow the resource to be accessed and utilized in a responsible and orderly manner as required under both Colorado law, and consistent with local County and Municipal Regulations. Specific Reclamation Elements and Methods: This application provides substantial detail of features utilizing aerial photography that is ortho-rectified to approximately 1.0± percent of surveyed accuracy. This highly accurate and detailed portrayal of planned extraction and reclamation is visible under Exhibit C-1: Existing Conditions, Exhibit C-2: Extraction Plan Map, and Exhibit F - Reclamation Map. How reclamation will occur over affected lands is further detailed under Exhibit L - Reclamation Costs. As extraction progresses over the Fields south of the Big Thompson River, the resulting 1.25H:1V slopes (2H:1V, where indicated) created during extraction will be concurrently modified when and where practical. Concurrent reclamation is a natural incentive for Operations to speed site recovery while generally serving to lower attending financial warranty burdens. The cut slopes along the extraction limits perimeter will be finished graded by pushing the resulting pit bottom with a dozer until the resulting basin slopes conform with Rule 3.1.5(7). Since the primary end use is Developed Water Resources, the basins are intended to hold waters based upon the rights assigned by decree, or as stipulated in regulatory compliance with the Colorado Division of Water Resources, Office of the State Engineer (OSE). This may include the need to augment water sufficient to cover the anticipated exposed groundwaters of the basins in the unlined state. The entire unlined basin is or will be sufficiently covered under an approved substitute supply plan. In order to again liberate waters set aside for augmentation, the basins will at some point in the life of the activity be lined to segregate the basin from Colorado groundwaters. Lining of basins involves the placement of low permeability compactable fill, from on -site or other suitably sourced geologic materials, into the keyway; the same keyway used to facilitate discharge to keep the basins dry and free of groundwaters at the time of extraction. The balance of the basin floors and slopes are also covered and compacted with the same materials until it meets the standards established under the August 1999 State Engineer Guidelines for Lining Page 15 6.4.5 EXHIBIT E - Reclamation Plan Criteria. Typical to obtaining approval for the constructed liner, the lined basin must pass a 90 -day leak test. Correspondence from the OSE approving the construction of the lined basin will be submitted to the OMLR on receipt; or as part of any request for release of the permit, in part or whole. Essentially, the pushed parent rock material will form the minimum 3h:ly slopes of the basin and be compacted to a permeability of 10'; forming a lined basin that complies with Colorado Water Law and Guidelines mentioned, above. In this manner, the lined basins will maintain a required separation and accounting of stored water from the underlying ground waters. Evidence of compliance with the rules and regulations of the Colorado Division of Water Resources will be provided to the OMLR on completion of the lined basins. Because Varra Companies, Inc. has sufficient water rights, the lining of the reservoirs is an option only; as in the absence of lined basins those water rights are sufficient to cover evaporative losses in an unlined state; therefore, there is no warranty needed for this consideration beyond the dedication of those waters necessary to supplement evaporation from exposed surface area of exposed groundwater during the life of the OMLR permit. A Backfill Notice is included with this application as an Addendum at the back of Exhibit E - Reclamation Plan, to facilitate the fill of portions of the extracted lands for final end -use potentials beyond water storage, which may include residential, commercial or industrial structures or uses otherwise approved, now or in the future, by Weld County, Colorado; or a Colorado municipality, as applicable. The extent and nature of the water storage basin represents the maximum build -out respective of optimal extraction of commercial product and resulting final slopes. As part of reclamation, lands situated above the anticipated final water level of the completed basins, and within 10.0± feet below the anticipated final water level of the basins, will be graded to 3H:1V, or flatter. Lands below 10.0± feet from the anticipated final water level of the basins will also be graded to 3H:1V, or flatter, unless 2H:1V slopes are otherwise approved by subsequent permit revision. Naturally occurring or previously established slopes may exceed 2H:1V where not otherwise affected by extraction activities and may not be altered as part of reclamation unless necessary to facilitate the reclamation of affected lands. All affected lands between the extraction limits and remaining above the anticipated high-water mark of the basins will be capped with a minimum of six (6.0±) inches of soil, as supported by Exhibit I & J - Soils and Vegetation Information. Timing and use of soil are detailed further under Exhibit I & J - Soils and Vegetation Information and Exhibit L - Reclamation Costs. Where compacted lands exist, and are to be revegetated, those locations will be ripped prior to re- Page 16 6.4.5 EXHIBIT E - Reclamation Plan soil application. There are no known areas of compaction at the time of this application which would require such activity; and ripping remains a contingency of the application. The final land configuration will ultimately result in two (2) reservoir basins totaling 234.06± surface acres, with a static water elevation surface area of 217.44± acres (refer to Exhibit F: Reclamation Map). The balance of unoccupied affected lands above the anticipated static water level will be stabilized where necessary utilizing the seed mixture as shown under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. Lands not otherwise occupied for developed water resources will be later developed to the highest possible end -use, and will likely comprise a mixed use which may include other general agricultural uses as well as light residential, commercial or industrial uses. The Primary Revegetation Seed Mixture, combines a thoughtful mingling of predominantly native grasses of diverse height, form, color and function, to assure that the reclaimed site can provide for a multiple -use benefit. Should post resource recovery land development be deferred, or even negated, all affected land remaining above the anticipated final water level of the resulting ponds will be stabilized with a diverse and durable cover of predominantly native grasses. This is compatible with, and an improvement over the diminished lands located in the floodplain of the two rivers, and area monocultures of residential bluegrass lawns and surrounding cropped land. Combined with the creation of waterfowl habitat, the baseline reclamation plan provided for under this submittal will provide less fragmentation of the area ecology than what may otherwise exist or transpire. As such, the operation will result in immediate and enduring positive impacts to area habitat as a long-term beneficial buffer against continued developmental impacts to the river ecosystem. Consistent with previous discussions with conservationists from the Division of Wildlife; operations will result in a desirable establishment of irregularities for the finished reservoirs. For example: The basin irregularities will be provided for, both by direct concurrent grading, post mine landform grading and establishment, and use of fill from excess or residual materials and reject fines from the operations. Shallower locations due to variations in site geology may allow for the creation of other shoreline features through the placement of fill. Due to the unpredictable nature of the anticipated geology [actual depth of material and type will vary - extraction and pond depths are approximated typical maximum extent] and other factors, it is a near misrepresentation to Page 17 6.4.5 EXHIBIT E - Reclamation Plan forecast the final appearance of the ponds, as it creates an unrealistic expectation in a regulated environment on the minds of various regulating agents, the general public, and on Operations. Simultaneously, setting false expectations about the final appearance of the ponds, beyond that already portrayed, will drain flexibility from Operations essential to the creation of more desirable effects, while simultaneously exerting pressure for needless and on- going revisions to the permit. It should be remembered that the Annual Report to the OMLR will provide a graphic record of this effort. Since the pace occurs over many years, there is ample time for reflection and analysis of the effort. Time and timing will also come into play respective of materials to be used as fill. The utilization of fill is dependent upon the space available for deposition over completed areas of extraction in relation to the rate of creation of reject fines and or other deposit materials. Other influences will be the attending space for stockpiling, uses, or market conditions for fill material. Some locations will be more advantageous to fill at a given point in time than others, and the attending circumstances cannot be reasonably anticipated. The random nature of this limitation will actually aid in furthering the establishment of preferred non -geometric patterns of the finished ponds. Exhibit F - Reclamation Plan Map, represents the regulated base for which reclamation must be judged as adequate for release. At the very least, the basins delineated under Exhibit F - Reclamation Plan Map, provide desirable shoreline irregularity and slopes in conformance with existing statutory requirements. Anything more is a bonus, for everyone, and every opportunity will be made to take advantage of it, as stated above. Since the creation of aesthetic effects, edge effect, and other natural landforms, remain subjective and empirical, the stated intentions and any resulting efforts to achieve such effects, beyond those identified in the approved seed mixture and as portrayed in Exhibit F - Reclamation Plan Map, is commendable, and to be encouraged. Placement of soil and initial stabilization of affected lands with a stabilizing cover of grasses will better assure a foundation for later vertical development and establishment of cover; whether resulting from natural invasion or direct planning of trees, shrubs, and forbs. By themselves, the grasses will provide a stable foundation for later enhancements, while visibly improving wildlife habitat by interrupting area monocultures. While end use development beyond that already described cannot be fully determined or detailed at this time, the trend toward continued residential, commercial and industrial development is self- evident on surrounding lands. Although the establishment of native grasses is a primal requirement under this permit, the incorporation of forbs, shrubs and trees remains at the Page 18 6.4.5 EXHIBIT E - Reclamation Plan discretion of the landowner. Markets and the inherent values of the landowner to enhance the multiple end use worth of the property will serve to encourage the vertical development and diversity of the area vegetation with the contribution of forbs, shrubs, and trees. The purpose is to add cover, food source for wildlife and pollinators, and stratified creatures that will come to inhabit and depend upon the natural configuration, character and extent of the finished landform and diverse stabilizing cover. It should also be kept in mind that extraction is occurring within an area formerly occupied by monocultural crops, The cottonwoods along the lower terrace of the two rivers will be preserved in the majority. A light culling of a few cottonwoods may occur to assure the integrity of the intended conveyor line and wash basin; or as needed to assure the protection of personnel. The riverine areas will otherwise remain untouched, further complementing the utility of the reclaimed and restored expanse. Whatever long-term development occurs at the location, and on surrounding lands, resource recovery and correlated reclamation at this location will tend to direct human densities away from the two rivers. The reduced densities will produce direct and indirect long-term wildlife benefits and diverse multiple end -use potentials involving inherent wetland development, water resources development, water fowl improvement, and other desirable effects. The long-term worth of this effect will serve to increase the other long-term values for everyone in the area communities formed by the towns of Evans and Milliken; and greater Weld County. The final acreage of land remaining for development relative to surface acres of resulting ponds is illustrated on the following Exhibit F - Reclamation Plan Map. The map details the post resource recovery land form establishment. The size of the resulting basins is a function of area geology and available resource relative to man-made obstructions that serve to prohibit a greater linkage. The estimated timetable for extraction, commencing approximately spring to winter 2022; is estimated to take 25-30± years combined, or longer, followed by an additional five years to complete reclamation; or a total estimated life of the mine of 30-35± years; ending approximately winter 2052 to 2057. This is a life of the mine operation and all timetables are estimates and may prove shorter or longer than stated. The final determination will occur five years after the deposit is exhausted and all marketable product has been removed and necessary infill completed at the location to the point of final reclamation as approved or modified under the terms of the permit is completed. Continued...next page... Page 19 6.4.5 EXHIBIT E - Reclamation Plan Miscellaneous considerations: Fertilizer may be utilized as part of revegetation efforts. The need for fertilization and any subsequent fertilizer rates will be determined based upon soil tests taken at the time of reapplication of salvaged soil to affected lands remaining above water level. Status of fertilization and soil test results can be included in OMLR Annual Reports, as warranted. Refer to Exhibit I - Soils Information. Weed Control may involve a mix of mechanical or benign vinegar -based sprays as control methods. Treatment and control of noxious or nuisance weeds will be reported in OMLR Annual Reports as warranted. A Backfill Notice follows this page. The flexible use of inert fill will facilitate the timely reclamation of affected lands. Page 110 6.4.5 EXHIBIT E - Reclamation Plan BACKFILL NOTICE: Inert fill may be imported, or utilized from existing on -site sources, to meet or exceed planned post extraction land use development potentials over the project area during the life of the operation. The extent and location of fill will be field determined. All inert materials used for backfilling will be consistent with OMLR Rules and Regulations, and those of the Colorado Department of Health and Environment. All backfill material will be placed with sufficient fines to minimize voids and settling of backfilled areas and slopes. There are no known or expected acid forming or toxic producing materials or refuse at this location, nor will materials known to possess such qualities be knowingly utilized for fill. Any other refuse or reject materials that do not meet the definition of inert and requiring removal and disposal will be placed in closed containers and taken to an appropriate landfill for disposal, unless it is otherwise 'inert,' per Rule 3.1.5(9), of the OMLR Rules and Regulations. All materials, whether extracted on -site or imported, will be handled in such a manner so as to prevent any unauthorized release of pollutants to surface or ground water resources. All fill will be integrated to meet or exceed the reclamation plan and correlated end uses authorized under the approved Colorado Office of Mined Land Reclamation permit. All fill above the anticipated static water level of the resulting basins will be soiled and stabilized according to the approved reclamation plan, or as otherwise allowed according to allowed under this application or locally approved land uses. The location and extent of fill utilized over extracted lands will be designated in required OMLR Annual Reports, permit revision, or as part of any request for release of the permitted area, in part or whole. I, Garrett C. Varra, hereby attest that the material to be utilized as inert fill in the area described as the Two Rivers Sand, Gravel and Reservoir Project; is clean and inert as defined in Rule 1.1(20), of the OMLR Rules and Regulations. Garrett C. Varra, President Varra Companies, Inc. Page I 1 BACKFILL NOTICE: Inert fill may be imported, or utilized from existing on -site sources, to meet or exceed planned post extraction land use development potentials over the project area during the life of the operation. The extent and location of fill will be field determined. All inert materials used for backfilling will be consistent with OMLR Rules and Regulations, and those of the Colorado Department of Health and Environment. All backfill material will be placed with sufficient fines to minimize voids and settling of backfilled areas and slopes. There are no known or expected acid forming or toxic producing materials or refuse at this location, nor will materials known to possess such qualities be knowingly utilized for fill. Any other refuse or reject materials that do not meet the definition of inert and requiring removal and disposal will be placed in closed containers and taken to an appropriate landfill for disposal, unless it is otherwise 'inert,' per Rule 3.1.5(9), of the OMLR Rules and Regulations. All materials, whether extracted on -site or imported, will be handled in such a manner so as to prevent any unauthorized release of pollutants to surface or ground water resources. All fill will be integrated to meet or exceed the reclamation plan and correlated end uses authorized under the approved Colorado Office of Mined Land Reclamation permit. All fill above the anticipated static water level of the resulting basins will be soiled and stabilized according to the approved reclamation plan, or as otherwise allowed according to allowed under this application or locally approved land uses. The location and extent of fill utilized over extracted lands will be designated in required OMLR Annual Reports, permit revision, or as part of any request for release of the permitted area, in part or whole. These representations are authorized as is or otherwise modified under the signed original approved OMLR permit, until or unless subsequently modified by an approved OMLR Technical Revision. Pae 1 6.4.6 EXHIBIT F - Reclamation Plan Map The map(s) of the proposed affected land, by all phases of the total scope of the mining operation, shall indicate the following: (a) The expected physical appearance of the area of the affected land, correlated to the proposed mining and reclamation timetables. The map must show proposed topography of the area with contour lines of sufficient detail to portray the direction and rate of slope of all reclaimed lands; and (b) Portrayal of the proposed final land use for each portion of the affected lands. Please refer to the included Reclamation Map. "°"`r Two Rivers Sand, Grovel Reservoir Project NOTES SCALE 1 inch = TOO feel °"'": Exhibit F: Reclamation Plan Map DATE 02 February 2022 DEvISION PAGE: 1 OF 1 Pae 1 6.4.7 EXHIBIT G - Water Information (1) If the operation is not expected to directly affect surface or groundwater systems, a statement of that expectation shall be submitted. (2) If the operation is expected to directly affect surface or groundwater systems, the Operator/Applicant shall: (a) Locate on the map (in Exhibit C) tributary water courses, wells, springs, stock water ponds, reservoirs, and ditches on the affected land and on adjacent lands where such structures may be affected by the proposed mining operations; (b) Identify all known aquifers; and (c) Submit a brief statement or plan showing how water from de -watering operations or from runoff from disturbed areas, piled material and operating surfaces will be managed to protect against pollution of either surface or groundwater (and, where applicable, control pollution in a manner that is consistent with water quality discharge permits), both during and after the operation. (3) The Operator/Applicant shall provide an estimate of the project water requirements including flow rates and annual volumes for the development, mining and reclamation phases of the project. (4) The Operator/Applicant shall indicate the projected amount from each of the sources of water to supply the project water requirements for the mining operation and reclamation. (5) The Operator/Applicant shall affirmatively state that the Operator/Applicant has acquired (or has applied for) a National Pollutant Discharge Elimination System (NPDES) permit from the Water Quality Control Division at the Colorado Department of Health, if necessary. (1) Operations will not adversely affect surface and groundwater systems. The manner and method of extraction is detailed under Exhibit D — Extraction Plan. Anticipated effects on surface flows are anticipated to be minor to none. Essentially, the flood plain covers a majority of the property and unless under flood conditions, upland overland flows are generally diverted by levees, surrounding roads, or grassed drainage channels; or otherwise by draining internally into existing or planned basins. a) Impacts to groundwater and area wells from groundwater discharge during mining was evaluated by AWES, LLC in their 27 July 2020 report, as included in this submittal. The report concludes: 'The results of analytical and numerical solutions indicate that the proposed mine dewatering activities will not adversely affect the regional groundwater hydrology. Based on the location of registered water wells, the saturated aquifer thickness west of the mine is sufficient to provided adequate well Pae 2 6.4.7 EXHIBIT G - Water Information yields. The predicted drawdown associated with the mine dewatering represents the worst -case scenario and a substantial amount of time will be required before maximum drawdowns will occur.' b) POST RECLAMATION IMPACTS have been minimized: i. As reflected in the comments which follow, the operation has sufficient water to leave the resulting basin in an unlined state, negating the requirement to line the basin for purposes of augmenting for evaporative loss. This satisfies any costs for lining the basin since lining the basin is optional and strictly a burden of the operator to pursue to liberate his water from the unlined state. ii. The AWES report of 27 July 2020 evidences that there will be no measurable impacts of either shadowing or mounding if the resulting basin were lined. The operation therefore includes lining of the basin as an optional phase of the reclamation of the resulting basin. Satisfaction of Colorado State Standards as to the integrity and functionality of the resulting lined basin will be made in cooperation with the Colorado Division of Water Resources, and any resulting submittals and approvals made available to the OMLR at the time of the Annual Report, or by separate cover. Whether the basin is lined or unlined, no measurable impacts to the prevailing hydrologic balance are foreseen. iii.The Flow Technologies Report of 22 January 2020, provides a plan of modified basin design to be incorporated into this submittal as a means to minimize erosion of the basin berms while optimizing the integrity of the basin from the South Platte and Big Thompson Rivers during a 100 -year flood event. iv.Addendum to the Flow Technologies Report, above; find overflow protection design specifications of 30 August 2013, as determined by Varra Companies, Inc., Brad Jones, P.E. (2) (a) Please refer to Exhibit C-1: Existing Conditions Map. (b) The known aquifer under the site is the stream alluvium. (c) Discharge water will be dissipated with hard surface riprap or established grassed waterways. Other waters are retained by internal pit drainage, directed by vegetated berms or established waterways or through the maintenance or establishment of a stabilizing cover of vegetation, or as otherwise established under an approved Colorado Department of Health stormwater permit and/or stormwater discharge permit. (3) The three components of the project water requirements are water removed for dust control, water removed with the product, and evaporation from exposed ground water. Dust will be controlled using truck sprinklers, and the estimated frequency is one to ten loads per day depending upon field conditions. Dust will be controlled using truck sprinklers, and the estimated frequency varies daily Pae I3 6.4.7 EXHIBIT G - Water Information according to seasonal influences of rain, snow, freezing, and temperatures (Refer to Seasonal Temperatures and Precipitation. At 3,000 gallons of truck capacity, the annual demand is 10.6 acre-feet. (Refer to following Chart (days of hot, freezing, rainy and snowy days derived from; https://www.bestplaces.net/weather/county/colorado/weld): 3,000 gallons per Truck Dust Suppression Month Active Days* Hot Days Rainy Days Snowy Days # Days # Trucks per day Total Trucks per month # gallons per Month total gallons per year Total Acre Feet January 25 0 4 39 1 18 54,000 0.16 February 23 0 4 34 1 16 48,000 0.15 March _ April 28 26 0 0 6 8 36 24 2 3 34 48 102,000 144,000 0.31 0.44 May 25 1 10 0 9 5 70 210,000 0.64 June 26 7 0 9 0 2 10 240 720,000 2.21 July 25 16 0 7 0 -9 10 250 750,000 2.3 August 27 12 0 8 0 -4 10 270 810,000 2.48 September 25 4 7 0 4 5 105 315,000 0.97 October November 25 23 0 0 5 5 19 34 3 2 57 30 171,000 90,000 0.52 0.28 December 25 0 4 38 1 18 54,000 0.16 303 40 77 226 1156 Annually 3,468,000 10.6 Acre Feet 1040 Trucks 1 Apr _Oct = � 3,120,0001 90%oor 9.6 Acre Feet After the water table is encountered, the water removed with the estimated 1,200,000 tons of product is 35.32 acre-feet per year. The estimated net evaporation is 2.64 feet per year. At the maximum potentially exposed ground water of 217.44± acres, the annual evaporation is 574.25± acre-feet. The monthly distribution of these estimates is shown in the following table. The reclamation plan provides that the pits may be lined after being mined. The lined pits will not require replacement water and will be used for storage. There may be incidental demand for water to establish vegetation on the site after lining is completed. However, the ultimate demand for water will be zero. Continued... next page... Pae I4 6.4.7 EXHIBIT G - Water Information MONTH PRODUCT (9.59 GAL. WATER/TON) DUST CONTROL NET EVAPOATION Tons af Trucks af ac x %ev af November 60,000 1.77 30 0.28 217.44 0.104 22.61 December 54,000 1.59 18 0.16 217.44 0.000 0.00 January 54,000 1.59 18 0.16 217.44 0.000 0.00 February 93,000 2.73 16 0.15 217.44 0.113 24.57 March April _ _ 127,500 138,000 3.75 4.06 34 48 0.31 217.44 F 0.44 217.44 _ 0.138 0.221 30.01 48.05 May 139,500 4.11 70 0.64 217.44 0.288 62.62 June 135,000 3.97 240 2.21 217.44 0.413 89.80 July 127,500 3.75 250 2.30 217.44 0.453 98.50 August 118,500 3.49 270 2.48 217.44 0.418 90.89 September 93,000 2.73 105 0.97 217.44 0.294 63.93 October 60,000 1.77 57 0.52 217.44 0.199 43.27 Apr -Oct 811,500 23.88 1040 9.56 I 497.06 TOTAL 1,200,000 35.32 1156 10.62 . 574.25 (4) Water available for supply are from Six sources: Beeline, Big Thompson, South Platte Ditch, Hayseed Ditch as decreed in Case No. 90CW174, four shares of the Rural Ditch Company as decreed in Case No. 03CW306, five shares of Last Chance Ditch Company, 25.0 shares of Godding Ditch Company, and water decreed in Case No. 01CW274. From April through October, water use at the site will be replaced to the stream system using the historical consumptive use credits from any of the sources and/or from storage. Because storage is available to regulate the supplies, only the annual historical consumptive use for the sources is shown in the following table. Source Annual Consumptive Use, a -f Beeline 87 Big Thompson & South Platte 274 Hayseed 123 Rural 434 Last Chance 1,191 Godding 384 Total = 2,493 Page I5 6.4.7 EXHIBIT G - Water Information The storage sites are lined pits described in Case No. 01CW274 decree. Water available under these storage decrees will also be stored and used for VCI operations. The storage facilities are listed in the following table. Those currently lined and approved by the state are 112, Von Ohlen, and Dakolios. VCI STORAGE FACILITIES (All Values in Acre -Feet) Reservoir Active Capacity, a -f Dead Storage, a -f 112 1,552 0 Dakolios 1,104 0 Von Ohlen 1,300 0 Kurtz 4,000 0 Total NOT TO EXCEED 7,500 A -F PER YEAR plus refill of 3,00 a -f 0 (4) A Colorado Wastewater Discharge Permit System Permit will be applied for with the Colorado Department of Health, and no discharge of waters will occur until an approved permit has been obtained. (6) The application provides for the lining of the extracted basins (please refer to the AWES Dewatering Evaluation Report of 27 July 2020. Lining will involve the utilization of suitably derived on -site materials to meet final3H:1V slopes. Subsequently, the same materials may be compacted to satisfy standards for lined basins as established and governed by the Colorado Department of Water Resources Office of the State Engineer. Once operations near completion of any lined basin, the OSE will be contacted and the lined basins will be approved by the OSE prior to use. The OSE approval letter will be provided to the OMLR as a condition of the permit as evidence that the lined basin has met the specifications necessary to pass a liner test as part of the OSE approval process. Consistent with conclusion in the AWES Report, lining of the completed basins will have 'will have a de-minimis effect on groundwater hydrology.' The report continues, adding that, `Predicted post lining head levels immediately up and downgradient of the barrier walls are within the range of normal seasonal water table elevation changes.' NOTE: Information showing baseline piezometer well readings and respective locations immediately follow this page... PRO"°" Two Rivers Sand, Gravel Reservoir Project nPw" Exhibit G. Water Information Map 234.06±Acres Basins Total PENSION LEGEND 1 inch = 300 feet DATE 22 Feb eery 2022 PAGE- 1 OF 1 AMERICAN WATER ENGINEERING SERVICES, LLC DEWATERING EVALUATION VARRA TWO RIVERS MINE 14822 396 HWY EVANS, COLORADO AWES PROJECT # 2020-VCI-P124 JULY 27, 2020 Prepared for: Varra Companies, Inc. 8120 Gage Street Frederick, CO 80516 m 71115 3;nOjk imagery Date' 6,'1'lr.2U31 Iat 11.311fl9"Ih-.lI31.1.. .b''tleY.1V.I24 email 1hi'lsY11 Prepared by: AWES, LLC 4809 Four Star Ct. Fort Collins, CO 80524 Introduction The following report presents the results of a hydrogeologic evaluation regarding a proposed dry mine gravel quarry operation to be operated by Varra Companies, Inc., (VCI) near Evans, Colorado. Varra identifies the proposed mine as Pit 124. This evaluation consisted of reviewing available hydrogeologic data and inputting those data into a numerical groundwater flow model. The model was then used to estimate the effects of dewatering operations on the surrounding groundwater hydrology. This report was prepared as part of an OMLR 112 permit application. The site location is depicted on Figure 1. Background Information The proposed gravel quarry is located in sections 3 and 4 of Township 4 North, Range 66 West and sections 33 and 34, Township 5 North, Range 66 West of the 6th Principal Meridian. The surrounding land use consists of agricultural, rural residential and oil and gas gathering. The proposed mine area occupies an estimated 380 acres with an extraction area of 270 acres. The anticipated extraction depth will vary between 12 and 44 feet below grade. Information provided by geotechnical investigation data, monitoring well water level data and water resource evaluation reports document the local and regional hydrogeology. In January 2015, 12 soil borings were drilled from ground surface to bedrock to determine the potential aggregate mass within the proposed mine boundary. These borings were completed as groundwater monitoring wells. Bedrock elevations were also obtained from studies by Colton and Finch, 1974. The depth to bedrock within the proposed mine boundary varied between 12 and 44 feet below ground surface. In general soil conditions consist of less than one to six feet of top soil and sandy clay underlain by sand and gravel with occasional clay and poorly graded sand lenses. The average hydraulic conductivity of the sand and coarse gravel deposits is estimated at 125 feet per day (Schneider, 1983) which is consistent with published values and pump test evaluations conducted by the author in similar geologic settings. The average effective porosity of the local sand and gravel deposits is estimated at 0.27. The natural hydraulic gradient as documented by Dewatering Evaluation Report Varra Pit 124 Weld County, Colorado Page 2 past water resource investigation reports is on the order of 0.002 feet per foot. The average measured depth to groundwater within the mine area is 9 feet below ground surface. The natural groundwater flow direction varies from southeast to east, northeast within the model and mine area. Seasonal water table fluctuations of between one and three feet are common for this area; however, fluctuations of greater than ten feet have been documented during drought conditions (Schneider, 1983). The mine area is depicted on Figure 2. The water table in the pit will be drawn down to bedrock by allowing groundwater to flow from the side walls of the excavation into ditches excavated into the bedrock or pit bottom at the toe of the excavation walls. The ditches are sloped so water drains to predetermined pump locations. The water is then pumped from the excavation into irrigation ditches, which eventually outfall to the South Platte or Big Thompson rivers. Project Assumptions The following are assumptions made in estimating the effects of mine dewatering operations. • The aquifer within the model boundary is homogeneous and anisotropic. • The average water table altitude within the mine area varies between 4674 and 4681 feet above mean sea level. • The average horizontal hydraulic conductivity (K) of the sand and gravel deposits is 125 feet per day and the vertical K value is 12.5 feet per day. Silty sands, which are present throughout the majority of the northern model boundary, were assigned a horizontal K of 50 feet per day and a vertical K of 5 feet per day. • The vertical hydraulic conductivity of the river beds is 4 feet per day. • The hydraulic conductivity of the barrier wall material is 0.003 feet per day with a lining thickness of four feet. • Other than dewatering associated with the Pit 124 mine operations no other aquifer stresses such as drought and surrounding well use were modeled. • All groundwater solutions are steady state. • The bedrock which underlies the coarse alluvial deposits is an impermeable barrier. Dewatering Evaluation Report Varra Pit 124 Weld County, Colorado Page 3 Model Parameters The effects of dewatering on groundwater flow within the study area were evaluated by using the three dimensional groundwater flow model Visual ModFlow Pro. The general parameters used in the model are presented below. Plate 1 depicts model boundary conditions. The model grid is depicted on Plate 2. • The model boundary is 12800 feet (east -west) by 10050 feet (north -south); • The model grid is 251 rows by 320 columns or 80,320 cells; • Constant head boundaries were assigned for the dewatering line sinks; • River boundaries were assigned for the South Platte and Big Thompson rivers; • Barrier walls were assigned to the excavation limits of central and northeast and northwest pits for shadow and mounding simulations; and, • General head boundaries were assigned to the model limits (north, south, east and west). A uniform flow field was defined in the model with an unconfined aquifer. The natural groundwater flow direction varies from southeast to east, northeast within the model boundary. Water levels obtained from published water level data and existing monitoring well data were used to generate water level contours unaffected by any pumping influences. Monitoring wells within the mine boundaries were used to calibrate the model based on current conditions. Ground surface and bedrock elevations were obtained from site surveys, drill hole data and USGS maps. The ground surface and bedrock elevations were input into the geo-statistical model Surfer®, which created surface and bedrock contour maps. These surface and bedrock elevation data were imported into Visual ModFlow to define the ground surface and bedrock elevations within the flow model. The river stage elevations were extrapolated from survey data. The model was calibrated by using model assigned observation wells outside of the proposed excavations. Measured water levels (obtained from monitoring well data) were compared to the model predicted elevations. The model was adjusted using trial and error methods of reassigning river boundary conductance and general head elevations until the model predicted water table elevations closely matched measured water levels. Water table contours generated from measured water levels (VCI monitoring wells) are presented on Plate 3. The calculated head values for the model assigned wells were then used as observed levels so that subsequent model simulations would predict changes to groundwater hydrology compared to the calibrated simulation. The calibration simulation included seepage from the river boundaries. The calibration simulation is depicted on Plate 4. The model calculated head values referenced above are depicted on Plates 5 and 5A. Dewatering Evaluation Report Varra Pit 124 Weld County, Colorado Page 4 To simulate mine dewatering constant head line sinks were assigned to cells within the pit areas with head values approximately four feet above the bedrock elevation, which accounts for the predicted seepage face. To account for significant differences in bedrock elevations linear gradients were assigned to the line sinks. Varra does not intend to mine more than two pits at any one time and as a worst case scenario dewatering was simulated for the entire central and northwest pits — the largest pits within the mine boundary. Predicted groundwater contours resulting from mine dewatering are presented on Plate 6. Varra intends to line the mined out pits for water storage. To evaluate the effects of lining the three cells on the local groundwater hydrology, barrier walls were assigned near the excavation limits of the referenced cells. Plate 1 depicts boundary conditions for the lined pits. As mentioned model assigned wells were used to obtain pre -mining model predicted water levels at four locations (MW -1 — MW -4). These predicted water levels were used as a comparison to various simulations, including shadow and mounding effects. To simulate filled ponds, the interior of the reservoirs were assigned constant head values at an elevation slightly below ground surface elevations (4675 feet above mean sea level). A simulation was then run to predict the effects of the lined reservoirs on the groundwater hydrology. Plate 1 depicts the initial calibration computer simulation output. Table 1, presents the predicted water level changes as a result of lining the mined out pits. Table 1— Lined Pit Water Level Comparison Points Point Calibration Water Level Post Lining Water Level Elevation Difference (ft) MW -1 4680.39 4680.64 0.25 MW -2 4681.37 4681.82 0.45 MW -3 4674.07 4673.90 -0.17 MW -4 4675.32 4674.91 -0.41 Results A review of plate 6 shows that the groundwater hydrology north of the Big Thompson River and east and south of the South Platte River is unaffected by dewatering. The model predicts a drawdown of 4 to 5 feet 1,550 feet west of Pit 124. A review of Table 1, shows that the lining of mined pits will have a de minimis effect on groundwater hydrology. Predicted post lining head levels immediately up and downgradient of the barrier walls are within the range of normal seasonal water table elevation changes. Conclusions The results of analytical and numerical solutions indicate that the proposed mine dewatering activities will not adversely affect the regional groundwater hydrology. Based on the location of registered water wells, the saturated aquifer thickness west of the mine is sufficient to provided adequate well yields. The predicted drawdown associated with the mine dewatering represents Dewatering Evaluation Report Varra Pit 124 Weld County, Colorado Page 5 the worst case scenario and a substantial amount of time will be required before maximum drawdowns will occur. In the author's opinion one cannot reasonably differentiate the head differences of seasonal groundwater fluctuations and head differences possibly created by lining mined pits — they are both within expected seasonal head variations. The permeability of the aquifer materials are sufficient to mitigate pressure gradients created by the impermeable liners. This mine is bounded on three sides by rivers and the surface water gains and losses to and from the aquifer will mask any possible hydrology changes created by pit lining. If there are unregistered domestic wells located within the area influenced by pumping, it may be advisable to conduct a physical well survey prior to the mine start-up. Though there is sufficient aquifer thickness to provide good well yields in most areas there may be partially penetrating wells that might be affected by mine dewatering. This report was prepared by AWES, LLC ci) Na- Date: 07/28/2020 Joby L. Adams, P.G. Principal/Hydrogeologist REFERENCES Colton, R.B., and Fitch, H.R., 1974, Map showing potential sources of gravel and crushed -rock aggregate in the Boulder -Fort Collins -Greeley area, Front Range Urban Corridor, Colorado: U.S. Geol. Survey Misc. Geol. Inv. Map I -855-D. Schneider, P. A., 1983, Shallow groundwater in the Boulder —Fort Collins —Greeley area, Colorado, 1975-77: U.S. Geological Survey Water Resources Investigation Report 83-4058. WesTest, Inc., 2015. Geotechnical Investigation, Two Rivers Property, Weld County, CO, February 12, 2015. FIGURES Figure 1- Site Location Map _ s 1 Mill d _ i00 EEI U UYI] IO3M1.4ETIRS Map created with TOPO!I Z20112 National Geographic (i5z.n nationalgeographic.comtopo] TN roc 9° Va -:-a Companies - Conrad Capital Group Property Figure 2 - Mine Area Map "°" Two Rivers °R`"'"° Raw Extraction Limits with Reclaimed 3H:1V Slopes 232.68±Acres Extraction/Basin Total DATE 25 September 20. PLATES Plate 1- Model Boundary Conditions 0 Lo 0 0 o o m o O O O O O O O N O 1\ General Head Boundaries MW -1 - MW- .. River Boundaries •., Barrier - - Constant Boundaries i 1 Walls MW -3 Monitoring Wells [ MW Head . J } 0 2000 4000 6000 8000 10000 1200012800 Two Rivers Boundary Conditions Drawdown - Shadow/Mounding Simulations AWES, LLC Fort Collins, CO 970-590-3807 Varra Companies Pit 124 Plate 2 - Model Grid Model Grid 0 Lo 0 0 0 ro 0 o 0 0 N 0 2000 4000 6000 8000 10000 12800 Two Rivers Model Grid Drawdown - Shadow/Mounding Simulations AWES, LLC Fort Collins, CO 970-590-3807 Varra Companies Pit 124 Plate 3 - Average VCI Measured Groundwater Elevations (9/2015 - 8/2019) 4500- 4000- 3500- 3000- 2500- 2000- 1500- 1000- 500- 0 /////////// tabC° �6g) l),(3 t,(0 �c�`b� c) ((,:83 � 0 00 U, 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 Note: Surfer Generated Contours Plate 4 - Groundwater Flow Calibration Simulation o4775° o o 0J o o 0 o_ 0 0 o_ 0 N 4775°° h' . Co i } o A mr O O \ . 4) 0Abp X O, 0 PO O O O O' P'� AN O I\ O O 1 o �'r' O <0 4705. 0 '4700. 0 1695. 695 0 4690. 0 I I I I I I 0 2000 4000 6000 8000 10000 1200012800 Two Rivers Groundwater Flow Calibration Drawdown - Shadow/Mounding Simulations AWES, LLC Fort Collins, CO 970-590-3807 Varra Companies Pit 124 Plate 5 - Model Predicted Head Values - Calibration Simulation Calculated vs. Observed Head : Steady state • Layer #1 95% confidence interval 95°/° interval MW -2/A Observed = 4681.42 Calculated = 4681.37 MW -4/A Observed = 4675.32 Calculated = 4675.32 ; MW -3/A m Observed = 4674.04 Calculated = 4674.07 ti 4673.89 4675.89 4677.89 Observed Head (ft) Max. Residual: 0.064 (ft) at MIN -1/A Min. Residual: 0.004 (ft) at MW -4/A Residual Mean : 0.011 (ft) Abs. Residual Mean : 0.038 (ft) 4679.89 Num. of Data Points : 4 Standard Error of the Estimate : 0.025 (ft) Root Mean Squared : 0.044 (ft) Normalized RMS : 0.599 ( % Correlation Coefficient : 1 Two Rivers Model Well Calibration Drawdown - Shadow/Mounding Simulations ,AWES, LI.C 'Fort Collins, CO 970-590-3807 Varra Companies Pit 124 Plate 5A - Model Predicted Head Values - Calibration Simulation Calculated vs. Observed Head : Steady state ■ Layer #1 95% confidence interval 95°% interval MW -11A Observed = 4680.33 Calculated = 4680.39 I rn cO ui_ i_ m m m MW-4IA Observed = 4675.32 Calculated = 4675.32 MW -3/A Observed = 4674.04 Calculated = 4674.07 4673.69 4675.89 Max. Residual: 0.064 (ft) at MW -1/A Min. Residual: 0.004 (ft) at MVV-4/A Residual Mean : 0.011 (ft) Abs. Residual Mean : 0.038 (ft) 4677.89 4679.89 Observed Head (ft) Num. of Data Points : 4 Standard Error of the Estimate : 0.025 (ft) Root Mean Squared : 0.044 (ft) Normalized RMS : 0.599 ( °/a ) Correlation Coefficient : 1 Two Rivers Model Well Calibration Drawdown - Shadow/Mounding Simulations AWES, !.[.C Fort Collins, CO 970-590-3807 Varra Companies Pit 124 Plate 6 - Groundwater Contours - Mine Dewatering 0 O p o m O17o lxo o // o 1p O MW -3 A A? 66. 4' vb MW -1 • b° O 0 0 • nO A A' 4712•° 4706. 0 ,Vo 0 O0 o tt-bv b b b 44 4700. 0 46s • 0 O 0 0 O_ 0 N bg0 A . Co i } F 0 2000 4000 6000 8000 10000 1200012800 Two Rivers - Central and NW Pit Dewatering Drawdown - Shadow/Mounding Simulations Six Foot Contours AWES, LLC Fort Collins, CO 970-590-3807 Varra Companies Pit 124 Plate 7 - Post Mining Groundwater Contours (Post Lining) OLc) 0 0 co Q o v3 o o_ 0 v 0 o_ 0 N )4 II • A° MW -1 O M ^ �Q ° O A MW- MW -3 MW -4 . r, s 0 2000 4000 6000 8000 10000 12800 Two Rivers Barrier Wall Simulation Pond Constant Head 4675 Drawdown - Shadow/Mounding Simulations AWES, LLC Fort Collins, CO 970-590-3807 Varra Companies Pit 124 Plate 8 - Post Lining Predicted Water Levels Calculated vs. Observed Head : Steady state ■ Layer #1 — 95% confidence interval 95% interval 00 m I- n N- r`co [D is MW -11A Observed = 4680,33 Calculated = 4680.64 l MW -4/A Observed = 4675.32 Calculated = 4674.91 MW -31A Observed = 4674.04 Calculated = 4673.90 4673.74 4675.74 4677.74 Observed Head (ft) • Max. Residual: -0.409 (ft) at MW -4/A Min. Residual: -0.143 (ft) at MW -3/A 'Residual Mean : 0.039 (ft) I Abs. Residual Mean 0.315 (ft) 4679.74 4667.74 Num. of Data Points - 4I Standard Error of the Estimate : 0.191 (ft) Root Mean Squared : 0.333 (ft)I Normalized RMS . 4.507 ( % )! Correlation Coefficient : 0.999 t wo Rivers Barrier Wall Simulation Pond Constant Head 4675 IDrawdown - Shadow/Mounding Simulations :AWES. LLC Fort Collins, CO ;970-590-3807 Varra Companies Pit 124 Plate 8A - Post Lining Predicted Water Levels Calculated vs. Observed Head : Steady state • Layer #1 95% confidence inteniai 95% interval MW -2/A Observed = 4681.42 Calculated = 4681-82 MW -4/ Observed = 4675.32 Calculated = 4674.91 — - - MW -3/A Observed = 4674.04 Calculated = 4673.90 cry r - Q. 4673.74 4675.74 4677.74 Observed Head (ft) Max. Residual: -0.409 (ft) at MW -4/A 'Min. Residual: -0143 (ft) at MW -3/A Residua! Mean : 0.039 (ft) Abs. Residual Mean : 0.315 (ft) 4679.74 4681.74 Num. of Data Points : 4 Standard Error of the Estimate : 0.191 (ft) Root Mean Squared : 0.333 (ft) Normalized RMS : 4.507 ( % ) Correlation Coefficient : 0.999 Two Rivers Barrier Wall Simulation Pond Constant Head 4675 ,Drawdown - Shadow/Mounding Simulations AWES, LLC Fort Collins, CO 970-590-3807 Varra Companies Pit 124 TWO RIVERS RIVERSIDE BERM FAILURE ANALYSIS AND FLOOD CONTROL MITIGATION PLAN January 22, 2020 Prepared by: Flow irr• af. U ��Y.... is 7echnologjes Hydrology Hydraulics Water Resources Prepared for: Varra Companies, Inc 8120 Gage Street Frederick, Colorado 80516 Phone: 303-666-6657 P.O. Box 6100 Breckenridge, CO 80424 Phone: 970-547-3823 www.flowtechnologies.biz Project No.: FT 1910 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 TABLE OF CONTENTS DISCLAIMER ABSTRACT PURPOSE I. INTRODUCTION II. SITE DESCRIPTION III. STUDY METHODOLOGY IV. RESULTS IV. MITIGATING MEASURES VI. WATER SURFACE PROFILE FOR SOUTH PLATTE RIVER ALONG CENTRAL PIT VII. SUMMARY AND CONCLUSIONS REFERENCES APPENDIX LIST OF FIGURES 3 4 5 6 6 9 15 21 21 23 24 25 Figure 1. Two Rivers. Vicinity map. 7 Figure 2. Two Rivers. Site map. 7 Figure 3. Two Rivers. FEMA 100-yr floodplain. 9 Figure 4. Central Pit. Pit fill time and water surface elevation vs. head cut elevation 17 for 100 ft riverside berm. Figure 5. Central Pit. Pit fill time and water surface elevation vs. head cut elevation 18 for 150 ft riverside berm. Figure 6. Central Pit. Pit fill time and water surface elevation vs. head cut elevation 19 for 200 ft riverside berm. Figure 7. Pit fill time and water surface elevation vs. head cut elevation for a typical 20 riverside berm. Figure 8. Central Pit. South Platte River 100-yr water surface profile. 22 Figure 9. River stations for Figure 8. 22 pg. 2 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 DISCLAIMER This study is based on innovative methodology that applies a dam -breach head cutting/erosion computer model (WinDAM C) to gravel pit riverside berms. Such methodology may be unprecedented. The study methodology is based on scientific procedures and associated research, but there are no known historic events nor studies with which to compare methods and results. Analyses in this study - as with any computer modeling of natural processes - is not an exact science and claims can not be made as to its accuracy. However, results provide estimates and relative comparisons of potential for head cutting/erosion on gravel pit riverside berms. This analyses is helpful for decision making, relative comparisons, "what if" scenarios, estimating relative extent of critical head cut/erosion parameters such as berm width, head cut length, and associated depth relative to time. All services provided by Flow Technologies hereunder are provided "as is" without any warranty whatsoever. No representation or other affirmation of fact, regarding the services provided hereunder shall be deemed a warranty for any purpose or give rise to any liability of Flow Technologies whatsoever. In no event shall Flow Technologies be liable for any incidental, indirect, exemplary, special, punitive or consequential damages, under any circumstances, including, but not limited to: lost profits; revenue or savings; or the loss of use of any data, even if client or Flow Technologies have been advised of, knew, or should have known, of the possibility thereof. pg. 3 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 TWO RIVERS GRAVEL PIT MINE BERM FAILURE ANALYSIS AND FLOOD CONTROL MITIGATION PLAN January 15, 2020 ABSTRACT Varra Companies, Inc is considering gravel mining on its Two Rivers property (Site) located between the Big Thompson and South Platte Rivers just upstream from the confluence. As part of the extraction plan, a riverside berm width needs to be approximated that is sufficient to prevent head cutting/erosion from capturing the river. Site -specific analyses were performed that adopted a dam -breach erosion model (WinDAM C) for estimating head cutting/erosion from a 100-yr flood including head cut length, depth, width, and head cutting time progression. A conservative philosophy was applied throughout the study. Because of the many "uncertainties" when evaluating natural occurrences - analytical approaches, scenarios, and modeling input parameters were biased so that results are conservative (tend toward the most head cutting and erosion). Study results indicate that the Northwest and Northeast Pits riverside berms adjacent to the Big Thompson River have sufficient width (approximately 100 ft) to prevent complete riverside berm failure and river capture, and the Central Pit riverside berm adjacent to the South Platte River of approximately 100 ft (per the site plan) also has sufficient width to prevent complete riverside berm failure and river capture. However for conservatism, additional berm widths of 150 — and 200 ft were also evaluated so that decisions can be made as to the best berm width to prevent river capture in addition to maximum extraction of gravel. Additional "analytical assurance," was performed via an HEC-RAS 100-yr flood water surface profile analysis for the South Platte River along Central Pit. That analysis indicates that only about 40% of the riverside berm along Central Pit is susceptible to overtopping, head cutting/erosion thereby decreasing the chances of river capture. Information presented in this study is intended to assist design of ultimate pit extents and design of berm head cutting/erosion protection should study results indicate the necessity. pg. 4 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 PURPOSE The purpose of this report is to present analyses and methodology to demonstrate that potential failure of riverside berms for three gravel pits on the Two Rivers property may not occur from floods up to the 100-yr event. Note that "riverside berm" as used in this report refers to the land between the riverbank and riverside rim of a pit. "Earthen berm" refers to the existing constructed earthen embankments that surround the site for the purpose of flood protection. pg. 5 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 I. INTRODUCTION Varra Companies, Inc is interested in mining the Two Rivers property (Site), located between the Big Thompson and South Platte Rivers just upstream from their confluence, for gravel mining. As part of the extraction plan, a riverside berm width needs to be determined that is sufficient to prevent head cutting/erosion from capturing the river, but not in excess so that extraction can be maximized. Site -specific analyses were performed that adopted WinDAM C (National Resource Conservation Service, 2016), a dam -breach erosion model, for estimating head cutting/erosion from a 100-yr flood including head cut length, depth, width, and head cutting time progression. II. SITE DESCRIPTION 2.1 Location and Size The Site - approximately 232.7 acres in size — is located between the Big Thompson and South Platte Rivers just upstream from their confluence (Figures 1 & 2). It consists of three fields — Central, Northwest, and Northeast (154.3, 54.9, and 23.5 acres, respectively) that will be mined in succession. Planned extractions volumes for Central, Northwest, and Northeast Fields are 5,665, 1,648, and 659 acre -ft, respectively. pg. 6 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 2.2Topography The site is relatively flat north and south, and gradually slopes from west to east with elevations ranging from about 4688 ft to 4679 ft. 2.3. Local Roads County Road 396 passes through the Site in addition to private roads for the purpose of farming and gas well operations. 2.4. Surrounding Development Surrounding development is rural and industrial consisting of farmland, and oil and gas wells. The site is mainly used for agricultural purpose and contains a dwelling, barn, and garage. Other than that, it is mainly undeveloped. 2.5 Oil and Gas Wells One gas facility is located on the eastern -most edge of the site in the approximate north -south center. Natural gas and oil wells, including collection and conveyance facilities, are located throughout the site. 2.6 Soils and Vegetation Soil conditions generally consist of varying thicknesses of top soil underlain by sand and gravel deposits. A detailed soil description and geotechnical information is contained in Geotechnical Investigation (WesTest, 2015). Vegetation consists of trees, grasses, and shrubs on the riverbank, and native grasses on the site.. 2.7. Drainageways As previously mentioned, the Big Thompson River flows along the northern portion of the Site from west to east (Figure 2), and the South Platte River flows along the southern portion of the site from west to east. The Site is located in the floodplain of each river. 2.8. Potential for site flooding All of the site is located in the FEMA 100-yr floodplain (Figure 3) (Weld County Online Mapping). Because the site has a high potential for flooding (being located between two rivers in a flat floodplain), earthen flood control berms — with heights from about 3 to 6 ft) - were constructed around the site and appear in good condition. The earthen berms were likely constructed by land owners (assuming in the late 1940's based on aerial photos) to protect their pg. 8 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 farmland from frequent flooding. It is estimated (engineering judgment) that the earthen berm will protect the site from a 10-yr flood, but that varies throughout. Design and construction information is not readily available. Note that the term "earthen berm" is referred to within this report for Two Rivers. However, embankments along rivers are technically "levees" but those at the site are not FEMA certified; thus, FEMA doesn't recognize them for flood insurance studies. wFro COUNTY Two R vers 1Da yr • P 1 : �jE— — ..L .___r., .,ji?,-.hh--�''� Two Rivers ti's I FFoodwny` Esan a I ... Al loiir Al C. F1. r• . aef Figure 3 Two Rivers FEMA 100-yr floodplain III. STUDY METHODOLOGY Two Rivers site is unique and complex because it is located between the Big Thompson and South Platte Rivers just upstream from their confluence. The site is capable of experiencing flooding_from both rivers at the same time, so when all three pits are at maximum extraction flood waters can enter them from anywhere around the perimeters with potential for head cutting/erosion. Head cutting on a pit's inside perimeters is not a concern because the furthest the head cut can extend would essentially be to an adjacent pit within the site. However, head cutting on a pit's riverside berm has the potential to erode through the riverside berm between the pit and river which is the focus of this study. pg. 9 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Central Field is located on the South Platte River side of the site and riverside berm failure analyses will focus on that river's berm. And, Northwest and Northeast Fields are located on the Big Thompson River side of the site and berm failure analyses will focus on that river's berm. There will also be a riverside berm developed on the east side of Northeast pit as the result of mining. Head cutting will be evaluated with respect to possibility of a Northeast Pit berm head cut entering the Big Thompson River. Modeling analyses is based on a 100 -ft -wide riverside berm throughout the Site. Should it be determined that riverside berm width has possibility of river capture, then wider riverside berm widths will be evaluated via WinDAM C to determine adequacy. Because there is possibility for flooding and head cutting/erosion on any of the three pits, Varra Companies, Inc. plans on mitigation. That mitigation will be accomplished via a six -step approach: (1) Predict likely riverside berm head cut/erosion locations. (2) Perform head cutting and erosion analysis to predict riverside berm head cutting, length, width, and failure time (time from initial head cutting on pit side, to riverbank on riverside). (3) Determine pit fill time based on flood and groundwater inflows and compare to riverside berm head cut time and length. (4) If head cut length is less than riverside berm width at the time that head cut elevation equals pit water surface elevation, then head cutting/erosion ceases and will not capture the river. (5) If head cut length is not sufficient to prevent river capture assuming a 100 -ft -wide berm, assumed width will be increased and then repeating steps (2) — (4) until a sufficient riverside berm width is estimated. (6) Provide hard armoring in locations most susceptible to head cutting/erosion during reclamation as an additional measure of safety. The above six items are explained in detail below in sub -sections 3.1 through 3.6. A conservative philosophy was applied throughout the study. Because of the many "unknowns" when evaluating natural occurrences, analytical approaches, scenarios, and modeling input parameters were biased so that results tended toward the most head cutting and erosion. As with any computer models of natural processes — it is not an exact science. There are many uncertainties without the luxury of comparing results to an actual event. However, such modeling can still provide valuable information for planning and decision making. pg. 10 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 3.1 Develop a Representative Head cutting/Erosion Scenario Because a large flood will completely inundate the site, most any location around a pit rim is susceptible to head cutting/erosion. For the sake of head cutting analyses, a representative riverside berm head cutting/ erosion scenario will be applied to Central Pit, and Northwest Pit. The site was divided into two distinct berm failure scenarios — South Platte and Big Thompson Rivers. Although the complete site can experience significant flooding, floodplain flows would be of different magnitudes adjacent to the South Platte and Big Thompson Rivers. Although head cutting/erosion mechanics are essentially the same, the amount of flood flow from each river would vary which impacts the head cutting/erosion process and also the pit fill times. As with any floodplain, flows through site are 2 -dimensional and would and would need a 2 —D river model such as HEC-RAS to determine flow paths and quantities. Such a modeling effort is very data and time intensive, and beyond scope of this study. Rather, engineering judgment was applied as needed. For the South Platte River scenario, only Central Pit was evaluated. And for the Big Thompson River scenario, only Northwest Pit was evaluated although Northeast Pit is also located along the river. That is because the failure mechanics for Northwest Pit can be applied to Northeast Pit. And because Northeast Pit has a much smaller ultimate extraction volume than Northwest Pit, then if Northwest Pit doesn't have riverside berm failure issues (per the methods and assumptions of this analysis) neither will Northeast Pit. 3.2 Perform Head Cutting Analyses to Predict Berm Head Cutting, Length, Width, and Failure Time (Time From Initial Head Cutting On Pit Side, to Riverbank On Riverside) Based on the existing extraction plan, riverside berm widths vary from about 100 — to- 150 ft. To demonstrate the riverside berm width adequacy, a head cutting/erosion analysis was performed. As explained below in Section V, Hard Armoring, the pit locations most susceptible to head cutting will be armored, but analyses was performed with the intent to demonstrate that site plan riverside berm widths are sufficient to prevent river capture. 3.2.1 Head cutting and Erosion Analysis Methodology A special study was performed to evaluate head cutting progression (length, width, and time) and erosion for site -specific conditions. The riverside berm was treated as an earthen dam with the riverside berm width representing the crest and the pit side representing the face. Modeling will use site -specific soil physical parameters, flood inflow hydrograph, and dam breach state-of-the- art head cutting/erosion analyses. Analyses only considered bare ground without vegetation. The National Resource Conservation Service (MRCS) WinDAM C (Windows Dam Analysis Modules) (National Resource Conservation Service, 2016.) is the model of choice for this study. WinDam C is a modular software application for the analysis of overtopped earth embankments (adapted for gravel pit riverside berms in this case) and internal erosion. The model addresses pg. 11 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 routing of a flood over the dam and evaluation of bare earth. It can also evaluate the potential for vegetation or riprap to delay or prevent failure of the embankment (riverside berm in this case). The model is a three-phase erosion model: 1) Phase one of the erosion or failure process is failure of the vegetal cover (or, lack thereof) and development of concentrated flow. 2) Phase two is downward erosion in the area of concentrated flow, resulting in head cut formation. 3) Phase three is downward and upstream movement of the head cut, potentially breaching the dam (or, riverside berm in this case). Each phase is described by a set of threshold -rate relationships based on the process mechanics. A head cut erodibility index describes the resistance of the exposed geologic materials to erosive attack during the third phase of the process. For a complete erosion estimate, the geotechnical composition must be characterized. Typical parameters are representative particle size, percent clay fraction, plasticity index, total unit weight, undrained shear strength, and critical shear stress. Specific to WinDAM C software, the head cut erodibility index and detachment coefficient also need to be estimated. 3.2.2 WinDAM C Parameters Model parameters are listed in the Appendix. Riverside berm width ("dam crest") of 100 ft was applied for three different scenarios. The scenarios, Weakest, Best, and Strongest involve changing a critical parameter which would result in the model to predict weakest (most) head cut/erosion potential, strongest (least) head cut/erosion potential, and best which is in-between weakest and strongest. All parameters remained constant for the three scenarios except for the erodibility factor, "Kd" which is the most sensitive parameter. For this study, Kd had a range of two orders of magnitude from 100 for Weakest, to 0.1 for Strongest. Such a range of magnitude was chosen to cover a very large range of head cutting/erosion possibilities - due to the many uncertainties of such modeling - with the intent that the actual values would fall somewhere within the range of model results. Although some vegetation may exist on both the riverside and lateral berms during mining operations, only bare soil parameters were input for the sake of conservatism. If vegetation were considered, the modeling results would indicate less head cutting/erosion. pg. 12 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 3.2.3 Hydrograph Development WinDAM C is driven by a user -derived inflow flood hydrograph based on the 100-yr peak discharge of the South Platte River at the confluence of the Big Thompson River. Being that the Site is located just upstream from the confluence, that is a representative 100-yr peak flood because it includes both rivers. Flood hydrographs on the South Platte River representative of the 100-yr peak could not be located. Also, the stream gage at Kersey, Colorado was destroyed during the 2013 flood and that hydrograph data is not available. In lieu of that, a flood hydrograph of the Big Thompson River (Griffin, 2014; Kimbrough — Homes, 2014) at I-25 from the 2013 flood was modified by adjusting the ordinates to meet the South Platte River 100-yr peak discharge (FEMA, Flood Insurance Study, January 20, 2016). This is demonstrated in the Appendix. An earthen flood control berm — likely built by local industry (farmers and oil and gas companies) — surrounds the site. Based on engineering judgment, it is estimated the earthen berm will control a 10-yr flood event and that amount of flow was subtracted from the inflow hydrograph that drives WinDAM C, and also for pit fill -time calculations. For analysis, flow was also separated across the site to reflect the influence of each river on it's adjacent floodplain. Both rivers and the intermediate floodplain would flow as a single river during a large flood event with the South Platte River carrying the majority of flow, and floodplain flow gradually decreasing across the floodplain from south to north (South Platte to Big Thompson Rivers) due to the majority of flood flow in the South Platte River floodplain. The flood hydrograph at the site was proportioned - based on peak flow of each river (FEMA, Flood Insurance Study, January 20, 2016) - by having two-thirds flow through the south side of the Site (Central Field) and the remaining one third flow through the north side of the site, or Northwest and Northeast Fields. The proportioned inflow hydrographs are included in the Appendix. A thunderstorm event (vs., snowmelt) was the flood of choice in the analyses because there would be little warning time for Varra Company, Inc. to stop dewatering. Thus, it would take longer for the pit to fill via groundwater ingress and allowing more time for head cutting/erosion consistent with the conservative approach to this study. 3.3. Determine Pit Fill Time and Compare to Head cutting Time Pit fill time is critical because if the pit is full, head cutting/erosion will not occur. And if head cutting is in progress, then once head cut elevation intersects pit water surface elevation, head cutting/erosion will cease. Analyses were performed for the case of each pit initially empty for conservatism. 3.3.1 Determine Pit Fill Time pg. 13 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 WinDAM C estimates the amount of time for a dam (riverside berm) to head cut/erode. If the pit fills in less time than the head cutting erosion time, then head cutting/erosion ceases. That is because if the water surface elevation driving head cutting/erosion meets that in the pit, then there is no head differential for the head cutting/erosion process. In addition, WinDAM C estimates head cutting/erosion length from the pit rim with respect to time. Thus, the head cutting length at the time that the pit fills to the rim is known and can be used for sizing riverside berm width. For instance, say the pit fills in 4 hours and head cutting and erosion ceases at that time. And, during that 4 hours the head cut length is 50 feet. Then, a riverside berm width of 50 ft should be adequate. However for conservatism, a safety factor (say, 2 X) can be added. Two Rivers pits fill times are based on a combination of groundwater ingress with no dewatering (dewatering pumps stopped when flood warning received), right floodplain (South Platte River side) 100-yr flood inflow, and left floodplain (Big Thompson River side) 100-yr inflow. That information is presented in the Appendix. Calculations of pit fill times involves a reservoir (pit) routing procedure. That is, inflow equals outflow minus change in pit storage. Because there is no outflow in the pits, then inflow equals change in storage. An elevation -capacity table was developed and the flood hydrograph described above in subsection 3.2.3, Hydrograph Development, converted to volumes and cumulated. The cumulated volumes then compared to the elevation -storage table and inflow hydrograph times, and pit elevations vs fill times determined. This process is presented in the Appendix. 3.3.2 Flood Warning Time Should a large flood be imminent, appropriate flood threats will be issued by the Colorado Water Conservation Board (CWCB). And once flood threats are issued, Varra Companies, Inc will stop dewatering in active pits allowing for groundwater ingress which will result in higher pit water surface elevation, and decreased head cutting/erosion. Should a flood be imminent, a flood threat warning will be issued by CWCB and Varra Companies, Inc. stop dewatering thereby allowing pits to begin filling. Thus, an extra measure of confidence can be added to the results presented below because those results are based allowing groundwater ingress and higher pit water surface elevations. The Colorado Flood Threat Portal (http://www.coloradofloodthreat.com/) issued by the (CWCB) includes a daily statewide flood threat bulletin and map, 7-15 day flood threat outlook, and statewide 24 -hr precipitation map. That will be monitored by Varra Companies, Inc on an as - needed basis. 3.4 If head cut/erosion length is less than riverside berm width at the time that head cut elevation equals pit water surface elevation, then head cutting/erosion ceases and will not capture the river Refer to IV, Results. pg. 14 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 3.5 If head cut length is not sufficient to prevent river capture assuming a 100 -ft -wide riverside berm, assumed width will be increased and then repeating steps (2) — (4) until a sufficient riverside berm width is determined. Refer to Section IV, Results. 3.6 Provide hard armoring in locations most susceptible to head cutting/erosion during reclamation as an additional measure of safety. This will be discussed in a separate report by Varra Companies, Inc. Refer to Section V, Mitigating Measures. IV. RESULTS Study results are presented below. It is important to note that results apply to a typical pit riverside berm because it is unrealistic to try and model detailed sections on all riverside berms. Due to the large amount of possible combinations of parameters for WinDAM C, results are presented for the "Weakest, Best, and Strongest" soil parameter cases for Northwest Pit. That is, critical head cutting/erosion parameters are input such that the weakest case results in the most head cutting/erosion, strongest case results in the least, and best case results are in-between. Results for Central Pit are presented for Best soil parameter case scenario only because three different riverside berm widths were evaluated and results would be unnecessarily "busy." That is because for that scenario, analysis indicates possibility of the riverside berm breaching. Due to such, riverside berm widths of 150 and 200 ft were also analyzed. Presenting results for all three scenarios including weakest, best, and strongest case is confusing and not necessary, and results for best soil parameter case are adequate. Again, it is important to note that the results presented below have an additional level of conservatism because they do not consider flood warning time. In an actual flood event, a flood threat would likely be issued by CWCB as discussed above in Sub -section, 3.3.2. Upon that issuance, Varra Companies, Inc plans to stop dewatering of active Two Rivers pits by shutting off dewatering pumps. Without dewatering — and any other inflow — the pits would fill in a lesser time period. Thus if a flood threat is issued — say 3 days in advance of the flood - the pits would partially fill thereby decreasing head cutting/erosion and chance of capturing of the river. 4.1. Central Pit (South Platte River Side) Assumed 100 -ft -wide riverside berm width for Central Pit results are summarized in Figure 4. Figure 4 indicates that Best soil parameter case results in head cutting/erosion approximately 3 feet from the pit bottom with a remaining riverside berm length of 35 feet from the river. The large amount of head cutting/erosion can be explained by two reasons: (1) Central Pit will have a large volume upon ultimate extraction (5,665 acre -ft) but the inflow hydrograph has relatively low flows at the beginning for about 3 hours (see Appendix) while the pit is filling, and (2) the flows are sufficient to result in head cutting but not sufficient to result in the water surface in the pit to be higher as head cutting is occurring. As previously mentioned, the faster the pit pg. 15 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 water surface elevation intersects head cutting elevation, the sooner it ceases. Refer to Subsection 3.2.1 for the WinDAM C head cutting/erosion computational process. Due to uncertainties of head cut/erosion modeling, and per Subsection 3.5, additional riverside berm widths of 150 ft and 200 ft were also modeled for comparison (Figures 5 and 6). Options are then available for decision making of the best riverside berm width for site planning. Of course the widest riverside berm width is safest, but may be uneconomical for mining due to less available gravel. Assumed 150 ft -wide riverside berm width for Central Pit results summarized in Figure 5. Figure 5 indicates that Best soil parameter case results in head cutting/erosion approximately 4 feet from the pit bottom with a remaining riverside berm length of 120 feet from the river. Assumed 200 ft -wide riverside berm width for Central Pit results summarized in Figure 6. Figure 6 indicates that Best soil parameter case results in head cutting/erosion approximately 5 feet from the pit bottom with a remaining riverside berm length of 171 feet from the river. Based on the methodology, assumptions, and data of this study, none of the riverside berm widths evaluated breach through to the river. Of course a 200 -ft riverside berm is the most robust, but a 100 -ft riverside berm is still robust yet most practical for maximum extraction. Modeling results are intended to provide confidence that the riverside berm widths selected will not head cut/erode to such a degree that a riverside berm will breach. pg. 16 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 7echnotog1es Pit Elevation lit) Berm Cres X8..0 4675 0 Pit Toe 4.555.[ CENTRAL PIT FILL TIME VS HEADCUT 100 It Berm rreaQct rpft MrrAges Eirrabarpxrprevga.rope 3vess or �lsch'ge exceeded 100% of alluvat:ie at 0.25 hogs.) ---Best •--Fill rime ---KJ may- ,...7'''. IIe cuIj , 5tq s. _ _ _ ---_.-. Length 145 ft. 6aa p t bottom. Bennlength ISO itathese. Time (Nrs 4 Figure 4 Central Pit Pit fill time and water surface elevation vs. head cut elevation for 100 ft riverside berm. pg. 17 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 7echnotog1es Pit Elevation {ft} 590 C. Berm Cre • i25 0 '09'.0 '6-- 0 =6-0 0 4665 C. -650 C' fir# Toe ;6:Oo ItENTRAL PIT t FILL TIME ELEV VS HEADCUT ELEV :ISO ft Berm Meadcutfing initiates (Embankment slope stress 0. hours.) ---Best _filI rime - - �� .. su. xxs a dl. l.' Time (hr} 4 4.5 Figure 5 Central Pit Pit fill time and water surface elevation vs. head cut elevation for 150 ft riverside berm. pg. 18 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Pit Elevation Ota -d90 0 Berm Crest ,68: C. '53] C. .6'r C. -55: 0 '660 C. Pit Toe d=5 0 '6=0 0 CENTRAL PIT FILL TIME ELEV VS HEABCUT ELEV 2O0 if Berm . h1eadcuttorlg mmaies [trnba iorneni anp . stress or thscharge exceeded 100% of agoitgbie of 0-5 hours.) ---Best •-- Fill Time ,:,' length 1Ud it- frotnpn bottom. ' Barr lewd! 275 ft at has. Time (hn 4' Figure 6 Central Pit Pit fill time and water surface elevation vs. head cut elevation for 200 ft riverside berm. 4.2. Northwest and Northeast Pits (Big Thompson River Side) Northwest Pit_results are summarized in Figure 7. Per Figure 7, no soil parameter case results in head cutting/erosion at an elevation or length that is threatening to river capture. Regardless, hard armoring will be applied during reclamation to areas susceptible to head cutting/erosion as an extra measure of protection as explained in Section V, Hard Armoring. The main difference as to why Northwest Pit head cutting/erosion is less severe than Central Pit is due to the flood fill time. Figure 7 depicts a steep pit water surface elevation vs time curve as compared to Central Pit. That is due to a smaller pit volume with respect to flood inflow. Thus, head cutting/erosion ceases much sooner. Northeast Pit head cutting was not evaluated. It has a relatively small ultimate pit volume of 659 acre -ft and compared to Northwest and Central Pits, would fill in a relatively short time period which would prevent significant head cutting/erosion. pg. 19 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 4690.0 4685.0 Pit Crest Pit Elevation (ft) 4680.0 4675.0 4670.0 4665.0 4660.0 Pit Toe 4655.0 4650.0 NORTHWEST FIELD FILL TIME VS HEADCUT Headcutting initiates Headcutting stops (Embankment slope stress or Length— s 1 ft discharge exceeded 100% of allowable at 0.25 hours) Headcutting stops Length 30 = ft • Headcutting stops Length = 130 ft Weakest Best Strongest Fill Time 0 0.5 1 1.5 2 Time (hr) 2.5 3 Figure 7. Northwest Pit Pit fill time and water surface elevation vs. head cut elevation for a typical riverside berm. 3.5 The main differences in degree of head cutting/erosion between Central Pit (South Platte River side) and Northwest and Northeast Pits (Big Thompson Side) are, (1) pit fill times due to volume differences, and (2) inflow flood differences. pg. 20 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 V. MITIGATING MEASURES Study results presented above indicate that head cutting/erosion will not progress through the full length of a 100 -ft riverside berms. It is important to note that should a flood occur that results in head cutting/erosion of a riverside berm, Varra Companies, Inc. will immediately restore the damaged area to pre -flood conditions. As mentioned, this analysis conservative and riverside head cutting/erosion is based on the 100- yr flood. There is a small probability that such a flood event will occur during extraction and when the pit is dewatered. VI. WATER SURFACE PROFILE ELEVATION FOR SOUTH PLATTE RIVER ALONG CENTRAL PIT As an extra measure of confidence that the likelihood for head cutting into Central Pit will be small, the 100-yr water surface profile was evaluated via HEC-RAS (HEC-RAS). The 100-yr discharge was obtained from the Weld County FEMA Flood Insurance Study, (Weld County FIS). Earthen berm elevations were obtained from the Varra Companies, Inc. existing topo survey (Existing topo), and river cross-section data obtained from Google Earth and existing topo survey. Results are presented in Figure 8. Per Figure 8, approximately only 3,600 ft (Station 5200 to 8800) of the total 8,800 ft (40%) of the pit length along the river would be subject to overtopping from the 100-yr flood. Thus in addition to WinDAM C head cutting/erosion analysis, the riverside berm length overtopping analysis indicates that much of the riverside berm would not overtop thereby minimizing the susceptibility to Central Pit capturing the river. HEC-RAS program input and output data are presented in the Appendix. pg. 21 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 7echnotog1es SPRPlan SPR at T,,a Rr:Frs 4",1 SP 12 30 2019 r.ege-Bd 113 Figure 8. Central Pit South Platte River 100-yr water surface profile along Central Pit. pg. 22 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 VII. SUMMARY AND Figure 9. Central Pit CONCLUSIONS River stations for Figure 8. Varra Companies, Inc. is interested in mining Two Rivers property - located between the Big Thompson and South Platte Rivers just upstream from their confluence - for gravel mining. As part of the extraction plan, site -specific analyses were performed that adopted a dam -breach erosion model (WinDAM C) for estimating head cutting/erosion of riverside berms from a 100-yr flood including head cut length, depth, width, and head cutting time progression. WinDAM C model input data was based on site -specific soils testing, pit extraction plan, existing site topographic maps, riverside berm width assumptions, a historic flood hydrograph for the Big Thompson River, the September 2013 flood for the Big Thompson and South Platte Rivers, and FEMA Flood Insurance Study peak discharges. Study results indicate that the Northwest and Northeast riverside berms adjacent to the Big Thompson River have sufficient width (approximately 100 ft) to prevent complete berm failure and river capture. The Central pit riverside berm of approximately 100 ft (per the site plan) has sufficient width to prevent complete riverside berm failure and river failure. However for conservatism, additional riverside berm widths of 150 — and 200 ft were evaluated so that decisions can be made as to the best riverside berm width to prevent river capture combined with maximum extraction of gravel. Additional "analytical assurance," was performed via an HEC-RAS 100-yr flood water surface profile analysis for the South Platte River along Central Pit. That analysis indicates that only about 40% of the earthen berm along Central Pit is susceptible to overtopping thereby decreasing the chances of river capture. Should flooding occur that results in head cutting/erosion of a riverside berm, Varra Companies, Inc. will immediately restore the damaged area. A conservative philosophy was applied throughout the study. Because of the many "uncertainties" when evaluating natural occurrences - analytical approaches, scenarios, and modeling input parameters were biased so that results are conservative (tend toward the most head cutting and erosion). Head cutting/erosion analysis - as with any computer modeling of natural processes - is not an exact science. However, results provide an estimate and relative comparisons of potential for head cutting and erosion for design, planning, and decision making so river capture is minimized. pg. 23 JYow 7echnotog1es Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 REFERENCES Griffin, Steven, Peak Flow Hydrology Investigation for the September 2013 Flood at Interstate 25, 2014. HEC-RAS, Hydrologic Engineering Center River Analysis System, Version 5.0, U.S. Army Corps of Engineers Hydrologic Engineering Center, 609 Second Street, Davis, California. Kimbrough, Robert & Homes, Robert Jr., Flooding in the South Platte River and Fountain Creek Basins in Eastern Colorado, September 9 — 16, 2013, Scientific Investigation Report 2015-5119, U.S. Geological Survey, 2015, National Resource Conservation Service, WinDAM C Software Estimating Erosion of Earthen Embankments and Auxiliary Spillways of Dams, 2013. Topographic survey map. Emailed by Brad Jones, Varra Companies, Inc., Oct 2, 2019. Weld County FIS, Flood Insurance Study, Weld County, Colorado, Federal Emergency Management Agency, Flood Insurance Study No. 08123CV, Effective January 20, 2016. pg. 24 JYow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 APPENDIX pg. 25 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 WINDAM B INPUT HYDROGRAPH pg. 26 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 TWO RIVERS DESIGN HYDROGRAPHS (WINDAM C INPUT HGs) FOR REPRESENTATIVE HEADCUT AT BIG THOMPSON SIDE AND SOUTH PLATTE SIDE PITS Date Time (hr) (1) (2) 9/12/13 2400 0 4 8 10:00 12 16 18:45 20 9/13/13 1:00 24 32 36 40 44 9/14/13 12:00 48 52 56 60 64 68 72 76 80 84 88 92 9/16/13 15:00 96 BT Side SP Side SP BT Q Adjusted Q Adjusted Q- Q Q WinDAM WinDAM (cfs) (cfs) 10-yr Q (cfs) (cfs) Headcut Headcut (3) (4) (5) (6) (7) (8) (9) 100 540 0 500 1,500 3,000 16,200 2,700 6,000 4,250 22,950 9,450 5,000 27,000 13,500 15,000 15,500 17,000 18,000 6,000 32,400 18,900 17,500 16,000 15,000 14,000 13,000 11,500 10,000 9,000 7,500 7,000 5,500 3,400 18,360 4,860 0 0 167 333 500 1,000 900 1,800 2,000 4,000 0 3,150 6,300 300 4,500 9,000 3,000 5,000 10,000 4,000 5,167 10,333 4,333 5,667 11,333 5,333 6,000 12,000 6,000 6,300 12,600 6,600 5,833 11,667 5,667 5,333 10,667 4,667 5,000 10,000 4,000 4,667 9,333 3,333 4,333 8,667 2,667 3,833 7,667 1,667 3,333 6,667 667 3,000 6,000 0 2,500 5,000 2,333 4,667 1,833 3,667 1,620 3,240 pg. 27 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 * Interpolated values 1.11,1.1,111 1111.1 11111111,111 111V11,1 11,11111111. 1_11. 511111, 0 5n. k ru'3 rua sa.11 .1131J 2121.1 .vii iii _e,i i-u. ,14 yea', rd NOTES Methodology. This procedure done so that HG for WinDAM C can be based on an actual flood. The September 2013 Big Thompson flood HG was used because, (1) it was available, (2) was produced by a large rainstorm in the foothills, and (3) Qp similar to 100-yr flood which is used for WinDAM C design flood. A flood hydrograph for the September 2013 South Platte River flood near Greeley (closest to the site) is not available. The closest gage is at Kersey but was damaged during the flood on September 14, 2013 ("Flooding in the South Platte River and Fountain Creek Basins in Eastern Colorado, September 9-18, 2013, Robert Kimbrough and Robert Holmes, Jr.) . Due to such, and for the purpose of this study, it was assumed that the Big Thompson River hydrograph mentioned above is a reasonable representation of the South Platte River. The Big Thompson River, in addition to several similar rivers that flow from the foothills into the South Platte River, are tributary to the South Platte River which would reflect their hydrographs. The hydrograph ordinates were proportioned to the FEMA FIS 100-yr peak discharge for the South Platte River at Highway 85 which is assumed to be the discharge at Two Rivers for 100-yr flood; i.e., WinDAM C design flood. (1) Dates per USGS graph above. (2) Hour increments so can be entered in WinDAM as such approximates linear, ordinates were spaced several hours apart for simplicity. (3) Qs from USGS graph above. Linear extrapolation on both rising and falling limb. (4) Column (4) proportioned to design Q of 32,500 cfs at Two Rivers (Q100 for South Platte Rat HWY 85/Q100 for Big Thompson Rat Loveland per graph above (32,500/6,000)). Peak discharge for Big Thompson Rat Loveland not recorded and extrapolated from graph. (5) Discharge that enters site is (4) 100-yr Q less 10-yr discharge for both Big Thompson and S. Platte Rivers. It is assumed that flows less than 10-yr floods are controlled by berm that surrounds the site. BTR Q10 = 2,500 cfs; SPR Q10 = 11,000 cfs; Total Q10 = 13,500 cfs. (6) Q proportioned between Big Thompson floodplain and South Platte floodplain. BT Qp = 8,000 cfs at confluence with SP. SP Qp = SP Q100 at Hwy 85 = 32,500 cfs. Then BT Qp at confluence = 32,500 - 8,000 = 24,500 cfs. Ratio of Qp = 24,500/8,000 = 3.1 (say, 3). Then, Q ordinates = (5)/3. (7) (5) - (6). (8) (7) - 6,000 cfs. Based on 1,000 cfs entering each of 6 groins. Inflow channel to groin is 1,000 cfs as in Coulson. Values about the same as for NW Pit runs, so left NW Pit HG in Central Pit Berm Sizing WinDAM (file copied from NW Pit Best) because its output more reasonable. Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 pg. 29 flow . Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 TWO RIVERS FILL TIME ESTIMATES CENTRAL PIT Inc GW Inflow Rate - GW Inflow Rate - Pit Depth Pit Elev Pit Vol GW Inflow Rate Volume Ave Ave (af) (af) (af/day) (af/day) (af/hr) (1) (2) (3) (4) (5) (6) (7) 0 4688.0 5,665 0 459 5,158 215 10 4678.0 4000 1,665 2,633 5,158 215 20 4668.0 2300 1,700 4,443 5,158 215 30 4658.0 600 1,700 6,252 5,158 215 5,158 215 5,158 215 32 4656.0 0 600 9,858 5,158 215 5,158 215 5,158 215 5,158 215 5,158 215 HG Time River Inflow - Ave (hr) (cfs) (8) (9) River Inflow (af/hr) (10) Total Inflow Inflow Volume af/hr (11) (af) (14) Cummulative Elevation Inflow Volume (ft) (af) (15) 48 12,600 1,041 1,256 15068 27856 36 10,300 851 1,066 12788 20455 24 9,000 743 958 7667 12029 16 4,000 330 545 4363 8064 12 3,000 248 463 3702 6743 10 2,000 165 380 3041 4396 4682.0 8 1,500 124 339 1355 1868 4667.0 4 500 41 256 512 748 4660.0 2 250 21 236 236 459 4657.5 1 100 8 223 223 223 4657.0 0 0 0 4656.0 NOTES (1) Pit depth increments arbitrarily chose 10 ft. Pit depth from Joby analysis: (C:\DATA\Flow Technologies\Projects-FT\Varra\FT1910 -Two Rivers\H&H\GW Inflow - Joby). (2) Based on (1). Based on (1). El 4688 from Existing Topo, fn = C:\DATA\Flow Technologies\Projects-FT\Varra\FT1910 - Two Rivers\Drawings\Existing Topo.pdf. (3) From Brad Jones email 10/26/19, "update on individual extraction volumes." Email file also in, C:\DATA\Flow Technologies\Projects-FT\Varra\FT1910 - Two Rivers\H&H\Pit Volume, Fill Time\Two Rivers. Max volume computed from cubic yards, and other volumes extrapolated. (4) (4) minus (3). (5) From Joby analysis: (C:\DATA\Flow Technologies\Projects-FT\Varra\FT1910 - Two Rivers\H&H\GW Inflow - Joby). Mid -values extrapolated. (6) Average of 459 and 9,858. Average because no way of knowing inflow at times and water surface elevations of inflow HG, so average of high and low is reasonable. (7) (6) converted to af/hr so fill times can be computed in hours per (12). (8) & (9) From, C:\DATA\Flow Technologies\Projects-FT\Varra\FT1910 -Two Rivers\H&H\WinDAM C Inflow HG. **Note. It is assumed that 2/3 inflow floodplain HG enters Central Pit. (10) (9)*0.0826. (11) (7) +(10) (12), (13) Fill time for use in comparing fill time with head cut depth. However, it doesn't give pit water surface elevation. (14) From, "TWO RIVERS DESIGN HYDROGRAPHS (WINDAM C INPUT HGs) FOR REPRESENTATIVE HEADCUT AT BIG THOMPSON SIDE AND SOUTH PLATTE SIDE PITS." (14, (15) Cumulative volume for use in obtaining elevation from elevation -storage curve ((2), (3)). pg. 30 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Pit Elevation (ft) 4690 - Pit Crest 4685 _ 4680 4675 4670 4665 4660 Pit4T6ee 4650 CENTRAL PIT Elevation vs Capacity 1000 2000 3000 4000 5000 6000 Vol (af) pg. 31 flow . Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 TWO RIVERS FILL TIME ESTIMATES NORTHWEST FIELD Inc GW Inflow Rate - GW Inflow Rate - Pit Depth Pit Elev Pit Vol GW Inflow Rate Volume Ave Ave (af) (af) (af/day) (af/day) (af/hr) (1) (2) (3) (4) (5) (6) (7) 0 4685.0 1,648 0 459 5,158 215 10 4675.0 1000 648 2,633 5,158 215 20 4665.0 500 500 4,443 5,158 215 25 4660.0 125 375 6,252 5,158 215 30 4655.0 0 125 9,858 5,158 215 HG Time River Inflow - Ave (hr) (cfs) (8) (9) River Inflow (af/hr) (10) Total Inflow Inflow Volume af/hr (11) (af) (14) 48 6,300 520 735 8,824 36 5,167 427 642 7,701 24 4,500 372 587 4,693 16 2,000 165 380 3,041 8 500 41 256 2,050 4 167 14 1300 3 2 500 1 250 0 0 0 0 0 Cummulative Inflow Volume (af) (15) 16,524 12,393 7,734 5,091 3,350 1800 1500 500 250 Elevation (ft) 4684 Intern( 4665 Intern( 4663 Intern( 4655 Pit bot pg. 32 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 TWO RIVERS WINDAM C INPUT/OUTPUT DATA pg. 33 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22.2020 CENTRAL PIT BREACH PROGRESSION BEST SOIL PARAMETER CAS 100 FT BERM - 11.f_ G.50 4eac._a 0_75 L_25 ,eaa.La .36 L_75 dee.L a0 eee.53 a_CE-eee.75 2_L2 4e8Q.T5 a_a- a_ae 4,5S.CC 2_56 4eae_L7 0 E ess.ae 50 C55.5E '5 - _5 _00 4EEO.az 5 4e0.5 7_25 ,eeo_so 5 EL.," 5.50-CEL.5C 8.75 _25 e6G_55 5.56 4ii0.5C 4EEO.CC _0.50 4c5C.,C L0.75 ,eeo.e2 eCO.4a L2_25 ee3_L7 eeo.Le 57.55 ^4.44 25.7, • on Tablm Cat. 1673.5 46E7.5_ 4555 4555.5 465£.5 4656.5 4656.5 4655. 4655.- 4655.- ¢656.5 4655 4555.5 46- 4 55.- 4655.- 4655.- 4656. 4556.- 4551. 4656. 1ESE.5 1556.5 4656.5, a- Tailaato. 4854.] 1ESE.5 1ESE.5 465E.3 4[56.5 4555 4655.5 4555.5 4556.5 4556.5 4655. 46.55 1655 aese 4655 4555. 4E5E. 4555 465E. 46554655 . 45554655 1555 aese 4655 4555 4555. 4;56.55 pg. 34 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 CENTRAL PIT BREACH PROGRESSION BEST SOIL PARAMETER CAS 150 FT BERM 0_50 aese_La .25 aece.se 2.0G aece.4e 2_25 aese_sc 2.50 aeee.es 2.75 aece.ea 2.3, aece.es 2.5G eece.as 4e5, 52 aeea 55 aeea es 6.50 9.00 L2.00 4e59 49 L2.25 4e,5.42 964 E7 14P.2 956L.2, 127 SS L4.94 955E., Di Elevation 965E. D 965E. D 965E. D pg. 35 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 CENTRAL PIT BREACH PROGRESSION BEST SOIL PARAMETER CAS 200 FT BERM pg. 36 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 NORTHWEST PIT BREACH PROGRESSION BEST SOIL PARAMETER CASE pg. 37 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 NORTHWEST PIT BREACH PROGRESSION STRONG SOIL PARAMETER CASE 11 Da 5541,4 00 1453.05. 365, 33 3003 . Da 5.0.53 46. DO 4055 . 4.505. DO 5.0.53 46. 00 4055 . 0.045 00 5.0.53 46. oa 4.353 400E. 00 4055 . 00 5,343 00 5.0.53 0.0.05 03 5,343 DO 3003 . Da 4005 . DO 5,343 Da 4005 . 00 4.505 .00 pg. 38 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 CENTRAL PIT INPUT DATA BEST SOIL PARAMETER CASE 100 FT BERM (All other WinDAM input data can be obtained from program files upon request.) 11'71, of 7oRu- r _ Cencral _ r•c - ,E5x � -Eos CceEei 2JL5EA...ELx _ 3BEST a.R`*.E _ Berm _6.:h - _C5 _c • • • a no__ 5.,..... - - 2Di ..__ :_Ca SE 0-_E -- DC .75 '9.5 :25.25 16' 250.2, 222.5 5DD CO L1-5 -25 2DiD 2_EL 24E 5 2.5 7.5 =25 41,2.5 451 4C25 4752 4=-5 5DE.D 5=4_.-5 5222.E 6i25.2.5 5167 5292 54:7 55,2 EeO7 5'5=.25 5=2.5 59:6.75 ECC0 615, 6225 62:O 5222.25 ED66.5 5949.75 5522 57DE 5E42 545! 5i66. 5 E0e2.25 5221 5249.75 4'_5 5 5.: 475E..25 25er =.5=i.5 45ii 44!9.5 4'si's 205 95. SE325,0 2522 245, 2222 2249.,5 2156.5 2,,2.2.5 2DDL 2625 C 2455.25 145LESS 2221 22C 5 _i.5 2E72.25 _625 S7.Roo=e 2522 4i5i ELT, S�RCE SIRS ,oc_a_ DWRS_RL=,. _.E o 6.025 'axn=ny - EownetSe:. 51OC510Cie _3 5teeper than 2.1 MERm4 pg. 39 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 TWO RIVERS GROUNDWATER INFLOW Central Pk Analysis n'eevaaen Pemmnninl 'tromp, nit Inft 1350a 10.20.11 13561 20.30.11 139191 39 -325 aal�' voueadeaae 130565 1115, 135590 27233 599550 [=auapan m. contra! ve. Peril -note. n average..t.een me and mkt ynnre ets. ldaylRne anal axn' where o nefled. grain sine in mm and c-oso mat udll ben means {ton day. nod p to oi a aele fill ll tool nryr 9858 997069 6252 021 3151[5 2.3 051 1317, .159 059 23191 SAS 2s.,d ,25u. pg. 40 Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Central Pit 11/22/2019 Groin Training Channels Calculations (for future reference if needed) The open channel flow calculator Scl ct Chunncl -Ivpc. Trapezoid ♦ ! vzl' i2 �� I`z2 le a'-- 0 6-e _ ri ect nyIe Irapezoid Tnanyle C cle �. a Velocity(V)&Discherge(Q) V Scicot unit syslvtn'. Feet(ft) Channel slope: 0.01 ft/ft Water depth(y): 3 ft !Bottom width(b) 25 ft Flow velocity 19.9739 ft/s IleitSlopc (71): 1 to 1 (I -IM IRightSlope (72): 1 to 1 (I -M/)_ Flow discharge 921A105 ft^3/s Input n valuco.025 or select Calculate! (Status: Calculation finished Reset Wetted perimeter 3349 ft (flow area 84 _ ft2 __ IdOpwidth(l)31 ft Specific energy4.87 ft IFroude number 1.17 Ilslow status supercritical flow Critical depth_3.33 ft Critical slopc0.0071 ft/ft !Velocity head 1.87 ft C rem Or-din,rani! n1parl'uilt nr t i,11: n„ I_an/vr tNON. pg. 41 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 HEC-RAS HEC-RAS 5.0.0 U.S. Army Corps of Engineers Hydrologic Engineering Center 609 Second Street Davis, California PROJECT DATA Project Title: SPR WSP Project File : SPRWSP.prj Run Date and Time: 12/30/2019 8:30:25 PM Project in English units PLAN DATA Plan Title: SPR at Two Rivers WSP Plan File : C:\DATA\Flow Technologies\Projects-FT\Varra\FT1910 - Two Rivers\H&LLSPRWSP.p01 Geometry Title: SPR at Two Rivers Geometry File : C:\DATA\Flow Technologies\Projects -FT \V arra\FT1910 - Two Rivers\H&LLSPRWSP.g01 Flow Title Flow File SPR at Two Rivers C:\DATA\Flow Technologies\Projects -FT\Varra\FT1910 - Two Rivers\H&H\SPRWSP.f01 Plan Summary Information: Number of: Cross Sections = 5 Multiple Openings = 0 Culverts = 0 Inline Structures = 0 Bridges = 0 Lateral Structures = 0 Computational Information Water surface calculation tolerance = 0.01 Critical depth calculation tolerance = 0.01 Maximum number of iterations = 20 Maximum difference tolerance = 0.3 Flow tolerance factor = 0.001 Computation Options pg. 42 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Critical depth computed only where necessary Conveyance Calculation Method: At breaks in n values only Friction Slope Method: Average Conveyance Computational Flow Regime: Subcritical Flow FLOW DATA Flow Title: SPR at Two Rivers Flow File : C:\DATA \,Flow Technologies \Projects -FT\Varra\,FT1910 - Two Rivers \H&H\SPRWSP.f01 Flow Data (cfs) River Reach RS 10-yr 50-yr 100-yr 500-yr SPR Two Rivers 8880 8500 18600 24500 42500 Boundary Conditions River Reach Profile SPR Upstream Downstream Two Rivers 10-yr Normal S = 0.003 GEOMETRY DATA Geometry Title: SPR at Two Rivers Geometry File : C:\DATA\Flow Technologies \Projects -FT\Varra\FT1910 - Two Rivers \H&H\SPRWSP.g01 CROSS SECTION RIVER: SPR REACH: Two Rivers RS: 8880 INPUT Description: U/S end on private property. Station Elevation Data num= 7 Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev 0 4692 187 4691 715 4697 966 4692 1253 4697 1364 4692 1607 4699 pg. 43 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Manning's n Values num= 3 Sta n Val Sta n Val Sta n Val 0 .04 966 .03 1364 .04 Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr 966 1364 1510 1510 1510 .1 .3 Left Levee Station= 0 Elevation= 4697 CROSS SECTION OUTPUT Profile #10-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4695.55 Element 0.17 Wt. n -Val. 4695.38 Reach Len. (ft) 4693.90 Flow Area (sq ft) 0.002175 Area (sq ft) 8500.00 Flow (cfs) 1127.48 Top Width (ft) 3.27 Avg. Vel. (ft/s) 4.38 Hydr. Depth (ft) 182243.6 Cony. (cfs) 1510.00 Wetted Per. (ft) 745.99 268.83 117.24 4692.00 Shear (lb/sq ft) 0.35 0.23 0.23 1.01 Stream Power (lb/ft s) 1.19 0.75 0.56 2.11 Cum Volume (acre -ft) 181.90 178.62 103.94 0.00 Cum SA (acres) 64.14 49.77 33.28 Expan. Left OB Channel Right OB 0.040 0.030 0.040 1510.00 1510.00 1510.00 1946.94 453.61 197.82 1946.94 453.61 197.82 6529.01 1485.21 485.78 741.56 268.73 117.19 3.35 3.27 2.46 2.63 1.69 1.69 139984.7 31843.6 10415.3 Warning: Divided flow computed for this cross-section. Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #50-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) 4697.77 Element 0.17 Wt. n -Val. 4697.60 Reach Len. (ft) 4695.07 Flow Area (sq ft) 0.001196 Area (sq ft) 18600.00 Flow (cfs) 1558.42 Top Width (ft) Left OB Channel Right OB 0.040 0.030 0.040 1510.00 1510.00 1510.00 3913.67 1234.03 544.43 3913.67 1234.03 544.43 12717.92 4493.03 1389.05 966.00 398.00 194.42 pg. 44 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 3.27 Avg. Vel. (ft/s) 3.25 3.64 2.55 6.60 Hydr. Depth (ft) 4.05 3.10 2.80 537886.3 Cony. (cfs) 367784.7 129932.2 40169.5 1510.00 Wetted Per. (ft) 972.68 398.16 194.50 4692.00 Shear (lb/sq ft) 0.30 0.23 0.21 1.02 Stream Power (lb/ft s) 0.98 0.84 0.53 1.81 Cum Volume (acre -ft) 316.09 289.30 193.52 0.02 Cum SA (acres) 68.03 56.56 49.04 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #100-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4698.77 Element 0.18 Wt. n -Val. 4698.58 Reach Len. (ft) 4695.59 Flow Area (sq ft) 0.000949 Area (sq ft) 24500.00 Flow (cfs) 1592.56 Top Width (ft) 3.38 Avg. Vel. (ft/s) 7.58 Hydr. Depth (ft) 795434.2 Cony. (cfs) 1510.00 Wetted Per. (ft) 4692.00 Shear (lb/sq ft) 1.03 Stream Power (lb/ft s) 1.68 Cum Volume (acre -ft) 0.03 Cum SA (acres) Left OB Channel Right OB 0.040 0.030 0.040 1510.00 1510.00 1510.00 4863.63 1625.43 752.41 4863.63 1625.43 752.41 16261.38 6334.01 1904.61 966.00 398.00 228.56 3.34 3.90 2.53 5.03 4.08 3.29 527953.4 205644.5 61836 973.67 398.16 228.65 0.30 0.24 0.19 0.99 0.94 0.49 377.56 340.36 242.13 68.03 56.56 54.80 3 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION RIVER: SPR REACH: Two Rivers RS: 7340 pg. 45 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 INPUT Description: Upstream end of site. Station Elevation Data num= 7 Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev 0 4691 101 4689 170 4691 279 4687 318 4689 483 4686 647 4699 Manning's n Values num= 3 Sta n Val Sta n Val Sta n Val 0 .04 170 .03 318 .04 Bank Sta: Left Right Lengths: Left Channel Right 170 318 4289.03 4289.03 4289.03 Left Levee Station= 0 Elevation= 4694 CROSS SECTION OUTPUT Profile #10-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4693.43 Element 0.20 Wt. n -Val. 4693.23 Reach Len. (ft) 4690.66 Flow Area (sq ft) 0.000976 Area (sq ft) 8500.00 Flow (cfs) 574.24 Top Width (ft) 3.41 Avg. Vel. (ft/s) 7.23 Hydr. Depth (ft) 272035.3 Cony. (cfs) 4289.03 Wetted Per. (ft) 172.28 148.12 256.55 4687.00 Shear (lb/sq ft) 0.19 0.27 0.30 1.09 Stream Power (lb/ft s) 0.49 1.15 1.02 8.10 Cum Volume (acre -ft) 138.63 159.22 78.40 0.03 Cum SA (acres) 48.34 42.55 26.81 Coeff Contr. Expan. .1 .3 Left OB Channel Right OB 0.040 0.030 0.040 4289.03 4289.03 4289.03 549.51 665.40 1275.79 549.51 665.40 1275.79 1382.08 2803.62 4314.30 170.00 148.00 256.24 2.52 4.21 3.38 3.23 4.50 4.98 44232.2 89727.5 138075.6 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #50-yr E.G. Elev (ft) Vel Head (ft) 4695.94 Element Left OB Channel Right OB 0.40 Wt. n -Val. 0.040 0.030 0.040 pg. 46 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4695.54 Reach Len. (ft) 4289.03 4289.03 4289.03 4692.19 Flow Area (sq ft) 942.55 1007.58 1901.94 0.001200 Area (sq ft) 942.55 1007.58 1901.94 18600.00 Flow (cfs) 3733.04 6207.09 8659.87 603.41 Top Width (ft) 170.00 148.00 285.41 4.83 Avg. Vel. (ft/s) 3.96 6.16 4.55 9.54 Hydr. Depth (ft) 5.54 6.81 6.66 536880.5 Cony. (cfs) 107752.5 179164.7 249963.3 4289.03 Wetted Per. (ft) 174.59 148.12 285.81 4687.00 Shear (lb/sq ft) 0.40 0.51 0.50 1.09 Stream Power (lb/ft s) 1.60 3.14 2.27 8.47 Cum Volume (acre -ft) 231.92 250.45 151.12 0.03 Cum SA (acres) 48.34 47.10 40.72 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #100-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4697.06 Element 0.51 Wt. n -Val. 4696.55 Reach Len. (ft) 4692.87 Flow Area (sq ft) 0.001318 Area (sq ft) 24500.00 Flow (cfs) 616.03 Top Width (ft) 5.49 Avg. Vel. (ft/s) 10.54 Hydr. Depth (ft) 674772.6 Cony. (cfs) 4289.03 Wetted Per. (ft) 4687.00 Shear (lb/sq ft) Left OB Channel Right OB 0.040 0.030 0.040 4289.03 4289.03 4289.03 1112.64 1155.65 2193.80 1112.64 1155.65 2193.80 5138.79 8175.37 11185.84 170.00 148.00 298.03 4.62 7.07 5.10 6.54 7.81 7.36 141531.1 225164.0 308077.6 175.59 148.12 298.47 0.52 0.64 0.60 1.10 Stream Power (lb/ft s) 2.41 4.54 3.08 8.64 Cum Volume (acre -ft) 273.98 292.16 191.07 0.02 Cum SA (acres) 48.34 47.10 45.67 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate pg. 47 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION RIVER: SPR REACH: Two Rivers RS: 3051 INPUT Description: SE corner of site just upstream 90 degree bend. Station Elevation Data num= 5 Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev 0 4684 134 4679 528 4686 637 4683 919.69 4688.81 Manning's n Values num= 3 Sta n Val Sta n Val Sta n Val 0 .04 134 .035 528 .04 Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan. 134 528 1017 1017 1017 .1 .3 Left Levee Station= 0 Elevation= 4690 CROSS SECTION OUTPUT Profile #10-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4685.29 Element 0.54 Wt. n -Val. 4684.74 Reach Len. (ft) 4683.91 Flow Area (sq ft) 0.005087 Area (sq ft) 8500.00 Flow (cfs) 605.34 Top Width (ft) 5.70 Avg. Vel. (ft/s) 5.74 Hydr. Depth (ft) 119180.8 Cony. (cfs) 1017.00 Wetted Per. (ft) 134.84 323.28 148.15 4679.00 Shear (lb/sq ft) 1.02 0.91 0.28 1.08 Stream Power (lb/ft s) 5.92 5.58 0.67 1.52 Cum Volume (acre -ft) 90.18 80.77 9.24 0.13 Cum SA (acres) 33.37 19.35 6.90 Left OB Channel Right OB 0.040 0.035 0.040 1017.00 1017.00 1017.00 434.52 928.10 129.05 434.52 928.10 129.05 2511.64 5676.50 311.86 134.00 323.23 148.11 5.78 6.12 2.42 3.24 2.87 0.87 35216.5 79591.7 4372.6 Warning: Divided flow computed for this cross-section. Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than pg. 48 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #50-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4687.44 Element 0.68 Wt. n -Val. 4686.76 Reach Len. (ft) 4685.57 Flow Area (sq ft) 0.003844 Area (sq ft) 18600.00 Flow (cfs) 819.79 Top Width (ft) 6.26 Avg. Vel. (ft/s) 7.76 Hydr. Depth (ft) 299992.6 Cony. (cfs) 1017.00 Wetted Per. (ft) 4679.00 Shear (lb/sq ft) 1.11 Stream Power (lb/ft s) 8.48 7.06 1.78 1.58 Cum Volume (acre -ft) 150.84 118.27 28.47 0.13 Cum SA (acres) 33.37 20.42 12.30 Left OB Channel Right OB 0.040 0.035 0.040 1017.00 1017.00 1017.00 704.42 1677.19 589.35 704.42 1677.19 589.35 4836.78 11594.67 2168.55 134.00 394.00 291.79 6.87 6.91 3.68 5.26 4.26 2.02 78010.7 187006.3 34975.7 136.85 394.06 291.87 1.24 1.02 0.48 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #100-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) 4688.40 Element 0.76 Wt. n -Val. 4687.64 Reach Len. (ft) 4686.24 Flow Area (sq ft) 0.003449 Area (sq ft) 24500.00 Flow (cfs) 862.72 Top Width (ft) 6.60 Avg. Vel. (ft/s) 8.64 Hydr. Depth (ft) 417164.0 Cony. (cfs) 1017.00 Wetted Per. (ft) 4679.00 Shear (lb/sq ft) Left OB Channel Right OB 0.040 0.035 0.040 1017.00 1017.00 1017.00 822.65 2024.83 865.74 822.65 2024.83 865.74 5908.27 15033.41 3558.32 134.00 394.00 334.72 7.18 7.42 4.11 6.14 5.14 2.59 100600.7 255975.4 60587.9 137.73 394.06 334.81 1.29 1.11 0.56 pg. 49 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Alpha Frctn Loss (ft) C & E Loss (ft) 1.12 Stream Power (lb/ft s) 9.24 8.21 2.29 1.58 Cum Volume (acre -ft) 178.70 135.58 40.44 0.14 Cum SA (acres) 33.37 20.42 14.52 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION RIVER: SPR REACH: Two Rivers RS: 2034 INPUT Description: SE corner of site at river bend. Station Elevation Data num= 7 Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev 0 4683 80 4682 525 4678 560 4677 800 4680 820 4681 1430 4693 Manning's n Values num= 3 Sta n Val Sta n Val Sta n Val 0 .04 525 .035 800 .04 Bank Sta: Left Right Lengths: Left Channel Right Coeff Contr. Expan. 525 800 2034 2034 2034 .1 .3 Left Levee Station= 0 Elevation= 4688 CROSS SECTION OUTPUT Profile #10-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) 4683.64 Element 0.13 Wt. n -Val. 4683.51 Reach Len. (ft) 4680.88 Flow Area (sq ft) 0.000705 Area (sq ft) 8500.00 Flow (cfs) 947.75 Top Width (ft) 2.59 Avg. Vel. (ft/s) 6.51 Hydr. Depth (ft) 320144.9 Cony. (cfs) Left OB Channel Right OB 0.040 0.035 0.040 2034.00 2034.00 2034.00 1644.42 1413.63 220.80 1644.42 1413.63 220.80 3469.72 4745.70 284.58 525.00 275.00 147.75 2.11 3.36 1.29 3.13 5.14 1.49 130683.7 178742.6 10718.6 pg. 50 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 2034.00 Wetted Per. (ft) 525.54 275.03 147.80 4677.00 Shear (lb/sq ft) 0.14 0.23 0.07 1.22 Stream Power (lb/ft s) 0.29 0.76 0.08 2.60 Cum Volume (acre -ft) 65.91 53.43 5.15 0.02 Cum SA (acres) 25.68 12.37 3.45 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #50-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4685.72 Element 0.23 Wt. n -Val. 4685.49 Reach Len. (ft) 4682.35 Flow Area (sq ft) 0.000834 Area (sq ft) 18600.00 Flow (cfs) 1048.38 Top Width (ft) 3.54 Avg. Vel. (ft/s) 8.49 Hydr. Depth (ft) 644075.4 Cony. (cfs) 2034.00 Wetted Per. (ft) 4677.00 Shear (lb/sq ft) 1.17 Stream Power (lb/ft s) 0.84 1.68 0.25 2.91 Cum Volume (acre -ft) 111.29 75.84 14.44 0.03 Cum SA (acres) 25.68 12.61 6.00 Left OB Channel Right OB 0.040 0.035 0.040 2034.00 2034.00 2034.00 2683.66 1957.99 612.87 2683.66 1957.99 612.87 8515.93 8883.75 1200.33 525.00 275.00 248.38 3.17 4.54 1.96 5.11 7.12 2.47 294887.0 307623.9 41564.6 527.52 275.03 248.45 0.26 0.37 0.13 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #100-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) 4686.68 Element 0.28 Wt. n -Val. 4686.39 Reach Len. (ft) Left OB Channel Right OB 0.040 0.035 0.040 2034.00 2034.00 2034.00 pg. 51 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4682.96 Flow Area (sq ft) 0.000879 Area (sq ft) 24500.00 Flow (cfs) 1 1094.17 Top Width (ft) 3.94 Avg. Vel. (ft/s) 9.39 Hydr. Depth (ft) 826212.9 Cony. (cfs) 2034.00 Wetted Per. (ft) 4677.00 Shear (lb/sq ft) 1.17 Stream Power (lb/ft s) 3.01 Cum Volume (acre -ft) 0.03 Cum SA (acres) 3156.62 2205.73 857.25 3156.62 2205.73 857.25 1447.95 11125.80 1926.25 525.00 275.00 294.17 3.63 5.04 2.25 6.01 8.02 2.91 386058.8 375195.2 64959.0 528.42 275.03 294.25 0.33 0.44 0.16 1.19 2.22 0.36 132.25 86.19 20.33 25.68 12.61 7.18 Warning: The cross-section end points had to be extended vertically for the computed water surface. Warning: The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. Warning: The energy loss was greater than 1.0 ft (0.3 m). between the current and previous cross section. This may indicate the need for additional cross sections. Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION RIVER: SPR REACH: Two Rivers RS: 0 INPUT Description: Downstream corner of site berm. Station Elevation Data num= 6 Sta Elev Sta Elev Sta Elev Sta Elev Sta Elev 0 4680 175 4678 575 4679 600 4674 840 4681 860 4684 Manning's n Values num= 3 Sta n Val Sta n Val Sta n Val 0 .04 575 .035 840 .04 Bank Sta: Left Right Coeff Contr. Expan. 575 840 .1 .3 Left Levee Station= 0 Elevation= 4684 CROSS SECTION OUTPUT Profile #10-yr E.G. Elev (ft) 4681.02 Element Left OB Channel Right OB pg. 52 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 0.31 Wt. n -Val. 4680.70 Reach Len. (ft) 4679.92 Flow Area (sq ft) 0.003006 Area (sq ft) 8500.00 Flow (cfs) 829.79 Top Width (ft) 4.14 Avg. Vel. (ft/s) 6.70 Hydr. Depth (ft) 155044.8 Cony. (cfs) Wetted Per. (ft) 4674.00 Shear (lb/sq ft) 1.18 Stream Power (lb/ft s) Cum Volume (acre -ft) Cum SA (acres) 0.040 0.035 1178.74 875.09 1178.74 875.09 3870.67 4629.33 575.00 254.79 3.28 5.29 2.05 3.43 70603.2 84441.6 575.71 255.38 0.38 0.64 1.26 3.40 Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #50-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 4682.79 Element 0.51 Wt. n -Val. 4682.28 Reach Len. (ft) 4680.98 Flow Area (sq ft) 0.003004 Area (sq ft) 18600.00 Flow (cfs) 848.50 Top Width (ft) 5.50 Avg. Vel. (ft/s) 8.27 Hydr. Depth (ft) 339334.8 Cony. (cfs) Wetted Per. (ft) 4674.00 Shear (lb/sq ft) 1.09 Stream Power (lb/ft s) Cum Volume (acre -ft) Cum SA (acres) Left OB Channel Right OB 0.040 0.035 0.040 2083.07 1290.35 5.42 2083.07 1290.35 5.42 9978.48 8613.41 8.11 575.00 265.00 8.50 4.79 6.68 1.50 3.62 4.87 0.64 182045.5 157141.4 148.0 577.29 265.60 8.59 0.68 0.91 0.12 3.24 6.08 0.18 Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. CROSS SECTION OUTPUT Profile #100-yr E.G. Elev (ft) Vel Head (ft) W.S. Elev (ft) Crit W.S. (ft) 4683.64 Element 0.62 Wt. n -Val. 4683.01 Reach Len. (ft) 4681.44 Flow Area (sq ft) Left OB Channel Right OB 0.040 0.035 0.040 2507.86 1486.12 13.52 pg. 53 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 E.G. Slope (ft/ft) Q Total (cfs) Top Width (ft) Vel Total (ft/s) Max Chl Dpth (ft) Cony. Total (cfs) Length Wtd. (ft) Min Ch El (ft) Alpha Frctn Loss (ft) C & E Loss (ft) 0.003002 Area (sq ft) 24500.00 Flow (cfs) 853.42 Top Width (ft) 6.11 Avg. Vel. (ft/s) 9.01 Hydr. Depth (ft) 447179.3 Cony. (cfs) Wetted Per. (ft) 4674.00 Shear (lb/sq ft) 1.07 Stream Power (lb/ft s) Cum Volume (acre -ft) Cum SA (acres) 2507.86 1486.12 13.52 13577.73 10894.84 27.43 575.00 265.00 13.42 5.41 7.33 2.03 4.36 5.61 1.01 247823.7 198855.0 500.7 578.03 265.60 13.57 0.81 1.05 0.19 4.40 7.69 0.38 Note: Multiple critical depths were found at this location. The critical depth with the lowest, valid, energy was used. SUMMARY OF MANNING'S N VALUES River:SPR SPR Reach River Sta. nl n2 n3 Two Rivers Two Rivers Two Rivers Two Rivers Two Rivers 0 8880 7340 3051 2034 .04 .03 .04 .04 .03 .04 .04 .035 .04 .04 .035 .04 .04 .035 .04 SUMMARY OF REACH LENGTHS River: SPR Reach River Sta. Left Channel Right Two Rivers Two Rivers Two Rivers Two Rivers Two Rivers 0 8880 1510 1510 1510 7340 4289.03 4289.03 4289.03 3051 1017 1017 1017 2034 2034 2034 2034 pg. 54 flow Technologies Two Rivers Gravel Pit Mine Riverside Berm Failure Analysis and Flood Control Mitigation Plan January 22, 2020 SUMMARY OF CONTRACTION AND EXPANSION COEFFICIENTS River: SPR Reach River Sta. Contr. Expan. Two Rivers 8880 .1 .3 Two Rivers 7340 .1 .3 Two Rivers 3051 .1 .3 Two Rivers 2034 .1 .3 Two Rivers 0 .1 .3 Profile Output Table - Standard Table 1 Reach River Sta Profile Q Total Min Ch El (cfs) (ft) (ft) (ft) Two Rivers 8880 Two Rivers 8880 Two Rivers 8880 Two Rivers 7340 Two Rivers 7340 Two Rivers 7340 Two Rivers 3051 Two Rivers 3051 Two Rivers 3051 Two Rivers 2034 Two Rivers 2034 Two Rivers 2034 Two Rivers 0 Two Rivers 0 Two Rivers 0 10-yr 8500.00 4692.00 50-yr 18600.00 4692.00 100-yr 24500.00 4692.00 10-yr 8500.00 4687.00 50-yr 18600.00 4687.00 100-yr 24500.00 4687.00 10-yr 8500.00 4679.00 50-yr 18600.00 4679.00 100-yr 24500.00 4679.00 10-yr 8500.00 4677.00 50-yr 18600.00 4677.00 100-yr 24500.00 4677.00 10-yr 8500.00 4674.00 50-yr 18600.00 4674.00 100-yr 24500.00 4674.00 W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude 4 Chl (ft) (ft/ft) (ft/s) (sq ft) (ft) 4695.38 4693.90 4695.55 0.002175 3.27 2598.37 1127.48 4697.60 4695.07 4697.77 0.001196 3.64 5692.13 1558.42 4698.58 4695.59 4698.77 0.000949 3.90 7241.47 1592.56 4693.23 4690.66 4693.43 0.000976 4.21 2490.70 574.24 4695.54 4692.19 4695.94 0.001200 6.16 3852.07 603.41 4696.55 4692.87 4697.06 0.001318 7.07 4462.08 616.03 4684.74 4683.91 4685.29 0.005087 6.12 1491.68 605.34 4686.76 4685.57 4687.44 0.003844 6.91 2970.96 819.79 4687.64 4686.24 4688.40 0.003449 7.42 3713.22 862.72 4683.51 4680.88 4683.64 0.000705 3.36 3278.84 947.75 4685.49 4682.35 4685.72 0.000834 4.54 5254.51 1048.38 4686.39 4682.96 4686.68 0.000879 5.04 6219.60 1094.17 4680.70 4679.92 4681.02 0.003006 5.29 2053.83 829.79 4682.28 4680.98 4682.79 0.003004 6.68 3378.84 848.50 4683.01 4681.44 4683.64 0.003002 7.33 4007.50 853.42 0.44 0.36 0.34 0.35 0.42 0.45 0.64 0.59 0.58 0.26 0.30 0.31 0.50 0.53 0.55 pg. 55 Bottom Depth of Well (ft) Date P124-1 P124-2 Pit 124 Piezometer P124-3 P124-4 P124-5 P124-6 P124-7 P124-8 P124-9 P124-10 P124-11 P124-12 22.3 17.19 36.11 23.38 32.8 37.87 47.12 29.42 41.41 44.97 43.75 29.85 P124-1 P124-2 Measured Depth to Water (ft.) P124-3 P124-4 P124-5 P124-6 P124-7 P124-8 P124-9 P124-10 P124-11 P124-12 9/15/2015 18.90 9.31 10.61 9.62 8.75 9.94 12.05 8.78 12.30 17.97 17.51 9.46 10/14/2015 19.08 9.81 10.80 9.79 8.90 10.81 12.29 8.80 12.66 17.63 17.29 9.48 11/13/2015 19.20 9.51 10.39 9.31 8.49 10.46 11.89 8.13 11.89 16.56 16.47 8.71 12/11/2015 19.32 9.63 10.51 9.43 8.62 10.71 12.03 8.51 12.46 17.30 17.17 9.18 1/12/2016 19.46 9.66 dry 9.34 8.55 10.81 12.18 8.62 12.40 17.26 17.32 9.25 2/12/2016 19.54 9.64 dry 9.40 8.62 10.67 12.08 8.54 12.15 16.92 17.04 9.17 3/11/2016 19.55 9.65 dry 9.49 8.70 10.65 12.05 8.70 12.34 17.32 17.38 9.44 4/12/2016 19.55 9.65 dry 9.67 8.82 10.41 11.92 8.30 11.64 16.31 16.54 8.87 5/9/2016 18.84 9.19 10.02 9.37 8.33 8.97 10.76 6.62 9.37 13.81 14.26 6.87 6/9/2016 18.57 8.21 8.61 7.34 6.82 8.80 10.34 6.68 9.52 14.15 14.46 7.18 7/12/2016 18.83 9.50 10.40 9.90 9.07 9.61 11.51 8.51 11.63 17.76 17.26 9.38 8/12/2016 19.07 9.75 dry 9.87 9.19 10.68 12.22 9.24 12.97 18.14 18.19 10.03 9/13/2016 19.22 9.64 dry 9.72 8.93 10.10 12.17 8.60 12.12 17.99 17.86 9.65 10/10/2016 19.21 9.92 dry 9.95 9.19 10.91 12.48 8.93 12.62 17.66 17.51 9.53 11/9/2016 19.13 9.91 dry 9.73 9.05 10.80 12.22 8.77 12.41 17.23 17.18 9.37 12/2/2016 19.09 9.98 dry 9.76 9.05 11.03 12.35 9.01 12.81 18.35 17.55 9.72 1/13/2017 19.11 10.05 dry 9.85 9.11 11.63 11.33 8.76 13.05 17.68 17.20 9.33 2/10/2017 19.11 10.71 dry 10.53 9.76 11.66 13.01 9.45 13.24 17.97 17.96 10.09 3/10/2017 19.15 10.77 dry 10.66 9.91 11.79 13.09 9.58 13.36 18.17 18.07 10.21 4/11/2017 19.81 10.81 dry 10.63 9.93 11.90 13.23 9.95 13.92 19.10 18.69 10.66 5/12/2017 19.13 10.18 dry 9.86 9.18 11.04 12.68 8.78 12.06 17.00 17.09 9.23 6/9/2017 18.08 9.29 10.15 9.41 8.67 9.64 11.13 7.70 11.05 15.73 15.83 8.21 7/13/2017 18.61 9.62 dry 9.89 9.36 10.09 11.98 9.18 12.43 18.21 18.08 10.03 8/11/2017 18.75 9.14 dry 9.19 8.58 9.71 11.74 7.21 11.30 16.84 16.39 8.78 9/12/2017 18.89 9.98 dry 10.08 9.53 10.77 12.57 9.38 12.61 18.21 18.27 10.04 10/13/2017 18.77 9.87 dry 9.70 9.12 10.82 12.31 8.83 12.46 17.59 17.51 9.46 11/10/2017 18.78 9.86 dry 9.59 9.01 10.88 12.34 8.73 12.39 17.31 17.33 9.35 12/8/2017 18.86 9.98 dry 9.88 9.25 10.95 12.34 8.82 12.56 17.51 17.45 9.45 1/12/2018 18.94 10.03 dry 9.78 9.20 11.14 12.49 8.97 12.76 17.72 17.70 9.63 2/9/2018 19.00 10.12 dry 9.92 9.36 11.31 12.63 9.21 13.06 18.09 18.09 9.92 3/9/2018 19.05 10.27 dry 10.12 9.55 11.39 12.76 9.26 13.09 18.12 18.10 9.96 4/12/2018 19.09 10.37 dry 10.19 9.69 11.55 12.87 9.59 13.37 18.49 18.56 10.34 5/10/2018 18.93 10.31 dry 10.25 9.68 11.21 12.76 9.26 12.75 18.03 17.97 9.94 6/6/2018 18.87 9.98 dry 9.91 9.33 10.75 12.31 9.09 12.56 17.58 17.68 9.84 7/10/2018 19.13 10.07 dry 10.23 9.75 10.84 12.73 9.78 12.93 19.27 18.39 10.52 8/10/2018 19.15 9.85 dry 10.06 9.61 10.86 12.63 9.74 12.87 19.05 18.78 10.56 9/7/2018 19.27 10.33 dry 10.53 10.03 11.25 13.03 9.53 12.59 17.71 18.03 10.11 10/12/2018 19.31 10.33 dry 10.19 9.69 11.38 12.96 9.40 12.83 17.59 17.92 10.02 11/9/2018 19.30 10.09 dry 9.81 9.30 11.11 12.60 9.12 12.66 17.48 17.64 9.81 12/7/2018 19.35 10.17 dry 9.96 9.46 11.36 12.72 9.41 13.10 18.12 18.14 10.17 1/10/2019 19.36 10.29 dry 10.11 9.60 11.51 12.89 9.49 13.21 18.24 18.20 10.21 2/12/2019 19.40 10.27 dry 10.18 9.62 11.41 12.80 9.37 13.03 17.80 18.01 10.06 3/8/2019 19.39 10.29 dry 10.13 9.59 11.39 12.79 9.35 12.98 17.76 17.94 10.01 4/10/2019 19.36 10.30 dry 10.22 9.67 11.36 12.73 9.51 13.26 18.32 18.19 10.31 5/10/2019 19.27 10.43 dry 10.25 9.78 11.57 13.05 9.46 12.77 17.32 17.88 9.93 6/7/2019 19.12 10.22 dry 9.90 9.49 11.21 12.78 9.48 12.88 17.86 18.08 10.19 7/9/2019 19.21 9.36 dry 9.15 8.54 8.99 11.33 7.36 9.25 14.74 14.89 7.69 8/9/2019 19.29 9.49 dry 9.98 9.49 9.83 11.99 9.04 11.48 18.16 17.76 9.78 9/6/2019 19.41 9.94 dry 10.07 9.61 10.76 12.59 9.69 12.72 18.34 18.50 10.36 10/9/2019 19.40 10.13 dry 10.12 9.61 11.08 12.75 9.46 12.80 18.08 18.11 10.13 11/8/2019 19.33 9.97 dry 9.68 9.16 11.02 12.50 9.11 12.67 17.92 17.70 9.77 12/6/2019 19.31 10.13 dry 9.92 9.37 11.12 12.60 9.08 12.58 17.67 17.55 9.62 1/10/2020 19.26 10.19 dry 10.03 9.50 11.26 12.68 9.21 12.57 18.07 17.83 9.80 2/7/2020 19.19 10.23 dry 10.04 9.51 11.36 12.78 9.31 13.00 18.13 18.02 9.91 3/11/2020 19.15 10.24 dry 10.08 9.57 11.41 12.85 9.37 13.03 18.15 18.07 9.97 4/9/2020 19.07 10.13 dry 10.12 9.57 11.15 12.60 9.38 12.96 18.10 17.95 10.01 5/8/2020 18.94 10.12 dry 9.96 9.51 11.13 12.59 9.53 12.89 17.89 17.88 9.99 6/9/2020 19.05 10.02 dry 9.93 9.45 10.64 12.29 9.08 12.04 17.07 17.43 9.46 7/10/2020 19.12 9.91 dry 9.91 9.46 10.83 12.53 9.89 12.72 18.51 18.70 10.47 8/7/2020 19.04 10.03 dry 10.06 9.64 10.78 12.72 9.97 12.39 18.22 18.53 10.52 9/11/2020 19.14 10.23 dry 9.99 9.59 11.22 12.96 9.72 12.36 17.42 17.93 10.11 10/7/2020 19.21 10.40 dry 10.28 9.88 11.39 13.01 10.03 12.89 18.31 18.59 10.55 11/13/2020 19.14 10.07 dry 9.88 9.41 11.02 12.62 9.53 12.38 17.63 17.70 10.06 12/9/2020 19.16 10.05 dry 9.92 9.45 10.88 12.49 9.43 12.20 17.38 17.61 9.92 1/8/2021 19.18 10.07 dry 9.91 9.32 10.92 12.47 9.40 12.26 17.39 17.67 9.89 2/8/2021 19.20 10.23 dry 10.08 9.60 11.30 12.79 9.89 12.87 18.06 18.29 10.42 3/9/2021 19.17 10.23 dry 10.05 9.55 11.16 12.76 9.59 12.43 17.43 17.71 9.98 4/9/2021 19.17 10.11 dry 10.02 9.51 11.08 12.54 9.71 12.80 18.18 18.16 10.25 5/7/2021 19.15 10.28 dry 10.23 9.67 10.90 12.64 9.15 12.01 17.13 17.23 9.48 6/11/2021 19.10 8.27 8.72 7.66 7.38 9.30 10.93 8.34 10.47 16.08 16.23 8.61 7/8/2021 19.24 9.12 10.09 8.99 8.68 9.81 11.56 9.02 11.66 17.24 17.13 9.40 8/10/2021 19.31 9.79 dry 9.71 9.25 10.59 12.34 9.45 12.40 18.06 17.85 9.91 9/10/2021 19.37 10.17 dry 10.08 9.67 11.23 12.76 10.09 13.16 18.87 18.90 10.53 10/8/2021 19.41 10.31 dry 10.08 9.64 11.47 12.98 9.99 13.20 18.68 18.78 10.43 11/10/2021 19.36 9.91 dry 9.74 9.23 10.94 12.42 9.36 12.45 17.91 17.82 9.78 12/9/2021 19.38 10.07 dry 9.85 9.34 11.07 12.55 9.44 12.51 17.73 17.72 9.86 1/10/2022 19.41 10.07 dry 9.94 9.49 11.25 12.69 9.96 12.96 18.23 18.45 10.47 2/11/2022 19.40 10.22 dry 10.03 9.51 11.26 12.80 9.69 12.70 17.80 18.04 10.16 3/14/2022 19.40 10.10 dry 9.89 9.39 11.18 12.63 9.73 12.76 17.89 18.09 10.23 Top of pipe (ft.) Ground (ft.) Measured Bottom Depth of Well (ft) Elevation of Well Bottom (ft.) Date Pit 124 Piezometers P124-1 P124-2 P124-3 P124-4 P124-5 P124-6 P124-7 P124-8 P124-9 P124-10 P124-11 P124-12 4711.51 4690.59 4687.85 4685.07 4683.09 4692.07 4689.98 4682.23 4694.55 4697.09 4694.44 4683.49 4708.61 4686.58 4683.82 4681.02 4678.95 4688.14 4686.04 4678.28 4690.60 4693.17 4690.37 4679.34 22.3 17.19 36.11 23.38 32.8 37.87 47.12 29.42 41.41 44.97 43.75 29.85 4689.21 4673.40 4651.74 4661.69 4650.29 4654.20 4642.86 4652.81 4653.14 4652.12 4650.69 4653.64 9/15/2015 10/14/2015 11/13/2015 12/11/2015 1/12/2016 2/12/2016 3/11/2016 4/12/2016 5/9/2016 6/9/2016 7/12/2016 8/12/2016 9/13/2016 10/10/2016 11/9/2016 12/2/2016 1/13/2017 2/10/2017 3/10/2017 4/11/2017 5/12/2017 6/9/2017 7/13/2017 8/11/2017 9/12/2017 10/13/2017 11/10/2017 12/8/2017 1/12/2018 2/9/2018 3/9/2018 4/12/2018 5/10/2018 6/6/2018 7/10/2018 8/10/2018 9/7/2018 10/12/2018 11/9/2018 12/7/2018 1/10/2019 Elevation of Water (ft.) P112-1 P112-2 P112-3 P112-4 P112-5 P112-6 P112-7 P112-8 P112-9 P112-10 P112-11 P112-12 4692.61 4675.45 4674.34 4682.13 4677.93 4673.45 4682.25 4679.12 4676.93 4674.03 4692.43 4680.78 4677.05 4675.28 4674.19 4681.26 4677.69 4673.43 4681.89 4679.46 4677.15 4674.01 4692.31 4681.08 4677.46 4675.76 4674.60 4681.61 4678.09 4674.10 4682.66 4680.53 4677.97 4674.78 4692.19 4680.96 4677.34 4675.64 4674.47 4681.36 4677.95 4673.72 4682.09 4679.79 4677.27 4674.31 4692.05 4680.93 #VALUE! 4675.73 4674.54 4681.26 4677.80 4673.61 4682.15 4679.83 4677.12 4674.24 4691.97 4680.95 #VALUE! 4675.67 4674.47 4681.40 4677.90 4673.69 4682.40 4680.17 4677.40 4674.32 4691.96 4680.94 #VALUE! 4675.58 4674.39 4681.42 4677.93 4673.53 4682.21 4679.77 4677.06 4674.05 4691.96 4680.94 #VALUE! 4675.40 4674.27 4681.66 4678.06 4673.93 4682.91 4680.78 4677.90 4674.62 4692.67 4681.40 4677.83 4675.70 4674.76 4683.10 4679.22 4675.61 4685.18 4683.28 4680.18 4676.62 4692.94 4682.38 4679.24 4677.73 4676.27 4683.27 4679.64 4675.55 4685.03 4682.94 4679.98 4676.31 4692.68 4681.09 4677.45 4675.17 4674.02 4682.46 4678.47 4673.72 4682.92 4679.33 4677.18 4674.11 4692.44 4680.84 #VALUE! 4675.20 4673.90 4681.39 4677.76 4672.99 4681.58 4678.95 4676.25 4673.46 4692.29 4680.95 #VALUE! 4675.35 4674.16 4681.97 4677.81 4673.63 4682.43 4679.10 4676.58 4673.84 4692.30 4680.67 #VALUE! 4675.12 4673.90 4681.16 4677.50 4673.30 4681.93 4679.43 4676.93 4673.96 4692.38 4680.68 #VALUE! 4675.34 4674.04 4681.27 4677.76 4673.46 4682.14 4679.86 4677.26 4674.12 4692.42 4680.61 #VALUE! 4675.31 4674.04 4681.04 4677.63 4673.22 4681.74 4678.74 4676.89 4673.77 4692.40 4680.54 #VALUE! 4675.22 4673.98 4680.44 4678.65 4673.47 4681.50 4679.41 4677.24 4674.16 4692.40 4679.88 #VALUE! 4674.54 4673.33 4680.41 4676.97 4672.78 4681.31 4679.12 4676.48 4673.40 4692.36 4679.82 #VALUE! 4674.41 4673.18 4680.28 4676.89 4672.65 4681.19 4678.92 4676.37 4673.28 4691.70 4679.78 #VALUE! 4674.44 4673.16 4680.17 4676.75 4672.28 4680.63 4677.99 4675.75 4672.83 4692.38 4680.41 #VALUE! 4675.21 4673.91 4681.03 4677.30 4673.45 4682.49 4680.09 4677.35 4674.26 4693.43 4681.30 4677.70 4675.66 4674.42 4682.43 4678.85 4674.53 4683.50 4681.36 4678.61 4675.28 4692.90 4680.97 #VALUE! 4675.18 4673.73 4681.98 4678.00 4673.05 4682.12 4678.88 4676.36 4673.46 4692.76 4681.45 #VALUE! 4675.88 4674.51 4682.36 4678.24 4675.02 4683.25 4680.25 4678.05 4674.71 4692.62 4680.61 #VALUE! 4674.99 4673.56 4681.30 4677.41 4672.85 4681.94 4678.88 4676.17 4673.45 4692.74 4680.72 #VALUE! 4675.37 4673.97 4681.25 4677.67 4673.40 4682.09 4679.50 4676.93 4674.03 4692.73 4680.73 #VALUE! 4675.48 4674.08 4681.19 4677.64 4673.50 4682.16 4679.78 4677.11 4674.14 4692.65 4680.61 #VALUE! 4675.19 4673.84 4681.12 4677.64 4673.41 4681.99 4679.58 4676.99 4674.04 4692.57 4680.56 #VALUE! 4675.29 4673.89 4680.93 4677.49 4673.26 4681.79 4679.37 4676.74 4673.86 4692.51 4680.47 #VALUE! 4675.15 4673.73 4680.76 4677.35 4673.02 4681.49 4679.00 4676.35 4673.57 4692.46 4680.32 #VALUE! 4674.95 4673.54 4680.68 4677.22 4672.97 4681.46 4678.97 4676.34 4673.53 4692.42 4680.22 #VALUE! 4674.88 4673.40 4680.52 4677.11 4672.64 4681.18 4678.60 4675.88 4673.15 4692.58 4680.28 #VALUE! 4674.82 4673.41 4680.86 4677.22 4672.97 4681.80 4679.06 4676.47 4673.55 4692.64 4680.61 #VALUE! 4675.16 4673.76 4681.32 4677.67 4673.14 4681.99 4679.51 4676.76 4673.65 4692.38 4680.52 #VALUE! 4674.84 4673.34 4681.23 4677.25 4672.45 4681.62 4677.82 4676.05 4672.97 4692.36 4680.74 #VALUE! 4675.01 4673.48 4681.21 4677.35 4672.49 4681.68 4678.04 4675.66 4672.93 4692.24 4680.26 #VALUE! 4674.54 4673.06 4680.82 4676.95 4672.70 4681.96 4679.38 4676.41 4673.38 4692.20 4680.26 #VALUE! 4674.88 4673.40 4680.69 4677.02 4672.83 4681.72 4679.50 4676.52 4673.47 4692.21 4680.50 #VALUE! 4675.26 4673.79 4680.96 4677.38 4673.11 4681.89 4679.61 4676.80 4673.68 4692.16 4680.42 #VALUE! 4675.11 4673.63 4680.71 4677.26 4672.82 4681.45 4678.97 4676.30 4673.32 4692.15 4680.30 #VALUE! 4674.96 4673.49 4680.56 4677.09 4672.74 4681.34 4678.85 4676.24 4673.28 2/12/2019 3/8/2019 4/10/2019 5/10/2019 6/7/2019 7/9/2019 8/9/2019 9/6/2019 10/9/2019 11/8/2019 12/6/2019 1/10/2020 2/7/2020 3/11/2020 4/9/2020 5/8/2020 6/9/2020 7/10/2020 8/7/2020 9/11/2020 10/7/2020 11/13/2020 12/9/2020 1/8/2021 2/8/2021 3/9/2021 4/9/2021 5/7/2021 6/11/2021 7/8/2021 8/10/2021 9/10/2021 10/8/2021 11/10/2021 12/9/2021 1/10/2022 2/11/2022 3/14/2022 4692.11 4680.32 #VALUE! 4674.89 4673.47 4680.66 4677.18 4672.86 4681.52 4679.29 4676.43 4673.43 4692.12 4680.30 #VALUE! 4674.94 4673.50 4680.68 4677.19 4672.88 4681.57 4679.33 4676.50 4673.48 4692.15 4680.29 #VALUE! 4674.85 4673.42 4680.71 4677.25 4672.72 4681.29 4678.77 4676.25 4673.18 4692.24 4680.16 #VALUE! 4674.82 4673.31 4680.50 4676.93 4672.77 4681.78 4679.77 4676.56 4673.56 4692.39 4680.37 #VALUE! 4675.17 4673.60 4680.86 4677.20 4672.75 4681.67 4679.23 4676.36 4673.30 4692.30 4681.23 #VALUE! 4675.92 4674.55 4683.08 4678.65 4674.87 4685.30 4682.35 4679.55 4675.80 4692.22 4681.10 #VALUE! 4675.09 4673.60 4682.24 4677.99 4673.19 4683.07 4678.93 4676.68 4673.71 4692.10 4680.65 #VALUE! 4675.00 4673.48 4681.31 4677.39 4672.54 4681.83 4678.75 4675.94 4673.13 4692.11 4680.46 #VALUE! 4674.95 4673.48 4680.99 4677.23 4672.77 4681.75 4679.01 4676.33 4673.36 4692.18 4680.62 #VALUE! 4675.39 4673.93 4681.05 4677.48 4673.12 4681.88 4679.17 4676.74 4673.72 4692.20 4680.46 #VALUE! 4675.15 4673.72 4680.95 4677.38 4673.15 4681.97 4679.42 4676.89 4673.87 4692.25 4680.40 #VALUE! 4675.04 4673.59 4680.81 4677.30 4673.02 4681.98 4679.02 4676.61 4673.69 4692.32 4680.36 #VALUE! 4675.03 4673.58 4680.71 4677.20 4672.92 4681.55 4678.96 4676.42 4673.58 4692.36 4680.35 #VALUE! 4674.99 4673.52 4680.66 4677.13 4672.86 4681.52 4678.94 4676.37 4673.52 4692.44 4680.46 #VALUE! 4674.95 4673.52 4680.92 4677.38 4672.85 4681.59 4678.99 4676.49 4673.48 4692.57 4680.47 #VALUE! 4675.11 4673.58 4680.94 4677.39 4672.70 4681.66 4679.20 4676.56 4673.50 4692.46 4680.57 #VALUE! 4675.14 4673.64 4681.43 4677.69 4673.15 4682.51 4680.02 4677.02 4674.03 4692.39 4680.68 #VALUE! 4675.16 4673.63 4681.24 4677.45 4672.34 4681.83 4678.58 4675.74 4673.02 4692.47 4680.56 #VALUE! 4675.01 4673.45 4681.29 4677.26 4672.26 4682.16 4678.87 4675.91 4672.97 4692.37 4680.36 #VALUE! 4675.08 4673.50 4680.85 4677.02 4672.51 4682.19 4679.67 4676.51 4673.38 4692.30 4680.19 #VALUE! 4674.79 4673.21 4680.68 4676.97 4672.20 4681.66 4678.78 4675.85 4672.94 4692.37 4680.52 #VALUE! 4675.19 4673.68 4681.05 4677.36 4672.70 4682.17 4679.46 4676.74 4673.43 4692.35 4680.54 #VALUE! 4675.15 4673.64 4681.19 4677.49 4672.80 4682.35 4679.71 4676.83 4673.57 4692.33 4680.52 #VALUE! 4675.16 4673.77 4681.15 4677.51 4672.83 4682.29 4679.70 4676.77 4673.60 4692.31 4680.36 #VALUE! 4674.99 4673.49 4680.77 4677.19 4672.34 4681.68 4679.03 4676.15 4673.07 4692.34 4680.36 #VALUE! 4675.02 4673.54 4680.91 4677.22 4672.64 4682.12 4679.66 4676.73 4673.51 4692.34 4680.48 #VALUE! 4675.05 4673.58 4680.99 4677.44 4672.52 4681.75 4678.91 4676.28 4673.24 4692.36 4680.31 #VALUE! 4674.84 4673.42 4681.17 4677.34 4673.08 4682.54 4679.96 4677.21 4674.01 4692.41 4682.32 4679.13 4677.41 4675.71 4682.77 4679.05 4673.89 4684.08 4681.01 4678.21 4674.88 4692.27 4681.47 4677.76 4676.08 4674.41 4682.26 4678.42 4673.21 4682.89 4679.85 4677.31 4674.09 4692.20 4680.80 #VALUE! 4675.36 4673.84 4681.48 4677.64 4672.78 4682.15 4679.03 4676.59 4673.58 4692.14 4680.42 #VALUE! 4674.99 4673.42 4680.84 4677.22 4672.14 4681.39 4678.22 4675.54 4672.96 4692.10 4680.28 #VALUE! 4674.99 4673.45 4680.60 4677.00 4672.24 4681.35 4678.41 4675.66 4673.06 4692.15 4680.68 #VALUE! 4675.33 4673.86 4681.13 4677.56 4672.87 4682.10 4679.18 4676.62 4673.71 4692.13 4680.52 #VALUE! 4675.22 4673.75 4681.00 4677.43 4672.79 4682.04 4679.36 4676.72 4673.63 4692.10 4680.52 #VALUE! 4675.13 4673.60 4680.82 4677.29 4672.27 4681.59 4678.86 4675.99 4673.02 4692.11 4680.37 #VALUE! 4675.04 4673.58 4680.81 4677.18 4672.54 4681.85 4679.29 4676.40 4673.33 4692.11 4680.49 #VALUE! 4675.18 4673.70 4680.89 4677.35 4672.50 4681.79 4679.20 4676.35 4673.26 Big Thompson Confluence Mitigation Bank Floodplain Development Permit Package, Weld County, CO Prepared for Westervelt Ecological Services July 2019 0 Headwaters CORPORATION 4111 4th Avenue Suite 6 Kearney, NE 68845 Phone: (308) 237-5728 Big Thompson Confluence Mitigation Bank Floodplain Development Permit Package Weld County, CO Prepared For Westervelt Ecological Services Prepared By Headwaters Corporation 4111 4th Avenue, Suite 6 Kearney, NE 68845 Phone: (308) 237-5728 July 2019 Contributors: Justin Brei, P.E. Tom Smrdel Floodplain Development Permit Package, July 2019 1. BACKGROUND AND INTRODUCTION 1 2. PROJECT NARRATIVE 1 2.1. SITE RESTORATION PLAN 1 FLOODPLAIN BENCHES 1 BACKWATER WETLANDS 3 2.2. DESIGN SUMMARY 3 3. BASE FLOOD ELEVATION HYDRAULIC INVESTIGATION 4 3.1. INTRODUCTION 4 3.2. MODELING APPROACH AND METHODS 4 PROJECT SPECIFIC 2-D MODEL 4 TOPOGRAPHY 5 HYDROLOGY 5 HYDRAULICS 5 3.3. HYDRAULIC MODEL RESULTS 5 3.4. DISCUSSION AND CONCLUSIONS 7 4. WORKS CITED 7 Headwaters Corporation i Floodplain Development Permit Package, July 2019 1. BACKGROUND AND INTRODUCTION Westervelt Ecological Services has proposed a mitigation banking project at the confluence of the Big Thompson (BTR) and South Platte (SPR) rivers near Evans, Colorado. This mitigation involves stream and floodplain wetland restoration along a heavily incised reach of the lower BTR. The purpose of this report is to summarize the proposed restoration activities and to discuss the associated hydrologic and hydraulic conditions to support the issuance of a floodplain development permit. Permit applications and authorizations are located in Attachment A. Floodplain maps and a project design sheet are located in Attachment B. Deeds for the project parcels are located in Attachment C. The project site is located on a 72 -acre parcel in Weld County, CO near the town of Evans. Excavated material will be spoiled on an adjacent 28 -acre parcel. The project reach encompasses the lower 5,800 ft of the BTR, terminating at its confluence with the SPR, and includes the adjacent floodplain. The project site is located within a Zone A flood hazard area and can be found on FEMA tile 08123C -1707E. The existing alignment of the BTR within the project reach is greatly incised and disconnected from the adjacent floodplain. Historically, the project location was likely an active, dynamic floodplain for both the Big Thompson and South Platte Rivers which experienced frequent episodic flooding. Due largely to water development activities on both the BTR and SPR throughout the 1900s and early -2000s, floodplain connectivity and overland flow has been drastically reduced at the project site. The floodplain areas of the project site have transitioned to a primarily static upland vegetation community, resulting in an overall loss of ecological function. This reach of the SPR is discussed as a high priority for restoration in the Middle South Platte River Restoration Master Plan (MSPRMP) (CDM, 2016). This mitigation bank is currently undergoing the approval process with the U.S. Army Corps of Engineers, and is expected to be constructed in late 2019. Additionally, an application for a Nationwide Permit 27 for Section 404 is also being reviewed by USACE. The City of Evans, CO has expressed that they do not have additional floodplain permitting requirements, but this package will be submitted to the city engineer for their information and review. 2. PROJECT NARRATIVE 2.1. SITE RESTORATION PLAN The project includes excavation of floodplain benches along the mainstem of the BTR to increase floodplain connectivity and reduce overall stage and velocity of high flows. Approximately 4,020 linear feet of backwater channels will also be excavated along existing relic/abandoned channels, with additional associated wetland floodplains (Figure 1). Floodplain Benches Floodplain benches are created by regrading the existing banks of a degraded or incised channel and establishing a new bankfull bench which creates a lower floodplain within the river corridor (Figure 2). A healthy riparian zone that is inundated at frequent intervals promotes regeneration of riparian plant species and acts as a sediment trap and pollutant filter (CDM, 2016). The MSPRMP makes several refences to floodplain benches as a preferred restoration technique, and further recommends bench widths of 60 feet or wider (CDM, 2016). Headwaters Corporation 1 of 7 Floodplain Development Permit Package, July 2019 Figure 1: Project Overview Floodplain benches at the project site will create a bench with widths of 80-210 feet (most areas near 100 feet) along approximately 2,700 linear feet of the BTR channel. The BTR is heavily incised in this reach, and approximately four to six feet of excavation from the existing bank elevations will be required to achieve the desired wetland characteristics. These benches will slope slightly upward such that the outer boundary of the benches, where they meet the existing upland, will be 0.5 -feet higher than the river's edge of the bench. This will ensure that any inundation from flows high enough to submerge the floodplain benches will drain back to the river as it recedes. As designed, the floodplain benches will create a much larger channel cross section to carry peak flows, reducing the overall velocity of these high flows and allowing sediment and nutrient deposition along the bench. These lower velocities will also contribute to the increased stability of this design approach. Headwaters Corporation 2 of 7 Floodplain Development Permit Package, July 2019 Figure 2. Floodplain Bench Example (CDM, 2016) Backwater Wetlands The second major wetland feature of the project design is the restoration of backwater channels and associated wetlands. Before major water development in the area, overland flood flows would create high flow channels across sandy upland areas on the project site. When flood flows recede, these channels will often retain their downstream connection to the river and will partially inundate even without the presence of major overland flow, due to water backing up from the downstream connection. The design approach for the backwater channels and wetlands is to create two linear backwater features and restore an abandoned oxbow area. These backwater areas will be comprised of a wide, vegetated floodplain which will support a variety of wetland grasses, sedges, and woody species. Within this floodplain will be a one -foot -deep, 10 -foot -wide channel to provide a wetter ecosystem and support positive drainage of these features. These backwater features and their associated channels encompass a wetland area of 24.2 acres and an overall channel length of approximately 4,020 feet. The channels are slightly sloped upward from the main channel of the BTR and as water rises and falls within the BTR channel, water will move up and down the backwater channels. 2.2. DESIGN SUMMARY This project directly improves 2,700 feet of the BTR main channel and restores approximately 4,020 linear feet of additional habitat through the backwaters and oxbow area. Approximately 31.6 acres of wetlands are created or improved through this design. Total excavation is approximately 270,000 CY. Headwaters Corporation 3 of 7 Floodplain Development Permit Package, July 2019 3. BASE FLOOD ELEVATION HYDRAULIC INVESTIGATION 3.1. INTRODUCTION The purpose of this hydraulic investigation is to model the with -project conditions to understand the overall effect on river stage with respect to the base flood elevation (BFE). To quantify the localized effect the project has on river stage, identical model geometries depicting with- and without -project conditions were executed using HEC-RAS v5.0.5 (ACOE, 2015) in both a project -specific 2-D model and in the 1-D Colorado Hazard Mapping Program (CHAMP) Model (CWCB, 2017c), which has not yet been approved in the project area but is being used to revise FEMA flood mapping information in Weld County. 3.2. MODELING APPROACH AND METHODS Project Specific 2-D Model In addition to examining existing and with -project conditions using the 1-D CHAMP model, a 2-D model developed for the Big Thompson Confluence (BTC) project design was expanded to accommodate the BFE hydrology and inundation area, Figure 3. The model domain extends from the South Platte River at 35th Avenue in Evans, CO upstream to County Rd 27-1/2 on the BTR and to the BNSF RR Bridge on the South Platte, upstream of where floodwaters merge from the 2 rivers. Both model domains are identical and I Figure 3: Modified WES-BTC 2-D model domain (blue) showing project area (red) and 1-D CHAMP model cross sections (grey). Results for cross sections shown in green are in Table 1. Headwaters Corporation 4 of 7 Floodplain Development Permit Package, July 2019 consist of 91,930 computational points with cell sizes ranging from 40 feet in the overbank areas, to 15 feet in areas of smaller channels and ditches. Breaklines were added along roads, channels, levees and project features which correlate to the underlying topography. This model was run at a 30 second computational time -step for 72 hours with an 8 -hour warm-up period to achieve steady-state hydraulic conditions for both existing and with -project scenarios. Topography For existing conditions, the underlying DEM was compiled using 3 ft resolution FEMA LiDAR (FEMA, 2013 & FEMA, 2014) and a 2018 bathymetric survey of the Big Thompson and South Platte Rivers performed by Headwaters Corporation. This data was converted to 3 seamless rasters and merged together in RAS Mapper v1.0.0 to generate the terrain for the computational mesh. The with -project DEM was developed in AutoCAD Civil 3D and exported to raster and merged with the existing conditions terrain for the with - project condition. Both terrains are identical in resolution and domain and only the project area differs from baseline conditions to ensure direct comparability between existing and with -project conditions. Hydrology All hydrology data used for model inputs and BFE comparison are approved CHAMP data from the TSDN Y1 and Y2 studies available from the Colorado Hazard Mapping website. The C1100 (1%) recurrence interval flood for the Big Thompson River is 22,247 cfs at the confluence with the S. Platte (CWCB, 2017a). The South Platte River flow assumption for the BTR-1A study is 15,727 cfs from Appendix D.3 (CWCB, 2017b) which corresponds to a C110 (10%) recurrence interval flood on the SPR. Hydraulics All hydraulic assumptions for the project 2-D model were replicated from the BTR-1A TSDN 1-D CHAMP modeling effort and applied to the project 2-D model along with a calibrated channel n -value of 0.33 for the WES-BTC project. For comparison to 2-D model results, the approved 1-D CHAMP model was also altered to reflect with -project condition geometry in the areas of overlapping cross sections and run to develop base flood elevations through the project reach. The Big Thompson River and South Platte River 1-D model data were sourced from the Colorado Hazard Mapping Website and used for comparison in this study and are included in this submittal. 3.3. HYDRAULIC MODEL RESULTS Predicted water surface elevations reported by the CHAMP 1-D model and project 2-D model show similar patterns in the lower 19,000 feet of the lower BTR. Through the wetland restoration (excavation) area (STA 9+00 to 38+50), post -project river stage is generally lower and through the spoil area (STA 45+70 — 57+92), generally higher. The range of stage effects are -1.58 ft to +0.50 ft as reported by the CHAMP 1-D model between existing and with -project conditions. The effects reported in the project 2-D model are -0.75 ft to +0.33 ft between existing and with -project conditions. The average effects on stage according to the 1-D model are -0.18 ft between according to the 1-D model and converges with the existing conditions model at the County Rd 27-1/2 bridge. The 2-D model reports an average stage difference of +0.05 ft and converges at STA 75+00, just upstream of the spoil location. A comprehensive water surface profile and individual cross section station results are reported in Figure 4 and Table 1. Headwaters Corporation 5 of 7 Floodplain Development Permit Package, July 2019 4,705 4.700 0 4,695 4,690 4,685 4,680 4,675 Project Area 0 2.000 4.000 6.000 8,000 10.000 12.000 14.000 16,000 18.000 20.000 BT1-A River Station (distance from S. Platte Confluence ft) s 1-D CHAMP BFE • J. -D CHAMP with Project Existing 2-D Proposed 2-D Figure 4: Water surface profiles comparing existing and with -project conditions from both the 1-D CHAMP TSDN 1,1 model and the 2-D WES-BTC model results. Table 1: Table comparing CHAMP 1-D and WES-BTC 2-D model results for BFE in vicinity of the proposed project. RS 5792 and 5226 are in the spoil area and RS 3041 and 1708 are in the excavation area. 1-D CHAMP 2-D WES-BTC BT1-A XS RS WSE - Exist WSE - Project Delta WSE- Exist WSE- Project Delta 5792 4684.3 4684.8 0.50 4684.5 4684.8 0.32 5226 4683.9 4684.2 0.31 4683.6 4683.9 0.22 3041 4681.3 4681.2 -0.10 4682.0 4681.3 -0.74 1708 4680.9 4681.0 0.06 4681.1 4680.8 -0.38 Headwaters Corporation 6 of 7 Floodplain Development Permit Package, July 2019 3.4. DISCUSSION AND CONCLUSIONS Both models show a reduction in the BFE through the excavation area and a rise in BFE through the spoil area. These differences are reported highest in the 1-D model, likely due to lack of accommodation of the design topography in existing cross section locations and the breakdown of 1-D modeling assumptions in the dynamic nature of a river confluence. The 1-D model was not altered, as adding cross sections affect the existing condition hydraulic results. The project 2-D model is more appropriate for characterizing complex flow paths exhibited during high -flow events at the confluence of two rivers and has updated bathymetry to support this effort. The project 2-D model more accurately depicts the flow routing through the project and between the two rivers through higher resolution topography and hydraulic computations. The stage differences reported by the 2-D model show a max rise of 0.33 ft at XS 5853, at the upstream end of the spoil location. The BFE shows a max decrease of -0.77 ft at XS 3839, near the upstream end of the excavation reach. These reported changes are lower and attenuate more quickly than the 1-D results due to the ability to accurately route flow through the dynamic nature of this river confluence and the lack of need for 1-D modeling assumptions to accommodate these complexities. 4. WORKS CITED CDM Smith (2016). Middle South Platte River Restoration Master Plan. Denver, CO. Colorado Water Conservation Board (CWCB) (2017a). Colorado Hazard Mapping Program, Hydraulic Analysis Technical Support Data Notebook for the Big Thompson Watershed (HUC-8 10190006). CHAMP Y1 Hydro TSDN - Big Thompson. Colorado Water Conservation Board (CWCB) (2017b). Colorado Hazard Mapping Program, Hydraulic Analysis Technical Support Data Notebook for the South Platte River. CHAMP Hydrology TSDN, Colorado Water Conservation Board (CWCB) (2017c). Colorado Hazard Mapping Program, Y1-BigT- HydraModels: BTR_1A.PRJ Federal Emergency Management Agency (2013). Post -Flood DEM FINAL, October 16, 2013. Federal Emergency Management Agency (2014). Post -Flood Reflight DEM FINAL. October 1, 2014. U.S. Army Corps of Engineers, Hydrologic Engineering Center (2016). HEC-RAS, River Analysis System, 2D User's Manual, Version 5.0. Davis, CA Headwaters Corporation 7 of 7 ATTACHMENT A APPLICATIONS AND AUTHORIZATIONS FLOOD HAZARD DEVELOPMENT PERMIT (FHDP) APPLICATION DEPARTMENT OF PLANNING SERVICES * 1555 N. 17TH AVENUE * www.weldgov.com GREELEY, CO 80631 * 970-353-6100 EXT 3540 * FAX 970-304-6498 FOR PLANNING DEPARTMENT USE: AMOUNT $ APPLICATION RECEIVED BY DATE RECEIVED: CASE # ASSIGNED: PLANNER ASSIGNED: Parcel Number: 0 9 5 9. 3 4. 4 _ 0 0. 0 1 0 AND 0959-34-4-00-034 (12 digit number - found on Tax I.D. information, obtainable at the Weld County Assessor's Office www. weldgov.com). Legal Description Pt. South Half , Section 34, Township 5 N, Range 66 w Waterway Name: Big Thompson River Flood Insurance Rate Map (FIRM) Panel #: 08123C- 1707 E h ttps://msc.fema.gov/portal Floodzone: A �_ AE ® AH ® AO Q Parcel size: 72 _ acres Project located in designated floodway? Yesfl No.E1 If yes, a "No Rise" certificate is required. FEE OWNERfal OF THE PROPERTY: Name: Allely Family - Joyce Allely Company: Phone #: 307-344-2560 Street Address : 17 Dos Rios Email: zach_allely@hotmail.com City/State/Zip Code: Greeley, CO 80634 APPLICANT OR AUTHORIZED AGENT: (See Below*: Authorization must accompany all applications signed by Authorized Agent) Name: Lucy Harrington Company: Westervelt Ecological Services Phone #: 720-955-3029 Street Address : 7348 S. Alton Way, STE 9-D City/State/Zip Code: Centennial, CO 80112 Email: lharrington@westervelt.com Type of Proposed Development: (Please check all that apply) Residential Home ❑ New Construction ❑ Addition or Improvements ❑ In Subdivision ❑ Fill Material Subdivision ❑ Other Non -Residential ❑ New Construction ❑ Addition or Improvements • Fill Material • Watercourse Alteration Manufactured of Mobile ❑ On Single Lot ❑ In Mobile Home Park ❑ Fill Material ❑ In Mobile Home Description of Proposed Development**: Wetland Restoration / Mitigation Bank. See attached report. **Attach a detailed narrative of the project to this application. Signature: Owner or Authorized Agent Lucy Harrington Print: Owner or Authorized Agent 7/22/19 Date Signature: Owner or Authorized Agent Date Print: Owner or Authorized Agent Rev 1/2016 *If an Authorized Agent signs, a letter of authorization from all fee owners must be included with the application. If a corporation is the fee owner, notarized evidence must be included showing the signatory has to legal authority to sign for the corporation. DEPARTMENT OF PLANNING AND BUILDING DEPARTMENT OF PUHLIC HEALTH AND ENVIRONNMENT 1555 NORTH 171H AVENUE GREELEY, CO 80631 AUTHORIZATION FORM I, (We), //k(-1: p-14 (Ownet please print r , give permission to (:i...e3-47Kt)C' f f 1-_(e)(1- /(rr Sev-t//( .5 (Authorized Agent -- plrse print) to apply for any Planning, Building or Septic permits on our behalf, for the property located at (address or parcel number) below: YG /1.,1/21.O ..; s?-2f/z/000,3g ci M )3(:))./ Legal Description: Subdivision Name: of Section 317, Township 5 N, Range f a w Property Owners Information; / Address: )1`r �I t'I/Cll.c) T / (�'i �r Phone: fit: -la 47r71_ 2. _) 6 E-mail: -Z f0i. — �.� t. Lot Block Authorized Agent Contact Information: Address: Phone: 6,L7 gzi( o 7.3 en? A!/614 (4_.k:,r. Si i- b1_ ml/O(, ( D• ()//t'_ 6.< -x(72.7 rr 1,1 f(f Dr's /.3(31eYur'// (O71.1 Correspondence to be sent to: Owner Authorized Agent >C Both / by Mail Email X Additional Info: �w4)0124-55 : Jo AIL -5-z. Li I am' Dc's 121os Owner Signature: Owner Signature: ‘2_c Co ?SPY F/ Date: Date: I r d l FLOOD HAZARD DEVELOPMENT PERMIT (FHDP) APPLICATION DEPARTMENT OF PLANNING SERVICES * 1555 N. 17TH AVENUE * www.weldgov.com GREELEY, CO 80631 " 970-353-6100 EXT 3540 * FAX 970-304-6498 FOR PLANNING DEPARTMENT USE: AMOUNT $ APPLICATION RECEIVED BY DATE RECEIVED: CASE # ASSIGNED: PLANNER ASSIGNED: Parcel Number: 0 9 5 9- 3 4- 3 - 0 0- 4 0 6 (12 digit number • found on Tax I.D. information. obtainable at the Weld County Assessor's Office ww. v. weldgov.com). Legal Description PL South Half Waterway Name: Big Thompson River , Section 34, Township 5 N, Range 66 w Flood Insurance Rate Map (FIRM) Panel #: 08123C- 1707 E Floodzone: A ❑r AE ❑ AN El AO El Project located in designated floodway? Yes El FEE OWNER{S} OF THE PROPERTY: Name: Varra Companies, Inc. Parcel size: 28 acres htfps://msc. feina. goy/portal No El If yes, a "No Rise" certificate is required. Company: Phone #: 303-666-6657 Street Address : 8120 Gage Street Email: gvarra@varracompanies.com City/State/Zip Code: Erie, CO 80516 APPLICANT OR AUTHORIZED AGENT: (See Below': Authorization must accompany all applications signed by Authorized Agent) Name: Lucy Harrington Company: Phone #: Westervelt Ecological Services 720-955-3029 Street Address ' 7348 S. Alton Way, STE 9-D Email: lharrington@westervelt.com City/State/Zip Code: Centennial, CO 80112 Type of Proposed Development: (Please check all that apply) Residential Home ❑ New Construction ❑ Addition or Improvements ❑ In Subdivision ❑ Fill Material Subdivision ❑ Other Non -Residential ❑ New Construction ❑ Addition or Improvements Li Fill Material CI Watercourse Alteration Manufactured of Mobile ❑ On Single Lot ❑ In Mobile Home Park ❑ Fill Material ❑ In Mobile Home Description of Proposed Development**: Wetland Restoration / Mitigation Bank. See attached report. "'Attach a detailed narrative of the project to this application. Signature: Owner or Authorized Agent Lucy Harrington 7/22/19 Date Signature: Owner or Authorized Agent Date Print: Owner or Authorized Agent Print: Owner or Authorized Agent Rev 1/2016 if an Authorized Agent signs, a letter of authorization from all fee owners must be included with the application. If a corporation is the fee owner, notarized evidence must be included showing the signatory has to legal authority to sign for the corporation. DEPARTMENT OF PLANNING AND BUILDiNG DEPARTMENT OF PUBLIC HEALTH AND ENVIRONNMENT 1555 NORTI-1 17r" AVENUE GREELEY, CO 80631 AUTHORIZATION FORM I, (We), Varra Companies, Inc, , give permission to WesterveitEcological Service (Owner please print) (Authorized Agent - - please print) to apply for any Planning, Building or Septic permits on our behalf, for the property located at (address or parcel number) below: Parcel#: 09 593400006 Legal Description: South 1/2 of Section 34 , Township 5 N. Range 66 W Subdivision Name: Lot Block Property Owners Information: Address: 8120,Gage Street Erie, CO. 80516 Phone: 303-666-6657 E-mail: gvarraO7varracornpanies.corn Authorized Agent Contact Information; Address: 7345 S. Alton Way, Unit 9D, •Contcrnial,. CO. 80112 Phone: 720-955-3029 E -Mail: Iharrington@westeavelt.c:om Correspondence to be sent to; Owner _ Authorized AgentBoth X 1 by Mail, Email, X Additional Info: Owner Signature:w`r, Date;. / r' / l Owner Signature: _ Date: Chapter 23 Article XI Division 4 Standards I have read and understand the Standards in Division 4 of Chapter 23 Article 11 of the Weld County Code. Per my signature below I have received a copy of the Standards and the development in the floodplain that is described in my Floodplain Permit will remain in compliance with the aforementioned section of the Weld County Code. Signature: Date: 7/22/19 Name Print: Lucy Harrington ***Keep the a copy of the attached Standards in your files for reference*** CERTIFICATION I hereby affirm that this Floodplain Development Permit was prepared under my responsible charge for the owners thereof and to my knowledge is accurate and adherent to the applicable standards anal-Nul.cs provided by Weld County, Colorado. Signature: /• ••t '. PE#: Name Print: Company Name: W /1 t) .J 7 Address: City. State. Zip: ) Z ' ax: E -Mail: t 1\ . ,.•- ;' c -{ Date: PE Stamp ATTACHMENT B FLOOD MAPS AND PROJECT DESIGN r�T S2h:V.-1 24._.-5E V.2S'1:4 N C= CO R7 E25. - E2NE3 PT XC BEG Sv: COR E3434TAU" TO FT 33C'h OF c Y'; C OR ['/T V''f: ' S C V V.' LN 2L T TC REG EX.7 EC S RIOS ESTATES ; 133A.i ALSO EXC EEC AT FT S?.4E'"6 E 1c3E25. 5. S23D4- '.121.4.7"y' O7 NE COP SEC 34 S—C'C5C-'i,' 373 $' 547 .0,52 '6532'.N227C1:V63iCT 722 7E 45553 NFT354E5257 TO SEG 3 13A. ALSO EXC BEG SC4C1EE '866 22. C. V E COR SEC 5230- :"7 214 77' S.59O24 tid 526 71' C76D 7 ^7455 53' N74.7.0.-17 -1.D2 —TC REG :1 465A. ALSO EXC BEG '322 12"1: 8 535,G3'E 30." 2' O. NE COR :SEC S'='5DCI E 1 XC'',45r' `405OC5"..r# ' CO' ESC' TO BEG ALSO EXC. r'125W4 5 :?..0 BK.82= REC'4-748343 ALSO EXC.' 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ALSO EXC T-IAT PT Y:NG S Or N LN RIVER _CJCA-E3 IN SCI•O'OL 0 S: .RE1 ALSO EXC JNC' NT IV CO&:1 ':3O1 BIG THOMPSON CONFLUENCE FLOODPLAIN MAP CHAMP MODEL XS - BFE PARCEL BOUNDARY ZONE A BOUNDARY V D 250 500 t000 1.500 Feet GENERAL NOTES VEHICULAR \ ACCESS ROUTE PROJECT BOUNDARY 45, EXCAVATION AREA 150 150 300 EXCAVATION AREA PROJECT BOUNDARY T Q3 EXCAVATION AREA APPROXIMATE SCALE IN FEET BIG THOMPSON CONFLUENCE MITIGATION BANK Woz VO n OO y� F� zo ZO QZ O za Uy OO Oa OZ ' OQ > LLW U ~ w O Z 4 FIRCJECTNO SHEET IDENTIFICATION C-00 90% DESIGN SHT NOTES TO USERS LEGEND National Flood ogr e Flood Elevations iSFEs) to consult the 5lo. wirhin the Flood Insurance Study IFISInRepOr es 555 FIRM 51Sera- should be aware that BFEs shown on the rounded whole -loo! Crstal Base Flood the Summary°, Stillwater ,msclic5on Elevations andfor flood, Shown on this ma Boundaries of caT may nc protected 5, flood contra, structures The projeclim. Mercator 0.5,4 tum of 5efere5ced to Omween the National Geodetic Survey SSMC -3 ”5202 1315 EaSt.VVe5tHighway 35ver Spring Mary,d 20910-3282 15011715-3.2 r bench marks shown on this icas., contact the Informafio nf the National GeodeticSB 1 vn e,, 55s 50..51.5 Me 104 45 00 5015 40 20 37 5 080182 r , eld Cam, Unincorpoi Ated ,\reas 080266 } 4 „p�m cn.dlip �. •� Vnn¢ugmn66rl�A -: �..- 080266 JO 5 EL 10 320550,1 FT NOTE. NIAP AREA SHOWN ON THIS PANEL IS LOCATED WITHIN RANGE e6 WEST. xn, 080181 ,js0000 FT • 080182 \Sold County lnlnoo.Ponxted Area, 080266 ZONE AE 13755100 FT 1370000 Fr ZONE vf SPECIAL FLOOD OA.. -AS (Sri in„ SUBJECT TO 1NUNDAT,ON BY THE 1.5/5 ANNUAL CHANC, FLOOD Fl OODWAY Al55, IN /5151F .45 OTHFR Fl 555,1 ARFAS 555/55 COASTAL BARRIER RESOURCES SYSTEM (CB , AREAS nFFw1SF PaoTFCTFD,RFASIOP,5.) All. MAP SCALV = 500 Igo PANEL 1707E FLOOD INSURANCE RATE MAP WELD COUNTY, COLORADO AND INCORPORATED %RENS PANEL 1700 OF 2250 INDEX FOR LAYOUT, 5un5,5 5,55 Notice to User Tne Map Number shown he Communlly Number shown above snoultl used on ssurance ar55licalians for the skrbrect MAP NUMBER 08123C1707E EFFECTIVE DATE JANUARY 20, 2016 ATTACHMENT C DEEDS i %A Ad2't[16"1--_ 2408997 8-1461 P-493 09/30/94 03:48P PG 1 OF 1 R.C DOC Mary Arm Feuersteln Weld Co., Clerk & Recorder 5.00 QUIT CLAM DEED /J.-��Lr7 J Inc. .: ],osr ad dic xs is /7 +1.1 I. r-tl•J ipnec!e:� a /nrno.o. •40 3/' County of :Veld , and State of rrr Lore -do , for the consideration of I)ollrirs, in hand paid, hereby }: Il[.=-1 and quit rlainilsito ?price 7. 41.fe1, whose arlrlress is /7 ��r,t si17.d, �n£r, ler� r0lr7nrdo .S' 3'r' [, ollnt..y of '{'e ld , anti State of To (nnrrdr] property, in the , Ole following real County of 'Veld , and State of Colorado, to wit: /77/3- 12 Afi 34-5-6' ai R rc? j.{,'F/9/"/4L4/O Nf4 1 1 NC Beg. ref 5'U con. 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I 'l: W„ee 5: Dew;; l 0 ;0?,?v'-''ire — I'_-4' 4095664 04/03/2015 09:08 AM Total Pages: 3 Rec Fee: $21.00 Doc Fee: $335.00 Carly .toppes - CIerK and Recorder, Weld County, CO SPECIAL WARRANTY DEED lJOC FEE; 5333.94 THIS DF,I•'ll, in ndc ads Sad day of April, 2015 between Ca n rn d Capital O rd lr p, LLC, n Colorado !baited liability coin pally, o row County of \Veld and Siam of Colorado, gralsto;(a} and Vnrra Cornparlles, Ina.,a Colorado cu rporalion whose legal oddresv in 8129 Oaga St rear, Frederick Co, 80.51ft llo Cuurny of Ward End Elam of Colorado, gran tce(s); WITNESS, that ;ha grpntor(a), far and in canalde:scion of the sum of TillTEE MILLION TIIIILE HUNDRED FIFTY "I'IIOUSAFO AND moo 1IOLLARS (53,350,880,0M iho Hair and rnffceleri:y at whicli In hereby acl:no•.nledgcd, Linn granted, hnrpolnad, sold and conveyed, and by lhcso preterits does grant, Fir rgn hl, sell, annoy oral [nnfirm, unto ilia eraritre(s), 1iisfter heirs, arid nsaisns farov or, all ilia rant property. [nether with h:lliro vein en l t, if nny, ersuate, lying and being in :Ire County of i,Va Id and State of Colorado, dean ribed 1s or:aim Sue Annelle.] E.ftihlt A n ISO Ir n o w, t 15 street and number an: 11822 398 1I WY, Evans, CO 'I'OCETII ER with all rind singular the hercdltalrcnrs and nppurtunances thereunto bcloighrig, ar In anywise nppa,7alrslag, and Me roversfon end reversions, re ni mailer and reniainders, rents, issucn and profit thereof, and all the ward, rigid, line, intererl, t:lairn and Iran a d whnl_eovcr of tha grintet(a), either in law cr uqw fry, of, in and la the above 171 rgafned prerlifst'r rail'- the hcredi:anents and nplriirtt:nancos. TO HAVE AND. TO FIOLI' the nnld preininrs above bargained arid described, with the oepu rtc a am r, nor to the granrcc(s), hitl•,er heirs, and es:lgn; fataver. The granuar(s), fur I ilnl5clfliresaclf, his/her helm, and personal rupresenletivoa nr ;ncie5:ior9, does covenant rind agsce [liar THEY drab and will WILRRA+IT AND FOREVEFI OCIttivD the above -bargained preraLen In ilia Faint raid peaceable pggness Ian of tin; yranicols), Idx/liar bolo, and usalgns, against all arid ovary, person or persons clnilnfnr thn whole or any pmt thereof, by, through nr tinder liar gran lor(s)• ill WITNESS WHEREOF. Mu grnr e:(n1 hag executed [ilia decd tin the date set limb above. Conrad! Capital' Croup, LLC, n Colors ❑ I" rr lied Mobility tom pa ny 1-a'Z Tat e•b,O, ) .�— J nt.y 12, hilt] i:<en on t rat anent UrJD11 Men i gcmcnt Ina, a CCCCCC! Colorado Corporation as Manager vlC(� m'• SPiCU L 'WARRANTY REED Fide TON TO 4095664 04/03/2015 09:48 AM Page 2 of 3 STATE OF II i 4\n _`C COUNTY OF-.SW-SZ>ter-1 } ss. The foregoing instrument was neknowledgcd before me Thisri fl 0 t' 1+1-C. a Co lurado limfted Ile hllfry CCRrp Sn}' 9Y JAi •AM$5 D. Af1LLIK.GN A5 PRESIDENT Capflal Grob r, MANAGEMENT INCA DENT 6FSp M13 CO LORA D D CORPORATION A6 FIA NAG ER My Corp mission sAp fres: Wimen my hand and official seal. 4`16[2f_>za Jentes 111Cfl1&on Notary biiic fy Stift of Micll[Gm County of Berrien Ccrnm+gslon Expires 411 Acfing In the County of �I�r t,emn tilt N°.- 1172 UT Cl 4095664 04/03/2015 09:08 AM Page 3 of 3 EXHIBIT "A" THE W 112 OF 111E NW 1/4 AND THE NE 114 OF THE NW I/4 OF SECTION 3. TOWNSHTP 4 MORT II, RANGE 66 WEST OF THE 6TH P.M., COUNTY OF WELD, STATE OF COLORADO AND TIfE NE 1/4 or SECTION 4, TOWNSHIP 4 NORTH, RANGE 66 WEST OF TI1 E 6TH P.M., COUNTY OF WELD, STATE OF COLORADO AND TOE S 1/2 OF THE SE 1/4 OF SECTION 33, TOWNSHIP 5 NORTH, RANGE 66 WEST OF THE 6TH P.M., COUNTY OF WELD, STATE OF COLORADO AND ALL THAT PART OF THE W 1/2 OF THE SW 114 LYING SOUTH OF THE SOUTH R1GIITOF WAY OF COUNTY ROAD 378 (AKA W. 54th St Rd), IN SECTION 34, TOWNSHIP 5 NORTH, RANGE 66 WEST OF THE STi{ P.M., COUNTY OF WELD, STATE OF COLORADO, EXCEPT THAT PORTION AS CONVEYED BY DEED RECORDED FEBRUARY 3, 1983 AT RECEPTION NO. 19I6171, as Shown on Improvement Survey recorded October 26, 2005 at Reception No.3334443 and more particularly deseribed as follows: A tract of land located in the West One -Half Southwest One -Quarter (W1/2SW1/4) of Section Thirty -Four (34), Township Five (5) North, Range Sixty -Six (66) Wes! of tire 6th Principal Meridian, Weld County, Colorado heir' more pnrticulary described as: Considering the North line of the Swrthwvest Glee -Quarter (SW I/4) of said Section Thirty - Four (34) to hear South 88°54'53" East, and all bearings contained heroin being relative thereto: Beginning at a point whence the South One -Sixteenth (S 3/1 6) Corner of said Section Thirty -Four (34) and Section Thirty -Three (33), Township Five (5) North, Range Sixty -Six (66) Vest of the 6th Principal Meridian beats South 06°37'18" West, 231.18 feet; thence along the easterly right -of --way tide of Weld County Road 31, South 01°28'06" East, 211.06 feet; thence South 0I°27'53" East, 726.25 feet; thence leaving said easterly right-of-way Ilea of Weld County Road 31, North 52°25.34" East, 228.87 feet; thence,North 83°53'53" East 379.90 fret; thence, North 67°49'01" East, 174,21 feet; thence, North 84°46'00" East, 458.30 feet; thence, (L1) South 87°53'13" East, 66.99 feet; thence, (1,2) South 75°20'24" East, 80.92 feel; thence, (I;3) South 66°35'08" East 92.30 feet to a point on the east litre ot'the West One•IlalfSouthwest One -Quarter (W1/25WI/ I) of said Se et ion Thirty -Four (34); thence along said cast line of the West One-lfalf Southwest One -Quarter (W11251V1/4) of said Section Thirty -Four (34), North 02°26'26" West, 943.31 feet to the southeasterly right-of- way of Weld County Ro,,d 378; silence,!caving said east line of the Wcst One -Half Southwest One -Quarter (10/1/2SW1/4) of said Section Thirty-Four(34) and Wong said southeasterly right-of-way of Weld County Road 378, South 78°32'37" West, 54.05 feet; thence, South SO°?1'42" West, 1347,02 feet to the Point of Beginning. Pae 1 6.4.8 EXHIBIT H - Wildlife Information (1) In developing the wildlife information, the Operator/Applicant may wish to contact the local wildlife conservation officer. The Operator/Applicant shall include in this Exhibit, a description of the game and non -game resources on and in the vicinity of the application area, including: (a) a description of the significant wildlife resources on the affected land; (b) seasonal use of the area; (c) the presence and estimated population of threatened or endangered species from either federal or state lists; and (d) a description of the general effect during and after the proposed operation on the existing wildlife of the area, including but not limited to temporary and permanent loss of food and habitat, interference with migratory routes, and the general effect on the wildlife from increased human activity, including noise. (2) The application may be reviewed and commented upon by the State of Colorado Division of Wildlife (DOW). If the DOW has comments, they must be provided prior to the end of the public comment period specified in Subsection 1.7.1(2)(a) to be considered by the Board and Office. Wildlife residents and visitors observed on area lands, but not on site at the time of the inspection, include the occasional fall/winter roosting of Bald Eagle on nearby mature cottonwood trees, but with no evidence of nesting. Other resident birds of prey have been seen in the area, including hawks and owls. Game species such as wild turkey and white-tailed deer will traverse the river bottom, open spaces and fields nearby; as will fur bearers such as bank beaver, fox, racoon, rabbit, squirrels, and other non -game species. No significant impacts to wildlife or habitat loss is anticipated by planned operations due to the abundant natural conditions of the surrounding lands, general expanse of the project area and glacial speed of disturbance during planned operations. Still, like the mechanical attributes of the contemporaneous agricultural fields, temporary displacement of wildlife may occur over the immediate area of affected lands during active operations; while on -site speed limits will be posted at 15 mph to better assure the safety of wildlife in proximity to the activity. The abundant edge effect of surrounding unaffected vegetation along the two rivers and other open areas of the surrounding fields should more than compensate for any annoyance. Extensive operational setbacks from riverine locations provide ample protection to area wildlife within the adjacent riverine locations, while the balance of wildlife is culled on area roadways from increasing densities and unchecked lawlessness of urbanized traffic. Slower enforced speed limits along such corridors and migration routes in general, combined with a perpetual retention of the gravel surface of Weld County Road 396 will help limit wildlife mortality and disturbance. Pae 2 6.4.8 EXHIBIT H - Wildlife Information Any planned regional civilian recreational intrusion into the remaining secluded wildlife habitat of the riverine areas should be discouraged. Trails are best placed above the riverine habitat, unless a wildlife void is desired. Where recreational trails are desired, placement should be along banks with greater urban development, with designed setbacks for encroachment on trails from further development. The imitation of reclamation and restoration experience from operations such as this can be used in diverse applications in urban -centric endeavors. Methods might include the encouragement of native grasses and plants for landscapes, or as a means to invigorate habitat along recreational trails; while allowing vast areas to remain as a means to invigorate the impacted portions of trails already made comparatively sterile from frequent human visitation. For the stretch of the South Platte River, the South Bank would appear the most amenable for such a design. Without similar sensitivity in the expansion of trails, reduction of paved roadways and decreased densities of human habitat, the urban matrix will certainly come to accomplish what good practices at this location attempts to avoid and reverse. Trails and urban development must not intrude in a manner that would prevent the extraction of a valuable mineral deposit. There is a compelling interest for all citizens of the State of Colorado to reserve these areas to assure their continued economic vitality. Planned reclamation at the Two Rivers Project is well correlated with both state and federal perspectives, and will serve to provide a number of benefits to the community and to various wildlife species, especially waterfowl; including a return of native vegetation, cover, edge effect and creation of water bodies that will serve as additional sources for food, cover, and resting surfaces. The planned seed mixture will further add to the diversity of height, form, color and function of the resulting vegetative cover. An inspection of the location for any potential Preble's meadow jumping mouse and Ute ladies' tresses orchid was performed on 18 March 2020; as detailed in a report of 21 July 2018, by Ron Beane, Senior Wildlife Biologist, and Moneka Worah, Natural Resources Specialist with ERO Resources Corp. Subsequent review by U.S. Fish and Wildlife Service has been pending ever since. An updated report of 24 March 2022 has been submitted to U.S. Fish and Wildlife Service, and we anticipate their review and approval as early as this Spring, 2022. Both reports are included at the back of this Exhibit. Recent policy of the Division of Parks and Wildlife (DOP&W) no longer provides for a pre -submittal report. Regardless, District Wildlife Manager, Mike Grooms; visited the location on 29 September 2021, to discuss and orient to the potential influences and benefits that the planned project extraction and concurrent reclamation may have on Pae 3 6.4.8 EXHIBIT H - Wildlife Information seasonal and perennial resident wildlife and area wildlife visitors to, or in proximity of, the location. While no immediate impacts to critical nesting or migration of area wildlife are presently known along the reach of the two rivers as they occur within the project location, annual observations may occur in cooperation with the Division of Wildlife to assure impacts are considered and reasonable accommodation of field operations can be timely adjusted to accommodate a compelling benefit where and when practicable. All pertinent correspondence or related clearance letters are included at the back of this Exhibit, or as otherwise provided under Exhibit M — Other Permits. ERA Consultants in Natural Resources and the Environment Threatened and Endangered Species Habitat Assessment Two Rivers Parcels Varra Companies Weld County, Colorado Prepared for— Varra Companies, Inc. 8120 Gage Street Frederick, Colorado 80516 Prepared by— ERO Resources Corporation 1842 Clarkson Street Denver, Colorado 80218 (303) 830-1188 ERO Project #21-266 March 14, 2022 Denver • Durango • Hotchkiss • Idaho www.eroresources.com Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Contents Introduction 1 Project Description 1 Federal Nexus 1 Project Area Description 1 Ecological Features of the Project Area 3 Previous Surveys for Preble's near the Project Area 3 Best Management Practices (BMPs) Incorporated as Part of the Project 5 Voluntary Conservation Measures 6 Endangered Species Act Compliance 6 Threatened, Endangered, and Candidate Species Error! Bookmark not defined. Preble's Meadow Jumping Mouse 9 Ute Ladies' -Tresses Orchid 8 Species Background 8 Rationale for Excluding the Project Area as Potential ULTO Habitat 9 Rationale for Excluding the Project Area from Needing an Incidental Take Permit Under Section 10 (a)(1)(B) of the ESA 9 Conclusions 10 Recommendations 11 References 11 Tables Table 1. Small mammal species captured in the Two Rivers Parcels project area, September 2017 5 Table 2. Federally threatened, endangered, and candidate species potentially found in Weld County or potentially affected by projects in Weld County 7 Figures Figure 1. Vicinity Map 2 Figure 2. Small Mammal Trap Locations 4 Appendices Appendix A Photo Log Appendix B Qualifications of Surveyors Appendix C Trapping Results ERO Project #21-266 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado March 14, 2022 Introduction Varra Companies, Inc. retained ERO Resources Corporation (ERO) to prepare an evaluation for federally listed threatened and endangered species in an area proposed for aggregate mining. in Weld County, Colorado (project area). The project area occurs near the confluence of the Little Thompson and South Platte Rivers (Figure 1). This evaluation is the culmination of site evaluations in 2017 (ERO 2018), 2020 (ERO 2020), and 2021 and includes the results of a presence/absence survey for Preble's meadow jumping mouse (Zapus hudsonius preblei or Preble's) completed and previously submitted to the U.S. Fish and Wildlife Service (Service) in 2017 (ERO 2018). ERO wildlife biologists Ron Beane and Milu Velardi conducted presence/absence surveys for Preble's from September 11 through 15, 2017 (2017 field survey). Project Description The proposed project is an aggregate mining operation consisting of scraping and stockpiling topsoil and mining sand, gravel, and other aggregate materials from a series of mining cells in the project area. Mining would occur in phases in the individual cells. All mining would be restricted to current agricultural fields and no mining or mine operations would occur within 100 feet of the bankfull stage of the Little Thompson River or South Platte River. Aggregate processing would occur north of the Evans Town Ditch that parallels the Little Thompson River. An overhead conveyor would transport mined material from the mining cells to the processing area. No wetlands or waters of the U.S. would be impacted by the proposed project. Federal Nexus There is no federal nexus associated with this project. The mine plan has been specifically designed to avoid all wetlands and waters of the U.S., including access, processing, and staging areas. Project Area Description The project area is in portions of Sections 33 and 34, Township 5 North, Range 66 West, and Sections 3 and 4, Township 4 North, Range 66 West of the 6th Principal Meridian in Weld County, Colorado (Figure 1). The UTM coordinates of the approximate center of the project area are NAD 83 519043mE, 4466286mN, Zone 13N. The longitude/latitude of the project area is 104.775771°W/40.346911°N. The elevation of the project area is approximately 4,686 feet above sea level. Photos of the project area are in Appendix A. ERO Project #21-266 1 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Figure 1. Vicinity Map ERO Project #21-266 2 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Ecological Features of the Project Area The project area is bounded by the South Platte River on the south and east, the Big Thompson River and 54th Street on the north, and County Road 396 on the west (Figure 1). Overall, the project area is characterized as agricultural. Agricultural areas consist of irrigated cropland located on an elevated terrace between the South Platte and Big Thompson Rivers (Photos 1 and 2), and nonnative pasture north of the Big Thompson River (Photo 3). The Big Thompson River flows east through the project area and joins the South Platte River approximately 0.5 mile east. The vegetation in the Big Thompson River riparian area is dominated by an overstory of plains cottonwood (Populus deltoides), narrowleaf cottonwood (Populus angustifolia), Russian olive (Elaeagnus angustifolia), water birch (Betula occidentalis), thinleaf alder (Alnus incana), and box elder (Acer negundo) trees (Photo 4). The riparian corridor supports dense thickets of sandbar willow (Salix exigua) shrubs along the river banks. Upland shrub species including chokecherry (Prunus virginiana) and American plum (Prunus americana) occur in scattered stands. Other dominant herbaceous species in the riparian area include smooth brome (Bromus inermis), reed canarygrass (Phalaris arundinacea), and redtop (Agrostis gigantea). The South Platte River has been scoured by flooding over the last 10 years and is characterized as a wide, sandy floodplain with sparse vegetation dominated by a mixture of native and nonnative grasses with scattered patches of sandbar willow and plains cottonwood (Photo 5). The Evans Town Ditch parallels the Big Thompson River and consists of a concrete -lined channel with vegetated banks of nonnative grasses and Scotch thistle (Onopordum acanthium) (Photo 6). Previous Surveys for Preble's Near the Project Area ERO conducted live -trapping surveys for Preble's in 2017 in suitable habitat along the Little Thompson and South Platte Rivers in the project area, but outside of the mine area (Appendix B; Figure 2). ERO conducted the trapping survey using the methods outlined in the Service's Preble's Meadow Jumping Mouse Survey Guidelines, revised April 2004 (Service 2004). During the 2017 field survey, ERO placed live -traps beginning the afternoon of September 11 and collected traps on the morning of September 15, 2017. A total of 180 traps were checked each morning at sunrise, closed, and reopened each evening at dusk, for a total of 720 trap nights. No Preble's were found during the 2017 field survey. Four different species of small mammals, with 60 individuals, were trapped on -site (Table 1). Deer mice (Peromyscus maniculatus) were the most common species trapped, followed by house mice (Mus musculus), meadow voles (Microtus pennsylvanicus), and a single prairie vole (Microtus ochrogaster). ERO Project #21-266 3 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Figure 2. Small Mammal Trap Locations ERO Project #21-266 4 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Table 1. Small mammal species captured in the project area, September 2017. Deer Mouse House Mouse Meadow Vole Sept. 12 Prairie Vole Female Male Adult Juvenile Adult Juvenile 5 2 3 3 Unknown 2 Sept. 13 Female Male Unknown Adult Juvenile Adult Juvenile 4 2 7 2 2 1 1 1 1 1 Sept. 14 Female Male Adult 1 Juvenile Adult 3 Juvenile Unknown 4 1 2 Sept. 15 Female Male Unknown Adult 1 Juvenile 1 Adult 6 Juvenile 1 2 1 TOTAL 49 5 5 1 Deer mouse captures resulted in 82 percent of the total small mammals captured. House mouse and meadow vole were just over 8 percent of captures each, and the single prairie vole accounted for about 1 percent of the total small mammals captured. During the four nights of trapping, 136 of a total of 720 traps were found closed but empty (18 percent unavailable). On two occasions, a single trap was found open and broken. The large number of closed traps indicates the presence of other predatory mammals in the area. Several raccoon prints were observed on -site. Four other previous trapping surveys were conducted within 2 miles of the project area from 1997 to 2006. A positive trap location was found in June 2001 by Savage & Savage, approximately 1.7 miles southwest of the project area along the South Platte River (Savage and Savage 2001). The other three survey attempts did not result in positive trapping of Preble's (Service 2020). Best Management Practices (BMPs) Incorporated as Part of the Project The following BMPs have been incorporated into the project design to avoid and minimize adverse impacts on Preble's. • Work areas will be stabilized in a manner to prevent or minimize soil erosion. ERO Project #21-266 5 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado • The Contractor will protect the surrounding area and, from siltation. This will be accomplished by using silt fence and/or other measures, as necessary. The Contractor will repair all damage to erosion -control measures in the construction area due to rain, hail, and snow storms. • All temporarily disturbed areas will be reseeded with native seed mix as specified in the mine plan. The Primary Revegetation Seed Mixture combines a thoughtful mingling of predominantly native grasses of diverse height, form, color and function, to add cover, food source for wildlife and pollinators. • The cottonwoods along the lower terrace of the two rivers will be preserved. • All riverine areas will otherwise remain untouched. Voluntary Conservation Measures The following conservation measures consistent with Service recommendations for emergency flood response activities (Service 2013) have been incorporated into the project design to avoid and minimize adverse impacts on Preble's. Preconstruction design avoids riparian and wetland habitats. 1. All mining areas, access routes, staging areas, and work areas will all be outside riparian areas and in previously disturbed or modified cropland and nonhabitat areas. 2. The project avoids fragmenting linear riparian corridors. 3. The project will implement mine -site reclamation consisting of reseeding with native grasses and pollen producing species. 4. The project will avoid disturbing (e.g., crushing or trampling) or removing (e.g., cutting or clearing) all vegetation, such as willows, trees, shrubs, and grasses in riparian areas. A few tall trees and shrubs may be trimmed to provide a corridor for conveyors. Endangered Species Act (ESA) Compliance The project area does not fall within Service habitat or survey guidelines for the majority of the species listed by the Service as potentially occurring in Weld County (Table 2). The piping plover, pallid sturgeon, and western prairie fringed orchid are species that are affected by continued or ongoing water depletions to the Platte River system. Because there is no federal nexus, the project would avoid all waters of the U.S., and the project would not require a federal action, the project would not require Section 7 depletions consultation. ERO assessed the project area for suitable habitat for Preble's, eastern black rail (Laterallus jamaicensis ssp. Jamaicensis), monarch butterfly (Danaus plexippus), and Ute ladies' -tresses orchid (Spiranthes diluvialis or ULTO). Although the ESA does not apply to take of plants incidental to otherwise lawful activities, ERO evaluated impacts of the project on ULTO. ERO Project #21-266 6 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Table 2. Federally threatened, endangered, and candidate species potentially found in Weld County or potentially affected by projects in Weld County. Common Name Scientific Name Status* Habitat Suitable Habitat Present Mammals Preble's meadow jumping mouse (Preble's) Zapus hudsonius preblei T Shrub riparian/wet meadows Yes - All habitat would be avoided Birds Piping plover** Charadrius melodus T Sandy Lakeshore beaches and river sandbars No habitat, no depletions anticipated Eastern black rail ( Laterallus jamaicensis ssp. Jamaicensis T Wetland and marsh habitat that contains a mix of wet, saturated, and some dry edges. Vegetation structure consists of dense overhead cover interspersed with very shallow water (< 3 inches) No - All habitat would be avoided Fish Pallid sturgeon** Scaphirhynchus albus E Large, turbid, free -flowing rivers with a strong current and gravel or sandy substrate No habitat, no depletions anticipated Insects Monarch butterfly Danaus plexippus C Dependent on milkweeds (Asclepiadoideae) as host plants and forage on blooming flowers; a summer resident No - All habitat would be avoided Plants Ute ladies' -tresses orchid (ULTO) Spiranthes diluvialis T Moist to wet alluvial meadows, floodplains of perennial streams, and around springs and lakes below 6,500 feet in elevation No habitat Western prairie fringed orchid** Platanthera praeclara T Mesic and wet prairies, sedge meadows No habitat, no depletions anticipated *E = Federally Endangered Species; T = Federally Threatened Species; C = Candidate Species. **Water depletions in the South Platte River may affect the species and/or critical habitat in downstream reaches in other counties or states. Source: Service 2022. Eastern Black Rail Species Background The eastern black rail was listed as a threatened species on October 8, 2020, under the ESA (see Federal Register Vol. 85, No. 196:63764-63803). The eastern black rail is dependent on wetland and marsh habitat that contains a mix of wet, saturated, and some dry edges around the periphery. The subspecies requires dense overhead cover and soils that are moist to saturated (occasionally dry) and interspersed with or adjacent to very shallow water (Service 2018). Plant structure is considered more important than plant species composition in predicting habitat suitability. Shallow pools that are 1-3 cm deep may be the most optimal for foraging and for chick -rearing. In Colorado they have been documented in ERO Project #21-266 7 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado cattail/bullrush marshes and near pond edges. This species has been documented along the Arkansas River drainage in southeastern Colorado and the Republican River in east -central Colorado. Threats include habitat fragmentation and conversion resulting in the loss of wetland habitats, land management practices (e.g., incompatible fire management practices, grazing, and haying/mowing and other mechanical treatment activities) and increasing storm intensity and frequency. There are no exact counts of eastern black rail populations at the present time, so analysis units based on habitat have been identified across the United States. Potential Habitat and Effects The mine area completely avoids all wetland and riparian vegetation communities, thus there would be no effects on the species, and no further action is necessary. Monarch Butterfly Species Background Monarch butterflies occur throughout much on North America and is segregated into an eastern and western population. The monarch is the only butterfly known to make a two-way migration as birds do. Monarch butterflies are dependent on milkweeds (primarily Asclepias spp.) as a host plant for egg laying and larval development (Service 2021). Potential Habitat and Effects The project area is not within a designated migration corridor or breeding or overwintering area for this species (Service 2019), although some monarch butterflies migrate through Colorado in the summer. Several scattered milkweeds were observed in the project area, and ERO observed one migrating monarch butterfly during the 2021 site visit. This species may occasionally travel through the project area but is not likely to lay eggs because host plants are lacking Recommendations Because no host plants and other nectar -producing plants were identified in the project area, the proposed project is highly unlikely to affect the monarch butterfly and any inadvertent loss of potential seasonal habitat would not contribute to the decline of the species. No action is necessary. Ute Ladies' -Tresses Orchid Species Background ULTO is federally listed as threatened. ULTO occurs at elevations below 7,800 feet in moist to wet alluvial meadows, in floodplains of perennial streams, and around springs and lakes where the soil is seasonally saturated within 18 inches of the surface (Service 1992a). This species has also been found along irrigation canals, irrigated meadows, gravel pits, and other human -modified wetlands (Service 2018). Generally, the species occurs where the vegetative cover is relatively open and not overly dense or overgrazed. Once thought to be fairly common in low -elevation riparian areas in the interior western ERO Project #21-266 8 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado United States, ULTO is now rare (Service 1992). The species' known range is from Nevada to British Columbia. The largest known populations occur in Utah, followed by Colorado (NatureServe 2022). In Colorado, the Service requires surveys of appropriate sites within the 100 -year floodplain of the South Platte River, Fountain Creek, and the Yampa River and their perennial tributaries, or in any area with habitat in Boulder and Jefferson Counties (Service 1992b). Because ULTO has been found along other stream systems in Colorado since 1992, the Service has expanded the number of counties where surveys are required in suitable habitat (Service 2018). ULTO does not bloom until late July to early September (depending on the year), and timing of surveys must be synchronized with blooming (Service 1992b). Rationale for Excluding the Project Area as Potential ULTO Habitat Although the project area would be on private land with no federal nexus, ERO assessed the project area for potential ULTO habitat. The dense herbaceous vegetation along the Little Thompson River is unsuitable for ULTO. Vegetation is sparse along the South Platte River and could be suitable for ULTO; however, none of the areas with suitable habitat would be impacted by proposed project activities. Preble's Meadow Jumping Mouse Species Background A population of Preble's is known to occur along the South Platte River, with the nearest successful trapping location found approximately 1.7 miles southwest of the project area (Service 2020). Preble's was listed as a threatened species on May 13, 1998 under the ESA of 1973, as amended (63 Federal Register 66777 (December 3, 1998)). Under existing regulations, either a habitat assessment or a full presence/absence survey for Preble's is required for any habitat -disturbing activity in areas determined to be potential Preble's habitat (generally stream and riparian habitats along the Colorado Front Range and southeastern Wyoming). Typically, Preble's occurs in low undergrowth consisting of grasses and forbs, open wet meadows, riparian corridors, or where tall shrubs and low trees provide adequate cover (Service 2004; Meaney and Clippinger 1995). Preble's occurs below 7,600 feet in elevation, generally in lowlands with medium to high moisture (Service 2004; Natural Heritage Program 1996) along permanent or intermittent streams (Ryon 1996). Potential Habitat and Effects Suitable habitat for Preble's exists along a narrow riparian corridor that borders the Big Thompson River. Recent scouring of the South Platte River floodplain has degraded the vegetation communities along the river and Preble's habitat is absent or extremely limited at this time. Although mining activity will completely avoid wetland and riparian communities, a live -trapping surveys for Preble's in 2017 in suitable habitat along the Little Thompson and South Platte Rivers in the project area (Figure 2). No Preble's were captured during 750 trapnights of effort. Rationale for Excluding the Project Area from Needing an Incidental Take Permit (ITP) Under Section 10(a)(1)(B) of the ESA Current and previous trapping efforts in the vicinity of the project area indicate that a viable population of Preble's are unlikely to occur. In addition, based on guidance from the Department of the Interior (DOI) Principal Deputy Director (DOI 2018), it is ERO's professional opinion that the project would not ERO Project #21-266 9 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado result in "take" of a listed species, and application for an ITP under Section 10(a)(1)(B) of the ESA is not appropriate for the project. ERO has reviewed the guidance and completed the questionnaire to help decide on the need for an ITP (provided below). 1. Are there ESA listed species present in the area where your activity will occur or will they be present at some point in the duration of your activity? Answer: Unlikely. 2. Is it likely that any of these listed species will be exposed to your activities (or the results of your activity) during any of the various phases of your activity (construction, operation, maintenance, etc.)? Answer: No, all mining staging areas and processing would occur on previously disturbed agricultural areas. 3. Will that exposure likely result in any of the following actions to the listed species: pursuing, hunting, shooting, wounding, killing, capturing, or collecting or attempting to engage in any such conduct? Answer: No. 4. Is your activity likely to harass a listed species? • Will your activity, through an intentional or negligent act of omission, is likely to annoy the listed species to such an extent as to cause an injury to the species by significantly disrupting normal behavior patterns (e.g., breeding, feeding or sheltering, etc.). Answer: No, in the unlikely event that a Preble's occupies or travels through the area, the project has been designed to occur primarily in existing agricultural fields and all stream and riparian habitat would be avoided. 5. Is your activity likely to result in an act that actually injures or kills a listed species? Answer: No, see response to question 4. 6. Is your activity likely to harm a listed species through habitat modification (yes to all three questions below)? a) Is the activity likely to result in significant habitat modification or degradation? Answer: No, project activities would occur in existing agricultural fields and all stream and riparian habitat would be avoided. b) Will the modification or degradation significantly impair essential behavior patterns, including breeding, feeding, or sheltering? Answer: No, see response to question 4. c) As a result of a. and b. above, is it likely there will be an actual injury or death to a listed species? Answer: No. Conclusions No Preble's were found during the 2017 field survey. The known presence of Preble's approximately 1.5 miles from the project area along the South Platte River (Savage and Savage 2001) demonstrates that suitable habitat is present along the South Platte River in less disturbed areas further upstream. This suitable habitat consists of riparian areas with adjacent wet meadows. Dense shrub, grass, and forb ground cover along a reliable water source are also preferred by Preble's during the warm season. From ERO Project #21-266 10 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado early fall through spring, this suitable habitat consists of multistem vegetation (e.g., shrubs) under which the Preble's will burrow for hibernation (Colorado Parks and Wildlife 2015). Based on absence of any suitable habitat in the disturbance area, implementation of the voluntary conservation measures and BMPs, and the negative survey results of the 2017 field survey and previous years completed in the vicinity of the study area (Greystone, LLC 1997, 2001; Colorado Urban Wildlife 1997), ERO concludes that Preble's are not present in the proposed project area. Although grasses and shrubs are present along the riparian corridor included in the project area, these corridors lack the adjacent suitable upland habitat in many places, as well as the lack of suitable soil substrate and vegetation along the sandy shorelines found in sections of the project area. With the presence of more suitable habitat upstream and the level of disturbance already present in the project area, ERO concludes that no further surveys are needed. In addition, based on guidance from DOI (2018), even if habitat were present, it is ERO's professional opinion that the project would not result in "take" of a listed species, and application for an ITP under Section 10(a)(1)(B) of the ESA is not appropriate for the project. Recommendations Although not required by regulation, in order to best avoid potential impacts on small mammal habitat, including potential Preble's habitat, in the project area, ERO recommends compliance with the BMPs and voluntary conservation measure listed above and implementing the following avoidance measures: • Avoid all riparian habitat consisting of shrubs, grasses, and forbs to maintain current vegetation communities and allow for habitat connectivity to habitat upstream and downstream. • Restrict planned disturbances to existing areas of agricultural fields and roads. • Provide 100 -foot buffers between planned disturbance and the bankfull river/riparian corridor. • Limit traffic to existing roads and bridges. • Take appropriate measure to control noise and dust levels during construction activities. References Baker, Adam M., and Daniel A. Potter. 2020. "Invasive Paper Wasp Turns Urban Pollinator Gardens into Ecological Traps for Monarch Butterfly Larvae." Scientific Reports 10 (9553). https://www.nature.com/articles/s41598-020-66621-6#citeas. Colorado Parks and Wildlife. 2015. Preble's Meadow Jumping Mouse: Assessing Habitat Quality for Priority Wildlife Species in Colorado Wetlands. https://cpw.state.co.us/Documents/LandWater/WetlandsProgram/PrioritySpecies/Factsheet-and- Habitat-Scorecard_PreblesMeadowJumpingMouse.pdf. Colorado Urban Wildlife. 2001. Trapping survey result submitted to the U.S. Fish and Wildlife Service along the Clear Creek Trail. Reference provided by U.S. Fish and Wildlife Service (2022). ERO Project #21-266 11 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Department of the Interior (DOI). 2018. Guidance on trigger for an incidental take permit under Section 10(a)(l)(B) of the Endangered Species Act where occupied habitat or potentially occupied habitat is being modified. FWS/AES/067974. April 26. ERO Resources Corporation (ERO). 2018. Preble's Meadow Jumping Mouse (Zapus hudsonius preblei) Habitat Assessment & Conservation Plan Two Rivers Parcels - Varra Companies Weld County, Colorado. July 21. ERO Resources Corporation (ERO). 2020. Ecological Characterization Report: Two Rivers Sand and Gravel Reservoir, Milliken, Weld County, Colorado. April. Greystone Environmental Management LLC. 1997 and 2001. Trapping survey result submitted to the U.S. Fish and Wildlife Service along the Clear Creek Trail. Reference provided by U.S. Fish and Wildlife Service (2022). Meaney, C.A. and N.W. Clippinger. 1995. A survey of Preble's meadow jumping mouse (Zapus hudsonius preblei) in Colorado. Prepared for Judy Sheppard, Colorado Division of Wildlife. Natural Heritage Program. 1996. Vertebrate characterization abstract (State) Zapus hudsonius preblei. NatureServe. 2022. "NatureServe Explorer: An Online Encyclopedia of Life." 2022. https://explorer.natureserve.org/. Ryon, T.R. 1996. Evaluation of the historic capture sites of the Preble's meadow jumping mouse in Colorado. MS thesis, University of Colorado, Denver. 65 pp. Savage and Savage Inc. 2001. Trapping survey result submitted to the U.S. Fish and Wildlife Service along the South Platte River. Reference provided by U.S. Fish and Wildlife Service (2022). U.S. Fish and Wildlife Service. 1992a. "Endangered and Threatened Wildlife and Plants: Final Rule to List the Plant Spiranthes Diluvialis (Ute Ladies' -Tresses) as a Threatened Species." Federal Register 50 CFR Part 17 57 (12): 2048-54. U.S. Fish and Wildlife Service. 1992b. "Interim Survey Requirements for Spiranthes Diluvialis." U.S. Fish and Wildlife Service (Service). 2004. Survey Guidelines for Preble's Meadow Jumping Mouse. USFWS, Colorado Field Office. U.S. Fish and Wildlife Service. 2013. "Recommended Conservation Measures to Avoid and Minimize Impacts to the Preble's Meadow Jumping Mouse (Zapus Hudsonius Preblei), the Ute Ladies' -Tresses Orchid (Spiranthes Diluvialis), and the Colorado Butterfly Plant (Guara Neomexicana Spp. Coloradensis) from Emergency Flood Response Activities Along Streams, Rivers, or Transportation Corridors." U.S. Fish and Wildlife Service. 2018. "Endangered and Threatened Wildlife and Plants; Initiation of 5 - Year Status Reviews of 11 Species in the Mountain Prairie Region." Federal Register 83 (155). U.S. Fish and Wildlife Service. 2018. "Species Status Assessment Report for the Eastern Black Rail (Laterallus Jamaicensis Jamaicensis), Version 1.2." Atlanta, GA. U.S. Fish and Wildlife Service (Service). 2022. Endangered, Threatened, Proposed and Candidate Species. http://ecos.fws.gov/ipac/. Last accessed March 10, 2022. ERO Project #21-266 12 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Appendix A Photo Log ERO Project #21-266 Threatened and Endangered Species Habitat Assessment Two Rivers Parcels - Varra Companies Weld County, Colorado Appendix B Qualifications of Surveyors Qualifications of Surveyors Milu Velardi has an M.S. in Wildlife & Fisheries Resources from West Virginia University. She has more than five years of experience performing threatened and endangered species habitat assessments and conducting small mammal surveys. Milu is familiar with Zapus hudsonius preblei survey guidelines and has viewed Zapus hudsonius preblei in the field. Qualifications of Ronald D. Beane have been previously submitted to the U.S. Fish and Wildlife Service and are available upon request. Ron is a certified ecologist and a Zoology Research Associate with the Denver Museum of Nature and Science. He has performed small mammal investigations for more than 25 years throughout the western U.S. Ron has been involved in both Section 7 and Section 10 consultations with the U.S. Fish and Wildlife Service, prepared the Denver Area Block Clearance Assessment, and completed more than 100 habitat assessments and 50 presence/absence surveys for Preble's over the last 25 years. Currently, Ron is a member of the Preble's Meadow Jumping Mouse Recovery Team. ERO Project #21-266 Elm Fentfollins W indsor LDveland Ii Longmdnt • Gi eeley ■, IP Iattedille r, Firestone •Keentshury Fredcrlck: _ Varra Companies - Endangered Species Re-evaluation Sections 33 and 34, T5N, R66W; Sections 3 and 4, T4N, R66W; 6th PM UTM NAD 83: Zone 13N; 519043mE, 4466286mN Longitude 104.775771°W, Latitude 40.346911°N USGS Milliken, CO Quadrangle Weld County, Colorado 0 750 1,500 Feet A Figure 1 Vicinity Map Prepared for: Varra Companies, Inc. ERO File: 21_266 Figure 1.mxd (GS) March 11, 2022 ERO Resources Corp. Portions of this document include intellectual property of ESRI and Its licensors and are used herein under license. Copyright © 2022 ESRI and Its licensors. All rights reserved. 71.7 a T tart 9O - tra. aiotrap start 1.- - sp.- end.20,0.4 '0 `/` • � entl 10 a - - 85 .1 � *+ entli89 s end '61 • 0 •' 25 tart 21. "46 IN".- 0-..�� Stall 62 - T CP. •. 4 -.S * ti` - �_ .•-• y[� 7,0 entl 43 , ,y4, 0444,10,0 06'1550!.'•: t l� 50a d 45 , 'AA aiallihilri"e" S' t 1 _tart%44 'lstart.69 litjiirj Varra Companies - Endangered Species Re-evaluation Figure 2 Small Mammal Trap Locations s art 153 GPS Point Image Source. Maxar Technologies©, March 3, 2021 "rend 152 y' N Prepared for: Varra Companies, Inc. ERA 0 200 400 File. 21_266 Figure 2.mxd (GS) Feet March 11, 2022 [uo R�o�ras cow. ERO Consultants in Natural Resources and the Environment Preble's Meadow Jumping Mouse (Zapus hudsonius preblei) Habitat Assessment & Conservation Plan Two Rivers Parcels - Varra Companies Weld County, Colorado Prepared for— Varra Companies, Inc. 8120 Gage Street Frederick, Colorado 80516 Prepared by— ERO Resources Corporation 1842 Clarkson Street Denver, Colorado 80218 (303) 830-1188 July 21, 2018 Denver • Durango • Hotchkiss • Idaho www.eroresources.com ERO Project #6626 Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Contents Executive Summary Introduction 1 Purpose 1 Federal Nexus 1 Project Area Description 1 Ecological Features of the Project Area 2 Previous Surveys near the Survey Area 2 Endangered Species Act Compliance 2 Threatened, Endangered, and Candidate Species 4 Preble's Meadow Jumping Mouse 4 Trapping Methods 5 Survey Results 5 Ute Ladies' -Tresses Orchid 8 Colorado Butterfly Plant 8 Conclusions 10 Recommendations 10 References 11 Tables Table 1. Federally threatened, endangered, and candidate species potentially found in Weld County or potentially affected by projects in Weld County4 Table 2. Small mammal species captured in the study area 6 Figures Figure 1. Vicinity Map 3 Figure 2. Small Mammal Trap Locations 7 Appendices Appendix A Qualifications of Surveyors Appendix B Trapping Results i ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels—Varra Companies Weld County, Colorado Introduction Varra Companies, Inc. (Client) retained ERO Resources Corporation (ERO) to perform a presence/absence survey for the federally threatened Preble's meadow jumping mouse (Zapus hudsonius preblei or Preble's) within a proposed project area in Weld County, Colorado (survey area). The property occurs near the confluence of the Little Thompson and South Platte Rivers. A population of Preble's is known to occur along the South Platte River, with the nearest successful trapping location found approximately 1.7 miles southwest of the project area (CPW 2001). The 2017 field survey was conducted to document the extent of the Preble's population within the proposed survey area. ERO wildlife biologists Ron Beane and Milu Velardi conducted surveys for Preble's on September 11 through 15, 2017 (2017 field survey). The proposed project is an aggregate mining operation consisting of scraping and stock -piling topsoil and mining sand, gravel and other aggregate materials from a series of mining cells within the project area. Mining would occur in phases with the individual cells. All mining would be restricted to current agricultural fields and no mining of mine operations would occur within 100 -feet of the bank -full stage of the Little Thompson or South Platte Rivers. Aggregate processing would occur north of the canal that parallels the Little Thompson River. An overhead conveyor would transport mined material from the mining cells to the processing area. NO wetlands or waters of the U.S. would be impacted. Purpose The purpose of this report is to describe the methods and results of live -trapping efforts conducted in September 2017 and to request concurrence that no additional trapping efforts would be needed for this project moving forward. Federal Nexus Currently there is no federal nexus associated with this project. As currently designed there are no wetlands or waters of the U.S. exist in the proposed aggregate mining locations, including access, processing and staging areas. If any potential wetlands would be impacted the Client would be responsible for coordination and permitting with the U.S. Army Corp of Engineers. Project Area Description The project area is in portions of Sections 33 and 34, Township 5 North, Range 66 West, and Sections 3 and 4, Township 4 North, Range 66 West of the 6th Principal Meridian in Weld County, Colorado (Figure 1). The UTM coordinates of the approximate center of the survey area are NAD 83 519043mE, 4466286mN, Zone 13N. The latitude/longitude of the survey area is 40.346911°N/104.775771°W. The elevation of the survey area is approximately 4,686 feet. 1 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Ecological Features of the Project Area Surveys for Preble's (survey area) were conducted in suitable habitat along the Little Thompson River in the northern portion of the project area and the South Platte (Figure 2). The project area is characterized by four agricultural fields adjacent to riparian corridors to the north and south. The Little Thompson River is located on the northern boundary of the project area. The river flows east through the town of Berthoud, Colorado and joins the Big Thompson River near Greely, Colorado. The South Platte River flows east along the southern end of the project area. The vegetation along both rivers consists of a mixture of woodland, shrubland, and grassland areas. The vegetation in the riparian areas are dominated by an overstory of plains cottonwood (Populus deltoides), narrowleaf cottonwood (Populus angustifolia), water birch (Betula occidentalis), thinleaf alder (Alnus incana), and box elder (Acer negundo) trees. The riparian corridor supports dense thickets of sandbar willow (Salix exigua) shrubs along the creek banks. Upland shrub species including chokecherry (Prunus virginiana), American plum (Prunus americana), and western serviceberry (Amelanchier alnifolia) occur in scattered stands throughout the floodplain of the creeks. Other dominant herbaceous species in the riparian area include smooth brome (Bromus inermis) and redtop (Agrostis gigantea). The survey area includes the riparian corridors along both the South Platte and Little Thompson Rivers, as well as a canal that parallels the Little Thompson River to the north. Habitat along the southern portion of the Little Thompson contains mixed woodlands and shrubs while the northern portion of the river consists of tall grasses and shrubs. The survey area along the South Platte consists of its southern edge which contains mixed woodlands and shrubs and a mix of native and non-native shrubs and forbs. Previous Surveys near the Survey Area Four previous trapping surveys were conducted within two miles of the survey area from 1997 to 2006 (Service PMJM Trap Results 2014). A positive trap location was found in June of 2001 by Savage & Savage, approximately 1.7 miles southwest of the project area along the South Platte River. The other three survey attempts did not result in positive trapping of Preble's. Endangered Species Act Compliance The project area does not fall within U.S. Fish and Wildlife Service (Service) habitat or survey guidelines for the majority of the species listed by the Service as potentially occurring in Weld County (Table 1). The interior least tern, piping plover, whooping crane, pallid sturgeon, and western prairie fringed orchid are species that are affected by continued or ongoing water depletions to the Platte River system. Because there is no federal nexus and the project would avoid all waters of the U.S. and would not require a federal action, the project would not require Section 7 depletions consultation. ERO assessed the project area for suitable habitat for Preble's, Ute ladies' -tresses orchid (Spiranthes diluvialis or ULTO), and Colorado butterfly plant (Gaura neomexicana ssp. coloradensis or CBP). Although the ESA does not apply to take of plants incidental to otherwise lawful activities, ERO evaluated impacts of the project on ULTO and CBP. 2 ERO Resources Corporation \Maps\Small Mammal Tra ppng Elm Fortfollins ■ W lid SO t.velaid -- r--- Lvngrn Int • Gs erley .. IPIattedille Fire5t ne •Keen.:burg Frederick Varra Companies - Endangered Species Re-evaluation Sections 33 and 34, T5N, R66W; Sections 3 and 4, T4N, R66W; 6th PM UTM NAD 83: Zone 13N; 519043mE, 4466286mN Longitude 104.775771°W, Latitude 40.346911°N USGS Milliken, CO Quadrangle Weld County, Colorado 0 750 1,500 Feet A Figure 1 Vicinity Map Prepared for: Varra Companies, Inc. �� File: 6626 Figure 1.mxd (GS) October 27, 2017 ERO Resources Corp. Portions of this document include intellectual property of ESRI and Its licensors and are used herein under license. Copyright © 2016 ESRI and Its licensors. All rights reserved. Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Threatened, Endangered, and Candidate Species Table 1. Federally threatened, endangered, and candidate species potentially found in Weld County or potentially affected by projects in Weld County. Common Name Scientific Name Status* Habitat Suitable Habitat Present Mammals Black -footed ferret Mustela nigripes E No habitat Preble's meadow jumping mouse (Preble's) Zapus hudsonius preblei T Shrub riparian/wet meadows No habitat Birds Interior least tern** Sterna antillarum athalassos E Sandy/pebble beaches on lakes, reservoirs, and rivers No habitat, no depletions anticipated Mexican spotted owl Strix occidentalis lucida T Old growth/mature forests with complex structure; canyons with riparian or conifer communities No habitat Piping plover** Charadrius melodus T Sandy Lakeshore beaches and river sandbars No habitat, no depletions anticipated Whooping crane* Grus americana E Mudflats around reservoirs and in agricultural areas No habitat, no depletions anticipated Fish Pallid sturgeon** Scaphirhynchus albus E Large, turbid, free -flowing rivers with a strong current and gravel or sandy substrate No habitat, no depletions anticipated Plants Colorado butterfly plant (CBP) Gaura neomexicana ssp. coloradensis T Sub -irrigated, alluvial soils on level floodplains and drainage bottoms between 5,000 and 6,400 feet in elevation No habitat Ute ladies' -tresses orchid (ULTO) Spiranthes diluvialis T Moist to wet alluvial meadows, floodplains of perennial streams, and around springs and lakes below 6,500 feet in elevation No habitat Western prairie fringed orchid** Platanthera praeclara T Mesic and wet prairies, sedge meadows No habitat, no depletions anticipated *E = Federally Endangered Species; T = Federally Threatened Species; PT = Proposed Threatened Species **Water depletions in the South Platte River may affect the species and/or critical habitat in downstream reaches in other counties or states. Source: Service 2018. Preble's Meadow Jumping Mouse Preble's was listed as a threatened species on May 13, 1998 under the Endangered Species Act (ESA) of 1973, as amended (63 Federal Register 66777 (December 3, 1998)). Under existing regulations, either a habitat assessment or a full presence/absence survey for Preble's is required for any habitat -disturbing 4 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado activity within areas determined to be potential Preble's habitat (generally stream and riparian habitats along the Colorado Front Range and southeastern Wyoming). Typically, Preble's occurs in low undergrowth consisting of grasses and forbs, open wet meadows, riparian corridors, or where tall shrubs and low trees provide adequate cover (Service 2004; Meaney and Clippinger 1995). Preble's occurs below 7,600 feet in elevation, generally in lowlands with medium to high moisture (Service 2004; Natural Heritage Program 1996) along permanent or intermittent streams (Ryon 1996). Trapping Methods Prior to conducting the 2017 field survey for Preble's, ERO remotely reviewed the survey area to determine the location and extent of any potential Preble's habitat. ERO biologists conducted a preliminary site visit in August 2017 to determine locations of suitable habitat within the survey area for setting traps. It was the intent of the entire survey to be overly inclusive in determining areas to be surveyed for the presence or absence of Preble's. ERO conducted the trapping survey using the methods outlined in the U.S. Fish and Wildlife Service's Preble's Meadow Jumping Mouse Survey Guidelines, revised April 2004 (Service 2004). During the 2017 field survey, ERO placed live -traps beginning the afternoon of September 11 and collected traps on the morning of September 15, 2017. Trap points were placed approximately 10 meters apart along transect lines on the north and south sides of Little Thompson River and south side of the adjacent canal as well as the north side of the South Platte River. One trap was set at each point over a period of four nights. A total of 180 traps were checked each morning at sunrise, closed, and reopened each evening at dusk, for a total of 720 trap nights. Specific start and end locations of trap lines were determined based on availability of suitable habitat along the rivers and canal. The traps used were Sherman large folding and nonfolding aluminum and steel traps with galvanized treadles and doors. The traps were baited with Country Acres° Sweet Mix Plus (Omalene). All individuals captured were identified to genus and species, and age and sex were documented. Standard field procedures for small mammal trapping were used following the guidelines approved by the Animal Care and Use Committee of the American Society of Mammalogists (Sikes 2016). Survey Results Small mammal live -trapping was conducted over a period of four nights during September of 2017, resulting in a total of 720 trap nights. No Preble's were found during the 2017 field survey. Four different species of small mammals, with 177 individual mammals, were trapped on -site (Table 2). Deer mice (Peromyscus maniculatus) were the most common species trapped, followed by house mice (Mus musculus), meadow voles (Microtus pennsylvanicus), and prairie voles (Microtus ochrogaster). 5 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Table 2. Small mammal species captured in the Two Rivers Parcels project area, September 2017. Deer mouse Sept. 12 Peromyscus maniculatus House mouse Mus musculus Meadow vole Prairie vole Microtus Pennsylvaticus Microtus ochrogaster Female Male Adult 5 Juvenile 2 Adult 3 Juvenile 3 Unknown 2 Sept. 13 Female Male Unknown Adult Juvenile Adult Juvenile 4 2 7 2 2 1 1 1 1 1 Sept. 14 Female Male Adult 1 Juvenile Adult 3 Juvenile Unknown 4 1 2 Sept. 15 Female Male Unknown Adult 1 Juvenile 1 Adult 6 Juvenile 1 2 1 TOTAL 121 5 5 1 Deer mouse captures resulted in 68 percent of the total small mammals trapped. House mouse and meadow vole captures were equal in number of 3 percent of total individuals trapped, and the single prairie vole accounted for 0.05 percent of the total small mammals trapped. During the four nights of trapping, 136 of a total of 720 traps were found closed but empty (18% unavailable). On two occasions, a single trap was found open and broken. The large number of closed traps found indicates the presence of other predatory mammals in the area. Several raccoon prints were observed on site. Raccoons can contribute to the predation of the oats left in traps and will tamper with traps while removing both the cotton stuffing and oat bait. 6 ERO Resources Corporation Figure 2 Small Mammal Trap Locations staq • ` Varra Companies - Endangered Species Re-evaluation GPS Point Project Area Boundary Parcel Boundary Image Source: Google Earth©, September 2016 0 200 400 Feet N A i Prepared for. Star a Companies, Inc ERO File. 6626 Figure 2.rnxd (GS) October 27, 2017 Ero R�o��s cow. Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Ute Ladies' -Tresses Orchid Species Background ULTO is federally listed as threatened. ULTO occurs at elevations below 7,800 feet in moist to wet alluvial meadows, in floodplains of perennial streams, and around springs and lakes where the soil is seasonally saturated within 18 inches of the surface (Service 1992a). This species has also been found along irrigation canals, irrigated meadows, gravel pits, and other human -modified wetlands (Service 2018). Generally, the species occurs where the vegetative cover is relatively open and not overly dense or overgrazed. Once thought to be fairly common in low -elevation riparian areas in the interior western United States, ULTO is now rare (Service 1992a). The species known range is from Nevada to British Columbia. The largest known populations occur in Utah, followed by Colorado (NatureServe 2018). In Colorado, the Service requires surveys of appropriate sites within the 100 -year floodplain of the South Platte River, Fountain Creek, and the Yampa River and their perennial tributaries, or in any area with habitat in Boulder and Jefferson Counties (Service 1992b). Because ULTO has been found along other stream systems in Colorado since 1992, the Service has expanded the number of counties where surveys are required in suitable habitat (Service 2018). ULTO does not bloom until late July to early September (depending on the year), and timing of surveys must be synchronized with blooming (Service 1992b). Rationale for Excluding the Project Area as Potential ULTO Habitat ERO assessed the project area for potential ULTO habitat. The dense herbaceous vegetation along the Little Thompson the river is unsuitable for ULTO. Vegetation is more sparse along the South Platte River; however, none of these areas would be impacted by proposed project activities. Colorado Butterfly Plant Species Background The Colorado butterfly plant (CBP) is a short-lived perennial herb found in moist areas of floodplains. It occurs on subirrigated alluvial soils on level or slightly sloping floodplains and drainage bottoms at elevations of 5,000 to 6,400 feet. Colonies are often found in low depressions or along bends in wide, active, meandering stream channels that are periodically disturbed. Historically, the main cause of disturbance was probably flooding. CBP flowers from June to September and produces fruit from July to October (Spackman et al. 1997). This species is federally listed as threatened under the ESA and is found within a small area in southeastern Wyoming, western Nebraska, and north -central Colorado (NatureServe 2018). Rationale for Excluding the Project Area as Potential CBP Habitat The Service has not established formal survey guidelines for CBP but has indicated that areas similar to and slightly drier than ULTO habitat should be assessed. ERO determined that habitat for CBP does not occur in the project area for the same reasons as described for ULTO. 8 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Rationale for Excluding the Project Area from Needing an Incidental Take Permit Under Section 10 (a)(1)(B) of the ESA The project area does not provide habitat for ULTO or CBP. Current and previous trapping efforts within the vicinity of the survey area indicate that a viable population of Preble's are unlikely to occur. In addition, based on guidance from the Department of the Interior (DOI) Principal Deputy Director (DOI 2018), it is ERO's professional opinion that the project would not result in "take" of a listed species, and application for an incidental take permit (ITP) under Section 10 (a)(1)(B) of the ESA is not appropriate for the project. ERO has reviewed the guidance and completed the questionnaire to help decide on the need for an ITP (provided below). 1. Are there ESA listed species present in the area where your activity will occur or will they be present at some point in the duration of your activity? Answer: Unknown 2. Is it likely that any of these listed species will be exposed to your activities (or the results of your activity) during any of the various phases of your activity (construction, operation, maintenance, etc.)? Answer: Unlikely 3. Will that exposure likely result in any of the following actions to the listed species: pursuing, hunting, shooting, wounding, killing, capturing, or collecting or attempting to engage in any such conduct? Answer: No 4. Is your activity likely to harass a listed species? • Will your activity, through an intentional or negligent act of omission, is likely to annoy the listed species to such an extent as to cause an injury to the species by significantly disrupting normal behavior patterns (e.g., breeding, feeding or sheltering, etc.). Answer: No, in the unlikely event that a Preble's occupies or travels through the area, the project has been designed to occur primarily in existing agricultural field and all stream and riparian habitat would be avoided. 5. Is your activity likely to result in an act that actually injures or kills a listed species? Answer: No, 4 see above. 6. Is your activity likely to harm a listed species through habitat modification (yes to all three questions below)? a) Is the activity likely to result in significant habitat modification or degradation? Answer: No, project activities would occur within existing agricultural fields and all stream and riparian habitat would be avoided b) Will the modification or degradation significantly impair essential behavior patterns, including breeding, feeding, or sheltering? Answer: No, see response to question 5. c) As a result of a. and b. above, is it likely there will be an actual injury or death to a listed species? Answer: No. 9 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels— Varra Companies Weld County, Colorado Conclusions No Preble's were found during the 2017 field survey. The known presence of Preble's approximately 1.5 miles away from the survey area along the South Platte (Savage and Savage 2001) demonstrates that suitable habitat is present along the South Platte in less disturbed areas further upstream. This suitable habitat consists of riparian areas with adjacent wet meadows. Dense shrub, grass and forb ground cover along creeks, rivers, and associated waterbodies are also preferred by Preble's during the warm season. From early fall through spring, this suitable habitat consists of multi -stem vegetation (e.g. shrubs) under which the Preble's will burrow for hibernation (CPW 2015). Based on the negative survey results of this survey and previous years completed in the vicinity of the study area (Greystone, LLC 2001 and Colorado Urban Wildlife 1997), and the lack of abundant suitable habitat in the survey area, ERO concludes that Preble's are not present in the study area. Although grasses and shrubs are present along the riparian corridor included in the project area, these corridors lack the adjacent suitable upland habitat in many places, as well as the lack of suitable soil substrate and vegetation along the sandy shorelines found within sections of the project area. With the presence of more suitable habitat upstream and the level of disturbance already present in the project area, ERO concludes that no further surveys are needed. In addition, based on guidance from DOI (2018), even if habitat were present, it is ERO professional opinion that the project would not result in "take" of a listed species, and application for an incidental take permit (ITP) under Section 10 (a)(1)(B) of the ESA is not appropriate for the project. Recommendations Although not required by regulation, in order to best avoid potential impacts to small mammal habitat, including potential Preble's habitat, in the project area, ERO recommends the following avoidance measures: • Riparian habitat consisting of shrubs, grasses, and forbs remain intact in order to maintain current vegetation communities and allow for habitat connectivity to habitat upstream and downstream • Restrict planned disturbances to existing areas of agricultural fields and roads • Provide buffers between planned disturbance and existing riparian corridor • Limit traffic to existing roads and bridges • Limit hours of construction activities to daylight hours to minimize overlap with most active small mammal periods • Control noise and dust levels during construction activities 10 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado References Colorado Parks and Wildlife (CPW). 2015. Preble's Meadow Jumping Mouse: Assessing Habitat Quality for Priority Wildlife Species in Colorado Wetlands. https://cpw.state.co.us/Documents/LandWater/WetlandsProgram/PrioritySpecies/Factsheet-and- Habitat-Scorecard_PreblesMeadowJumpingMouse.pdf Colorado Urban Wildlife. 2001. Trapping survey result submitted to the U.S Fish and Wildlife Service along the Clear Creek Trail. Reference provided by U.S. Fish and Wildlife Service (2001). Department of Interior (DOI). 2018. Guidance on trigger for an incidental take permit under section 10 (a)( I )(B) of the Endangered Species Act where occupied habitat or potentially occupied habitat is being modified. FWS/AES/067974. April 26.ERO Resources Corporation (ERO). 2000. Trapping survey results submitted to the U.S. Fish and Wildlife Service along the Clear Creek Trail near 6th Avenue. Reference provided by U.S. Fish and Wildlife Service (2015). Greystone Environmental Management LLC. 1997 and 2001. Trapping survey result submitted to the U.S Fish and Wildlife Service along the Clear Creek Trail. Reference provided by U.S. Fish and Wildlife Service (2001). Meaney, C.A. and N.W. Clippinger. 1995. A survey of Preble's meadow jumping mouse (Zapus hudsonius preblei) in Colorado. Prepared for Judy Sheppard, Colorado Division of Wildlife. Natural Heritage Program. 1996. Vertebrate characterization abstract (State) Zapus hudsonius preblei. Ryon, T.R. 1996. Evaluation of the historic capture sites of the Preble's meadow jumping mouse in Colorado. MS thesis, University of Colorado, Denver. 65 pp. Savage and Savage Inc. 2001. Trapping survey result submitted to the U.S Fish and Wildlife Service along the South Platte River. Reference provided by U.S. Fish and Wildlife Service (2001). Sikes, R.S. The Animal Care and Use Committee of the American Society of Mammalogists. 2011. Guidelines of the American Society of Mammalogists for the use of wild mammals in research. Journal of Mammalogy 92 (1):235-253. U.S. Fish and Wildlife Service (Service). 2004. Survey Guidelines for Preble's Meadow Jumping Mouse. USFWS, Colorado Field Office. U.S. Fish and Wildlife Service (Service). 2014. 2014 Preble's Meadow Jumping Mouse Trap Results. U.S. Fish and Wildlife Service (Service). 2018. Endangered, Threatened, Proposed and Candidate Species. http://ecos.fws.gov/ipac/. Last accessed July 12, 2018. 11 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Appendix A Qualifications of Surveyors Qualifications of Surveyors Milu Velardi has an M.S. in Wildlife & Fisheries Resources from West Virginia University. She has more than five years of experience performing threatened and endangered species habitat assessments and conducting small mammal surveys. Milu is familiar with Zapus hudsonius preblei survey guidelines and has viewed Zapus hudsonius preblei in the field. Qualifications of Ronald D. Beane have been previously submitted to the U.S. Fish and Wildlife Service and are available upon request. Mr. Beane is a certified ecologist and a Zoology Research Associate with the Denver Museum of Nature and Science. He has performed small mammal investigations for more than 25 years throughout the Western US. Ron has been involved in both Section 7 and Section 10 Consultations with the U.S. Fish and Wildlife Service, prepared the Denver Area Block Clearance Assessment and completed more than 100 Habitat Assessments and 50 Presence / Absence Surveys for Preble's over the last 25 years. Currently Ron is a member of the Preble's Meadow Jumping Mouse recovery Team. 12 ERO Resources Corporation Preble's Meadow Jumping Mouse Habitat Assessment & Conservation Plan Two Rivers Parcels — Varra Companies Weld County, Colorado Appendix B Trapping Results 13 ERO Resources Corporation Date Species Age Sex Tuesday 9/12 PEMA adult M 181 traps PEMA juvenile M 151 open PEMA juvenile F 30 closed PEMA juvenile F PEMA juvenile M PEMA adult F PEMA adult M PEMA adult F PEMA adult F PEMA juvenile M MUMU unk unk MUMU unk unk PEMA adult M PEMA adult F PEMA adult F Wednesday 9/13 PEMA adult unk 180 traps PEMA juvenile M 143 open PEMA adult M 37 closed PEMA adult unk PEMA adult M PEMA juvenile F PEMA adult M PEMA adult M PEMA juvenile F PEMA adult F PEMA adult M PEMA adult F PEMA adult M PEMA juvenile M PEMA adult M MUMU adult F MUMU adult M MIPE adult M MIPE adult F MIOC adult unk Thursday 9/14 MUMU unk unk 180 traps PEMA unk unk 152 open PEMA adult F 28 closed PEMA juvenile unk PEMA adult M PEMA adult M PEMA adult M MIPE unk unk MIPE unk unk PEMA juvenile unk PEMA adult unk Friday 9/15 180 traps 109 open 71 closed PEMA adult M MIPE unk unk PEMA adult unk PEMA adult M PEMA juvenile unk PEMA adult M PEMA juvenile F PEMA adult M PEMA adult M PEMA adult M PEMA adult F PEMA juvenile M Page I 1 6.4.5 EXHIBIT I/J - Soils and Vegetation Information 6.4.9 EXHIBIT I - Soils Information (1) In consultation with the Soil Conservation Service or other qualified person, the Operator/Applicant shall indicate on a map (in Exhibit C) or by a statement, the general type, thickness and distribution of soil over the affected land. Such description will address suitability of topsoil (or other material) for establishment and maintenance of plant growth. The above information shall satisfy "completeness" requirements for purposes of determination of date of filing. (2) If necessary, at its discretion, the Board may require additional information on soils or other growth media to be stockpiled and used in revegetation to be submitted subsequent to the filing and notification of "completeness" of the application. 6.4.10 EXHIBIT J - Vegetation Information (1) The Operator/Applicant shall include in this Exhibit a narrative of the following items: (a) descriptions of present vegetation types, which include quantitative estimates of cover and height for the principal species in each life -form represented (i.e., trees, tall shrubs, low shrubs, grasses, forbs); (b) the relationship of present vegetation types to soil types, or alternatively, the information may be presented on a map; and (c) estimates of average annual production for hay meadows and croplands, and carrying capacity for range lands on or in the vicinity of the affected land, if the choice of reclamation is for range or agriculture. (2) The Operator/Applicant shall show the relation of the types of vegetation to existing topography on a map in Exhibit C. In providing such information, the Operator/Applicant may want to contact the local Soil Conservation District. Exhibit I & J - Soils & Vegetation Map, identifies the type and extent of soils over the project site and surrounding lands. Areas designated for resource recovery within the extraction limits will remove all recoverable soils. A portion of the available soils will be utilized for reclamation from a portion of either existing or future soil stockpiles, or suitable in situ soils, as circumstances warrant. The balance of soils not otherwise needed for reclamation of affected lands remaining above the anticipated static water level of the completed basins will be made available to meet the demands of the market. Interpretation of current soil conditions and vegetation suitable for reclamation relies in part on information and correlated available data from the U.S. Soil Conservation Service (SCS) Soil Surveys and updated digital information of the same by the renamed U.S. Natural Resources Page 12 6.4.5 EXHIBIT I/J - Soils and Vegetation Information Conservation Service (NRCS). Range Site Descriptions (uniquely designated for each Soil Unit as shown by number and boundary on Exhibit I/J: Soils and Vegetation Map) and other related soil and ecosystem information taken from these publications. The information extracted from this source is included at the back of this exhibit. SOIL LEGEND of on -site soils (Refer to Exhibit I/J: Soils & Vegetation Map): SOIL UNIT #3. AQUOLLS & AQUENTS, GRAVELLY SUBSTRATUM; CAPABILITY SUBCLASS VIw; SALT MEADOW RANGE SITE DESCRIPTION [A Horizon = 0-48" Depth - Atypical - Will vary randomly - poorly formed in alluvial floodplain] SOIL UNIT #4. AQUOLLS & AQUEPTS, flooded bottoms and depressions, 0% SLOPES; NO CAPABILITY SUBCLASS; AQUOLLS in SALT MEADOW & AQUEPTS in WET MEADOW RANGE SITE DESCRIPTION [A Horizon = 0-60" Depth - Atypical - Will vary randomly - poorly formed in alluvial floodplain] SOIL UNIT #51. OTERO SANDY LOAM, 1-3% SLOPE; CAPABILITY SUBCLASS IIIe IRRIGATED & VIe NON -IRRIGATED; SANDY PLAINS RANGE SITE DESCRIPTION [A Horizon = 0-12" Depth] SOIL UNIT #52. OTERO SANDY LOAM, 3-5% SLOPE; CAPABILITY SUBCLASS IIIe IRRIGATED & VIe NON -IRRIGATED; SANDY PLAINS RANGE SITE DESCRIPTION [A Horizon = 0-12" Depth] SOIL UNIT #53. OTERO SANDY LOAM, 5-9% SLOPE; CAPABILITY SUBCLASS IVe IRRIGATED & VIe NON -IRRIGATED; SANDY PLAINS RANGE SITE DESCRIPTION [A Horizon = 0-12" Depth] Interpretations of former native conditions of soils and vegetation are offset and updated by present day field investigations, aerial images, and other resources. Ultimately, what is applied relies upon an arena of experience that draws upon an empirical understanding of the web of environmental, technical, economic, industrial and regulatory factors acting in concert with historical land use influences that depart from the SCS/NRCS records reflected in the Soil Legend, above; and as shown on Exhibit I/J: Soils and Vegetation Map. The combined effort eventually finds itself as applied and established over the completed and newly adapted landscape of the future; as projected in the diverse exhibits made part of this application. The attending narrative descriptions in the included Soil Survey addendums and extracts, detail the native soils, vegetations, and associated ecological conditions likely prevalent over unaltered lands of like kind, and as they might present themselves over the identified parcels. The identified vegetation is an indicator of what did, or may, grow on the represented soils under native undisturbed soil conditions. This information is utilized to create the seed mixture(s) proposed under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. The species selected for reseeding are selected as offering the best genetic potential for establishment of a diverse and enduring stabilizing cover in the reclamation and restoration of the affected lands. Page 13 6.4.5 EXHIBIT I/J - Soils and Vegetation Information A portion of in situ soils may be used in an over the shoulder method to resoil the completed banks of basin slopes or other upland areas in time. Commonly, soils will be parked in stockpiles until ready for application in a manner more fully described below. Consistent with existing zoned agricultural practices, soil from an adjacent wetland bank was approved by the City of Evans, and completed in early 2021. The City of Evans approved (refer to the Addendum at the back of this Exhibit) the placement of these soils within the floodplain of the upper North-East portion of Central Field, as shown on Exhibit C-2: Extraction Plan Map. These orphan soils are in place, seeded, and the area remains under continuing agricultural production, yet are no longer part of the area floodplain. The current extent of this 200,000± cu.yd. stockpile is represented on Exhibit L: Financial Warranty Map. This stockpile location area will also receive a portion of soils removed from planned extraction locations over other areas of Central and North-West Fields. It should be noted that a monoculture of cultivated corn occupies a majority of the planned areas of extraction, and will gradually be turned out of production through extraction. This soil may be utilized to line the resulting basins, for reclamation of affected lands above the static water level, or for market as warranted. At this time there is little to find in dominant preferred species of cover typifying the cropped fields or riverine areas. Beyond the row crops, the former pasturelands appear impacted by overgrazing, monocultures of smooth brome, annuals, and other comparatively recent impacts. Reclamation will not return the former Fields to agricultural crop production. Further, present day impacts over the planned Processing and Wash Pond locations do not reflect representative or realistic percent cover of a desirable matrix of native vegetation communities intended for reclamation. Consequently, the reclamation target will be to establish a stabilizing foliar cover of predominantly native vegetation (refer to seed mixture) of approximately 20 percent [determined as measured at the stem three inches above the ground surface respective of the foliar diameter of the established grass species, as determined by ocular estimates, or utilizing standard vegetation cover analysis such as line transect, as warranted]. For clarity, topsoil is generally regarded as the plow layer (upper six inches) on agricultural soils, or the A-1 soil profile horizon otherwise. The solum, or soil, includes the topsoil plus all other material found above the regolith of the parent rock, and generally no deeper than the optimal depth of roots of perennial plants and trees, or which otherwise meets the definition of soil. One soil differs from another soil by its unique properties and characteristics (such as horizon profile development, structure, texture, color, percent organic matter, chemical composition, etc.) and is identified as such by soil scientists, and detailed in available SCS (NRCS) Soil Survey documents. The affected soils to be extracted as permitted are designated under the soil survey to fall predominantly under Unit 3: Aquolls and Aquents, gravelly substratum; and may include minor components of Unit 10: Blankard sandy loam (refer to extracts and tables from the 1980 Weld County Soil Survey - Southern Part). Occurring in flood plain locations, as they do at this location, while described as 'deep,' would apply more commonly to the Mollisols that appear to form a minor component of the area soils, while the majority of the location is more characteristic of Aquolls, Aquent or Entisol soil formations, which are commonly poorly formed soils in floodplain locations, and lacking a typical profile or horizon development; or, in the case of the Blankard Series, having a shallow A -profile of 0-5 inches in depth overlying sand and gravel. The lack of a Page 14 6.4.5 EXHIBIT I/J - Soils and Vegetation Information deep, well developed soil profile is in part due to alluvial flooding which both scours and lays down sediment of diverse textural classes over time, but which lacks the appearance of an Inceptisol which is also commonly associated with flood plain locations. Deeper profiles may occur, however they are difficult to map under the best of conditions as they may vary every three (3) feet. Fundamentally, previous crop production activities over Unit 3 soils created a plow layer over the majority of Central Field, to an approximate depth of six inches; and likely contains the greater percentage of desirable organic matter and texture amenable to plant establishment and sustainability. These former rangelands turned to croplands have no predictable soil profile of consequence as you progress increasingly below the cropped layer. Other minor areas of impact over the remaining acres found within the parcel, have poorly developed soils whose depths vary from zero to eight inches. While anomalous pockets of deeper soil depths may occur, for purposes of this submittal, we will assume a soil depth to the plow layer of six inches over affected lands, excluding any obvious previously disturbed ground where soil has been removed (trenches, structures, etc.). Regardless, there is sufficient soil to assure a resoil depth of approximately six inches over the basin banks above the anticipated static water level of the reservoirs. The predominantly Otero Series soils underlying planned processing and product stockpile and transportation north of the Evans Canal are shallow soils of a foot or less over eolian deposits and alluvium; or sandstone bedrock, as in the case for the Tassel Series Soils. These soils are best left undisturbed where possible and simply reclaimed in place once processing and related activities are completed. For purposes of this submittal, all lands within the indicated permit boundary will be considered affected lands, but only those locations between the existing access roads, and which otherwise remain above the anticipated static water level of the resulting basins, will be soiled and seeded to establish vegetation consistent with the approved reclamation plan. All other previously disturbed lands outside of this area may be seeded to establish the desired vegetative cover where reaffected by planned activities, but in its previously disturbed state will not receive additional soil resources beyond what already remains, if any. Fortunately, the act of extraction serves to return affected lands to a stable configuration, and in a manner that creates a more enduring and beneficial habitat of indigenous vegetation and abundant water. Soil salvage will commence with the removal of the surface layer of soil to a mean depth of 6.0± inches, depending upon equipment and equipment operator limitations. Additional depths of soil (to the extent it occurs) will be removed in like manner until commercially viable overburden and aggregate are reached, unless already exposed as a result of poor soil development or flood based deposition. Soil salvage will be conducted primarily with excavators, but may include other heavy equipment such as bulldozers as warranted. To minimize the undesirable effects of soil blowing and loss, and to avoid damage to the soil resource via compaction, soil will be stripped wherever possible when soil is moist, and not dry or wet. Any portion of the solum suitable for plant regrowth will be utilized to meet the minimum depth of soil replacement for reclamation, with the excess made commercially available for export from the property. Generally, soil will be retained in sufficient volume to reclaim all lands remaining between the anticipated static water level of the basins and existing access roads which surround them at any given point in time during resource recovery operations. As detailed under Exhibit L — Page 15 6.4.5 EXHIBIT I/J - Soils and Vegetation Information Reclamation Costs, the initial exposure of lands requiring revegetation will be approximately 6.15± acres, requiring 4,961± cu.yds of soil. Total replacement volume required for Central and North- West Fields combined is 16.52± cu.yds of soil. Once removed from its native location, soil retained for reclamation will be stockpiled over the North-East portion of Central Field, in an area already improved above the prior floodplain; or otherwise windrowed along the perimeter of the basin area of extraction or area to be resoiled and seeded with the reclamation seed mixture specified under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture, or as otherwise determined under an approved revision. Stabilization of inactive soil stockpiles will provide an opportunity to gauge the performance of the seed mixture while attempting to provide a stabilizing cover of vegetation over the stockpiled soil until it is ready for replacement on finished slopes and affected lands remaining above the anticipated static water level of the completed reservoir basins. Direct precipitation from short duration high intensity rainstorm events, and wind, are the common erosion forces opposed to soil stability over in situ or established perimeter basin slopes at this location. The more uncommon flood event is considered under Exhibit G: Water Information, in the included Flow Technologies, Flood Control Mitigation Plan of 22 January 2020. Never the less, with few exceptions, the natural forces are commonly slight since the location geology and agricultural uses form a nearly flat table beyond the slopes of the extracted basins. Further, extraction will result in basin slopes that cause water from direct precipitation to drain internally, minimizing concentrated flows to existing area drainageways outside of the basin areas; while acting as detention and temporarily lowering any intersecting flood velocity and peak flows during a flood event. Additional conservation measures will be taken for common storm events to assure site stability and protection of off -site areas. An example would be directing overland flows, beyond the influence of the extracted basins, to existing or established grassed water ways. The operator's stormwater management plan may address additional detailed information about maintaining on -site stability consistent with its pending Colorado Department of Health stormwater permit. The measures taken to stabilize soil stockpiles described above, should be adequate for controlling erosion from wind and direct precipitation at those locations. Wind born effects are reduced by surface roughing during continued development of agricultural row crops, or from the natural consequence of extraction activity, itself. Due to the flat topography of the parcel, the interception of upland overland flows by local irrigation ditches and surrounding roads, there is little upland watershed that would impact these locations as a result of nominal storm related events. The greater threat of erosion will be to resoiled slopes pending establishment of vegetation during reclamation. While some sheet and rill erosion can be anticipated on unprotected areas following seed bed preparation and seeding, planned conservation measures should help to limit erosion potential that would threaten the revegetation efforts. Prior to resoiling, the foundation material that will underlie the soil will be sculpted to establish initial soil stabilization features, and left rough to aid in resoil adherence. Soil will be placed over a 12-18± inch minimum friable, or otherwise unconsolidated, subsoil. A 12-18± inch swale with Page 16 6.4.5 EXHIBIT I/J - Soils and Vegetation Information slopes of 3H:1V or flatter will be placed above finished slopes where necessary to direct any upland surface flows around the finished slopes to an established stable drainage corridor or grass -way. Resoiled areas will be allowed sufficient time to settle prior to seeding. Seeding will commonly follow in the fall or spring as detailed under Exhibit E — Reclamation Plan. Resoiling will occur when soil moisture is adequate to prevent blowing, yet dry enough to prevent compaction. Part of the soil rebuilding process on the reconstituted soils will be in establishing structure to the soils to facilitate plant -soil -water relationships. Overly compacted soils will tend to limit soil structure development and create a poor seedbed for later establishment, so revegetation may be deferred if soils to be reclaimed are manipulated while wet, instead of moist. Once applied to the surface, the new soils will be exposed to the raw forces of erosion until adequate vegetative cover and root mass develops. Erosion requires both detachment and transportation in order to occur. Running water, wind, and raindrop impact are the main forces of erosion acting upon the soil. The use of a sterile hybrid live cover crop will aid in the stabilization of the soil by allowing a quick vegetative cover to become established in advance of the native grasses. The hybrid will also serve as an aid to reduce competition resulting from the establishment and growth of unwanted pioneer species (weeds) on disturbed ground. The attending reclamation seed mixture, and as approved, has a provision for the use of a sterile hybrid grass in lieu of mulch. Mulch, even when crimped with specialized equipment, is subject to being blown off the property, or reduced to an ineffective stubble. Often, it has been observed to intercept rainfall where it quickly evaporates from the stubble surface, limiting the benefits of light precipitation by preventing infiltration and percolation of moisture to the root zone. The hybrid on the other hand will establish quickly, but since it is sterile, will not continue to compete with the emerging native grasses. After two to three years, the hybrid grass will begin to die out just as the native grasses emerge and improve their dominance over the revegetated areas. Increasing Organic matter, such as the incorporation of manure into fallow soils, will aid in the restructuring of the new soils by increasing the moisture and fertility holding capacity of the upper profile seed bed, while simultaneously facilitating healthier plant -soil -water relations and overall root development of the emerging grasses. As the roots of the emerging grasses develop and mature over time, the resulting root mass will serve to build upon the base percent organic matter content of the new soils, thereby increasing the potential for long term survival and spread of the established grasses. Soil testing may occur on the new soils to better gauge the need or success of any applied organic soil amendments respective of the resulting vegetative cover. The addition of fertilizer may also aid in the establishment, growth and survival of the emerging grasses. Fertilizer may be applied to the seeded areas at rates determined from soil tests of the reapplied soils. To this end, soils may be sampled as needed. Sampling will utilize a hand auger and approved NRCS soil sample bags, and utilizing recommended procedures. Any soil testing will be conducted by the CSU Soil Laboratory in Ft. Collins, Colorado. The tests will be used to monitor soil quality and suitability of any amendments. Fertilizer may be withheld until after emergence to deter the encouragement of weed species. The use, composition and rates of Page 17 6.4.5 EXHIBIT I/J - Soils and Vegetation Information fertilization will be determined prior to the time of seeding where appropriate, and may be reported in the OMLR Annual Reports, as appropriate. WEED MANAGEMENT PLAN: Mapping and Identification: Field identification and location of targeted weed species is fundamental to determining the extent and character of weed infestation; and in the subsequent development of a treatment plan. Due to the complex nature of identification, assistance with identification and mapping will be sought from among Weld County Weed and Pest Division; Colorado State University Cooperative Extension Service; U.S. Natural Resources and Conservation Service; as well as on-line and internal resources. Mapping will attempt to identify general areas of infestation within the permit boundary, and vectors of infestation from inside or outside the permit boundary. Vectors are a consideration in prevention of future infestation, which may affect on -site behaviors, including method and means of access within permitted lands. An expectation that vectors from adjacent lands must be treated by adjacent landowners if treatment on permitted lands is to be fruitful is part of continuing treatment considerations. Since the list of noxious weed continues to grow; and considering the development of new treatments; this management plan is intended to retain the flexibility needed to meet future conditions and capabilities in the arena of weed management and control. The primary species to be identified, mapped (if found), and treated will include those species on the State of Colorado noxious weed list, as updated. It should be noted that many weeds are sourced and vectored from adjacent lands and waterways. Weed management will suffer to diminishing effects that may beyond the capacities of the Operator to ameliorate if responsible weed management fails on those lands. Consideration of due diligence should apply respective of on -site efforts and limitations due to sources and vectors beyond the reach of the Operator. Treatment: Once the nature and extent of weeds have been mapped, and vectors identified; a course of treatment options will be considered in order of priority of economy and effectiveness. The overall object of weed management will be to control weeds by establishing a healthy competitive stand of vegetation that wins the competition for plant available water. This effort is linked to on -site soil management; including monitoring of soil fertility and percent organic matter on problem lands; relative to distribution and amount of field available moisture on affected areas. Physical weed control at the site will utilize non -chemical means, unless, due to weed morphology, or other factors, circumstance require application of other methods or an approved herbicide. If chemical weed control is utilized, it will be conducted in compliance with manufacturer's Page 18 6.4.5 EXHIBIT I/J - Soils and Vegetation Information recommendations and in conformance with applicable federal, state, or local laws. Chemical treatment of weeds will be the last option considered except where all other methods of competitive control fails; including mechanical cutting, tilling, or removal of noxious weeds. Where possible, pre -emergent weed control chemicals will be utilized. An exception to chemical weed control would be operator applied concentrated vinegar based organic weed control that does not harm soil or water. This is especially advantageous in application near water bodies. In general, weeds will be mowed or mechanically removed before a seed head can develop. This will take priority over recently seeded areas expressing emergent grasses. Where mechanical means fail; chemical applications may follow according to recommendations from previously stated sources, and applied accordingly (see above) to prevent damage to grasses, aquatic species and wildlife. An example of Chemical treatment and primary noxious weeds can be found at the Colorado State University Extension Service website: http://www.ext.colostate.edu/. Still, predominant weed control efforts will focus upon prevention, principally through the establishment of a diverse stabilizing cover of grasses, as described earlier. Regardless of control methodology, the intent of mechanical and chemical methods will be to prevent weed species from reproducing vegetatively, or by seed in percentages that threaten the preferred species. In general, the idea is to aid the grasses in out competing weed species for plant available water and nutrients in the new soils, until such a time that the grasses are fully established over the applied areas, are dominant over the weeds, and capable of self -regeneration. It should be understood that some weeds will remain. Total eradication of weeds is unlikely under the best circumstances, and is not a reasonable expectation or likely outcome. COMPANIES. INC PP0"C° Two Rivers Sand, Gravel Reservoir Project °"vdh Exhibit I/J: Soils and Vegetation Map 234.06±Acres Basins Total eCebe 1 Inch = 300 leek DATE 22 February 2022 REVISION USDA United States aim Department of Agrculture NRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Weld County, Colorado, Southern Part Two Rivers Ranch June 25, 2019 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nres.usda. gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface 2 How Soil Surveys Are Made 5 Soil Map 8 Soil Map (Two Rivers Ranch Area Soils) 9 Legend 10 Map Unit Legend (Two Rivers Ranch Area Soils) 11 Map Unit Descriptions (Two Rivers Ranch Area Soils) 12 Weld County, Colorado, Southern Part 14 1—Altvan loam, 0 to 1 percent slopes 14 3—Aquolls and Aquents, gravelly substratum 15 4—Aquolls and Aquepts, flooded 17 10 —Ellicott -Ellicott sandy -skeletal complex, 0 to 3 percent slopes, rarely flooded 19 19 —Colombo clay loam, 0 to 1 percent slopes 21 21—Dacono clay loam, 0 to 1 percent slopes 22 32 —Kim loam, 1 to 3 percent slopes 23 33 —Kim loam, 3 to 5 percent slopes 24 37 —Nelson fine sandy loam, 0 to 3 percent slopes 25 47 —Olney fine sandy loam, 1 to 3 percent slopes 26 51 —Otero sandy loam, 1 to 3 percent slopes 28 52 —Otero sandy loam, 3 to 5 percent slopes 29 53 —Otero sandy loam, 5 to 9 percent slopes 30 61 —Tassel fine sandy loam, 5 to 20 percent slopes 31 68—Ustic Torriorthents, moderately steep 32 69—Valent sand, 0 to 3 percent slopes 33 72 —Vona loamy sand, 0 to 3 percent slopes 35 85 —Water 36 Soil Information for All Uses 37 Suitabilities and Limitations for Use 37 Land Classifications 37 Ecological Site Name: NRCS Rangeland Site (Two Rivers Ranch Area Soils) 37 Farmland Classification (Two Rivers Ranch Area Soils) 42 Ecological Site Assessment 49 All Ecological Sites — Rangeland (Two Rivers Ranch Area Soils) 49 Map —Dominant Ecological Site (Two Rivers Ranch Area Soils) 50 Legend —Dominant Ecological Site (Two Rivers Ranch Area Soils) 51 Table —Ecological Sites by Map Unit Component (Two Rivers Ranch Area Soils) 52 References 55 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil -vegetation -landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 Custom Soil Resource Report scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil -landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil -landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field -observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and 6 Custom Soil Resource Report identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 7 Soi I Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 Custom Soil Resource Report Soil Map (Two Rivers Ranch Area Soils) 517100 40° 21' 30" N 40° 20' 9" N 517500 517900 518300 Map Scale: 1:17,500 if printed on A landscape (11" x 8.5") sheet. 0 250 500 0 500 1000 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 1000 Feet 2000 3000 518700 Meters 1500 9 519100 519100 519500 519930 519500 519900 520300 520300 520700 R. 40° 21' 30" N 40° 20' 9" N Custom Soil Resource Report MAP LEGEND Area of Interest (AO') Area of Interest (AO') Soils Soil Map Unit Polygons P j Soil Map Unit Lines a Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background I. Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA -N RCS certified data as of the version date(s) listed below. Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 17, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 17, 2015 —Oct 21, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 10 Custom Soil Resource Report Map Unit Legend (Two Rivers Ranch Area Soils) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 1 Altvan loam, 0 to 1 percent slopes 0.7 0.0% 3 Aquolls and Aquents, gravelly substratum 699.0 50.0% 4 Aquolls and Aquepts, flooded 118.2 8.5% 10 Ellicott -Ellicott sandy -skeletal complex, 0 to 3 percent slopes, rarely flooded 103.7 7.4% 19 Colombo clay loam, 0 to 1 percent slopes 76.3 5.5% 21 Dacono clay loam, 0 to 1 percent slopes 33.9 2.4% 32 Kim loam, 1 to 3 percent slopes 21.4 1.5% 33 Kim loam, 3 to 5 percent slopes 1.8 0.1% 37 Nelson fine sandy loam, 0 to 3 percent slopes 1.4 0.1% 47 Olney fine sandy loam, 1 to 3 percent slopes 9.2 0.7% 51 Otero sandy loam, 1 to 3 percent slopes 9.4 0.7% 52 Otero sandy loam, 3 to 5 percent slopes 36.5 2.6% 53 Otero sandy loam, 5 to 9 percent slopes 14.7 1.0% 61 Tassel fine sandy loam, 5 to 20 percent slopes 125.1 9.0% 68 Ustic Torriorthents, moderately steep 32.0 2.3% 69 Valent sand, 0 to 3 percent slopes 13.0 0.9% 72 Vona loamy sand, 0 to 3 percent slopes 1.0 0.1% 85 Water 99.8 7.1% Totals for Area of Interest 1,397.0 100.0% 11 Custom Soil Resource Report Map Unit Descriptions (Two Rivers Ranch Area Soils) The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the 12 Custom Soil Resource Report basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha -Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 13 Custom Soil Resource Report Weld County, Colorado, Southern Part 1—Altvan loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 361j Elevation: 4,500 to 4,900 feet Mean annual precipitation: 14 to 16 inches Mean annual air temperature: 46 to 48 degrees F Frost -free period: 130 to 150 days Farmland classification: Not prime farmland Map Unit Composition Altvan and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Altvan Setting Landform: Terraces Down -slope shape: Linear Across -slope shape: Linear Parent material: Old alluvium Typical profile H1 - 0 to 10 inches: loam H2 - 10 to 25 inches: clay loam H3 - 25 to 60 inches: gravelly sand Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.20 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Available water storage in profile: Low (about 5.7 inches) Interpretive groups Land capability classification (irrigated): 3s Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Minor Components Cascajo Percent of map unit: 9 percent Hydric soil rating: No 14 Custom Soil Resource Report Aquic haplustolls Percent of map unit: 1 percent Landform: Swales Hydric soil rating: Yes 3—Aquolls and Aquents, gravelly substratum Map Unit Setting National map unit symbol: 3627 Elevation: 4,000 to 7,200 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 45 to 55 degrees F Frost -free period: 80 to 155 days Farmland classification: Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Map Unit Composition Aquolls and similar soils: 55 percent Aquents, gravelly substratum, and similar soils: 30 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Aquolls Setting Landform: Swales, streams, flood plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Recent alluvium Typical profile H1 - 0 to 48 inches: loam H2 - 48 to 60 inches: gravelly sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.20 to 2.00 in/hr) Depth to water table: About 6 to 48 inches Frequency of flooding: Frequent Frequency of ponding: None Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Moderate (about 8.0 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6w Custom Soil Resource Report Hydrologic Soil Group: D Ecological site: Salt Meadow (R067BY035CO) Hydric soil rating: Yes Description of Aquents, Gravelly Substratum Setting Landform: Stream terraces Down -slope shape: Linear Across -slope shape: Linear Parent material: Recent alluvium Typical profile H1 - 0 to 48 inches: variable H2 - 48 to 60 inches: very gravelly sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat): Moderately high to very high (0.57 to 19.98 in/hr) Depth to water table: About 6 to 24 inches Frequency of flooding: Frequent Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to moderately saline (0.0 to 8.0 mmhos/cm) Available water storage in profile: Moderate (about 6.6 inches) Interpretive groups Land capability classification (irrigated): 6w Land capability classification (nonirrigated): 6w Hydrologic Soil Group: D Ecological site: Salt Meadow (R067BY035CO) Hydric soil rating: Yes Minor Components Bankard Percent of map unit: 10 percent Hydric soil rating: No Ustic torrifluvents Percent of map unit: 5 percent Hydric soil rating: No Custom Soil Resource Report 4—Aquolls and Aquepts, flooded Map Unit Setting National map unit symbol: 3621 Elevation: 3,600 to 4,700 feet Mean annual precipitation: 12 to 16 inches Mean annual air temperature: 50 to 55 degrees F Frost -free period: 100 to 165 days Farmland classification: Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Map Unit Composition Aquolls and similar soils: 55 percent Aquepts, flooded, and similar soils: 25 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Aquolls Setting Landform: Drainageways, plains, depressions Down -slope shape: Linear Across -slope shape: Linear Parent material: Recent alluvium Typical profile H1 - 0 to 8 inches: variable H2 - 8 to 60 inches: stratified sandy loam to clay Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to high (0.06 to 6.00 in/hr) Depth to water table: About 6 to 36 inches Frequency of flooding: Frequent Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Moderately saline to strongly saline (8.0 to 16.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 5.0 Available water storage in profile: Low (about 4.7 inches) Interpretive groups Land capability classification (irrigated): 6w Land capability classification (nonirrigated): 6w Hydrologic Soil Group: D 17 Custom Soil Resource Report Ecological site: Salt Meadow (R067BY035CO) Hydric soil rating: Yes Description of Aquepts, Flooded Setting Landform: Stream terraces Down -slope shape: Linear Across -slope shape: Linear Parent material: Recent alluvium Typical profile H1 - 0 to 8 inches: variable H2 - 8 to 60 inches: stratified sandy loam to clay Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to high (0.06 to 6.00 in/hr) Depth to water table: About 6 to 36 inches Frequency of flooding: Frequent Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Moderately saline to strongly saline (8.0 to 16.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 5.0 Available water storage in profile: Low (about 4.7 inches) Interpretive groups Land capability classification (irrigated): 6w Land capability classification (nonirrigated): 6w Hydrologic Soil Group: D Ecological site: Wet Meadow (R067BY038CO) Hydric soil rating: Yes Minor Components Thedalund Percent of map unit: 10 percent Hydric soil rating: No Haverson Percent of map unit: 10 percent Hydric soil rating: No Custom Soil Resource Report 10 —Ellicott -Ellicott sandy -skeletal complex, 0 to 3 percent slopes, rarely flooded Map Unit Setting National map unit symbol: 2xsth Elevation: 3,950 to 5,960 feet Mean annual precipitation: 13 to 17 inches Mean annual air temperature: 50 to 54 degrees F Frost -free period: 135 to 165 days Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Map Unit Composition Ellicott, rarely flooded, and similar soils: 65 percent Ellicott sandy -skeletal, rarely flooded, and similar soils: 25 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ellicott, Rarely Flooded Setting Landform: Drainageways, flood plains on intermittent streams Down -slope shape: Linear Across -slope shape: Concave Parent material: Noncalcareous, stratified sandy alluvium Typical profile A - 0 to 4 inches: sand AC - 4 to 13 inches: sand Cl - 13 to 30 inches: sand C2 - 30 to 44 inches: sand C3 - 44 to 80 inches: coarse sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Negligible Capacity of the most limiting layer to transmit water (Ksat): High to very high (13.00 to 39.96 in/hr) Depth to water table: More than 80 inches Frequency of flooding: Rare Frequency of ponding: None Salinity, maximum in profile: Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm) Available water storage in profile: Very low (about 2.1 inches) Custom Soil Resource Report Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 7s Hydrologic Soil Group: A Ecological site: Sandy Bottomland (R067BY031 CO) Hydric soil rating: No Description of Ellicott Sandy -skeletal, Rarely Flooded Setting Landform: Channels on intermittent streams, channels on drainageways Down -slope shape: Linear Across -slope shape: Concave, linear Parent material: Noncalcareous, stratified sandy alluvium Typical profile A - 0 to 4 inches: very gravelly coarse sand AC - 4 to 13 inches: very gravelly sand Cl - 13 to 30 inches: very gravelly sand C2 - 30 to 44 inches: very gravelly sand C3 - 44 to 80 inches: very gravelly coarse sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Negligible Capacity of the most limiting layer to transmit water (Ksat): High to very high (13.00 to 39.96 in/hr) Depth to water table: More than 80 inches Frequency of flooding: Rare Frequency of ponding: None Salinity, maximum in profile: Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm) Available water storage in profile: Very low (about 1.2 inches) Interpretive groups Land capability classification (irrigated): 4s Land capability classification (nonirrigated): 8s Hydrologic Soil Group: A Ecological site: Sandy Bottomland (R067BY031 CO) Hydric soil rating: No Minor Components Haverson Percent of map unit: 10 percent Landform: Terraces Landform position (three-dimensional): Tread Down -slope shape: Linear Across -slope shape: Linear Ecological site: Overflow (R067BY036CO) Hydric soil rating: No 20 Custom Soil Resource Report 19 —Colombo clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 361v Elevation: 4,600 to 4,780 feet Mean annual precipitation: 12 to 16 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 130 to 160 days Farmland classification: Prime farmland if irrigated Map Unit Composition Colombo and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transacts of the mapunit. Description of Colombo Setting Landform: Terraces, flood plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Stratified, calcareous alluvium Typical profile H1 - 0 to 14 inches: clay loam H2 - 14 to 21 inches: stratified loam to clay loam H3 - 21 to 60 inches: stratified sand to loam to clay loam Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 9.4 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: Clayey Plains (R067BY042CO) Hydric soil rating: No 21 Custom Soil Resource Report Minor Components Nunn Percent of map unit: 5 percent Hydric soil rating: No Heldt Percent of map unit: 5 percent Hydric soil rating: No Dacono Percent of map unit: 5 percent Hydric soil rating: No 21—Dacono clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 361y Elevation: 4,550 to 4,970 feet Mean annual precipitation: 14 to 18 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 140 to 160 days Farmland classification: Prime farmland if irrigated Map Unit Composition Dacono and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Dacono Setting Landform: Terraces Down -slope shape: Linear Across -slope shape: Linear Parent material: Mixed alluvium Typical profile H1 - 0 to 12 inches: clay loam H2 - 12 to 21 inches: clay loam H3 - 21 to 27 inches: clay loam H4 - 27 to 60 inches: very gravelly sand Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches 22 Custom Soil Resource Report Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Moderate (about 6.3 inches) Interpretive groups Land capability classification (irrigated): 2s Land capability classification (nonirrigated): 3s Hydrologic Soil Group: C Ecological site: Clayey Plains (R067BY042CO) Hydric soil rating: No Minor Components Heldt Percent of map unit: 5 percent Hydric soil rating: No Nunn Percent of map unit: 5 percent Hydric soil rating: No Altvan Percent of map unit: 5 percent Hydric soil rating: No 32 —Kim loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: 362b Elevation: 4,900 to 5,250 feet Mean annual precipitation: 13 to 17 inches Mean annual air temperature: 46 to 52 degrees F Frost -free period: 125 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Kim and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kim Setting Landform: Alluvial fans, plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Mixed eolian deposits derived from sedimentary rock 23 Custom Soil Resource Report Typical profile H1 - 0 to 12 inches: loam H2 - 12 to 40 inches: loam H3 - 40 to 60 inches: fine sandy loam Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Available water storage in profile: Moderate (about 9.0 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Minor Components Otero Percent of map unit: 10 percent Hydric soil rating: No 33 —Kim loam, 3 to 5 percent slopes Map Unit Setting National map unit symbol: 362c Elevation: 4,900 to 5,250 feet Mean annual precipitation: 13 to 17 inches Mean annual air temperature: 46 to 52 degrees F Frost -free period: 125 to 150 days Farmland classification: Farmland of statewide importance Map Unit Composition Kim and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kim Setting Landform: Alluvial fans, plains 24 Custom Soil Resource Report Down -slope shape: Linear Across -slope shape: Linear Parent material: Mixed eolian deposits derived from sedimentary rock Typical profile H1 - 0 to 12 inches: loam H2 - 12 to 40 inches: loam H3 - 40 to 60 inches: fine sandy loam Properties and qualities Slope: 3 to 5 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Available water storage in profile: Moderate (about 9.0 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological site: Loamy Plains (R067BY002CO) Hydric soil rating: No Minor Components Otero Percent of map unit: 10 percent Hydric soil rating: No 37 —Nelson fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 362h Elevation: 4,800 to 5,050 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 57 degrees F Frost -free period: 145 to 190 days Farmland classification: Farmland of statewide importance Map Unit Composition Nelson and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. 25 Custom Soil Resource Report Description of Nelson Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Residuum weathered from sandstone Typical profile H1 - 0 to 9 inches: fine sandy loam H2 - 9 to 30 inches: fine sandy loam H3 - 30 to 34 inches: weathered bedrock Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: 20 to 40 inches to paralithic bedrock Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to high (0.06 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Low (about 3.7 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Minor Components Thedalund Percent of map unit: 10 percent Hydric soil rating: No Olney Percent of map unit: 5 percent Hydric soil rating: No 47 —Olney fine sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: 362v Elevation: 4,600 to 5,200 feet Mean annual precipitation: 11 to 15 inches 26 Custom Soil Resource Report Mean annual air temperature: 46 to 54 degrees F Frost -free period: 125 to 175 days Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Map Unit Composition Olney and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Olney Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Mixed deposit outwash Typical profile H1 - 0 to 10 inches: fine sandy loam H2 - 10 to 20 inches: sandy clay loam H3 - 20 to 25 inches: sandy clay loam H4 - 25 to 60 inches: fine sandy loam Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Moderate (about 7.0 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4c Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Minor Components Zigweid Percent of map unit: 10 percent Hydric soil rating: No Vona Percent of map unit: 5 percent Hydric soil rating: No Custom Soil Resource Report 51 —Otero sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: 3630 Elevation: 4,700 to 5,250 feet Mean annual precipitation: 12 to 15 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 130 to 180 days Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Map Unit Composition Otero and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Otero Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Eolian deposits and/or mixed outwash Typical profile H1 - 0 to 12 inches: sandy loam H2 - 12 to 60 inches: fine sandy loam Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Moderate (about 7.7 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No 28 Custom Soil Resource Report Minor Components Kim Percent of map unit: 10 percent Hydric soil rating: No Vona Percent of map unit: 5 percent Hydric soil rating: No 52 —Otero sandy loam, 3 to 5 percent slopes Map Unit Setting National map unit symbol: 3631 Elevation: 4,700 to 5,250 feet Mean annual precipitation: 12 to 15 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 130 to 180 days Farmland classification: Farmland of statewide importance Map Unit Composition Otero and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Otero Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Eolian deposits and/or mixed outwash Typical profile H1 - 0 to 12 inches: sandy loam H2 - 12 to 60 inches: fine sandy loam Properties and qualities Slope: 3 to 5 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Moderate (about 7.7 inches) 29 Custom Soil Resource Report Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Minor Components Kim Percent of map unit: 12 percent Hydric soil rating: No Vona Percent of map unit: 3 percent Hydric soil rating: No 53 —Otero sandy loam, 5 to 9 percent slopes Map Unit Setting National map unit symbol: 3632 Elevation: 4,700 to 5,250 feet Mean annual precipitation: 12 to 15 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 130 to 180 days Farmland classification: Not prime farmland Map Unit Composition Otero and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Otero Setting Landform: Plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Eolian deposits and/or mixed outwash Typical profile H1 - 0 to 12 inches: sandy loam H2 - 12 to 60 inches: fine sandy loam Properties and qualities Slope: 5 to 9 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 5.95 in/hr) 30 Custom Soil Resource Report Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Moderate (about 7.7 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: A Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Minor Components Kim Percent of map unit: 10 percent Hydric soil rating: No Cushman Percent of map unit: 5 percent Hydric soil rating: No 61 —Tassel fine sandy loam, 5 to 20 percent slopes Map Unit Setting National map unit symbol: 363c Elevation: 4,850 to 5,200 feet Mean annual precipitation: 12 to 19 inches Mean annual air temperature: 46 to 52 degrees F Frost -free period: 110 to 165 days Farmland classification: Not prime farmland Map Unit Composition Tassel and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Tassel Setting Landform: Breaks Down -slope shape: Linear Across -slope shape: Linear Parent material: Residuum weathered from sandstone Typical profile H1 - 0 to 11 inches: fine sandy loam H2 - 11 to 15 inches: very fine sandy loam H3 - 15 to 20 inches: weathered bedrock 31 Custom Soil Resource Report Properties and qualities Slope: 5 to 20 percent Depth to restrictive feature: 10 to 20 inches to paralithic bedrock Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Available water storage in profile: Very low (about 2.0 inches) Interpretive groups Land capability classification (irrigated): 6e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: D Ecological site: Sandstone Breaks (R067BY056CO) Hydric soil rating: No Minor Components Otero Percent of map unit: 8 percent Hydric soil rating: No Terry Percent of map unit: 7 percent Hydric soil rating: No 68—Ustic Torriorthents, moderately steep Map Unit Setting National map unit symbol: 3631 Elevation: 4,450 to 5,100 feet Mean annual precipitation: 10 to 16 inches Mean annual air temperature: 46 to 54 degrees F Frost -free period: 120 to 160 days Farmland classification: Not prime farmland Map Unit Composition Ustic torriorthents and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ustic Torriorthents Setting Landform: Escarpments, breaks Down -slope shape: Linear 32 Custom Soil Resource Report Across -slope shape: Linear Parent material: Gravelly alluvium Typical profile H1 - 0 to 10 inches: gravelly sand H2 - 10 to 60 inches: gravelly sand Properties and qualities Slope: 9 to 15 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): High to very high (5.95 to 19.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Very low (about 1.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7s Hydrologic Soil Group: A Hydric soil rating: No Minor Components Columbo Percent of map unit: 10 percent Hydric soil rating: No Eckley Percent of map unit: 3 percent Hydric soil rating: No Otero Percent of map unit: 2 percent Hydric soil rating: No 69—Valent sand, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2tczd Elevation: 3,000 to 5,210 feet Mean annual precipitation: 13 to 20 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 130 to 166 days Farmland classification: Farmland of local importance Custom Soil Resource Report Map Unit Composition Valent and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Valent Setting Landform: Interdunes Landform position (two-dimensional): Footslope, toeslope Landform position (three-dimensional): Base slope Down -slope shape: Linear Across -slope shape: Linear Parent material: Noncalcareous eolian sands Typical profile A - 0 to 5 inches: sand AC - 5 to 12 inches: sand Cl - 12 to 30 inches: sand C2 - 30 to 80 inches: sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Excessively drained Runoff class: Negligible Capacity of the most limiting layer to transmit water (Ksat): High to very high (6.00 to 39.96 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 1 percent Salinity, maximum in profile: Nonsaline (0.1 to 1.9 mmhos/cm) Available water storage in profile: Very low (about 2.4 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 6e Hydrologic Soil Group: A Ecological site: Deep Sand (R067BY015CO), Sands (North) (PE 16-20) (R072XA021 KS) Hydric soil rating: No Minor Components Dailey Percent of map unit: 5 percent Landform: Interdunes Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down -slope shape: Linear Across -slope shape: Concave Ecological site: Deep Sand (R067BY015CO), Sandy (North) Draft (April 2010) (PE 16-20) (R072XA022KS) Hydric soil rating: No Custom Soil Resource Report Julesburg Percent of map unit: 5 percent Landform: Interdunes Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down -slope shape: Linear Across -slope shape: Linear Ecological site: Sandy Plains (R067BY024CO), Sandy (North) Draft (April 2010) (PE 16-20) (R072XA022KS) Hydric soil rating: No Vona Percent of map unit: 5 percent Landform: Interdunes Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down -slope shape: Linear Across -slope shape: Linear Ecological site: Sandy Plains (R067BY024CO), Sandy (North) Draft (April 2010) (PE 16-20) (R072XA022KS) Hydric soil rating: No 72 —Vona loamy sand, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 363r Elevation: 4,600 to 5,200 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 55 degrees F Frost -free period: 130 to 160 days Farmland classification: Farmland of local importance Map Unit Composition Vona and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Vona Setting Landform: Terraces, plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Alluvium and/or eolian deposits Typical profile H1 - 0 to 6 inches: loamy sand H2 - 6 to 28 inches: fine sandy loam H3 - 28 to 60 inches: sandy loam 35 Custom Soil Resource Report Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): High (1.98 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Moderate (about 6.5 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: A Ecological site: Sandy Plains (R067BY024CO) Hydric soil rating: No Minor Components Remmit Percent of map unit: 10 percent Hydric soil rating: No Valent Percent of map unit: 5 percent Hydric soil rating: No 85 —Water Map Unit Composition Water: 95 percent Minor components: 5 percent Estimates are based on observations, descriptions, and transects of the mapunit. Minor Components Aquolls Percent of map unit: 5 percent Landform: Marshes Hydric soil rating: Yes 36 Soil Information for All Uses Suitabilities and Limitations for Use The Suitabilities and Limitations for Use section includes various soil interpretations displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each interpretation. Land Classifications Land Classifications are specified land use and management groupings that are assigned to soil areas because combinations of soil have similar behavior for specified practices. Most are based on soil properties and other factors that directly influence the specific use of the soil. Example classifications include ecological site classification, farmland classification, irrigated and nonirrigated land capability classification, and hydric rating. Ecological Site Name: NRCS Rangeland Site (Two Rivers Ranch Area Soils) An ecological site name provides a general description of a particular ecological site. For example, "Loamy Upland" is the name of a rangeland ecological site. An "ecological site" is the product of all the environmental factors responsible for its development. It has characteristic soils that have developed over time; a characteristic hydrology, particularly infiltration and runoff, that has developed over time; and a characteristic plant community (kind and amount of vegetation). The vegetation, soils, and hydrology are all interrelated. Each is influenced by the others and influences the development of the others. For example, the hydrology of the site is influenced by development of the soil and plant community. The plant community on an ecological site is typified by an association of species that differs from that of other ecological sites in the kind and/or proportion of species or in total production. Descriptions of ecological sites are provided in the Field Office Technical Guide, which is available in local offices of the Natural Resources Conservation Service. Descriptions of those displayed in this map and summary table may also be accessed through the Ecological Site Assessment tab in Web Soil Survey. 37 Custom Soil Resource Report Ecological sites and their respective unique set of characteristics are uniquely identified by the Ecological Site ID. The same Ecological Site Name may be assigned to multiple Ecological Site IDs. If you wish to display a map of unique ecological sites, it is recommended that you select the Ecological Site ID attribute from the choice list. 38 Custom Soil Resource Report Map —Ecological Site Name: NRCS Rangeland Site (Two Rivers Ranch Area Soils) 40° 21' 30" N 40° 20'9"N 8 r 517100 517100 517530 517900 518300 518700 519100 519500 519900 520300 520700 u 517500 517900 518300 Map Scale: 1:17,500 if printed on A landscape (11" x 8.5") sheet. 518700 0 250 500 0 500 1000 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 1000 Feet 2000 3000 Meters 1500 39 519100 519500 519930 i i lg} i �y. ..4;7�.-7.-2,I X7,2 �5 520300 520700 40° 21' 30" N 4L- R. 40° 20' 9" N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AO') Area of Interest (AO') Soils Soil Rating Polygons 0 Clayey Plains 0 Deep Sand 0 Loamy Plains 0 Salt Meadow 0 Sandstone Breaks 0 Sandy Bottomland 0 Sandy Plains 0 Not rated or not available Soil Rating Lines P i Clayey Plains P j Deep Sand P j Loamy Plains Salt Meadow P j Sandstone Breaks P j Sandy Bottomland P i Sandy Plains Not rated or not available Soil Rating Points O Clayey Plains O Deep Sand O Loamy Plains ▪ Salt Meadow O Sandstone Breaks O Sandy Bottomland O Sandy Plains ▪ Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background I. Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA -N RCS certified data as of the version date(s) listed below. Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 17, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 17, 2015 —Oct 21, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 40 Custom Soil Resource Report Table —Ecological Site Name: NRCS Rangeland Site (Two Rivers Ranch Area Soils) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Altvan loam, 0 to 1 percent slopes Loamy Plains 0.7 0.0% 3 Aquolls and Aquents, gravelly substratum Salt Meadow 699.0 50.0% 4 Aquolls and Aquepts, flooded Salt Meadow 118.2 8.5% 10 Ellicott -Ellicott sandy- skeletal complex, 0 to 3 percent slopes, rarely flooded Sandy Bottomland 103.7 7.4% 19 Colombo clay loam, 0 to 1 percent slopes Clayey Plains 76.3 5.5% 21 Dacono clay loam, 0 to 1 percent slopes Clayey Plains 33.9 2.4% 32 Kim loam, 1 to 3 percent slopes Loamy Plains 21.4 1.5% 33 Kim loam, 3 to 5 percent slopes Loamy Plains 1.8 0.1% 37 Nelson fine sandy loam, 0 to 3 percent slopes Sandy Plains 1.4 0.1% 47 Olney fine sandy loam, 1 to 3 percent slopes Sandy Plains 9.2 0.7% 51 Otero sandy loam, 1 to 3 percent slopes Sandy Plains 9.4 0.7% 52 Otero sandy loam, 3 to 5 percent slopes Sandy Plains 36.5 2.6% 53 Otero sandy loam, 5 to 9 percent slopes Sandy Plains 14.7 1.0% 61 Tassel fine sandy loam, 5 to 20 percent slopes Sandstone Breaks 125.1 9.0% 68 Ustic Torriorthents, moderately steep 32.0 2.3% 69 Valent sand, 0 to 3 percent slopes Deep Sand 13.0 0.9% 72 Vona loamy sand, 0 to 3 percent slopes Sandy Plains 1.0 0.1% 85 Water 99.8 7.1% Totals for Area of Interest 1,397.0 100.0% Rating Options —Ecological Site Name: NRCS Rangeland Site (Two Rivers Ranch Area Soils) Class: NRCS Rangeland Site 41 Custom Soil Resource Report Aggregation Method: Dominant Condition Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole. A map unit is typically composed of one or more "components". A component is either some type of soil or some nonsoil entity, e.g., rock outcrop. For the attribute being aggregated, the first step of the aggregation process is to derive one attribute value for each of a map unit's components. From this set of component attributes, the next step of the aggregation process derives a single value that represents the map unit as a whole. Once a single value for each map unit is derived, a thematic map for soil map units can be rendered. Aggregation must be done because, on any soil map, map units are delineated but components are not. For each of a map unit's components, a corresponding percent composition is recorded. A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit. Percent composition is a critical factor in some, but not all, aggregation methods. The aggregation method "Dominant Condition" first groups like attribute values for the components in a map unit. For each group, percent composition is set to the sum of the percent composition of all components participating in that group. These groups now represent "conditions" rather than components. The attribute value associated with the group with the highest cumulative percent composition is returned. If more than one group shares the highest cumulative percent composition, the corresponding "tie -break" rule determines which value should be returned. The "tie -break" rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie. The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred. Component Percent Cutoff: None Specified Components whose percent composition is below the cutoff value will not be considered. If no cutoff value is specified, all components in the database will be considered. The data for some contrasting soils of minor extent may not be in the database, and therefore are not considered. Tie -break Rule: Lower The tie -break rule indicates which value should be selected from a set of multiple candidate values, or which value should be selected in the event of a percent composition tie. Farmland Classification (Two Rivers Ranch Area Soils) Farmland classification identifies map units as prime farmland, farmland of statewide importance, farmland of local importance, or unique farmland. It identifies the location and extent of the soils that are best suited to food, feed, fiber, forage, and oilseed crops. NRCS policy and procedures on prime and unique farmlands are published in the "Federal Register," Vol. 43, No. 21, January 31, 1978. 42 Custom Soil Resource Report Map —Farmland Classification (Two Rivers Ranch Area Soils) 40° 21' 30" N 40° 20' 9" N Map Scale: 1:17,500 if printed on A landscape (11" x 8.5") sheet. N 0 250 500 0 500 1000 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 1000 Feet 2000 3000 Meters 1500 43 Custom Soil Resource Report Area of Interest (AO') Area of Interest (AO') Soils Soil Rating Polygons Not prime farmland 0 0 0 0 0 0 0 0 All areas are prime farmland Prime farmland if drained Prime farmland if protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated and drained Prime farmland if irrigated and either protected from flooding or not frequently flooded during the growing season 0 0 0 0 0 0 0 Prime farmland if subsoiled, completely removing the root inhibiting soil layer Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Prime farmland if irrigated and reclaimed of excess salts and sodium Farmland of statewide importance Farmland of statewide importance, if drained Farmland of statewide importance, if protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if irrigated MAP LEGEND 0 0 0 0 0 Farmland of statewide importance, if drained and either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if irrigated and drained Farmland of statewide importance, if irrigated and either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if subsoiled, completely removing the root inhibiting soil layer Farmland of statewide importance, if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 0 0 0 0 0 0 0 Farmland of statewide importance, if irrigated and reclaimed of excess salts and sodium Farmland of statewide importance, if drained or either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if warm enough, and either drained or either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if warm enough Farmland of statewide importance, if thawed Farmland of local importance Farmland of local importance, if irrigated 0 0 Farmland of unique importance Not rated or not available Soil Rating Lines O %0 Not prime farmland • j All areas are prime farmland • j Prime farmland if drained • j Prime farmland if protected from flooding or not frequently flooded during the growing season • j Prime farmland if irrigated • j Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season • %0 Prime farmland if irrigated and drained • j Prime farmland if irrigated and either protected from flooding or not frequently flooded during the growing season 44 Custom Soil Resource Report • j Prime farmland if subsoiled, completely removing the root inhibiting soil layer • j Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Prime farmland if irrigated and reclaimed of excess salts and sodium • j Farmland of statewide importance • j Farmland of statewide importance, if drained • j Farmland of statewide importance, if protected from flooding or not frequently flooded during the growing season • j Farmland of statewide importance, if irrigated 0 Farmland of statewide importance, if drained and either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if irrigated and drained Farmland of statewide importance, if irrigated and either protected from flooding or not frequently flooded during the growing season 0 Farmland of statewide importance, if subsoiled, completely removing the root inhibiting soil layer 0 Farmland of statewide importance, if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Farmland of statewide importance, if irrigated and reclaimed of excess salts and sodium 0 Farmland of statewide importance, if drained or either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if warm enough, and either drained or either protected from flooding or not frequently flooded during the growing season i i Farmland of statewide importance, if warm enough Farmland of statewide importance, if thawed Farmland of local importance Farmland of local importance, if irrigated • j Farmland of unique importance Not rated or not available Soil Rating Points 0 0 0 0 0 Not prime farmland All areas are prime farmland Prime farmland if drained Prime farmland if protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated and drained O Prime farmland if irrigated and either protected from flooding or not frequently flooded during the growing season 0 0 . O O O 0 Prime farmland if subsoiled, completely removing the root inhibiting soil layer Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Prime farmland if irrigated and reclaimed of excess salts and sodium Farmland of statewide importance Farmland of statewide importance, if drained Farmland of statewide importance, if protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if irrigated 45 Custom Soil Resource Report 0 • • 0 0 Farmland of statewide importance, if drained and either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if irrigated and drained Farmland of statewide importance, if irrigated and either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if subsoiled, completely removing the root inhibiting soil layer Farmland of statewide importance, if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 ■ 0 O O Farmland of statewide importance, if irrigated and reclaimed of excess salts and sodium Farmland of statewide importance, if drained or either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if warm enough, and either drained or either protected from flooding or not frequently flooded during the growing season Farmland of statewide importance, if warm enough Farmland of statewide importance, if thawed Farmland of local importance O Farmland of unique importance Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background I. Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 17, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 17, 2015 —Oct 21, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 46 Custom Soil Resource Report Table —Farmland Classification (Two Rivers Ranch Area Soils) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Altvan loam, 0 to 1 percent slopes Not prime farmland 0.7 0.0% 3 Aquolls and Aquents, gravelly substratum Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season 699.0 50.0% 4 Aquolls and Aquepts, flooded Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season 118.2 8.5% 10 Ellicott -Ellicott sandy - skeletal complex, 0 to 3 percent slopes, rarely flooded Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 103.7 7.4% 19 Colombo clay loam, 0 to 1 percent slopes Prime farmland if irrigated 76.3 5.5% 21 Dacono clay loam, 0 to 1 percent slopes Prime farmland if irrigated 33.9 2.4% 32 Kim loam, 1 to 3 percent slopes Prime farmland if irrigated 21.4 1.5% 33 Kim loam, 3 to 5 percent slopes Farmland of statewide importance 1.8 0.1% 37 Nelson fine sandy loam, 0 to 3 percent slopes Farmland of statewide importance 1.4 0.1% 47 Olney fine sandy loam, 1 to 3 percent slopes Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 9.2 0.7% 51 Otero sandy loam, 1 to 3 percent slopes Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 9.4 0.7% 52 Otero sandy loam, 3 to 5 percent slopes Farmland of statewide importance 36.5 2.6% 53 Otero sandy loam, 5 to 9 percent slopes Not prime farmland 14.7 1.0% 61 Tassel fine sandy loam, 5 to 20 percent slopes Not prime farmland 125.1 9.0% 68 Ustic Torriorthents, moderately steep Not prime farmland 32.0 2.3% 47 Custom Soil Resource Report Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 69 Valent sand, 0 to 3 percent slopes Farmland of local importance 13.0 0.9% 72 Vona loamy sand, 0 to 3 percent slopes Farmland of local importance 1.0 0.1% 85 Water Not prime farmland 99.8 7.1% Totals for Area of Interest 1,397.0 100.0% Rating Options —Farmland Classification (Two Rivers Ranch Area Soils) Aggregation Method: No Aggregation Necessary Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole. A map unit is typically composed of one or more "components". A component is either some type of soil or some nonsoil entity, e.g., rock outcrop. For the attribute being aggregated, the first step of the aggregation process is to derive one attribute value for each of a map unit's components. From this set of component attributes, the next step of the aggregation process derives a single value that represents the map unit as a whole. Once a single value for each map unit is derived, a thematic map for soil map units can be rendered. Aggregation must be done because, on any soil map, map units are delineated but components are not. For each of a map unit's components, a corresponding percent composition is recorded. A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit. Percent composition is a critical factor in some, but not all, aggregation methods. The majority of soil attributes are associated with a component of a map unit, and such an attribute has to be aggregated to the map unit level before a thematic map can be rendered. Map units, however, also have their own attributes. An attribute of a map unit does not have to be aggregated in order to render a corresponding thematic map. Therefore, the "aggregation method" for any attribute of a map unit is referred to as "No Aggregation Necessary". Tie -break Rule: Lower The tie -break rule indicates which value should be selected from a set of multiple candidate values, or which value should be selected in the event of a percent composition tie. 48 Custom Soil Resource Report Ecological Site Assessment Individual soil map unit components can be correlated to a particular ecological site. The Ecological Site Assessment section includes ecological site descriptions, plant growth curves, state and transition models, and selected National Plants database information. All Ecological Sites — Rangeland (Two Rivers Ranch Area Soils) An "ecological site" is the product of all the environmental factors responsible for its development. It has characteristic soils that have developed over time; a characteristic hydrology, particularly infiltration and runoff, that has developed over time; and a characteristic plant community (kind and amount of vegetation). The vegetation, soils, and hydrology are all interrelated. Each is influenced by the others and influences the development of the others. For example, the hydrology of the site is influenced by development of the soil and plant community. The plant community on an ecological site is typified by an association of species that differs from that of other ecological sites in the kind and/or proportion of species or in total production. An ecological site name provides a general description of a particular ecological site. For example, "Loamy Upland" is the name of a rangeland ecological site. An "ecological site ID" is the symbol assigned to a particular ecological site. The map identifies the dominant ecological site for each map unit, aggregated by dominant condition. Other ecological sites may occur within each map unit. Each map unit typically consists of one or more components (soils and/or miscellaneous areas). Each soil component is associated with an ecological site. Miscellaneous areas, such as rock outcrop, sand dunes, and badlands, have little or no soil material and support little or no vegetation and therefore are not linked to an ecological site. The table below the map lists all of the ecological sites for each map unit component in your area of interest. 49 Custom Soil Resource Report Map —Dominant Ecological Site (Two Rivers Ranch Area Soils) 40° 21' 30" N 40° 20'9"N 8 r 517100 517500 517900 518300 517100 517530 517900 518300 518700 519100 519500 519900 520300 520700 Map Scale: 1:17,500 if printed on A landscape (11" x 8.5") sheet. 518700 YN 0 250 500 1000 Feet ,N\ 0 500 1000 2000 3000 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 Meters 1500 50 519100 519500 519930 l fib.wa) Valli �3 � 47-:--72``--- '�72,_ 6'8 1 U 520300 520700 �5 R. 40° 21' 30" N 40° 20' 9" N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AO') Area of Interest (AO') Soils Soil Rating Polygons R067BY002CO 0 R067BY015CO 0 R067BY024CO 0 R067BY031CO 0 R067BY035CO 0 R067BY042CO 0 R067BY056CO 0 Not rated or not available Soil Rating Lines • i R067BY002CO P. j R067BY015CO P. j R067BY024CO , i R067BY031CO , i R067BY035CO P. j R067BY042CO R067BY056CO Not rated or not available Soil Rating Points O R067BY002CO O R067BY015CO O R067BY024CO O R067BY031CO O O R067BY035CO R067BY042CO ▪ Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background I. Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA -N RCS certified data as of the version date(s) listed below. Soil Survey Area: Weld County, Colorado, Southern Part Survey Area Data: Version 17, Sep 10, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 17, 2015 —Oct 21, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 51 Custom Soil Resource Report Table —Ecological Sites by Map Unit Component (Two Rivers Ranch Area Soils) Map unit symbol Map unit name Component name (percent) Ecological site Acres in AOI Percent of AOI 1 Altvan loam, 0 to 1 percent slopes Altvan (90%) R067BY002CO - Loamy Plains 0.7 0.0% Cascajo (9%) Aquic Haplustolls (1%) 3 Aquolls and Aquents, gravelly substratum Aquolls (55%) R067BY035CO - Salt Meadow 699.0 50.0% Aquents, gravelly substratum (30%) R067BY035CO - Salt Meadow Bankard (10%) Ustic Torrifluvents (5%) 4 Aquolls and Aquepts, flooded Aquolls (55%) R067BY035CO — Salt Meadow 118.2 8.5% Aquepts, flooded (25%) R067BY038CO - Wet Meadow Haverson (10%) Thedalund (10%) 10 Ellicott -Ellicott sandy -skeletal complex, 0 to 3 percent slopes, rarely flooded Ellicott, rarely flooded (65%) R067BY031CO- Sandy Bottomland 103.7 7.4% Ellicott sandy- skeletal, rarely flooded (25%) R067BY031 CO — Sandy Bottomland Haverson (10%) R067BY036CO — Overflow 19 Colombo clay loam, 0 to 1 percent slopes Colombo (85%) R067BY042CO - Clayey Plains 76.3 5.5% Dacono (5%) Heldt (5%) Nunn (5%) 21 Dacono clay loam, 0 to 1 percent slopes Dacono (85%) R067BY042CO — Clayey Plains 33.9 2.4% Altvan (5%) Heldt (5%) Nunn (5%) 32 Kim loam, 1 to 3 percent slopes Kim (90%) R067BY002CO — Loamy Plains 21.4 1.5% Otero (10%) 33 Kim loam, 3 to 5 percent slopes Kim (90%) R067BY002CO - Loamy Plains 1.8 0.1% 52 Custom Soil Resource Report Map unit symbol Map unit name Component name (percent) Ecological site Acres in AOI Percent of AOI Otero (10%) 37 Nelson fine sandy loam, 0 to 3 percent slopes Nelson (85%) R067BY024CO - Sandy Plains Thedalund (10%) Olney (5%) 1.4 0.1% 47 Olney fine sandy loam, 1 to 3 percent slopes Olney (85%) R067BY024CO - Sandy Plains Zigweid (10%) Vona (5%) 9.2 0.7% 51 Otero sandy loam, 1 to 3 percent slopes Otero (85%) R067BY024CO - Sandy Plains Kim (10%) Vona (5%) 9.4 0.7% 52 Otero sandy loam, 3 to 5 percent slopes Otero (85%) R067BY024CO - Sandy Plains Kim (12%) Vona (3%) 36.5 2.6% 53 Otero sandy loam, 5 to 9 percent slopes Otero (85%) R067BY024CO - Sandy Plains Kim (10%) Cushman (5%) 14.7 1.0% 61 Tassel fine sandy loam, 5 to 20 percent slopes Tassel (85%) R067BY056CO - Sandstone Breaks Otero (8%) Terry (7%) 125.1 9.0% 68 Ustic Torriorthents, moderately steep Ustic Torriorthents (85%) Columbo (10%) Eckley (3%) Otero (2%) 32.0 2.3% 69 Valent sand, 0 to 3 percent slopes Valent (85%) R067BY015CO — Deep Sand R072XA021KS - Sands (North) (PE 16-20) Dailey (5%) R067BY015CO — Deep Sand R072XA022KS - Sandy (North) Draft (April 2010) (PE 16-20) Julesburg (5%) R067BY024CO - Sandy Plains 13.0 0.9% 53 Custom Soil Resource Report Map unit symbol Map unit name Component name (percent) Ecological site Acres in AOI Percent of AOI R072XA022KS - Sandy (North) Draft (April 2010) (PE 16-20) Vona (5%) R067BY024CO - Sandy Plains R072XA022KS - Sandy (North) Draft (April 2010) (PE 16-20) 72 Vona loamy sand, 0 to 3 percent slopes Vona (85%) R067BY024CO - Sandy Plains 1.0 0.1% Remmit (10%) Valent (5%) 85 Water Water (95%) 99.8 7.1% Aquolls (5%) Totals for Area of Interest 1,397.0 100.0% 54 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep -water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nres. usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nres. usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nres.usda.gov/wps/portal/nres/detail/soils/ home/?cid=nrcs142p2_053374 142 p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 55 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430 -VI. http://www.nrcs.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=nres142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf 56 ESD Plants ESIS Data Access > Return to Reports Selection Screen Report Selections > General > Physiographic Features > Climate Features > Water Features > Soil Features > Plant Communities > Site Interpretations > Supporting Information > Rangeland Health Reference Sheet Complete Report > HTML Printable Format FSGD ESI Forestland Ecological Site Description ESI Rangeland United States Department of Agriculture Natural Resources Conservation Service Ecological Site Description Section I: Ecological Site Characteristics Ecological Site Identification and Concept Site stage: Provisional Provisional: an ESD at the provisional status represents the lowest tier of documentation that is releasable to the public. It contains a grouping of soil units that respond similarly to ecological processes. The ESD contains 1) enough information to distinguish it from similar and associated ecological sites and 2) a draft state and transition model capturing the ecological processes and vegetative states and community phases as they are currently conceptualized. The provisional ESD has undergone both quality control and quality assurance protocols. It is expected that the provisional ESD will continue refinement towards an approved status. Site name: Sandy Plains / Eriogonum effusum / Bouteloua gracilis - Calamovilfa longifolia (/ spreading buckwheat / blue grama - prairie sandreed) Site type: Rangeland Site ID: R067BY024CO Major land resource area (MLRA): 067B -Central High Plains, Southern Part MLRA 678, Eastern Colorado MLRA 67B -Central High Plains, Southern Part is located in eastern Colorado. It is comprised of rolling plains and river valleys. Some canyonlands occur in the southeast portion. The major rivers are the South Platte and Arkansas which flow from the Rocky Mountains to Nebraska and Kansas. Other rivers in the MLRA include the Cache la Poudre and Republican. The rivers have many tributaries. This ecological site is traversed by 1-25, 1-70 and I-76, and U.S. Highways 50 and 287. Major land uses include 54% rangeland, 35% cropland, and 2% pasture and hayland. Urban and developed open space, and miscellaneous land occupy approximately 9% of the remainder. Cities in this area include Fort Collins, Greeley, Sterling, and Denver. Other cities include Limon, Cheyenne Wells, and Springfield. Land ownership is mostly private. Federal lands include Pawnee and Comanche National Grasslands (U.S. Forest Service), Sand Creek Massacre National Historic Site (National Park Service), and Rocky Mountain Arsenal National Wildlife Refuge (U.S. Fish & Wildlife Service). State Parks include Cherry Creek and Chatfield Reservoirs, and Barr and Jackson Lakes. This region is periodically affected by severe drought, including the historic "Dust Bowl" of the 1930s. Dust storms may form during drought years, in windy periods. Elevations range from 3,400 to 6,000 feet. The Average annual precipitation ranges from 14-17 inches per year, and ranges from 13 inches to over 18 inches, depending on location. Precipitation occurs mostly during the growing season, often during rapidly developing thunderstorms. Mean annual air temperature (MAAT) is 48-52°F. Summer temperatures may exceed 100°F. Winter temperatures may be sub -zero, and snowfall varies from 20-40 inches per year. Snow cover frequently melts between snow events. 1of18 Ecological Site Concept The Sandy Plains ecological site is a mixed grass prairie site dominated by warm -season tallgrasses with an understory of warm -season shortgrass. Cool -season midgrasses are secondary. A variety of forbs and shrubs occur on the site. The site occurs in upland positions on plains. Physiographic Features This site occurs on interdunes in dune fields and on terraces or narrow to broad, flat interfluves on dissected plains. Landform: (1)Interdune (2) Interfluve (3) Terrace Minimum Maximum Elevation (feet): 3400 6000 Slope (percent): 0 6 Water table depth (inches): 80 80 Flooding Frequency: None None Ponding Depth (inches): 0 0 Frequency: None None Runoff class: Very low Medium Aspect: No Influence on this site Climatic Features Average annual precipitation across the MLRA extent is 14 to 17 inches, and ranges from 13 inches to over 18 inches, depending on location. The average is 15 inches. Precipitation increases from north to south. Mean Annual Air Temperature (MAAT) is 50°F in the northern part and increases to 52°F in the southern part. Portions of Morgan and Weld counties (in the northern part) are cooler and drier, the MAAT is 48°F, and average precipitation is 13 to14 inches per year. Two-thirds of the annual precipitation occurs during the growing season from mid -April to late September. Snowfall averages 30 inches per year, area -wide, but varies by location from 20 to 40 inches per year. Winds are estimated to average 9 miles per hour annually. Daytime winds are generally stronger than at night, and occasional strong storms may bring periods of high winds with gusts to more than 90 mph. High -intensity afternoon thunderstorms may arise. The average length of the freeze -free period (28°F) is 155 days from April 30th to October to 3rd. The average frost -free period (32°F) is 136 days from May 11th to September 24th. July is the hottest month, and December and January are the coldest months. Summer temperatures average 90°F and occasionally exceed 100°F. Summer humidity is low and evaporation is high. Winters are characterized with frequent northerly winds, producing severe cold with temperatures occasionally dropping to -30°F or lower. Blizzard conditions may form quickly. For detailed information, visit the Western Regional Climate Center website: Western Regional Climate Center>Historical Data>Western U.S. Climate summaries, NOAA Coop Stations>Colorado http://www.wrcc.dri.edu/summary/Climsmco.html Eastern Colorado was strongly affected by extended drought conditions in the "Dust Bowl" period of the 1930's, with recurrent drought cycles in the 1950s and 1970s. Extreme to exceptional drought conditions have re -visited the area from 2002 to 2012, with brief interludes of near normal to normal precipitation years. Long-term effects of these latest drought events have yet to be determined. Growth of native cool -season plants begin about April 1 and continue to mid -June. Native warm - season plants begin growth about May 1 and continue to about August 15. Regrowth of cool -season plants occur in September in most years, depending on moisture. Note: The climate described here is based on historic climate station data in the past 30 to 50 years, and is averaged to provide an overview of annual precipitation, temperatures, and growing season. Future climate is beyond the scope of this document. However, research to determine the effects of elevated CO2 and/or heating on mixed -grass prairie ecosystems, and how it may relate to future plant communities (i.e. potential shifts in dominant and sub -dominant groups, changes in growing season length, responses of cool - season and warm -season grasses, etc.) is on -going. Frost -free period (days): Freeze -free period (days): Mean annual precipitation (inches): Averaged 129 150 15.89 Monthly Precipitation (Inches)j Jan Feb Mar Apr May Jun Jul Auu Sep Oct Nov Dec High 0.48 0.47 1.29 2.06 3.04 3.05 3.07 2.97 1.58 1.69 0.85 0.49 Medium 0.27 0.28 0.69 1.25 1.93 2.11 2.13 1.92 1.01 0.70 0.44 0.28 Low 0.11 0.10 0.34 0.58 1.17 1.30 1.32 1.13 0.50 0.32 0.20 0.14 2 of 18 4 inches 3 inches 2 inches 1 inches 0 inches Monthly Temperature (°F) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High 43.4 46.4 55.4 63.7 73.3 83.6 90.2 87.8 79.4 66.7 52.7 42.8 Low 13.5 16.4 24.3 32.1 42.4 51.6 57.3 55.9 46.2 33.8 22.3 13.7 103 F 83 F 63 F 43 F 23 F F Jan Feb. Mar Apr May Jun J.II .er, Sep Oct Nov Dec 30 Year Annual Rainfall (inches): 1981 N 1982 N 1983 N 1984 N 1985 N 1986 N 1987 N 1988 N 1989 N 1990 N 1991 N 1992 N 1993 N 1994 N 1995 N 15.24 15.13 16.97 15.59 14.68 13.69 17.02 13.14 14.65 16.99 16.42 16.51 15.4 13.19 18.42 1996 N 1997 H 1998 N 1999 N 2000 N 2001 N 2002 D 2003 N 2004 N 2005 N 2006 N 2007 N 2008 N 2009 N 2010 N 14.51 19.95 14.69 18.27 12.04 14.77 9.74 13.37 16.69 15.36 15.07 15.32 14.25 18.71 14.96 D -Drought N -Normal H -Heavy 24 inches 19 inches 14 inches 9 inches 4inches '80 '81 82 '83 '84 '85 .86 87 '88 '89 90 '91 '92 93 '94 '95 '96 '97 '98 '99 '00 0i '02 '03 '04 '05 '06 '07 '08 09 'i0 '11 Climate stations: (1) BRIGGSDALE [USC00050945], Weld County CO 80611. Period of record 1981-2010 (2) BRIGHTON 3 SE [USC00050950], Adams County CO 80601. Period of record 1981-2010 (3) BYERS 5 ENE [USC00051179], Adams County CO 80103. Period of record 1981-2010 (4) CHEYENNE WELLS [USC00051564], Cheyenne County CO 80810. Period of record 1981-2010 (5) FLAGLER 1S [USC00052932], Kit Carson County CO 80815. Period of record 1981-2010 (6) FT MORGAN [USC00053038], Morgan County CO 80701. Period of record 1981-2010 (7) GREELEY UNC [USC00053553], Weld County CO 80631. Period of record 1981-2010 (8) KIT CARSON [USC00054603], Cheyenne County CO 80825. Period of record 1981-2010 (9) NUNN [USC00056023], Weld County CO 80648. Period of record 1981-2010 3 of 18 (10) SPRINGFIELD 7 WSW [USC00057866], Baca County CO 81073. Period of record 1981-2010 (11) LIMON WSMO [USW00093010], Lincoln County CO 80828. Period of record 1981-2010 Influencing Water Features There are no water features of the ecological site or adjacent wetland/riparian regimes that influence the vegetation and/or management of the site that make it distinctive from other ecological sites. Many of the map units in this ESD have a 1% to 3% hydric component for swales, drainageways, or playas. Representative Soil Features The soils on this site are very deep, well to somewhat excessively drained soils that formed from eolian sand or alluvium. They typically have a moderately rapid to moderately slow permeability class, but range to slow in some soils. The available water capacity is typically low. Available water is the portion of water in a soil that can be readily absorbed by plant roots. This is the amount of water released between the field capacity and the permanent wilting point. As fineness of texture increases, there is a general increase in available moisture storage from sands to loams and silt loams. The soil moisture regime is typically aridic ustic. The soil temperature regime is mesic. The surface layer of the soils in this site are typically sandy loam or fine sandy loam, but may include loamy sand. The surface layer ranges from a depth of 4 to 9 inches thick. The subsoil is typically sandy loam, fine sandy loam, or sandy clay loam, but may include loamy sand. Soils in this site can have free carbonates below 6 inches. These soils are susceptible to erosion by wind. The potential for wind erosion accelerates with a decrease in vegetative cover, clay percentage, and/or particle size. Surface soil structure is granular to subangular blocky, and structure below the surface is prismatic or subangular blocky. Soil structure describes the manner in which soil particles are aggregated and defines the nature of the system of pores and channels in a soil. Together, soil texture and structure help determine the ability of the soil to hold and conduct the water and air necessary for sustaining life. Major soil series correlated to this ecological site include: Ascalon (loamy sand or sandy loam), Bijou, Blakeland, Bresser, Gilcrest, Haxtun, Julesburg, Manter, Olnest, Otero, Paoli, Truckton, and Vona. Other soil series that have been correlated to this site, but may eventually be re -correlated include: Eastonville, Fort Collins (sandy loam), Haverson (sandy loam), Nunn (sandy loam), Olney, Platner (sandy loam and fine sandy loam), Stoneham (sandy loam), Sundance (sandy loam), and Weld (sandy loam). The attributes listed below represent 0-40 inches in depth or to the first restrictive layer. Note: Revisions to soil surveys are on -going. For the most recent updates, visit the Web Soil Survey, the official site for soils information: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx Parent materials Kind: Eolian sands, Alluvium Surface texture: (1) Sandy loam (2) Loamy sand (3) Fine sandy loam Surface fragments <=3" (% cover): Surface fragments >3" (% cover): Subsurface fragments <=3" (% volume): Subsurface fragments >3" (% volume): Drainage class: Well drained to somewhat excessively drained Permeability class: Moderately slow to moderately rapid Depth (inches): Available water capacity (inches): Electrical conductivity (mmhos/cm): Sodium adsorption ratio: Calcium carbonate equivalent (percent): Soil reaction (1:1 water): Soil reaction (0.01M CaCl2): Ecological Dynamics of the Site Minimum 0 0 0 0 Minimum Maximum 80 80 3.00 6.00 0 2 0 5 0 10 6.6 8.4 6.0 7.9 Plant Communities Maximum 0 0 5 0 The information in this ESD, including the state -and -transition model diagram (STM), was developed using archeological and historical data, professional experience, and scientific studies. The information is representative of a dynamic set of plant communities that represent the complex interaction of several ecological processes. The plant composition has been determined by study of rangeland relic areas, areas protected from excessive disturbance, seasonal use pastures, short duration/time controlled grazing strategies, and historical accounts. 4 of 18 The Sandy Plains ecological site is characterized by four states: Reference, Warm -Season Shortgrass, Increased Bare Ground, and Tilled State. The Reference State is characterized by a dominance of warm -season tallgrasses (prairie sandreed, sand bluestem, and switchgrass). Warm -season shortgrass (blue grama) is the primary understory species. The Warm -Season Shortgrass State is dominated by a warm - season short bunchgrass (blue grama). The Increased Bare Ground State is characterized by early successional warm -season (Fendler threeawn) and cool -season short bunchgrasses (squirreltail) and annual grasses and forbs. The Tilled State has been mechanically disturbed by equipment and includes either a variety of reseeded warm and cool -season grasses (Seeded Community) or early successional plants as well as annual grasses and forbs (Go -Back Community). The degree of grazing has a significant impact on the ecological dynamics of the site. This region was historically occupied by large grazing animals such as bison and elk, along with pronghorn and mule deer. Grazing by these large herbivores, along with climatic fluctuations, and seasonal weather fluctuations, had a major influence on the dynamics of the ecology of this site. Deer and pronghorn are widely distributed throughout the MLRA. Secondary influences of herbivory by species such as prairie dogs and other small rodents, insects and root feeding organisms have impacted the vegetation and continues today. Historically, it is believed, grazing patterns by herds of large ungulates was driven by water distribution, precipitation events, drought events, and fire. It is believed that grazing periods would have been shorter, followed by longer recovery periods. These large migrating herds impacted the ecological processes of nutrient and hydrologic cycles, by urination, trampling (incorporation of litter into the soil surface), and breaking of surface crust, to increase water infiltration. This is an important site for livestock grazing, especially beef cattle. Today the management of livestock grazing by humans has been a major influence on the ecological dynamics of the site. This management, coupled with the effects of annual climatic variations, largely dictates the plant communities for the site. Prescribed grazing that mimics the historic grazing of herds of migratory herbivores, as described earlier, has been shown to result in desired improvements based on management goals for this ecological site. Recurrent drought has historically impacted the vegetation of this region. Changes in species composition will vary depending upon the duration and severity of the drought cycle, and prior grazing management. Recent drought events (since 2002) have increased mortality of blue grama and other bunchgrasses significantly in some locales. This site developed with occasional fires being part of the ecological processes. Historic fire frequency (pre -industrial), is estimated at 10-14 years (Guyette 2012), randomly distributed, and started by lightning at various times throughout the growing season. Early human inhabitants were also likely to start fires for various reasons (deliberate or accidental). It is believed that fires were set as a management tool for attracting herds of large migratory herbivores (Stewart, 2002). The impact of fire over the past 100 years has be relatively insignificant due to the human control of wildfires and the lack of acceptance of prescribed fire as a management tool. Grazing by large herbivores, without adequate recovery periods following each grazing occurrence, will cause blue grama to increase. Blue grama may eventually form a sod -like appearance. Prairie sandreed, sand bluestem, and switchgrass will decrease. Prairie sandreed may persist in remnant amounts protected by remaining shrubs. Cool season grasses such as needleandthread and western wheatgrass will decrease in frequency and production. Key shrubs such as western sand cherry and fourwing saltbush will decrease in frequency and production. American vetch and other highly palatable forbs will also decrease. Fendler threeawn, annuals and bare ground increases under heavy continuous grazing, excessive defoliation, or long- term non-use. Much of this ecological site has been tilled and used for crop production. Other areas of this ecological site have been converted to suburban residence and small acreages, especially near the larger communities. The following is a diagram illustrates the common plant communities that can occur on the Sandy Plains site and the community pathways (CP) among plant communities. Plant Communities are identified by 1.1, 1.2 etc. and are described in the narrative. Bold lines surrounding each state represent ecological thresholds. Transitions (T) indicate the transition across an ecological threshold to another state. Once a threshold has been crossed into another state, it may not be feasible to return to the original state, even with significant management inputs and practices. The ecological processes plant communities, community pathways, transition and/or restoration pathways will be discussed in more detail in the plant community descriptions following the diagram. Warm -Season Shortgrass Plant Community This plant community evolves with moderate to heavy continuous grazing caused by lack of adequate recovery periods between grazing events. Blue grama dominates this plant community and has taken on a sodbound appearance. Large amounts of sand dropseed and Fendler threeawn are common. White sage (aka Louisiana sage), lupine, stickleaf, croton, hairy goldaster, loco, wormwood, fringed sage and soapweed have increased. Sand sagebrush may increase on sandy loam or coarser subsoils. Sand bluestem, switchgrass, western sandcherry and fourwing saltbush have been removed. Prairie sandreed and needle and thread may persist in remnant amounts protected by remaining shrubs. Western wheatgrass may be found in small depressions. A significant amount of production and diversity has been lost when compared to the Reference Plant Community. The soil is stable at this stage however, the nutrient cycle, water cycle, community dynamics and energy flow are all impaired do to the substantial increase of blue grama and loss of warm- season tallgrasses, nitrogen fixing legumes and shrubs. Desertification is advancing. Production varies from 200 to 900 pounds of air-dry vegetation per acre per year depending on weather and averages 700 pounds. Plant Growth Curve Growth curve number: Growth curve name: Growth curve description: CO6710 Warm -Season Dominant; MLRA-67B; upland coarse -textured soils. Percent Production by Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 0 5 20 40 20 10 5 0 0 0 5 of 18 F u Increased Bare Ground Plant Community This plant community can develop by long-term heavy continuous grazing, and/or excessive defoliation (i.e. occupation by prairie dogs). Fendler threeawn is the dominant species. Sand dropseed may also be present in varying amounts. A number of annual plants such as Russian thistle, kochia, knapweed and cheatgrass will increase or invade. Field bindweed is often present on prairie dog towns. Litter levels are extremely low. The nutrient cycle, water cycle, and energy flow are greatly reduced. Infiltration is greatly reduced and erosion is occurring. Pedestalling is evident. Organic matter/carbon reserves are greatly reduced. Desertification is obvious. Production can vary from 50 to 400 pounds of air-dry vegetation per acre per year depending on weather conditions and the plants that are present. Plant Growth Curve Growth curve number: Growth curve name: Growth curve description: OO6710 Warm -Season Dominant; MLRA-67B; upland coarse -textured soils. Percent Production by Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 0 5 20 40 20 10 5 0 0 0 Growth Curl, F u Go -Back Plant Community Go -back land is created when the soil is tilled or farmed (sodbusted) and abandoned. All of the native plants are destroyed, soil organic matter is reduced, soil structure is changed and a plowpan or compacted layer is formed. Residual synthetic chemicals often remain from past farming operations and erosion processes may be active. Go -back land evolves through several plant communities beginning with an early annual plant community, which initiates the revegetation process. Plants such as Russian thistle, kochia and other annuals begin to establish. These plants give some protection from erosion and start to build minor levels of soil organic matter. This early annual plant community lasts for two to several years. Fendler threeawn, sand dropseed and several other early perennials can dominate the plant community for several years. Eventually other native species become reestablished. In much of the MLRA go -back land has eroded where tillage or farming and severe erosion has occurred. If the parent material that the original soil developed from is lost, then another ecosite will evolve. If the same parent material is present, then re -seeding or the slow process of developing soil and vegetation will start by similar processes as mentioned above. This is a very slow process (100 years or more). Reference Plant Community This is the interpretive plant community and is considered to be the Reference Plant Community. This plant community evolved with grazing by large herbivores, and is well suited for grazing by domestic livestock. It can be found on areas that are properly managed with prescribed grazing that allows for adequate recovery periods following each grazing event. The potential vegetation is about 70-85% grasses and grass- like plants, 10-15% forbs, and 5-15% woody plants. The dominant tall warm season grasses are prairie sandreed, sand bluestem and switchgrass. Blue grama dominates the understory. Important cool season grasses and grass -likes are needle and thread and sun sedge. Key forbs and shrubs are American vetch, pacific 6 of 18 peavine (manystem pea), purple prairie clover, and spreading buckwheat. This plant community is diverse, and productive. Litter is properly distributed with very little movement off -site, and natural plant mortality is very low. It is well -suited to carbon sequestration, effective water cycle, and wildlife use by many species, livestock use, and is aesthetically pleasing. Community dynamics, nutrient cycle, water cycle, and energy flow are functioning properly. This community is resistant to disturbances except moderate to heavy continuous grazing, tillage, and/or development into urban or other uses. Total annual production ranges from 800 to 2,200 pounds of air-dry vegetation per acre and will average 1,650 pounds during an average year. These production figures are the fluctuations expected during favorable, normal and unfavorable years due to the timing and amount of precipitation and temperature. Total annual production should not be confused with species productivity, which is annual production and variability by species throughout the extent of the community phase. Reference Plant Community Plant Species Composition Grass/Grasslike Group Group name Common name Symbol Forb Group Group name 2 -2 Shrub/Vine Group Group name 3 -3 Grass, perennial Indian ricegrass sand bluestem Fendler threeawn sideoats grama buffalograss blue grama sun sedge prairie sandreed thickspike wheatgrass needle and thread prairie Junegrass thin paspalum western wheatgrass switchgrass little bluestem Indiangrass sand dropseed Common name Farb, perennial Cuman ragweed tarragon white sagebrush woolly locoweed Texas croton purple prairie clover winged buckwheat shaggy dwarf morning-glory hairy false goldenaster manystem pea dotted blazing star rush skeletonplant tenpetal blazingstar crownleaf evening primrose broadbeard beardtongue silverleaf Indian breadroot slimflower scurfpea upright prairie coneflower scarlet globemallow white heath aster prairie spiderwort American vetch Common name Shrub (>.5m) leadplant sand sagebrush prairie sagewort fourwing saltbush spreading buckwheat spinystar broom snakeweed plains pricklypear western sandcherry soapweed yucca 2GP ACHY ANHA ARPUL BOCU BODA2 BOGR2 CAINH2 CALO ELLAL HECOC8 KOMA PASE5 PASM PAV I2 SCSC SONU2 SPCR Symbol 2FP AMPS ARDR4 ARLU ASMO7 CRTE4 DAPUP ERAL4 EVNU HEVI4 LAPO2 LIPU LYJU MEDE2 OECO2 PEAN4 PEAR6 PSTE5 RACO3 SPCO SYERE TROC VIAM Symbol 2SHRUB AMCA6 ARFI2 ARFR4 ATCA2 EREF ESVIV GUSA2 OPPO PRPUB YUGL Scientific name Achnatherum hymenoides Andropogon hallii Aristida purpurea var longiseta Bouteloua curtipendula Bouteloua dactyloides Bouteloua gracilis Carex Mops subsp. heliophila Calamovilfa longifolia Elymus lanceolatus subsp. lanceolatus Resperostipa comata subsp. comata Koeleria macrantha Paspalum setaceum Pascopyrum smithii Panicum virgatum Schizachyrium scoparium Sorghastrum nutans Sporobolus cryptandrus Scientific name Ambrosia psilostachy Artemisia dracunculus Artemisia ludoviciana Astragalus mollissimus Croton texensis Dales purpurea var. purpurea Eriogonum alatum Evolvulus nuttallianus Reterotheca villosa Lathyrus polymorphus Liatris punctata Lygodesmiajuncea Mentzelia decapetala Oenothera coronopifolia Penstemon angustifolius Pediomelum argophyllum Psoralidium tenuiflorum Ratibida columnifera Sphaeralcea coccinea Symphyothchum ericoides var. ericoides Tradescantia occidentalis Vicia americana Scientific name Amorpha canescens Artemisia filifolia Artemisia frigida Atriplex canescens Eriogonum effusum Escobaria vivipara var. vivipara Gutierrezia sarothrae Opuntia polyacantha Prunus pumila var besseyj Yucca glauca Annual Production pounds per acre) Low High 1155 1403 O 83 17 33 83 248 O 17 17 83 O 17 330 495 17 83 330 495 O 83 83 165 17 50 O 17 17 116 83 165 17 83 O 83 17 50 Annual Production pounds per acre) Low High 165 248 33 83 O 17 O 17 O 17 O 17 O 17 17 33 O 17 O 17 O 17 17 33 17 33 O 17 O 17 O 17 17 33 O 17 O 17 17 33 17 33 O 17 17 33 17 33 Annual Production pounds per acre) Low High 83 248 17 83 O 50 O 33 O 17 O 33 17 33 O 17 O 17 O 17 O 50 O 17 7 of 18 Annual Production by Plant Type Annual Production (lbs/ac) Representative Plant type Low value High Forb 150 200 255 Grass/Grasslike 600 1300 1690 Shrub/Vine 50 150 255 Total: 800 Plant Growth Curve Growth curve number: Growth curve name: Growth curve description: 1650 2200 OO6709 Warm season dominant, cool season sub -dominant; MLRA-67B; upland coarse textured soils. Percent Production by Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 2 7 25 35 15 10 5 1 0 0 At -Risk Plant Community This plant community develops with continuous grazing without adequate recovery periods between grazing events, and/or extended drought, and/or reduced fire frequency. When compared to the Reference Plant Community sand bluestem, prairie sandreed, switchgrass, leadplant and western sandcherry have decreased in frequency and production. Blue grama has increased. Sand dropseed, Fendler threeawn, hairy goldaster, croton, slimflower scurfpea, western ragweed, stickleaf, heath aster, lupine, loco, milkvetch and plains pricklypear cactus have increased. Soils that have a sandy loam or coarser subsoil will show an increase in sand sagebrush. Continuous spring grazing with summer deferment will reduce the cool -season component (needle and thread, western wheatgrass, sun sedge) of this plant community and increase the warm -season component. Continuous summer grazing with spring deferment will reduce the warm -season component (sand bluestem, prairie sandreed, and switchgrass) of this plant community and increase the cool -season component. The risk of losing key warm -season tallgrasses, important forbs and shrubs is a major concern. Blue grama is increasing at the expense of the tallgrasses and deep-rooted shrubs. Water cycle, nutrient cycle and energy flow may become impaired due to a shift in root structure and species composition. Less litter is being produced. Production in this community can vary from 400 to 1,200 pounds of air-dry vegetation per acre per year depending on weather conditions and averages 900 pounds. Plant Growth Curve Growth curve number: Growth curve name: Growth curve description: OO6710 Warm -Season Dominant; MLRA-67B; upland coarse -textured soils. Percent Production by Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 0 5 20 40 20 10 5 0 0 0 Growth Curl, F u 8 of 18 Seeded Plant Community This plant community can vary considerably depending on how eroded the soil was, the species seeded, the quality of the stand that was established and how long ago the stand was established. The management of the stand since establishment will significantly affect the species composition and annual production. Low Plant Density, Increased Litter Plant Community Most of the species occurring in the Reference Plant Community are present in this plant community but are reduced in abundance and production. Much of the nutrients are tied up in excessive litter and standing dead canopy. The semiarid environment and the absence of animal traffic to break down litter slow nutrient recycling. Aboveground litter also limits sunlight from reaching plant crowns. Many plants, especially bunchgrasses die off. Accumulation of litter and absence of grazing or fire reduce seed germination and establishment. This plant community is at risk of losing many key species and if left ungrazed or ungrazed without fire can go to a vegetative state resembling the Increased Bare Ground Plant Community. This plant community will change rapidly if plant manipulation is allowed to occur (grazing by domestic livestock or possibly fire). In advanced stages, plant mortality can increase and erosion potential increases as bare areas increase. Production can vary from 300 to 1500 pounds of air-dry vegetation per acre per year depending on weather conditions and the plants that are present. Plant Growth Curve Growth curve number: Growth curve name: Growth curve description: CO6711 Warm season dominant, cool season sub -dominant, excess litter; MLRA-67B; upland coarse texture soil. Percent Production by Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 2 8 20 35 17 10 5 3 0 0 F od d u Section II: Ecological Site Interpretations Animal Community WILDLIFE INTERPRETATIONS: The combination of grasses, forbs and shrubs found on the ecological site provide habitat for numerous wildlife species. Historic large grazers that influenced these communities were bison, elk, mule deer, and pronghorn. Herbivory and soil disturbance by black -tailed prairie dogs influenced ecological processes, supporting unique wildlife species. Bison are no longer widely distributed in their historic range. Prairie dogs occupy a small fraction of their historic range. Pronghorn are the most abundant ungulates using this ecological site, followed by mule deer. Domestic grazers share these habitats with wildlife. The grassland communities of eastern Colorado are home to many bird species. Changes in the composition of the plant community when moving from the Reference Community to other communities on this ecological site may result in species shifts in bird species. The occasional wetland or spring found on this site provides essential seasonal water needed for reproductive habitat by some reptiles and amphibians. Because of a lack of permanent water, fish are not common. 1.1 Reference Plant Community: Blue Grama, Prairie Sandreed, Sand Bluestem Plant Community The structural diversity found on the Reference Plant Community is attractive to a number of wildlife species. Common grassland bird species expected on the Reference community include Cassin's and Brewer's sparrow, chestnut collared longspur, lark bunting, western meadowlark, ferruginous hawk and Swainson's hawk. The combination of mid -tall grasses and shrubs provides habitat for lesser prairie chicken in the southeastern parts of this site. Greater prairie chicken and sharp -tailed grouse use this site in the northern portion of the MLRA. Scaled quail may also use this community in the southern half of the MLRA. White-tailed jackrabbit, badger, pronghorn, coyote, plains pocket gopher, long-tailed weasel, and several species of mice are mammals that commonly use this plant community. Reptiles using this community include western hognose snake, and ornate box turtle. 1.2 At -Risk Plant Community: Increased Blue Grama, Decreased Prairie Sandreed, Decreased Sand Bluestem Plant Community All Reference Plant Community species are expected to be found in this community. However, the loss of some of the vegetative structural diversity may make it less attractive to some of the Reference species such as lesser prairie chicken, greater prairie chicken, and sharp - 9 of 18 tailed grouse. 1.3 Low Plan Density, Increased Litter Plant Community: Blue Grama, Warm -Season Tallgrasses, Low Plant Density, Increased Standing Dead Canopy, Increased Litter and Decadence The same species found in the At -Risk Plant Community are expected to be found in the Low Plant Density Plant Community. 2.1 Warm -Season Shortgrass Plant Community: Blue Grama Many of the Reference Plant Community species are expected in the Warm -Season Shortgrass plant community, however, the loss of some of the vegetative structural diversity in this community may make it less attractive to lesser prairie chicken, greater prairie chicken, as well as for scaled quail. Swift fox will increase in this community. 3.1 Increased Bare Ground Plant Community: Fendler Threeawn, Sand Dropseed, Herbaceous Invasive and Increased Bare Ground Although not likely abundant, mountain plover, black -tailed prairie dog, and burrowing owl are expected on these communities where soils are loamier. Rodents will likely decrease because of less cover. Scaled quail may use these sites when adequate cover is available due to increased annual forb abundance compared to other plant communities. Grasshoppers will be the common insect, although some pollinators searching out the nectar from the annual flowers may still be found. Prairie rattlesnake and other reptiles using the Reference Plant Community will still be found here. Swainson's hawks will continue to be found here because it will be easy to spot prey in this community. 4.1 Go -Back Plant Community: Fendler Threeawn, Sand Dropseed and Annual Grasses/Forbs The wildlife found here will be similar to the Increased Bare Ground Plant Community. 4.2 Seeded Plant Community: Adapted Seed Mixes Wildlife use of tilled and replanted fields is dependent on the plant species used in the planted seed mix. Many of these sites currently support plains sharp -tailed grouse, lesser prairie chicken, greater prairie chicken, ring-necked pheasant, and grasshopper sparrow. Purpose of the seeding (i.e. reclamation, soil erosion control, livestock grazing, targeted wildlife species, etc.) would affect the usability for wildlife. If wildlife use is a primary concern, then formulate a seed mix accordingly. GRAZING INTERPRETATIONS: The following table lists suggested initial stocking rates for an animal unit (1000 pound beef cow) under continuous grazing (year long grazing or growing season long grazing) based on normal growing conditions. However, continuous grazing is not recommended. These estimates should only be used as preliminary guidelines in the initial stages of the conservation planning process. Often, the existing plant composition does not entirely match any particular plant community described in this ecological site description. Therefore, field inventories are always recommended to document plant composition, total production, and palatable forage production. Carrying capacity estimates that reflect on -site conditions should be calculated using field inventories. If the following production estimates are used, they should be adjusted based on animal kind/class and on the specific palatability of the forage plants in the various plant community descriptions. Under a properly stocked, properly applied, prescribed grazing management system that provides adequate recovery periods following each grazing event, improved harvest efficiencies will eventually result in increased carrying capacity. See USDA-NRCS Colorado Prescribed Grazing Standard and Specification Guide (528). The stocking rate calculations are based on the total annual forage production in a normal year multiplied by 25% harvest efficiency divided by 912.5 pounds of ingested air-dry vegetation for an animal unit per month. Plant Community (PC) Production (lbs./acre) and Stocking Rate (AUM/acre) Reference PC - (1650) (0.45) At -Risk PC - (900) (0.25) Warm -Season Shortgrass PC - (700) (0.19) Low Plant Density, Increased Litter PC - (*) (*) Increased Bare Ground PC - (*) (*) Grazing by domestic livestock is one of the major income -producing industries in the area. Rangeland in this area may provide yearlong forage under prescribed grazing for cattle, sheep, horses and other herbivores. * Highly variable; stocking rate needs to be determined on site. Plant Preference by Animal Kind Animal kind: Sheep, Deer, antelope Common name Scientific name Indian ricegrass Achnatherum hymenoides Cu man ragweed Ambrosia psilostachL sand bluestem Andropogon hallii tarragon Artemisia dracunculus sand sagebrush Artemisia filifolia Plant part J F MA M J J AS OND Entireplant DDDPP PDDDDDD Entireplant UUUDDDUUUUUU Entireplant UUUDDDUUUUUU Leaves UUUUUUUUUUUU Leaves UUUNNNNNNUUU 10 of 18 prairie sagewort white sagebrush Fendler threeawn woolly locoweed sideoats grama blue grama sun sedge prairie sandreed purple prairie clover thickspike wheatgrass winged buckwheat spinystar shaggy dwarf morning- glory broom snakeweed needle and thread hairy false goldenaster prairie Junegrass manystem pea dotted blazing star rush skeletonplant tenpetal blazingstar crownleaf evening primrose plains pricklypear thin paspalum western wheatgrass switchgrass broad beard beardtongue silverleaf Indian breadroot western sandcherry slimflower scurfpea upright prairie coneflower little bluestem Indiangrass scarlet globemallow sand dropseed prairie spiderwort American vetch soapweed yucca Artemisia frigida Artemisia ludoviciana Aristida purpurea var. longiseta Astragalus moilissimus Bouteloua curtipendula Bouteloua gracilis Carex Mops subsp. heliophila Calamovilfa longifolia Dalea purpurea var. purpurea Elymus lanceolatus subsp. lanceolatus Eriogonum alatum Escobaria vivipara var. vivipara Evolvulus nuttallianus Gutierrezia sarothrae Hesperostipa comata subsp. comata Heterotheca villosa Koeleria macrantha Lathyrus polymorphus Liatris punctata Lygodesmia juncea Mentzelia decapetala Oenothera coronopifolia Opuntia polyacantha Paspalum setaceum Pascopyrum smithii Panicum virgatum Penstemon angustifolius Pediomelum argophyllum Prunus pumila var. bessey Psoralidium tenuiflorum Ratibida columnifera Schizachyrium scoparium Sorghastrum nutans Sphaeralcea coccinea Sporobolus cryptandrus Tradescantia occidentalis Vicia americana Yucca glauca Animal kind: Cattle, Horse, Bison, elk Common name Scientific name Indian ricegrass Cuman ragweed tarragon sand sagebrush prairie sagewort white sagebrush Fendler threeawn woolly locoweed sideoats grama blue grama prairie sandreed purple prairie clover winged buckwheat spinystar shaggy dwarf morning- glory broom snakeweed needle and thread hairy false goldenaster prairie Junegrass manystem pea dotted blazing star rush skeletonplant Achnatherum hymenoides Ambrosia psilostachL Artemisia dracunculus Artemisia filifolia Artemisia frigida Artemisia ludoviciana Aristida purpurea var. longiseta Astragalus moilissimus Bouteloua curtipendula Bouteloua ,gracilis Calamovilfa longifolia Dalea purpurea var. purpurea Eriogonum alatum Escobaria vivipara var. vivipara Evolvulus nuttallianus Gutierrezia sarothrae Hesperostipa comata subsp. comata Heterotheca villosa Koeleria macrantha Lathyrus polymorphus Liatris punctata Lygodesmia juncea Leaves UUUDDDDDDUUU Entireplant UUUUUUDDDUUU Entireplant NNNNNNNNNNNN Entireplant T T T T T T T T T T T T Entireplant UUUDDDP PPUUU Entireplant DDDPP PP PPDDD Leaves UUUPPPDDDDDD Entireplant UUUDDDUUUUUU Entireplant UUUPP PP PPUUU Entireplant NNNDDDNNNNNN Entireplant UUUUUUUUUUUU Entireplant NNNNNNNNNNNN Entireplant UUUDDDDDDUUU Leaves NNNNNNNNNNNN Entireplant NNNDDDNNNDDD Entireplant NNNNNNNNNNNN Entireplant NNNDDDNNNUUU Entireplant UUUPP PP PPUUU Entireplant UUUDDDP PPUUU Entireplant NNNNNNNNNNNN Entireplant NNNNNNNNNNNN Entireplant NNNUUUUUUNNN Entireplant NNNNNNNNNNNN Entireplant NNNUUUNNNNNN Entireplant UUUPP PDDDDDD Entireplant UUUDDDUUUUUU Entireplant UUUPP PP PPUUU Entireplant NNNUUUUUUNNN Leaves DDDUUUUUUDDD Entireplant NNNUUUUUUNNN Entireplant UUUPP PP PPUUU Entireplant NNNDDDDDDNNN Entireplant UUUDDDUUUUUU Entireplant UUUPP PP PPUUU Entireplant NNNUUUDDDNNN Entireplant NNNNNNNNNNNN Entireplant DDDPP PP PPDDD Entireplant DDDPP PNNNDDD Plant part J F MA M J J AS OND Entireplant DDDPP PDDDDDD Entireplant UUUDDDUUUUUU Entireplant UUUUUUUUUUUU Leaves UUUNNNNNNUUU Leaves UUUNNNNNNUUU Entireplant UUUUUUUUUUUU Entireplant NNNNNNNNNNNN Entireplant T T T T T T T T T T T T Entireplant UUUDDDP PPUUU Entireplant DDDPP PP PPDDD Entireplant UUUDDDDDDUUU Entireplant UUUPP PP PPDDD Entireplant UUUUUUDDDUUU Entireplant NNNNNNNNNNNN Entireplant UUUUUUDDDUUU Entireplant NNNNNNNNNNNN Entireplant UUUPP PDDDDDD Entireplant UUUUUUDDDUUU Entireplant UUUDDDUUUDDD Entireplant UUUDDDUUUUUU Entireplant UUUUUUDDDUUU Entireplant UUUUUUUUUUUU 11 of 18 tenpetal blazingstar crownleaf evening primrose plains pricklypear thin paspalum switchgrass broad beard beardtongue silverleaf Indian bread root western sandcherry slimflower scurfpea upright prairie coneflower little bluestem Indiangrass scarlet globemallow prairie spiderwort American vetch soapweed yucca Legend: P=Preferred; unknown Mentzelia decapetala Entire plant UUUUUUUUUUUU Oenothera coronopifolia Opuntia polyacantha Paspalum setaceum Panicum virgatum Penstemon anqustifolius Entireplant UUUUUUUUUUUU Entireplant NNNNNNNNNNNN Entireplant NNNUUUUUUNNN Entireplant UUUDDDDDDUUU Entireplant UUUDDDUUUUUU Pediomelum argophylium Entire plant UUUUUUUUUUUU Prunus pumila var. bessey Leaves DDDPP PP PPDDD Psoralidium tenuiflorum Entire plant NNNNNNNNNNNN Ratibida columnifera Schizachyrium scoparium Sorghastrum nutans Sphaeralcea coccinea Tradescantia occidentalis Vicia americana Yucca glauca D=Desirable; U=Undesirable; Hydrology Functions Water is the principal factor limiting forage production on this site. This site is dominated by soils in hydrologic group A. Infiltration and runoff potential for this site varies from high to moderate depending on soil hydrologic group and ground cover. Areas where ground cover is less than 50% have the greatest potential to have reduced infiltration and higher runoff (refer to NRCS Section 4, National Engineering Handbook (NEH-4) for runoff quantities and hydrologic curves). Entireplant UUUUUUDDDUUU Entireplant UUUDDDP PPUUU Entireplant UUUDDDP PP DDD Entireplant UUUDDDDDDUUU Entireplant UUUUUUUUUUUU Entireplant DDDPP PP PPDDD Entireplant DDDPP PNNNDDD N=Not consumed; E=Emergency; T=Toxic; X=Used, but degree of utilization Recreational Uses This site provides hunting, hiking, photography, bird watching and other opportunities. The wide varieties of plants that bloom from spring until fall have an esthetic value that appeals to visitors. Wood Products No appreciable wood products are present on the site. Other Products Site Development & Testing Plan General Data (MLRA and Revision Notes, Hierarchical Classification, Ecological Site Concept, Physiographic, Climate, and Water Features, and Soils Data): Updated, All "Required" items complete to Provisional level Community Phase Data (Ecological Dynamics, STM, Transition & Recovery Pathways, Reference Plant Community, Species Composition List, Annual Production Table): Updated. All "Required" items complete to Provisional "+" level. NOTE: Annual Production Table is from the "Previously Approved" ESD (2004). The Species Composition List is also from the 2004 version, with minor edits. These will need review for future updates at Approved level. Each Alternative State/Community Complete to Provisional level Supporting Information (Site Interpretations, Assoc. & Similar Sites, Inventory Data References, Agency/State Correlation, References) Updated. All "Required" items complete to Provisional level. Livestock Interpretations updated to reflect Total Annual Production revisions in each plant community (Provisional "+"). Wildlife interpretations, general narrative, and individual plant communities updated (Provisional "+"). Hydrology, Recreational Uses, Wood Products, Other Products, and Plant Preferences table, were carried over from previously "Approved" ESD (2004). Reference Sheet The current Reference Sheet was previously approved in 2007. It will be updated at the next "Approved" level. "Future work, as described in a project plan, to validate the information in this provisional ecological site description is needed. This will include field activities to collect low and medium intensity sampling, soil correlations, and analysis of that data. Annual field reviews should be done by soil scientists and vegetation specialists. A final field review, peer review, quality control, and quality assurance reviews of the ESD will be needed to produce the final document." (NI 430_306 ESI and ESD, April, 2015) 12 of 18 Other Information Relationship to Other Hierarchical Classifications: NRCS Classification Hierarchy: Physiographic Divisions of the United States (Fenneman, 1946): Physiographic Division>Physiographic Province>Physiographic Section>Land Resource Region>Major Land Resource Area (MLRA)>Land Resource Unit (LRU). USFS Classification Hierarchy: National Hierarchical Framework of Ecological Units (Cleland et al, 181-200): Domain>Division>Province>Section>Subsection>Landtype Association> Landtype>Landtype Phase. Supporting Information Associated Sites Site name Loamy Plains Deep Sand Choppy Sands Sandy Bottomland Sandstone Breaks Similar Sites Site name Deep Sand Choppy Sands Site ID Site narrative R067BY002CO Loamy Plains R067BY015CO Deep Sand R067BY022CO Choppy Sands R067BY031CO Sandy Bottomland R067BY056CO Sandstone Breaks Site ID Site narrative R067BY015CO The Deep Sand site supports a higher overall production; sand sage and sand bluestem more prevalent; soils are sand and loamy sand (very deep) with less developed soil horizons. R067BY022CO The Choppy Sands site is associated with steeper slopes, and is more susceptible to blowouts. State Correlation This site has been correlated with the following states: co Inventory Data References Information presented here has been derived from data collection on private and federal lands using: • Double Sampling (clipped 2 of 5 plots)* • Rangeland Health** • Soil Stability** • Line Point Intercept : Foliar canopy, basal cover (Forb, Graminoid, Shrub, subshrub, Lichen, Moss, Rock fragments, bare ground, % Litter)*** • Soil pedon descriptions collected on site**** *NRCS double -sampling method, CO NRCS Similarity Index Worksheet 528(1). **Interpreting Indicators of Rangeland Health, Version 4, 2005 ***Monitoring Manual for Grassland, Shrubland and Savanna Ecosystems, Volume II, 2005 ****Field Book for Describing and Sampling Soils, Version 3, 2012 NRI- references to Natural Resource Inventory data SCS-RANGE-417 Production & Composition Record for Native Grazing Lands Additional reconnaissance data collection using numerous ocular estimates and other inventory data; NRCS clipping data for USDA program support; Field observations from experienced range trained personnel. Specific data information is contained in individual landowner/user case files and other files located in county NRCS field offices. Those involved in developing the 2004 site description include: Harvey Sprock, Rangeland Management Specialist, CO-NRCS; Ben Berlinger, Rangeland Management Specialist, CO-NRCS; Scott Woodall, Rangeland Management Specialist, CO-NRCS; James Borchert, Soil Scientist, CO-NRCS; Dave Sharman, Resource Conservationist, CO-NRCS; Terri Skadeland, Biologist, CO-NRCS; Dave Cook, Rangeland Management Specialist, NE-NRCS; Chuck Ring, Rangeland Management Specialist, WY-NRCS. Inventory Data References by Plot (Range -417, Wood -4, Wood -5) Sample ID State County Data source Number Year code code State R-417 0018108005 1981 08 005 Colorado 0018408005 1984 08 005 Colorado 0018408075 1984 08 075 Colorado County Arapahoe Arapahoe Logan Other Inventory Data References Data source Number of records Sample period State County 13 of 18 NRI NRI NRI NRI NRI NRI NRI NRI NRI NRI NRI NRI 2 3 1 1 1 2 3 3 4 1 3 4 2009 Colorado Adams 2008 Colorado Cheyenne 2008 Colorado Elbert 2008 Colorado Kit Carson 2013 Colorado Kit Carson 2010 Colorado Lincoln 2013 Colorado Lincoln 2011 Colorado Morgan 2012 Colorado Morgan 2007 Colorado Weld 2011 Colorado Weld 2009 Colorado Weld Hierarchical Classification Relationships MLRA 67B is in the Colorado Piedmont and Raton Sections of the Great Plains Province (USDA, 2006). The MLRA is further defined by LRUs A, B, and C. Features such as climate, geology, landforms, and key vegetation further refine these LRU concepts, and are described in other sections of the Ecological Site Description (ESD). NOTE: To date, these LRU's are DRAFT. LRU A is the northeast portion of MLRA 67B, to an extent of approximately 9.0 million acres. Most of the LRU is rangeland, and includes the Pawnee National Grassland, managed by the U.S. Forest Service. Dryland winter wheat/fallow rotations (that may include dryland corn, sunflowers, and/or sorghum) are grown in most counties. Irrigated cropland is utilized in the South Platte Valley. Small acreage and urban ownership are more concentrated on the Front Range. This LRU is found in portions of Adams, Arapahoe, Elbert, Kit Carson, Larimer, Lincoln, Logan, Washington, and Weld counties. Other counties include Boulder, Cheyenne, Denver, Jefferson, and Yuma. The soil moisture regime is Aridic Ustic. The mean annual air temperature (MAAT) is 50° F. LRU B is in the southeast portion of MLRA 67B (2.6 million acres) and include portions of Baca, Bent, Cheyenne, Kiowa, Las Animas, and Prowers counties. Most of the LRU remains agricultural. Most of LRU B is rangeland and includes the Comanche National Grassland. Dryland winter wheat/fallow rotations (that may include dryland corn, sunflowers, and/or sorghum) are grown. Irrigated cropland is used in the Arkansas Valley. The soil moisture regime is Aridic Ustic and the MAAT is 52°F. LRU C occurs in portions of Morgan and Weld counties (approximately 1.2 million acres). Most of LRU C is in rangeland. Dryland winter wheat/fallow rotations (that may include dryland corn, sunflowers, and/or sorghum) are grown. The soil moisture regime is Ustic Aridic and the MAAT is 48°F. REVISION NOTES: The Sandy Plains site was developed by an earlier version of the Sandy ESD (2004, re -named Sandy Plains in 2007). This earlier version of the Sandy ESD (2005) was based on input from NRCS (formerly Soil Conservation service) and historical information obtained from the Loamy Plains range site descriptions (1975, revised 1980). This ESD meets the Provisional requirements of the National Ecological Site Handbook (NESH). This ESD will continue refinement towards an Approved status according to the NESH. Other References Data collection for this ecological site was done in conjunction with the progressive soil surveys within the 67B Central High Plains (Southern Part) of Colorado. It has been mapped and correlated with soils in the following soil surveys: Adams County, Arapahoe County, Baca County, Bent County, Boulder County, Cheyenne County, El Paso County Area, Elbert County, Eastern Part, Kiowa County, Kit Carson County, Larimer County Area, Las Animas County Area, Lincoln County, Logan County, Morgan County, Prowers County, Washington County, Weld County, Northern Part, and Weld County, Southern Part. Agricultural Applied Climate Information system (AgACIS), powered by ACIS NOAA Regional Climate Centers, Frost/Freeze dates (1971-2000) http://agacis.rcc-acis.org Accessed February, 2017 Andrews, R. and R. Righter. 1992. Colorado Birds. Denver Museum of Natural History, Denver, CO. 442 Armstrong, D.M. 1972. Distribution of mammals in Colorado. Univ. Kansas Museum Natural History Monograph #3. 415. Butler, LD., J.B. Cropper, R.H. Johnson, A.J. Norman, G.L. Peacock, P.L. Shaver and K.E. Spaeth. 1997, revised 2003. National Range and Pasture Handbook. National Cartography and Geospatial Center's Technical Publishing Team: Fort Worth, TX. http://www.glti.nrcs.usda.gov /technical/publications/nrph.html Accessed August 2015 Cleland, D., P. Avers, W.H. McNab, M. Jensen, R. Bailey, T. King, and W. Russell. 1997. National Hierarchical Framework of Ecological Units, published in Ecosystem Management: Applications for Sustainable Forest and Wildlife Resources, Yale University Press Colorado Climate Center Monthly Data Access (1981-2010) Total Monthly Precipitation http://ccc.atmos.colostate.edu/cgi-bin/monthlydata.pl Accessed February, 2017 Colorado Parks & Wildlife. Grassland Species Plan (2003) http://cpw.state.co.us/learn/Pages/GrasslandSpecies.aspx Accessed March, 2017 Colorado Parks & Wildlife. Quick Key to Amphibians and Reptiles of Colorado. 2013. Colorado Parks & Wildlife, Denver, CO. cpw.state.co.us Cooperative climatological data summaries. NOAA. Western Regional Climate Center: Reno, NV. Web. http://www.wrcc.dri.edu/climatedata /climsum Accessed February, 2017 14 of 18 Fitzgerald, J.P., C.A. Meaney, and D.M. Armstrong. 1994. Mammals of Colorado. Denver Museum of Natural History, Denver, CO. 467. Guyette, Richard P., M.C. Stambaugh, D.C. Dey, RM Muzika. (2012). Predicting fire frequency with chemistry and climate. Ecosystems, 15: 322-335 Hammerson, G.A. 1986. Amphibians and reptiles in Colorado. University Press of Colorado & Colorado Division of Wildlife 1999. Herrick, Jeffrey E., J.W. Van Zee, K.M. Haystad, L.M. Burkett, and W.G. Witford. 2005. Monitoring Manual for Grassland, Shrubland, and Savanna Ecosystems, Volume II. U.S. Dept. of Agriculture, Agricultural Research Service. Jornada Experimental Range, Las Cruces, N.M. Kingery, H., Ed. (1998) Colorado Breeding Birds Atlas. Dist. CO Wildlife Heritage Foundation: Denver, CO. 636. National Water & Climate Center. USDA-NRCS. USDA Pacific Northwest Climate Hub: Portland, OR. http://www.wcc.nrcs.usda.gov/ Accessed February, 2017. NRCS National Water and Climate Center: https://www.wcc.nrcs.usda.gov/ Accessed February, 2017 Pellant, M., P. Shaver, D.A. Pyke, J.E. Herrick. (2005) Interpreting Indicators of Rangeland Health, Version 4. BLM National Business Center Printed Materials Distribution Service: Denver, CO. PLANTS Database. 2015. USDA-NRCS. Web. http://plants.usda.gov/java/ Accessed January, 2017 PRISM Climate Data. 2015. Prism Climate Group. Oregon State Univ. Corvallis, OR. http://www.prism.oregonstate.edu/ Accessed August 2015. Rennicke, J. 1990. Colorado Wildlife. Falcon Press, Helena and Billings, MT and CO Div. Wildlife, Denver CO. 138. Romme, W., C. Allen, J. Bailey, W. Baker, B. Bestelmeyer, P. Brown, K. Eisenhart, et al. 2007. Historical and Modern Disturbance Regimes of Pinon-Juniper vegetation in the Western U.S. The Nature Conservancy and Colorado Forest Restoration Institute: Fort Collins, CO. 13. Schoeneberger, P.J., D.A. Wysockie, E.C. Benham, and Soil Survey Staff. 2012. Field book for describing and sampling soils, Version 3.0. Natural Resources Conservation Service, National Soil Survey Center: Lincoln, NE. Stewart, Omer C., 2002. Forgotten Fires. Univ. of Oklahoma Press, Publishing Division: Norman, OK U.S. Dept. of Agriculture, Agricultural Research Service. September, 1991. Changes in Vegetation and Land Use I eastern Colorado, A Photographic study, 1904-1986. U.S. Dept. of Agriculture, Natural Resources Conservation Service. 2006. Land Resource Regions and Major Land Resource areas of the United States, the Caribbean, and the Pacific Basin. US Department of Agriculture Handbook 296. U.S. Dept. of Agriculture, Natural Resources Conservation Service. 2009. Part 630, Hydrology, National Engineering Handbook U.S. Dept. of Agriculture, Natural Resources Conservation Service. National Geospatial Center of Excellence. Colorado Annual Precipitation Map from 1981-2010, Annual Average Precipitation by State U.S. Dept. of Agriculture, Natural Resources Conservation Service. 1972-2012. National Engineering Handbook Hydrology Chapters. http://www.nres.usda.gov/wps/portal/nres/detailfull/national/water/?&cid=stelprdb1043063 Accessed August 2015. U.S. Dept. of Agriculture, Natural Resources Conservation Service. National Soil Survey Handbook title 430 -VI. http://www.nrcs.usda.gov /wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_054242 Accessed July 2015 U.S. Dept. of Agriculture, Natural Resources Conservation Service. Web Soil Survey.http://websoilsurvey.sc.egov.usda.gov /App/WebSoilSurvey.aspx Accessed January, 2017. U.S. Dept. of Agriculture, Soil Survey Division Staff. 1993. Soil Survey Manual. U.S. Dept. of Agriculture.1973. Soil Survey of Baca County, Colorado. U.S. Dept. of Agriculture. 1970. Soil Survey of Bent County, Colorado. U.S. Dept. of Agriculture. 1970. Soil Survey of Boulder County, Colorado. U.S. Dept. of Agriculture. 1992. Soil Survey of Cheyenne County, Colorado. U.S. Dept. of Agriculture. 1960. Soil Survey of Elbert County, Eastern Part, Colorado. U.S. Dept. of Agriculture. 1981 Soil Survey of El Paso County Area, Colorado. U.S. Dept. of Agriculture.1981. Soil Survey of Kiowa County, Colorado. U.S. Dept. of Agriculture. 2003. Soil Survey of Kit Carson County, Colorado. U.S. Dept. of Agriculture. 1981. Soil Survey of Larimer County Area, Colorado. U.S. Dept. of Agriculture. 2009. Soil Survey of Las Animas County Area, Parts of Huerfano and Las Animas Counties, Colorado. U.S. Dept. of Agriculture. 2004. Soil Survey of Lincoln County, Colorado. U.S. Dept. of Agriculture. 1977. Soil Survey of Logan County, Colorado. U.S. Dept. of Agriculture. 1968 . Soil Survey of Morgan County, Colorado. 15 of 18 U.S. Dept. of Agriculture.1965. Soil Survey Prowers County, Colorado. U.S. Dept. of Agriculture. 1986. Soil Survey of Washington County, Colorado. U.S. Dept. of Agriculture. 1982. Soil Survey of Weld County, Northern Part, Colorado. U.S. Dept. of Agriculture. 1980. Soil Survey of Weld County, Southern Part, Colorado. Additional Literature: Clark, J., E. Grimm, J. Donovan, S. Fritz, D. Engrstom, and J. Almendinger. 2002. Drought cycles and landscape responses to past Aridity on prairies of the Northern Great Plains, USA. Ecology, 83(3), 595-601. Collins, S., and S. Barber. (1985). Effects of disturbance on diversity in mixed -grass prairie. Vegetatio, 64, 87-94. Egan, Timothy. 2006. The Worst Hard Time. Houghton Mifflin Harcourt Publishing Company: New York, NY. Hart, R. and J. Hart. 1997. Rangelands of the Great Plains before European Settlement. Rangelands, 19(1), 4-11. Hart, R. 2001. Plant biodiversity on shortgrass steppe after 55 years of zero, light, moderate, or heavy cattle grazing. Plant Ecology, 155, 111-118. Heitschmidt, Rodney K., J.W. Stuth, (edited by). 1991. Grazing Management, an Ecological Perspective. Timberland Press, Portland, OR. Jackson, D. 1966. The Journals of Zebulon Montgomery Pike with letters & related documents. Univ. of Oklahoma Press, First edition: Norman, OK. Mack, Richard N., and J.N. Thompson. 1982. Evolution in Steppe with Few Large, Hooved Mammals. The American Naturalist. 119, No. 6, 757-773 Reyes -Fox, M., Stelzer H., Trlica M.J., McMaster, G.S., Andales, A.A., LeCain, D.R., and Morgan J.A. 2014. Elevated CO2 further lengthens growing season under warming conditions. Nature, April 23, 2014 issue at http://www.nature.com/nature/journal/v510/n7504 /full/nature13207.html, accessed March, 2017. Stahl, David W., E.R. Cook, M.K. Cleaveland, M.D. Therrell, D.M. Meko, H.D. Grissino-Mayer, E. Watson, and B.H. Luckman. Tree -ring data document 16th century megadrought over North America. 2000. Eos, 81(12), 121-125. The Denver Posse of Westerners. 1999. The Cherokee Trail: Bent's Old Fort to Fort Bridger. The Denver Posse of Westerners, Inc. Johnson Printing: Boulder, CO U.S. Dept. of Agriculture. 2004. Vascular plant species of the Comanche National Grasslands in southeastern Colorado. US Forest Service. Rocky Mountain Research Station. Fort Collins, CO. Zelikova, Tamara Jane, D.M. Blumenthal, D.G. Williams, L. Souza, D.R. LeCain, J.Morgan. 2014. Long-term Exposure to Elevated CO2 Enhances Plant Community Stability by Suppressing Dominant Plant Species in a Mixed -Grass Prairie. Ecology, 2014 issue at www.pnas.org/cg i/doi/10.1073/pnas.1414659111 Acknowledgments: Project Staff: Kimberly Diller, Ecological Site Specialist, NRCS MLRA, Pueblo SSO Andy Steinert, MLRA 67B Soil Survey Leader, NRCS MLRA Fort Morgan SSO Ben Berlinger, Rangeland Management Specialist, Ret. NRCS La Junta, CO Program Support: Rachel Murph, NRCS State Rangeland Management Specialist -QC, Denver, CO David Kraft, NRCS MLRA Ecological Site Specialist -QA, Emporia, KS Josh Saunders, Rangeland Management Specialist -QC, NRCS Fort Morgan, CO Patty Knupp, Biologist, Area 3, NRCS Pueblo, CO Noe Marymor, Biologist, Area 2, NRCS Greeley, CO Richard Mullaney, Resource Conservationist, Ret., NRCS, Akron, CO Chad Remley, Regional Director, N. Great Plains Soil Survey, Salina, KS B.J. Shoup, State Soil Scientist, Denver Eugene Backhaus, State Resource Conservationist, Denver Carla Green Adams, Editor, NRCS, Denver, CO Partners/Contributors: Rob Alexander, Agricultural Resources, Boulder Parks & Open Space, Boulder, CO David Augustine, Research Ecologist, Agricultural Research Service, Fort Collins, CO John Fusaro, Rangeland Management Specialist, NRCS, Fort Collins, CO Jeff Goats, Resource Soil Scientist, NRCS, Pueblo, CO Clark Harshbarger, Resource Soil Scientist, NRCS, Greeley, CO Mike Moore, Soil Scientist, NRCS MLRA Fort Morgan SSO Tom Nadgwick, Rangeland Management Specialist, NRCS, Akron CO Dan Nosal, Rangeland Management Specialist, NRCS, Franktown, CO Steve Olson, Botanist, USFS, Pueblo, CO Randy Reichert, Rangeland Specialist, ret., USFS, Nunn, CO Don Schoderbeck, Range Specialist, CSU Extension, Sterling CO Terri Schultz, The Nature Conservancy, Ft. Collins, CO 16 of 18 Chris Tecklenburg, Ecological Site Specialist, Hutchison, KS Site Authors Harvey Sprock, Ben Bellinger, Scott Woodall, James Borchert, Dave Sharman, Terri Skadeland, Dave Cook, Chuck Ring Quality Assurance Provisional Status Verfied by David Kraft (5/31/2018) Reference Sheet Author(s)/participant(s): Harvey Sprock, Daniel Nosal Contact for lead author: Harvey Sprock, Area Rangeland Management Specialist, Greeley, CO Date: 1/11/2005 MLRA: 067B Ecological Site: Sandy Plains R067BY024CO This must be verified based on soils and climate (see Ecological Site Description). Current plant community cannot be used to identify the ecological site. Composition (indicators 10 and 12) based on: X Annual Production, Foliar Cover, Biomass Indicators. For each indicator, describe the potential for the site. Where possible, (1) use numbers, (2) include expected range of values for above- and below -average years for each community and natural distrurbance regimes within the reference state, when appropriate and (3) cite data. Continue descriptions on separate sheet. 1. Number and extent of rills: None 2. Presence of water flow patterns: Typically none to slight. If present, are broken, irregular in appearance or discontinuous with numerous debris dams or vegetative barriers. 3. Number and height of erosional pedestals or terracettes: Pedestalled plants caused by wind or water erosion would be minor. 4. Bare ground from Ecological Site Description or other studies (rock, litter, standing dead, lichen, moss, plant canopy are not bare ground): 3% or less bare ground, with bare patches ranging from 3-5 inches in diameter. Prolonged drought or wildfire events will cause bare ground to increase upwards to 5-10% with bare patches ranging from 8-12 inches in diameter. 5. Number of gullies and erosion associated with gullies: None 6. Extent of wind scoured, blowouts and/or depositional areas: A minor amount of wind scouring may occur on naturally disturbed areas. Fire or extended drought can exacerbate the appearance. Typically, wind scouring should be insignificant. 7. Amount of litter movement (describe size and distance expected to travel): Litter should be uniformly distributed with little movement. On steep slopes or knolls, litter may move from a few inches to 1-2 feet depending on intensity of wind/rainfall event. 8. Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values): Stability class rating anticipated to be 3-5 in the interspaces at soil surface. 9. Soil surface structure and SOM content (include type and strength of structure, and A -horizon color and thickness): SOM ranges from 2-4%. A -horizon ranges from 0-6 inches. Soils are deep, dark brown, weak fine granular structure. 10. Effect on plant community composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff: Diverse grass, forb, shrub canopy and root structure reduces raindrop impact and slows overland flow providing increased time for infiltration to occur. Extended drought and/or wildfire may reduce canopy cover and litter amounts resulting in decreased infiltration and increased runoff on steeper slopes. 17 of 18 11. Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site): None 12. Functional/Structural Groups (list in order of descending dominance by above -ground weight using symbols: >>, >, = to indicate much greater than, greater than, and equal to) with dominants and sub -dominants and "others" on separate lines: Dominant: warm season tall rhizomatous > Sub -dominant: warm season short bunchgrass = warm season tall bunchgrass > cool season grasses/grasslikes > shrubs > warm season mid bunchgrass > Other: leguminous forbs > warm season forbs > cool season forbs Additional: 13. Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence): Minimal 14. Average percent litter cover (35-60%) and depth (.25-.50inches): Litter cover during and following drought can range from 20-30% and 5-15% following wildfire. 15. Expected annual production (this is TOTAL above -ground production, not just forage production): 800 lbs./ac. low precip years; 1650 lbs./ac. average precip years; 2200 lbs./ac. high precip years. After extended drought or the first growing season following wildfire, production may be significantly reduced by 300 - 650 lbs./ac. or more. 16. Potential invasive (including noxious) species (native and non-native). List Species which BOTH characterize degraded states and have the potential to become a dominant or co -dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicator, we are describing what is NOT expected in the reference state for the ecological site: Invasive plants should not occur in reference plant community. Following fire or extended drought, cheatgrass, Russian thistle, kochia may invade assuming a seed source is available. 17. Perennial plant reproductive capability: The only limitations are weather -related, wildfire, natural disease, and insects that may temporarily reduce reproductive capability. Reference Sheet Approval Approval Date Herman B. Garcia, State Rangeland Management Specialist 12/5/2007 r Back to Top NRCSHome USDA I Accessibility I FirstGov I Privacy Policy I Freedom of Information Act I Nondiscrimination Statement 18 of 18 USDA United States aim Department of Agrculture NRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Weld County, Colorado, Southern Part Two Rivers Ranch Ecological Site Descriptions June 26, 2019 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nres.usda. gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) 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USDA is an equal opportunity provider and employer. 3 Contents Preface 2 Soil Information for All Uses 5 Ecological Site Assessment 5 Ecological Site Information for: R067BY024CO - Sandy Plains 5 R067BY024CO - Sandy Plains— Reference Plant Community 5 Ecological Site Information for: R067BY038CO — Wet Meadow 9 R067BY038CO — Wet Meadow— Reference Plant Community 9 Ecological Site Information for: R067BY056CO - Sandstone Breaks 13 R067BY056CO - Sandstone Breaks— Reference Plant Community 13 References 17 4 Soil Information for All Uses Ecological Site Assessment Individual soil map unit components can be correlated to a particular ecological site. The Ecological Site Assessment section includes ecological site descriptions, plant growth curves, state and transition models, and selected National Plants database information. Ecological Site Information for: R067BY024CO - Sandy Plains R067BY024CO - Sandy Plains — Reference Plant Community This is the interpretive plant community and is considered to be the Reference Plant Community. This plant community evolved with grazing by large herbivores, and is well suited for grazing by domestic livestock. It can be found on areas that are properly managed with prescribed grazing that allows for adequate recovery periods following each grazing event. The potential vegetation is about 70-85% grasses and grass -like plants, 10-15% forbs, and 5-15% woody plants. The dominant tall warm season grasses are prairie sandreed, sand bluestem and switchgrass. Blue grama dominates the understory. Important cool season grasses and grass -likes are needle and thread and sun sedge. Key forbs and shrubs are American vetch, pacific peavine (manystem pea), purple prairie clover, and spreading buckwheat. This plant community is diverse, and productive. Litter is properly distributed with very little movement off -site, and natural plant mortality is very low. It is well -suited to carbon sequestration, effective water cycle, and wildlife use by many species, livestock use, and is aesthetically pleasing. Community dynamics, nutrient cycle, 5 Custom Soil Resource Report water cycle, and energy flow are functioning properly. This community is resistant to disturbances except moderate to heavy continuous grazing, tillage, and/or development into urban or other uses. Total annual production ranges from 800 to 2,200 pounds of air-dry vegetation per acre and will average 1,650 pounds during an average year. These production figures are the fluctuations expected during favorable, normal and unfavorable years due to the timing and amount of precipitation and temperature. Total annual production should not be confused with species productivity, which is annual production and variability by species throughout the extent of the community phase. 6 Custom Soil Resource Report Plant Community Tables— R067BY024CO - Sandy Plains — Reference Plant Community Plant Type Low Representative Value High Grass/Grasslike 600 1,300 1,690 Forb 150 200 255 Shrub/Vine 50 150 255 Totals 800 1,650 2,200 Grass/Grasslike Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 1:1 1155 1403 Indian ricegrass Achnatherum hymenoides 17 33 sand bluestem Andropogon hallii 83 248 Fendler threeawn Aristida purpurea var. longiseta 0 17 sideoats grama Bouteloua curtipendula 17 83 buffalograss Bouteloua dactyloides 0 17 blue grama Bouteloua gracilis 330 495 sun sedge Carex inops ssp. heliophila 17 83 prairie sandreed Calamovilfa longifolia 330 495 thickspike wheatgrass Elymus lanceolatus ssp. lanceolatus 0 83 needle and thread Hesperostipa comata ssp. comata 83 165 prairie Junegrass Koeleria macrantha 17 50 paspalum Paspalum setaceum 0 17 western wheatgrass Pascopyrum smithii 17 116 switchgrass Panicum virgatum 83 165 little bluestem Schizachyrium scoparium 17 83 Indiangrass Sorghastrum nutans 0 83 sand dropseed Sporobolus cryptandrus 17 50 7 Custom Soil Resource Report Forb Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 2: 2 165 248 Cuman ragweed Ambrosia psilostachya 0 17 tarragon Artemisia dracunculus 0 17 white sagebrush Artemisia ludoviciana 0 17 woolly locoweed Astragalus mollissimus 0 17 Texas croton Croton texensis 0 17 purple prairie clover Dalea purpurea var. purpurea 17 33 winged buckwheat Eriogonum alatum 0 17 shaggy dwarf morning-glory Evolvulus nuttallianus 0 17 hairy false goldenaster Heterotheca villosa 0 17 manystem pea Lathyrus polymorphus 17 33 dotted blazing star Liatris punctata 17 33 rush skeletonplant Lygodesmia juncea 0 17 tenpetal blazingstar Mentzelia decapetala 0 17 crownleaf evening primrose Oenothera coronopifolia 0 17 broadbeard beardtongue Penstemon angustifolius 17 33 silverleaf Indian breadroot Pediomelum argophyllum 0 17 slimflower scurfpea Psoralidium tenuiflorum 0 17 upright prairie coneflower Ratibida columnifera 17 33 scarlet globemallow Sphaeralcea coccinea 17 33 white heath aster Symphyotrichum ericoides var. ericoides 0 17 prairie spiderwort Tradescantia occidentalis 17 33 American vetch Vicia americana 17 33 8 Custom Soil Resource Report Shrub/Vine Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 3: 3 83 248 leadplant Amorpha canescens 0 50 sand sagebrush Artemisia filifolia 0 33 prairie sagewort Artemisia frigida 0 17 fourwing saltbush Atriplex canescens 0 33 spreading buckwheat Eriogonum effusum 17 33 spinystar Escobaria vivipara var. vivipara 0 17 broom snakeweed Gutierrezia sarothrae 0 17 plains pricklypear Opuntia polyacantha 0 17 western sandcherry Prunus pumila var. besseyi 0 50 soapweed yucca Yucca glauca 0 17 Growth Curve Name Warm season dominant, cool season sub -dominant; MLRA-67B; upland coarse textured soils. Growth Curve Description Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0% 0% 2% 7% 25% 35% 15% 10% 5% 1% 0% 0% Ecological Site Information for: R067BY038CO — Wet Meadow R067BY038CO — Wet Meadow — Reference Plant Community This plant community is the interpretive plant community. This community evolved with grazing by large herbivores and is well suited for grazing by domestic livestock. Historically, fires occurred infrequently. This plant community can be found on areas that receive adequate recovery periods following each grazing event during the growing season. The potential vegetation is about 85-95% grasses and grass -likes, 5-10% forbs and 1-5% woody plants. Warm -season tallgrasses dominate this community. The major grasses include big bluestem, Indiangrass, prairie cordgrass and switchgrass. Other grasses and grass - 9 Custom Soil Resource Report likes occurring in the community include western wheatgrass, Canada wildrye, mountain rush, Baltic rush, spikerushes, bulrushes and Nebraska sedge. Key forbs and shrubs include American licorice, Colorado butterfly plant, prairie gentian and false indigo bush. This plant community is diverse, stable, and productive. The high water table supplies much of the moisture for plant growth. Plant litter is properly distributed with little movement and natural plant mortality is very low. This is a sustainable plant community in terms of soil stability, watershed function and biologic integrity. Total annual production ranges from 3,500 to 5,000 pounds of air-dry vegetation per acre with a Representative Value of 4,000 pounds. 10 Custom Soil Resource Report Plant Community Tables— R067BY038CO — Wet Meadow — Reference Plant Community Plant Type Low Representative Value High Grass/Grasslike 3,310 3,600 4,370 Forb 155 280 425 Shrub/Vine 35 120 205 Totals 3,500 4,000 5,000 Grass/Grasslike Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 1 3400 3800 big bluestem Andropogon gerardii 600 1000 American sloughgrass Beckmannia syzigachne 0 40 Nebraska sedge Carex nebrascensis 200 400 Canada wildrye Elymus canadensis 80 200 slender wheatgrass Elymus trachycaulus 40 120 smooth horsetail Equisetum laevigatum 0 40 mountain rush Juncus arcticus ssp. littoralis 40 80 mountain rush Juncus arcticus ssp. littoralis 40 80 vine mesquite Panicum obtusum 0 40 western wheatgrass Pascopyrum smithii 200 400 switchgrass Panicum virgatum 600 800 bulrush Scirpus 40 80 little bluestem Schizachyrium scoparium 40 80 Indiangrass Sorghastrum nutans 600 1000 prairie cordgrass Spartina pectinata 600 1000 11 Custom Soil Resource Report Forb Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 2: Forbs 200 400 swamp milkweed Asclepias incarnata 0 40 threelobe beggarticks Bidens tripartite 0 40 false boneset Brickellia eupatorioides 0 40 carelessweed Cyclachaena xanthiifolia 0 40 showy prairie gentian Eustoma exaltatum ssp. russellianum 40 200 Colorado butterfly plant Oenothera coloradensis ssp. coloradensis 40 80 American licorice Glycyrrhiza lepidota 40 80 Maximilian sunflower Helianthus maximiliani 0 40 Colorado butterfly plant Oenothera coloradensis ssp. coloradensis 0 40 Pennsylvania smartweed Polygonum pensylvanicum 0 40 giant goldenrod Solidago gigantea 0 40 white heath aster Symphyotrichum ericoides 0 40 Shrub/Vine Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 3 40 200 desert false indigo Amorpha fruticosa 40 80 Woods' rose Rosa woodsii 0 40 western snowberry Symphoricarpos occidentalis 0 40 Growth Curve Name Warm -Season Dominant, Cool -Season Subdominant; MLRA-67B; lowland water -influenced soils Growth Curve Description Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0% 0% 2% 8% 20% 30% 20% 12% 5% 3% 0% 0% 12 Custom Soil Resource Report Ecological Site Information for: R067BY056CO - Sandstone Breaks R067BY056CO - Sandstone Breaks — Reference Plant Community This plant community is the interpretive plant community for this site. This community developed with grazing by large herbivores and is suited to grazing by domestic livestock. Historically, fires likely occurred infrequently. This plant community can be found on areas where grazed plants receive adequate periods of recovery during the growing season. The potential vegetation is about 70-90% grasses and grass -likes, 5-15% forbs and 5-15% woody plants. Mid and tallgrasses dominate this community. The principal grasses are prairie sandreed, little bluestem and sideoats grama. Secondary grasses are blue grama, switchgrass and needle and thread. Other important grasses are sand bluestem and big bluestem. Threadleaf and sun sedge are common. Dominant forbs are American vetch, dotted gayfeather, purple prairie clover and upright prairie coneflower. Key shrubs are chokecherry, skunkbush sumac, western sandcherry, golden and wax currant. Other shrubs may include hackberry, mountain mahogany, and others. Trees are occasionally present. One -seed juniper occurs in the southeastern counties. This is a sustainable plant community in terms of soil stability, watershed function and biological integrity. Litter is properly distributed where vegetative cover is continuous. Some litter movement may occur on steeper, wind-swept slopes. Decadence and natural plant mortality is very low. Community dynamics, nutrient cycle, water cycle and energy flow are functioning properly. This community is resistant to many disturbances except continuous grazing, tillage and/or development into urban or other uses. Areas having lost all vegetation, such as livestock and vehicle trails are subject to wind and water erosion. Total annual production ranges from 700 to 1600 pounds of air-dry weight with a Represenative Value of 1,100 pounds. 13 Custom Soil Resource Report Plant Community Tables— R067BY056CO - Sandstone Breaks — Reference Plant Community Plant Type Low Representative Value High Grass/Grasslike 600 880 1,260 Forb 50 110 170 Shrub/Vine 50 110 170 Tree 0 5 10 Totals 700 1,105 1,610 Grass/Grasslike Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 1 770 990 Indian ricegrass Achnatherum hymenoides 0 11 big bluestem Andropogon gerardii 22 77 sand bluestem Andropogon hallii 22 110 Fendler threeawn Aristida purpurea var. longiseta 0 11 sideoats grama Bouteloua curtipendula 55 165 blue grama Bouteloua gracilis 55 110 hairy grama Bouteloua hirsuta 0 11 threadleaf sedge Carex filifolia 11 22 sun sedge Carex inops ssp. heliophila 11 33 prairie sandreed Calamovilfa longifolia 110 165 Canada wildrye Elymus canadensis 11 22 squirreltail Elymus elymoides ssp. elymoides 0 11 thickspike wheatgrass Elymus lanceolatus ssp. lanceolatus 11 22 needle and thread Hesperostipa comata ssp. comata 22 77 prairie Junegrass Koeleria macrantha 11 22 plains muhly Muhlenbergia cuspidata 0 11 marsh muhly Muhlenbergia racemosa 0 11 ring muhly Muhlenbergia torreyi 0 11 western wheatgrass Pascopyrum smithii 11 33 switchgrass Panicum virgatum 0 55 little bluestem Schizachyrium scoparium 110 165 sand dropseed Sporobolus cryptandrus 11 22 14 Custom Soil Resource Report Forb Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 2 55 165 Cuman ragweed Ambrosia psilostachya 0 11 tarragon Artemisia dracunculus 0 11 white sagebrush Artemisia ludoviciana 0 11 woolly locoweed Astragalus mollissimus 0 11 Texas croton Croton texensis 0 11 purple prairie clover Dalea purpurea var. purpurea 11 22 annual buckwheat Eriogonum annuum 0 11 shaggy dwarf morning-glory Evolvulus nuttallianus 0 11 hairy false goldenaster Heterotheca villosa 0 11 manystem pea Lathyrus polymorphus 0 11 common starlily Leucocrinum montanum 0 11 dotted blazing star Liatris punctata 11 22 rush skeletonplant Lygodesmia juncea 0 11 lacy tansyaster Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida 0 11 tenpetal blazingstar Mentzelia decapetala 0 11 crownleaf evening primrose Oenothera coronopifolia 0 11 New Mexico groundsel Packera neomexicana var. mutabilis 0 11 broadbeard beardtongue Penstemon angustifolius 0 11 woolly plantain Plantago patagonica 0 11 slimflower scurfpea Psoralidium tenuiflorum 0 11 upright prairie coneflower Ratibida columnifera 0 11 scarlet globemallow Sphaeralcea coccinea 0 11 white heath aster Symphyotrichum ericoides 0 11 stemless four -nerve daisy Tetraneuris acaulis 0 11 stiff greenthread Thelesperma filifolium 0 11 prairie spiderwort Tradescantia occidentalis 0 11 American vetch Vicia americana 0 11 15 Custom Soil Resource Report Shrub/Vine Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 3 55 165 leadplant Amorpha canescens 0 11 prairie sagewort Artemisia frigida 0 11 fourwing saltbush Atriplex canescens 11 22 alderleaf mountain mahogany Cercocarpus montanus 0 11 common hackberry Celtis occidentalis 0 11 spreading buckwheat Eriogonum effusum 11 22 spinystar Escobaria vivipara var. vivipara 0 11 broom snakeweed Gutierrezia sarothrae 0 11 winterfat Krascheninnikovia lanata 11 22 plains pricklypear Opuntia polyacantha 0 11 littleleaf mock orange Philadelphus microphyllus 0 11 western sandcherry Prunus pumila var. besseyi 11 33 chokecherry Prunus virginiana 11 33 skunkbush sumac Rhus trilobata 0 22 golden currant Ribes aureum 11 22 wax currant Ribes cereum 11 22 soapweed yucca Yucca glauca 0 11 Tree Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 4: Tree 0 10 oneseed juniper Juniperus monosperma 0 11 Growth Curve Name Warm season dominant, cool season sub -dominant; MLRA-67B; upland coarse textured soils. Growth Curve Description Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0% 0% 2% 7% 25% 35% 15% 10% 5% 1% 0% 0% 16 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep -water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nres. usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nres. usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nres.usda.gov/wps/portal/nres/detail/soils/ home/?cid=nrcs142p2_053374 142 p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 17 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430 -VI. http://www.nrcs.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=nres142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf 18 USDA Natural Resources Conservation Service Ecological site R067BY035CO Salt Meadow Accessed: 02/24/2021 General information Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site. Wyoming Nebraska Colorad❑ Kansas Figure 1. Mapped extent Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated. MLRA notes Major Land Resource Area (MLRA): 067B —Central High Plains, Southern Part MLRA 67B -Central High Plains, Southern Part is located in eastern Colorado. It is comprised of rolling plains and river valleys. Some canyonlands occur in the southeast portion. The major rivers are the South Platte and Arkansas which flow from the Rocky Mountains to Nebraska and Kansas. Other rivers in the MLRA include the Cache la Poudre and Republican. The rivers have many tributaries. This ecological site is traversed by 1-25, 1-70 and 1-76, and U.S. Highways 50 and 287. Major land uses include 54% rangeland, 35% cropland, and 2% pasture and hayland. Urban and developed open space, and miscellaneous land occupy approximately 9% of the remainder. Cities in this area include Fort Collins, Greeley, Sterling, and Denver. Other cities include Limon, Cheyenne Wells, and Springfield. Land ownership is mostly private. Federal lands include Pawnee and Comanche National Grasslands (U.S. Forest Service), Sand Creek Massacre National Historic Site (National Park Service), and Rocky Mountain Arsenal National Wildlife Refuge (U.S. Fish & Wildlife Service). State Parks include Cherry Creek and Chatfield Reservoirs, and Barr and Jackson Lakes. This region is periodically affected by severe drought, including the historic "Dust Bowl" of the 1930s. Dust storms may form during drought years, in windy periods. Elevations range from 3,400 to 6,000 feet. The Average annual precipitation ranges from 14-17 inches per year, and ranges from 13 inches to over 18 inches, depending on location. Precipitation occurs mostly during the growing season, often during rapidly developing thunderstorms. Mean annual air temperature (MAAT) is 48-52°F. Summer temperatures may exceed 100°F. Winter temperatures may be sub -zero, and snowfall varies from 20-40 inches per year. Snow cover frequently melts between snow events. Classification relationships MLRA 67B is in the Colorado Piedmont and Raton Sections of the Great Plains Province (USDA, 2006). The MLRA is further defined by LRUs A, B, and C. Features such as climate, geology, landforms, and key vegetation further refine these LRU concepts, and are described in other sections of the Ecological Site Description (ESD). NOTE: To date, these LRU's are DRAFT. LRU A is the northeast portion of MLRA 67B, to an extent of approximately 9.0 million acres. Most of the LRU is rangeland, and includes the Pawnee National Grassland, managed by the U.S. Forest Service. Dryland winter wheat/fallow rotations (that may include dryland corn, sunflowers, and/or sorghum) are grown in most counties. Irrigated cropland is utilized in the South Platte Valley. Small acreage and urban ownership are more concentrated on the Front Range. This LRU is found in portions of Adams, Arapahoe, Elbert, Kit Carson, Larimer, Lincoln, Logan, Washington, and Weld counties. Other counties include Boulder, Cheyenne, Denver, Jefferson, and Yuma. The soil moisture regime is Aridic Ustic. The mean annual air temperature (MAAT) is 50° F. LRU B is in the southeast portion of MLRA 67B (2.6 million acres) and include portions of Baca, Bent, Cheyenne, Kiowa, Las Animas, and Prowers Counties. Most of the LRU remains agricultural. Most of LRU B is rangeland and includes the Comanche National Grassland. Dryland winter wheat/fallow rotations (that may include dryland corn, sunflowers, and/or sorghum) are grown. Irrigated cropland is used in the Arkansas Valley. The soil moisture regime is Aridic Ustic and the MAAT is 52°F. LRU C occurs in portions of Morgan and Weld counties (approximately 1.2 million acres). Most of LRU C is in rangeland. Dryland winter wheat/fallow rotations (that may include dryland corn, sunflowers, and/or sorghum) are grown. The soil moisture regime is Ustic Aridic and the MAAT is 48°F. REVISION NOTES: The Salt Meadow site was developed by an earlier version of the Salt Meadow ESD (2004, revised 2007). This earlier version of the Salt Meadow ESD (2004) was based on input from NRCS (formerly Soil Conservation service) and historical information obtained from the Siltstone Plains range site descriptions (1975). This ESD meets the Provisional requirements of the National Ecological Site Handbook (NESH). This ESD will continue refinement towards an Approved status according to the NESH. Ecological site concept This site occurs on nearly level floodplains. Primary grasses are warm -season mid/tall bunchgrass and cool -season mid rhizomatous grass with secondary warm -season tall rhizomatous grass and grasslike plants. Forbs and shrubs are a minor component. Associated sites R067BY031CO Sandy Bottomland Sandy Bottomland R067BY033CO Salt Flat Salt Flat R067BY038CO Wet Meadow Wet Meadow Similar sites R067BY033CO Salt Flat The Salt Flat site lacks water table and tall grass species with less overall production. R067BY038CO Wet Meadow The Wet Meadow site lacks alkali species (inland saltgrass, alkali sacaton) and has greater overall production. Table 1. Dominant plant species Tree Not specified Shrub Not specified Herbaceous (1) Sporobolus airoides (2) Panicum virgatum Physiographic features This site occurs on nearly level floodplains and terraces adjacent to streams and rivers. It is also found on drainageways associated with intermittent and perennial streams. There is an influential water table associated with this site. Table 2. Representative physiographic features Landforms (1) Flood plain (2) Drainageway (3) Terrace Flooding duration Very brief (4 to 48 hours) to brief (2 to 7 days) Flooding frequency None to frequent Ponding frequency None Elevation 3,600-5,600 ft Slope 0-3% Ponding depth 0 in Water table depth 12-48 in Aspect Aspect is not a significant factor Climatic features Average annual precipitation across the MLRA extent is 14 to 17 inches, and ranges from 13 inches to over 18 inches, depending on location. The average is 15 inches. Precipitation increases from north to south. Mean Annual Air Temperature (MAAT) is 50°F in the northern part and increases to 52°F in the southern part. Portions of Morgan and Weld counties (in the northern part) are cooler and drier, the MAAT is 48°F, and average precipitation is 13 to14 inches per year. Two-thirds of the annual precipitation occurs during the growing season from mid -April to late September. Snowfall averages 30 inches per year, area -wide, but varies by location from 20 to 40 inches per year. Winds are estimated to average 9 miles per hour annually. Daytime winds are generally stronger than at night, and occasional strong storms may bring periods of high winds with gusts to more than 90 mph. High -intensity afternoon thunderstorms may arise. The average length of the freeze -free period (28°F) is 155 days from April 30th to October to 3rd. The average frost -free period (32°F) is 136 days from May 11th to September 24th. July is the hottest month, and December and January are the coldest months. Summer temperatures average 90°F and occasionally exceed 100°F. Summer humidity is low and evaporation is high. Winters are characterized with frequent northerly winds, producing severe cold with temperatures occasionally dropping to -30°F or lower. Blizzard conditions may form quickly. For detailed information, visit the Western Regional Climate Center website: Western Regional Climate Center>Historical Data>Western U.S. Climate summaries, NOAA Coop Stations>Colorado http://www.wrcc.dri.edu/summary/Climsmco.html Eastern Colorado was strongly affected by extended drought conditions in the "Dust Bowl" period of the 1930's, with recurrent drought cycles in the 1950s and 1970s. Extreme to exceptional drought conditions have re -visited the area from 2002 to 2012, with brief interludes of near normal to normal precipitation years. Long-term effects of these latest drought events have yet to be determined. Growth of native cool -season plants begin about April 1 and continue to mid -June. Native warm -season plants begin growth about May 1 and continue to about August 15. Regrowth of cool -season plants occur in September in most years, depending on moisture. Note: The climate described here is based on historic climate station data in the past 30 to 50 years, and is averaged to provide an overview of annual precipitation, temperatures, and growing season. Future climate is beyond the scope of this document. However, research to determine the effects of elevated CO2 and/or heating on mixed -grass prairie ecosystems, and how it may relate to future plant communities (i.e. potential shifts in dominant and sub -dominant groups, changes in growing season length, responses of cool -season and warm -season grasses, etc.) is on -going. Table 3. Representative climatic features Frost -free period (average) 129 days Freeze -free period (average) 150 days Precipitation total (average) 16 in Climate stations used • (1) BRIGGSDALE [USC00050945], Briggsdale, CO • (2) NUNN [USC00056023], Nunn, CO • (3) CHEYENNE WELLS [USC00051564], Cheyenne Wells, CO • (4) FLAGLER 1S [USC00052932], Flagler, CO • (5) FT MORGAN [USC00053038], Fort Morgan, CO • (6) KIT CARSON [USC00054603], Kit Carson, CO • (7) SPRINGFIELD 7 WSW [USC00057866], Springfield, CO • (8) BRIGHTON 3 SE [USC00050950], Brighton, CO • (9) BYERS 5 ENE [USC00051179], Byers, CO • (10) GREELEY UNC [USC00053553], Greeley, CO • (11) LIMON WSMO [USW00093010], Limon, CO Influencing water features There is a seasonal water table that influences the kinds and amounts of vegetation on this site. The water table in some areas is anthropogenic, caused by seepage from nearby irrigation ditches, canals, and/or reservoirs. Wetland Description (Cowardin System) System Subsystem Class Palustrine N/A Emergent Wetland Note: This is not a wetland determination. Soil features The soils on this site are very deep, poorly to somewhat poorly drained soils that formed from alluvium. They typically have a slow to moderately rapid permeability class. The available water capacity is typically low, but ranges to moderate. Available water is the portion of water in a soil that can be readily absorbed by plant roots. This is the amount of water released between the field capacity and the permanent wilting point. As fineness of texture increases, there is a general increase in available moisture storage from sands to loams and silt loams. The high levels of salts decreases the available water capacity in these soils. The soil moisture regime is typically aquic, but may include oxyaquic. The soil temperature regime is mesic. The surface layer of the soils in this site are typically loam, clay loam, or fine sandy loam, but may include clay or sandy loam. The surface layer ranges from 4 to 10 inches thick. The subsoil is typically clay, clay loam, or loam, but may include stratified layers with sandy loam, sand, or coarse sand with varying amounts of rock fragments. Rock fragments range from 0 to 35 percent in the underlying material. Soils in this site typically have free carbonates at the surface, but some soils may be leached from 4 to 10 inches. These soils are saline and alkaline. The high levels of salinity adversely affects plant species composition and growth. These soils are susceptible to erosion by water and wind. Surface soil structure is typically granular, and structure below the surface is subangular blocky, but may include massive or single -grain. Soil structure describes the manner in which soil particles are aggregated and defines the nature of the system of pores and channels in a soil. Together, soil texture and structure help determine the ability of the soil to hold and conduct the water and air necessary for sustaining life. Major soil series correlated to this ecological site include: Apishapa, Las (saline), Loveland, and Wann (saline) Other soil series that have been correlated to this site, but may eventually be re -correlated include: Aida variant, Aquolls, Fluvaquents, Las, Nunn (wet), Nunn (water table), Wann, Heldt (saline), and Limon (saline) *Feature listed in "( )" relates to the salt content or the wetness of the soil. The attributes listed below represent 0-40 inches in depth or to the first restrictive layer. Note: Revisions to soil surveys are on -going. For the most recent updates, visit the Web Soil Survey, the official site for soils information: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx. The attributes listed below represent 0-40 inches in depth or to the first restrictive layer. Table 4. Representative soil features Surface texture (1) Loam (2) Clay loam (3) Fine sandy loam Drainage class Poorly drained to somewhat poorly drained Permeability class Slow to moderate Soil depth 80 in Surface fragment cover <=3" 0% Surface fragment cover >3" 0% Available water capacity (0-40in) ) 3-6.5 in Calcium carbonate equivalent (0-40in) ) 0-10% Electrical conductivity (0-40in) ) 2-16 mmhos/cm Sodium adsorption ratio (0-40in) ) 5-30 Soil reaction (1:1 water) (0-40in) ) 7.4-9 Subsurface fragment volume <=3" (Depth not specified) 0-35% Subsurface fragment volume >3" (Depth not specified) 0% Ecological dynamics The information in this ESD, including the state -and -transition model diagram (STM), was developed using archeological and historical data, professional experience, and scientific studies. The information is representative of a dynamic set of plant communities that represent the complex interaction of several ecological processes. The plant composition has been determined by study of rangeland relic areas, areas protected from excessive disturbance, seasonal use pastures, short duration/time controlled grazing strategies, and historical accounts. The Salt Meadow Ecological Site is characterized by three states: Reference, Warm -Season Shortgrass, and Increased Bare Ground State. The Reference State is characterized by warm -season bunchgrass (alkali sacaton, switchgrass), cool -season midgrass (western wheatgrass), warm -season tall rhizomatous grass, and a minor component of cool -season grasslike (Nebraska sedge). The Warm -Season Shortgrass State is characterized by a warm -season short rhizomatous grass (inland saltgrass). The Increased Bare Ground State is characterized by early successional cool -season grass (foxtail barley), annual grasses, and annual forbs. The site has a high water table throughout the growing season. The availability of water has a major influence on the vegetation that will persist on this site. This region was historically occupied by large grazing animals such as bison and elk, along with pronghorn and mule deer. Grazing by these large herbivores, along with climatic fluctuations, had a major influence on the ecological dynamics of this site. Deer and pronghorn are widely distributed throughout the MLRA. Secondary influences of herbivory by species such as prairie dogs and other small rodents, insects and root feeding organisms has impacted the vegetation and continues today. Historically, it is believed, due to the migratory nature of large ungulates, herbivory consisted of very short grazing events followed by long rest/recovery periods lasting several months or longer. These migrating herds significantly impacted the ecological processes of nutrient and hydrologic cycles. Herd behavior and movements were likely affected by water and forage availability, fire, drought, and predators. Recurrent drought has historically impacted the vegetation of this region. Changes in species composition will vary depending upon the duration and severity of the drought cycle, and prior grazing management. Recent drought events have significantly increased mortality of blue grama in some locales. Tillage or any type of mechanical treatment is not recommended on this site due to the salt content of the soils and the presence of a high water table. Disturbance of any kind will cause Inland saltgrass to increase. Irrigation (pumping) or drainage will cause water table levels to drop. Persistent water table alteration or drainage causes a complete alteration and/or disruption of the hydrologic function and biotic integrity resulting in the crossing of an ecological threshold and the replacement of the natural states and plant communities applicable to the site. This site developed with occasional fire as part of the ecological processes. Historic fire frequency (pre -industrial), is estimated at 10-14 years (Guyette 2012), randomly distributed, and started by lightning at various times throughout the growing season. It is thought that early human inhabitants also were likely to start fires for various reasons (deliberate or accidental). It is believed that fires were set as a management tool for attracting herds of large migratory herbivores (Stewart, 2002). The impact of fire over the past 100 years has been relatively insignificant due to the human control of wildfires and the lack of acceptance of prescribed fire as a management tool. Today, this is an important site for livestock grazing, especially beef cattle. Today the management of livestock grazing by humans has been a major influence on the ecological dynamics of the site. This management, coupled with the effects of annual climatic variations, largely dictates the plant communities for the site. Continuous grazing without adequate recovery opportunity following each grazing occurrence will cause prairie cordgrass, switchgrass, alkali sacaton and eventually western wheatgrass to decrease in frequency and production while inland saltgrass and Baltic rush increase. In time, the plant community will become dominated by inland saltgrass and develop into a sodbound condition with alkali sacaton and western wheatgrass persisting in remnant amounts. Heavy continuous grazing will ultimately result in a plant community dominated by foxtail barley, annual invaders and increased bare ground. Excessive litter, plant mortality and decadence can result from the lack of fire and/or non-use. The following diagram illustrates the common plant communities that can occur on the Salt Meadow site and the community pathways (CP) among plant communities. Plant Communities are identified by 1.1, 1.2 etc. and are described in the narrative. Bold lines surrounding each state represent ecological thresholds. Transitions (T) indicate the transition across an ecological threshold to another state. Once a threshold has been crossed into another state, it may not be feasible to return to the original state, even with significant management inputs and practices. The ecological processes plant communities, community pathways, transition and/or restoration pathways will be discussed in more detail in the plant community descriptions following the diagram. State and transition model Ecosystem states 1. Reference State 1.2 to 2 2 to 3 3. Increased Bare Ground State 2. Warm -Season Shortgrass State State 1 submodel, plant communities 1.1. Reference Plant Community 1.3. Excessive Litter Plant Community 1.1 to 1.2 1.2 to 1.1 1.2. At -Risk Plant Community State 2 submodel, plant communities 2.1. Warm -Season Shortgrass Plant Community State 3 submodel, plant communities 3.1. Increased Bare Ground Plant Community State 1 Reference State The Reference State is characterized by three distinct plant community phases: Reference, At -Risk, and Excessive Litter Plant Community. The plant communities, and various successional stages between them, represent the natural range of variability within the Reference State. Community 1.1 Reference Plant Community This plant community is the interpretive plant community for this site. This community evolved with grazing by large herbivores and is well suited for grazing by domestic livestock. Historically, fires occurred infrequently. This plant community can be found on areas that are grazed and where the grazed plants receive adequate periods of recovery during the growing season. The potential vegetation is about 80-95% grasses and grass -likes, 3-10% forbs and 2-10% woody plants. The community is dominated by tall and mid warm and cool -season grasses. Major grasses include alkali sacaton, switchgrass, prairie cordgrass and western wheatgrass. Other grasses and grass -likes occurring on the community include big bluestem, little bluestem, alkali cordgrass, Nebraska sedge, and Baltic rush. Key forbs and shrubs include American licorice, prairie gentian, rag sumpweed, and fourwing saltbush. The high water table supplies much of the moisture for plant growth. Plant litter is properly distributed with little movement and natural plant mortality is very low. This is a sustainable plant community in terms of soil stability, watershed function and biologic integrity. Total annual production ranges from 2,000 to 4,000 pounds of air-dry vegetation per acre with a Representative Value of 3,000 pounds. Table 5. Annual production by plant type Plant Type Low (Lb/Acre) Representative Value (Lb/Acre) High (Lb/Acre) Grass/Grasslike 1860 2625 3350 Shrub/Vine 55 180 325 Forb 85 195 325 Total 2000 3000 4000 Figure 7. Plant community growth curve (percent production by month). C06713, Warm -Season Dominant, Cool -Season Subdominant; MLRA-67B; lowland water -influenced soils. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 2 8 20 30 20 12 5 3 0 0 Community 1.2 At -Risk Plant Community This plant community developed with continuous grazing without adequate recovery opportunity between grazing events. Inland saltgrass has increased. Alkali sacaton, prairie cordgrass, switchgrass, Indiangrass, little bluestem, Canada wild rye and Nebraska sedge have decreased. Western wheatgrass may initially increase or decrease depending upon the season of use. Forbs and shrubs are still present in reduced amounts. This plant community is at risk of losing warm -season tall grasses, palatable forbs and shrubs. This community has decreased in plant frequency and production. Less litter can be expected however, the soil remains stable and can become very resistant to change depending on the degree to which the inland saltgrass has increased. Total annual production, during a normal year, ranges from 1,000 to 2,000 pounds per acre air-dry weight and will average 1,500 pounds. Figure 8. Plant community growth curve (percent production by month). C06713, Warm -Season Dominant, Cool -Season Subdominant; MLRA-67B; lowland water -influenced soils. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 2 8 20 30 20 12 5 3 0 0 Community 1.3 Excessive Litter Plant Community This plant community developed under the absence of grazing, fire and/or haying. The dominant plants are similar to those found in the Reference Plant Community. Plant density has been reduced. Grazing, haying or fire followed by prescribed grazing can quickly move this plant community back toward the Reference Plant Community. Much of the nutrients are tied up in excessive litter. Some organic matter oxidizes in the air rather than being incorporated into the soil due to the absence of animal impact. Increased litter levels and standing dead canopy prevent sunlight from reaching plant crowns and in time can stagnate the plant community. Bunchgrasses such as alkali sacaton, little bluestem and switchgrass have a tendency to exhibit dead centers and eventually entire plants can die off. Total annual production can vary substantially from 800 to 3,000 pounds of air-dry vegetation per acre depending on how long this plant community has developed in the absence of haying, grazing or fire. Figure 9. Plant community growth curve (percent production by month). C06715, Warm season/cool season co -dominant, excess litter; MLRA-67B; lowland water influenced soils.. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 1 7 20 35 20 10 5 2 0 0 Pathway 1.1 to 1.2 Community 1.1 to 1.2 Continuous grazing without adequate recovery opportunity between grazing events, and/or drought, shifts this plant community toward the At -Risk Plant Community. Recurring spring seasonal grazing will decrease cool -season plants. Recurring summer grazing will decrease warm - season plants and tend to increase cool -season plants over time. Biotic integrity will be altered and water & nutrient cycles may become impaired as a result of this community pathway. Pathway 1.1 to 1.3 Community 1.1 to 1.3 Non-use and/or lack of fire will cause the Reference Plant Community to shift toward the Excessive Litter Plant Community. Plant decadence and standing dead plant material will impede energy flow. Water and nutrient cycles will be impaired as a result of this community pathway. Pathway 1.2 to 1.1 Community 1.2 to 1.1 Grazing that allows for adequate recovery opportunity between grazing events, and proper stocking, will shift the At - Risk Plant community back toward the Reference Plant Community. Pathway 1.3 to 1.1 Community 1.3 to 1.1 The return of grazing with adequate recovery opportunity and/or normal fire frequency will cause a community pathway back toward the Reference Plant Community. This change can occur in a relatively short time frame with the return of these disturbances. State 2 Warm -Season Shortgrass State This state is characterized by the Warm -Season Shortgrass Plant Community. An ecological threshold has been crossed and a significant amount of production and diversity has been lost when compared to the Reference State. Significant biotic and edaphic (soil characteristics) changes have negatively impacted energy flow and nutrient and hydrologic cycles. This is a very stable state, resistant to change due to the high tolerance of inland saltgrass to grazing, the development of a shallow root system (aka root pan), and subsequent changes in hydrology and nutrient cycling. The loss of functional/structural groups such as warm -season mid/tallgrass, and cool/warm-season rhizomatous grass reduces the biodiversity and productivity of this site. Community 2.1 Warm -Season Shortgrass Plant Community This plant community develops under continuous grazing without adequate recovery opportunity between grazing events. The plant community exhibits a dense sod made up of primarily inland saltgrass. Remnant amounts of western wheatgrass and/or alkali sacaton may still be present. Tall grasses (prairie cordgrass, big bluestem, Indiangrass, switchgrass) as well as little bluestem, Nebraska sedge and fourwing saltbush have been removed. Scratchgrass (alkali muhly), foxtail barley, Baltic rush, and Kentucky bluegrass may be increasing or invading. This community remains stable but has lost much of its production and diversity. This plant community is extremely resistant to change because of the aggressive rhizomatous growth habit of inland saltgrass. Nutrient cycle is impaired due to the loss of tallgrass species, deep-rooted forbs (legumes and others) and shrubs. Desertification is advanced. Total annual production, during a normal year, ranges from 800 to 1,500 pounds per acre air-dry weight and will average 950 pounds. Figure 10. Plant community growth curve (percent production by month). CO6718, Warm -Season Dominant; MLRA-67B; lowland water -influenced soils. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 0 5 15 40 23 12 3 2 0 0 State 3 Increased Bare Ground State The Increased Bare Ground State develops with heavy continuous grazing, or excessive defoliation. An ecological threshold has been crossed. Erosion and loss of organic matter/carbon reserves are concerns. Nutrient and water cycles and energy flow are impaired. Community 3.1 Increased Bare Ground Plant Community This plant community develops under continuous and heavily grazed conditions, especially through the growing season. The plant composition is made up of foxtail barley, annuals and scattered areas of inland saltgrass and Baltic rush. Annuals such as Russian thistle, kochia and cocklebur have invaded the community. Kentucky bluegrass has invaded and may persist in localized areas. Compared to the Reference Plant Community, all perennial plants have been greatly reduced with only remnants of the most grazing tolerant species surviving. Plant diversity and production are very low. Planned rest periods during the growing season will improve the vigor of the plant species present. In southeastern Colorado, tamarisk may invade this plant community from an adjacent riparian area, along the Arkansas River and its tributaries. Bare ground may be enhanced by the tamarisk's presence. Wind and water erosion may occur at low amounts. Litter amounts are low. Mineral crusting caused by raindrop impact disrupts surface soil aggregates, increasing ponding and slowing infiltration. Compaction, if severe enough, can negatively affect water infiltration. Carbon storage/nutrient cycling has been greatly reduced. Animal wastes can contaminate ground water or runoff. Desertification is obvious. Total annual production, during a normal year, ranges from 50 to 400 pounds per acre air-dry weight. Figure 11. Plant community growth curve (percent production by month). C06714, Cool -Season Dominant, Warm -Season Subdominant; MLRA-67B; lowland water -influenced soils. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 2 7 25 40 15 7 3 1 0 0 Transition 1.2 to 2 State 1 to 2 Heavy continuous grazing without adequate recovery opportunity between grazing events will shift this plant community across an ecological threshold toward the Warm -Season Shortgrass State. Biotic integrity and hydrologic function will be impaired as a result of this transition. Transition 2 to 3 State 2 to 3 Heavy continuous grazing without adequate recovery opportunity between grazing events, or excessive defoliation, will cause a shift across an ecological threshold to the Increase Bare Ground State. Erosion, loss of organic matter/carbon reserves and flooding are concerns. Non-native exotic plants such as field bindweed and knapweeds are likely to invade. Additional community tables Table 6. Community 1.1 plant community composition Group Common Name Symbol Scientific Name Annual Production (Lb/Acre) Foliar Cover (%) Grass/Grasslike 1 2400-2850 alkali sacaton SPAI Sporobolus airoides 900-1050 — western wheatgrass PASM Pascopyrum smithii 450-690 — switchgrass PAVI2 Panicum virgatum 450-600 — prairie cordgrass SPPE Spartina pectinata 300-600 - Sandberg bluegrass POSE Poa secunda 90-300 — big bluestem ANGE Andropogon gerardii 90-210 — Canada wildrye ELCA4 Elymus canadensis 30-150 — Grass, perennial 2GP Grass, perennial 60-150 — alkali cordgrass SPGR Spartina gracilis 30-150 — little bluestem SCSC Schizachyrium scoparium 30-150 — Indiangrass SON U2 Sorghastrum nutans 0-150 — Nuttall's alkaligrass PUNU2 Puccinellia nuttalliana 30-90 — mountain rush JUARL Juncus arcticus ssp. littoralis 30-90 — slender wheatgrass ELTR7 Elymus trachycaulus 30-90 — Nebraska sedge CAN E2 Carex nebrascensis 30-90 — saltgrass DISP Distichlis spicata 30-90 — Grass -like, perennial 2GLP Grass -like, perennial 60-90 — vine mesquite PAOB Panicum obtusum 0-60 — marsh muhly MURA Muhlenbergia racemosa 0-30 — foxtail barley HOJU Hordeum jubatum 0-30 — Forb 2 90-300 American licorice GLLE3 Glycyrrhiza lepidota 30-150 — Forb, perennial 2FP Forb, perennial 30-150 — showy prairie gentian EUEXR Eustoma exaltatum ssp. russellianum 0-60 — leafy false goldenweed OOFOF Oonopsis foliosa var. foliosa 0-30 — Illinois bundleflower DEIL Desmanthus illinoensis 0-30 — false boneset BREU Brickellia eupatorioides 0-30 - Shrub/Vine 3 60-300 fourwing saltbush ATCA2 Atriplex canescens 0-150 - Shrub (>.5m) 2SHRUB Shrub (>.5m) 30-90 — rubber rabbitbrush ERNAN5 Ericameria nauseosa ssp. nauseosa var. nauseosa 30-60 — Animal community WILDLIFE INTERPRETATIONS: Salt Meadow sites support a unique suite of wildlife species due to their association with river and stream systems. Riparian corridors generally represent areas of increased biodiversity compared to adjacent upland sites, and these sites often occur in those riparian systems. Salt meadows provide habitat components for white-tailed and mule deer, wild turkey and bobwhite quail. These areas can also have increased diversity of herpetile species. 1. Reference Plant Community The Reference Plant Community provides important habitat components for white-tailed and mule deer, including foraging, bedding and fawning areas, especially when a healthy shrub component of snowberry is present. Wild turkey hens will use shrubs in this community for nesting and brood -rearing, but turkey use these sites incidentally the rest of the year. The taller grasses, especially switchgrass and prairie cordgrass, provide important nesting habitats for northern bobwhite quail, and snowberry provides the highest quality loafing and escape habitat for this species on this site. Plains and common garter snakes may be found in this plant community, especially if low areas with seasonal water are present. 2. At -Risk Plant Community The At -Risk Plant Community has reduced tall grasses and shrubs which degrade the overall quality of the site for wildlife. White-tailed and mule deer may move through this community and feed to some extent, but with reduced cover the value for bedding and fawning is also reduced. Northern bobwhite quail use of this community is reduced as well as the tall grass and shrub component declines. Quail will be absent from sites where these components are entirely absent. 3. Excessive Litter Plant Community The excessive plant litter community has greatly reduced value for wildlife due to the loss of tall grasses, reduced abundance of shrubs. White-tailed and mule deer may move through this community and feed to some extent, but with reduced cover the value for bedding and fawning is also reduced. Northern bobwhite quail use of this community is reduced as the tall grass and shrub component declines and because the litter layer is too thick and dense for quail to walk through. 4. Warm -Season Shortgrass Community The Warm -Season Shortgrass Community on this site represents the lowest amount of wildlife diversity as well. White-tailed and mule deer may move through this community but spend little time feeding or bedding. Wild turkey may use the edges of these meadows in the spring for breeding displays but nesting and brood -rearing value has been lost. If this plant community is adequately grazed during the summer and the pasture is of sufficient size, Canada geese and snow geese will graze on the new inland saltgrass regrowth during the spring, fall and winter. 5. Increased Bare Ground Community Due to the greatly reduced plant diversity of this site and impairment to nutrient cycling and water infiltration processes, the wildlife community that uses this site is also greatly reduced. GRAZING INTERPRETATIONS: The following table lists suggested initial stocking rates for an animal unit (1,000 pound beef cow) under continuous grazing (year -long grazing or growing season long grazing) based on normal growing conditions. However, continuous grazing is not recommended. These estimates should only be used as preliminary guidelines in the initial stages of the conservation planning process. Often, the existing plant composition does not entirely match any particular plant community described in this ecological site description. Therefore, field inventories are always recommended to document plant composition, total production, and palatable forage production. Carrying capacity estimates that reflect on -site conditions should be calculated using field inventories. If the following production estimates are used, they should be adjusted based on animal kind/class and on the specific palatability of the forage plants in the various plant community descriptions. Under a properly stocked, properly applied, prescribed grazing management system that provides adequate recovery periods following each grazing event, improved harvest efficiencies will eventually result in increased carrying capacity. See USDA -N RCS Colorado Prescribed Grazing Standard and Specification Guide (528). The stocking rate calculations are based on the total annual forage production in a normal year multiplied by 25% harvest efficiency divided by 912.5 pounds of ingested air-dry vegetation for an animal unit per month. Plant Community (PC) Production (lbs./acre) and Stocking Rate (AUM/acre) Reference PC - (3000) (0.82) At -Risk PC - (1500) (0.41) Warm -Season Shortgrass PC - (950) (0.26) Excessive Litter PC - (*) (*) Increased Bare Ground PC - (*) (*) Grazing by domestic livestock is one of the major income -producing industries in the area. Rangelands in this area provide yearlong forage under prescribed grazing for cattle, sheep, horses and other herbivores. * Highly variable; stocking rate needs to be determined on site. Hydrological functions Water is the principal factor limiting forage production on this site. This site is dominated by soils in hydrologic group C and D. Infiltration is moderate and runoff potential for this site varies from moderate to high depending on ground cover. Areas where ground cover is less than 50% have the greatest potential to have reduced infiltration and higher runoff (refer to NRCS Section 4, National Engineering Handbook (NEH-4) for runoff quantities and hydrologic curves). Recreational uses This site provides hunting, hiking, photography, bird watching and other opportunities. The wide varieties of plants that bloom from spring until fall have an esthetic value that appeals to visitors. Wood products No appreciable wood products are present on the site. Other products Site Development & Testing Plan General Data (MLRA and Revision Notes, Hierarchical Classification, Ecological Site Concept, Physiographic, Climate, and Water Features, and Soils Data): Updated, All "Required" items complete to Provisional level Community Phase Data (Ecological Dynamics, STM, Transition & Recovery Pathways, Reference Plant Community, Species Composition List, Annual Production Table): Updated. All "Required" items complete to Provisional "+" level. NOTE: Annual Production Table is from the "Previously Approved" ESD (2004). The Species Composition List is also from the 2004 version. These will need review for future updates at Approved level. Each Alternative State/Community Complete to Provisional level Supporting Information (Site Interpretations, Assoc. & Similar Sites, Inventory Data References, Agency/State Correlation, References) Updated. All "Required" items complete to Provisional level. Livestock Interpretations updated to reflect Total Annual Production revisions in each plant community (Provisional Wildlife Interpretations general narrative, and individual plant communities updated (Provisional "+"). Hydrology, Recreational Uses, Wood Products, Other Products, and Plant Preferences table, carried over from previously "Approved" ESD (2004). There are few existing NRI or 417 Inventories for this site. More field data collection is needed to support this site concept. Reference Sheet Rangeland Health Reference Sheet carried over from previously "Approved" ESD (2004). The current Reference Sheet was previously approved in 2007. It will be updated at the next "Approved" level. "Future work, as described in a project plan, to validate the information in this provisional ecological site description is needed. This will include field activities to collect low and medium intensity sampling, soil correlations, and analysis of that data. Annual field reviews should be done by soil scientists and vegetation specialists. A final field review, peer review, quality control, and quality assurance reviews of the ESD will be needed to produce the final document." (NI 430_306 ESI and ESD, April, 2015) Other information Relationship to Other Hierarchical Classifications: NRCS Classification Hierarchy: Physiographic Divisions of the United States (Fenneman, 1946): Physiographic Division>Physiographic Province>Physiographic Section>Land Resource Region>Major Land Resource Area (MLRA)>Land Resource Unit (LRU). USFS Classification Hierarchy: National Hierarchical Framework of Ecological Units (Cleland et al, 181-200): Domain>Division>Province>Section>Subsection>Landtype Association>Landtype>Landtype Phase. Inventory data references Information presented here has been derived from NRCS clipping data, numerous ocular estimates and other inventory data. Field observations from experienced range trained personnel were used extensively to develop this ecological site description. Specific data information is contained in individual landowner/user case files and other files located in county NRCS field offices. Those involved in developing the 2004 site description include: Harvey Sprock, Rangeland Management Specialist, CO -N RCS; Ben Berlinger, Rangeland Management Specialist, CO -N RCS; James Borchert, Soil Scientist, CO- NRCS; Terri Skadeland, Biologist, CO-NRCS. Other references Data collection for this ecological site was done in conjunction with the progressive soil surveys within the 67B Central High Plains (Southern Part) of Colorado. It has been mapped and correlated with soils in the following soil surveys: Adams County, Arapahoe County, Baca County, Bent County, Boulder County, Cheyenne County, El Paso County Area, Elbert County, Eastern Part, Kiowa County, Kit Carson County, Larimer County Area, Las Animas County Area, Lincoln County, Logan County, Morgan County, Prowers County, Washington County, Weld County, Northern Part, and Weld County, Southern Part. Agricultural Applied Climate Information system (AgACIS), powered by ACIS NOAA Regional Climate Centers, Frost/Freeze dates (1971-2000) http://agacis.rcc-acis.org Accessed February, 2017 Andrews, R. and R. Righter. 1992. Colorado Birds. Denver Museum of Natural History, Denver, CO. 442 Armstrong, D.M. 1972. Distribution of mammals in Colorado. Univ. Kansas Museum Natural History Monograph #3. 415. Butler, LD., J.B. Cropper, R.H. Johnson, A.J. Norman, G.L. Peacock, P.L. Shaver and K.E. Spaeth. 1997, revised 2003. National Range and Pasture Handbook. National Cartography and Geospatial Center's Technical Publishing Team: Fort Worth, TX. http://www.glti.nres.usda.gov/technical/publications/nrph.html Accessed August 2015 Cleland, D., P. Avers, W.H. McNab, M. Jensen, R. Bailey, T. King, and W. Russell. 1997. National Hierarchical Framework of Ecological Units, published in Ecosystem Management: Applications for Sustainable Forest and Wildlife Resources, Yale University Press Colorado Climate Center Monthly Data Access (1981-2010) Total Monthly Precipitation http://ccc.atmos.colostate.edu/cgi-bin/monthlydata.pl Accessed February, 2017 Colorado Parks & Wildlife. Grassland Species Plan (2003) http://cpw.state.co.us/learn/Pages/GrasslandSpecies.aspx Accessed March, 2017 Cooperative climatological data summaries. NOAA. Western Regional Climate Center: Reno, NV. Web. http://www.wrcc.dri.edu/climatedata/climsum Accessed February, 2017 Fitzgerald, J.P., C.A. Meaney, and D.M. Armstrong. 1994. Mammals of Colorado. Denver Museum of Natural History, Denver, CO. 467. Guyette, Richard P., M.C. Stambaugh, D.C. Dey, RM Muzika. (2012). Predicting fire frequency with chemistry and climate. Ecosystems, 15: 322-335 Hammerson, G.A. 1999. Amphibians and reptiles in Colorado, Second Edition. University Press of Colorado & Colorado Division of Wildlife 1999. Herrick, Jeffrey E., J.W. Van Zee, K.M. Haystad, L.M. Burkett, and W.G. Witford. 2005. Monitoring Manual for Grassland, Shrubland, and Savanna Ecosystems, Volume II. U.S. Dept. of Agriculture, Agricultural Research Service. Jornada Experimental Range, Las Cruces, N.M. Kingery, H., Ed. (1998) Colorado Breeding Birds Atlas. Dist. CO Wildlife Heritage Foundation: Denver, CO. 636. National Water & Climate Center. USDA-NRCS. USDA Pacific Northwest Climate Hub: Portland, OR. http://www.wcc.nrcs.usda.gov/ Accessed February, 2017. NRCS National Water and Climate Center: https://www.wcc.nrcs.usda.gov/ Accessed February, 2017 Pellant, M., P. Shaver, D.A. Pyke, J.E. Herrick. (2005) Interpreting Indicators of Rangeland Health, Version 4. BLM National Business Center Printed Materials Distribution Service: Denver, CO. PLANTS Database. 2015. USDA-NRCS. Web. http://plants.usda.gov/java/ Accessed January 2017. PRISM Climate Data. 2015. Prism Climate Group. Oregon State Univ. Corvallis, OR. http://www.prism.oregonstate.edu/ Rennicke, J. 1990. Colorado Wildlife. Falcon Press, Helena and Billings, MT and CO Div. Wildlife, Denver CO. 138. Romme, W., C. Allen, J. Bailey, W. Baker, B. Bestelmeyer, P. Brown, K. Eisenhart, et al. 2007. Historical and Modern Disturbance Regimes of Pinon-Juniper vegetation in the Western U.S. The Nature Conservancy and Colorado Forest Restoration Institute: Fort Collins, CO. 13. Schoeneberger, P.J., D.A. Wysockie, E.C. Benham, and Soil Survey Staff. 2012. Field book for describing and sampling soils, Version 3.0. Natural Resources Conservation Service, National Soil Survey Center: Lincoln, NE. Stewart, Omer C., 2002. Forgotten Fires. Univ. of Oklahoma Press, Publishing Division: Norman, OK U.S. Dept. of Agriculture, Agricultural Research Service. September, 1991. Changes in Vegetation and Land Use I eastern Colorado, A Photographic study, 1904-1986. U.S. Dept. of Agriculture, Natural Resources Conservation Service. 2006. Land Resource Regions and Major Land Resource areas of the United States, the Caribbean, and the Pacific Basin. US Department of Agriculture Handbook 296. U.S. Dept. of Agriculture, Natural Resources Conservation Service. 2009. Part 630, Hydrology, National Engineering Handbook U.S. Dept. of Agriculture, Natural Resources Conservation Service. National Geospatial Center of Excellence. Colorado Annual Precipitation Map from 1981-2010, Annual Average Precipitation by State U.S. Dept. of Agriculture, Natural Resources Conservation Service. 1972-2012. National Engineering Handbook Hydrology Chapters. http://www.nres.usda.gov/wps/portal/nres/detailfull/national/water/?&cid=stelprdb 1043063 Accessed August 2015. U.S. Dept. of Agriculture, Natural Resources Conservation Service. National Soil Survey Handbook title 430 -VI. http://www. nres. usda. gov/wps/portal/nres/detail/soils/ref/?cid=nres 142p2_054242 U.S. Dept. of Agriculture, Natural Resources Conservation Service. Web Soil Survey.http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx Accessed January, 2017. U.S. Dept. of Agriculture, Soil Survey Division Staff. 1993. Soil Survey Manual. U.S. Dept. of Agriculture.1973. Soil Survey of Baca County, Colorado. U.S. Dept. of Agriculture. 1970. Soil Survey of Bent County, Colorado. U.S. Dept. of Agriculture. 1970. Soil Survey of Boulder County, Colorado. U.S. Dept. of Agriculture. 1992. Soil Survey of Cheyenne County, Colorado. U.S. Dept. of Agriculture. 1960. Soil Survey of Elbert County, Eastern Part, Colorado. U.S. Dept. of Agriculture. 1981 Soil Survey of El Paso County Area, Colorado. U.S. Dept. of Agriculture.1981. Soil Survey of Kiowa County, Colorado. U.S. Dept. of Agriculture. 2003. Soil Survey of Kit Carson County, Colorado. U.S. Dept. of Agriculture. 1981. Soil Survey of Larimer County Area, Colorado. U.S. Dept. of Agriculture. 2009. Soil Survey of Las Animas County Area, Parts of Huerfano and Las Animas Counties, Colorado. U.S. Dept. of Agriculture. 2004. Soil Survey of Lincoln County, Colorado. U.S. Dept. of Agriculture. 1977. Soil Survey of Logan County, Colorado. U.S. Dept. of Agriculture. 1968. Soil Survey of Morgan County, Colorado. U.S. Dept. of Agriculture.1965. Soil Survey Prowers County, Colorado. U.S. Dept. of Agriculture. 1986. Soil Survey of Washington County, Colorado. U.S. Dept. of Agriculture. 1982. Soil Survey of Weld County, Northern Part, Colorado. U.S. Dept. of Agriculture. 1980. Soil Survey of Weld County, Southern Part, Colorado. Additional Literature: Clark, J., E. Grimm, J. Donovan, S. Fritz, D. Engrstom, and J. Almendinger. 2002. Drought cycles and landscape responses to past Aridity on prairies of the Northern Great Plains, USA. Ecology, 83(3), 595-601. Collins, S., and S. Barber. (1985). Effects of disturbance on diversity in mixed -grass prairie. Vegetatio, 64, 87-94. Colorado Parks & Wildlife. Quick Key to Amphibians and Reptiles of Colorado. 2013. Colorado Parks & Wildlife, Denver, CO. cpw.state.co.us Egan, Timothy. 2006. The Worst Hard Time. Houghton Mifflin Harcourt Publishing Company: New York, NY. Hart, R. and J. Hart. 1997. Rangelands of the Great Plains before European Settlement. Rangelands, 19(1), 4-11. Hart, R. 2001. Plant biodiversity on shortgrass steppe after 55 years of zero, light, moderate, or heavy cattle grazing. Plant Ecology, 155, 111-118. Heitschmidt, Rodney K., J.W. Stuth, (edited by). 1991. Grazing Management, an Ecological Perspective. Timberland Press, Portland, OR. Jackson, D. 1966. The Journals of Zebulon Montgomery Pike with letters & related documents. Univ. of Oklahoma Press, First edition: Norman, OK. Mack, Richard N., and J.N. Thompson. 1982. Evolution in Steppe with Few Large, Hooved Mammals. The American Naturalist. 119, No. 6, 757-773 Reyes -Fox, M., Stelzer H., Trlica M.J., McMaster, G.S., Andales, A.A., LeCain, D.R., and Morgan J.A. 2014. Elevated CO2 further lengthens growing season under warming conditions. Nature, April 23, 2014 issue at http://www.nature.com/nature/journal/v510/n7504/full/nature13207.html, accessed March, 2017. Stahl, David W., E.R. Cook, M.K. Cleaveland, M.D. Therrell, D.M. Meko, H.D. Grissino-Mayer, E. Watson, and B.H. Luckman. Tree -ring data document 16th century megadrought over North America. 2000. Eos, 81(12), 121-125. The Denver Posse of Westerners. 1999. The Cherokee Trail: Bent's Old Fort to Fort Bridger. The Denver Posse of Westerners, Inc. Johnson Printing: Boulder, CO U.S. Dept. of Agriculture. 2004. Vascular plant species of the Comanche National Grasslands in southeastern Colorado. US Forest Service. Rocky Mountain Research Station. Fort Collins, CO. Zelikova, Tamara Jane, D.M. Blumenthal, D.G. Williams, L. Souza, D.R. LeCain, J.Morgan. 2014. Long-term Exposure to Elevated CO2 Enhances Plant Community Stability by Suppressing Dominant Plant Species in a Mixed -Grass Prairie. Ecology, 2014 issue at www.pnas.org/cgi/doi/10.1073/pnas.1414659111 Acknowledgments Project Staff: Kimberly Diller, Ecological Site Specialist, NRCS MLRA, Pueblo SSO Andy Steinert, MLRA 67B Soil Survey Leader, NRCS MLRA Fort Morgan SSO Ben Berlinger, Rangeland Management Specialist, Ret. NRCS La Junta, CO Program Support: Rachel Murph, NRCS State Rangeland Management Specialist -QC, Denver, CO David Kraft, NRCS MLRA Ecological Site Specialist -QA, Emporia, KS Josh Saunders, Rangeland Management Specialist -QC, NRCS Fort Morgan, CO Patty Knupp, Biologist, Area 3, NRCS Pueblo, CO Noe Marymor, Biologist, Area 2, NRCS Greeley, CO Richard Mullaney, Resource Conservationist, Ret., NRCS, Akron, CO Chad Remley, Regional Director, N. Great Plains Soil Survey, Salina, KS B.J. Shoup, State Soil Scientist, Denver Eugene Backhaus, State Resource Conservationist, Denver Carla Green Adams, Editor, NRCS, Denver, CO Partners/Contributors: Rob Alexander, Agricultural Resources, Boulder Parks & Open Space, Boulder, CO David Augustine, Research Ecologist, Agricultural Research Service, Fort Collins, CO John Fusaro, Rangeland Management Specialist, NRCS, Fort Collins, CO Jeff Goats, Resource Soil Scientist, NRCS, Pueblo, CO Clark Harshbarger, Resource Soil Scientist, NRCS, Greeley, CO Mike Moore, Soil Scientist, NRCS MLRA Fort Morgan SSO Tom Nadgwick, Rangeland Management Specialist, NRCS, Akron CO Dan Nosal, Rangeland Management Specialist, NRCS, Franktown, CO Steve Olson, Botanist, USFS, Pueblo, CO Randy Reichert, Rangeland Specialist, ret., USFS, Nunn, CO Don Schoderbeck, Range Specialist, CSU Extension, Sterling CO Terri Schultz, The Nature Conservancy, Ft. Collins, CO Chris Tecklenburg, Ecological Site Specialist, Hutchison, KS Rangeland health reference sheet Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site. Author(s)/participant(s) Harvey Sprock, Ben Berlinger, Daniel Nosal Contact for lead author Harvey Sprock, Area Rangeland Management Specialist, Greeley, CO Date 01/12/2005 Approved by Herman B. Garcia, State Rangeland Management Specialist Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators 1. Number and extent of rills: None 2. Presence of water flow patterns: None 3. Number and height of erosional pedestals or terracettes: None 4. Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground): None 5. Number of gullies and erosion associated with gullies: None 6. Extent of wind scoured, blowouts and/or depositional areas: None 7. Amount of litter movement (describe size and distance expected to travel): Typically slight, however during major flooding events this site slows water flow and captures litter and sediment. 8. Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values): Stability class rating anticipated to be near 6 at soil surface. 9. Soil surface structure and SOM content (include type of structure and A -horizon color and thickness): SOM ranges from 2-4 %. Soils are deep, poorly drained with a water table depth from 5-36 inches. Color of the A -horizon is dark grayish brown at 0-11 inches in depth. Surface structure is moderate fine granular. 10. Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff: Diverse grass, grasslike, forb and shrub functional/structural groups and diverse root structure/patterns reduces raindrop impact slows overland flow providing increased time for infiltration to occur. 11. Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site): None 12. Functional/Structural Groups (list in order of descending dominance by above -ground annual -production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to): Dominant: warm season mid bunchgrass > Sub -dominant: warm season tall bunchgrass > cool season mid rhizomatous > warm season tall rhizomatous > cool season mid bunchgrass > cool season grasslikes > forbs > Other: shrubs Additional: 13. Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence): None to slight. Expect slight shrub and grass mortality/decadence during and following extended drought or long-term lack of disturbance. 14. Average percent litter cover r/o) and depth ( in): 15. Expected annual annual -production (this is TOTAL above -ground annual -production, not just forage annual - production): 2000 lbs./ac. low precip years; 3000 lbs./ac. average precip; 4000 lbs./ac. high precip years. Extended drought may reduce annual production by 700 — 900 lbs./ac. 16. Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co -dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site: Invasive plants should not occur in reference plant community. 17. Perennial plant reproductive capability: The only limitations are weather -related, wildfire, natural disease, and insects that temporarily reduce reproductive capability. USDA United States aim Department of Agrculture NRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Weld County, Colorado, Southern Part Two Rivers Ranch Salt Meadow Ecology July 3, 2019 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nres.usda. gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface 2 Soil Information for All Uses 5 Ecological Site Assessment 5 Ecological Site Information for: R067BY035CO - Salt Meadow 5 R067BY035CO - Salt Meadow— Reference Plant Community (Two Rivers Ranch Salt Meadow Ecology) 5 4 Soil Information for All Uses Ecological Site Assessment Individual soil map unit components can be correlated to a particular ecological site. The Ecological Site Assessment section includes ecological site descriptions, plant growth curves, state and transition models, and selected National Plants database information. Ecological Site Information for: R067BY035CO - Salt Meadow R067BY035CO - Salt Meadow — Reference Plant Community (Two Rivers Ranch Salt Meadow Ecology) This plant community is the interpretive plant community for this site. This community evolved with grazing by large herbivores and is well suited for grazing by domestic livestock. Historically, fires occurred infrequently. This plant community can be found on areas that are grazed and where the grazed plants receive adequate periods of recovery during the growing season. The potential vegetation is about 80-95% grasses and grass -likes, 3-10% forbs and 2-10% woody plants. The community is dominated by tall and mid warm and cool -season grasses. Major grasses include alkali sacaton, switchgrass, prairie cordgrass and western wheatgrass. Other grasses and grass -likes occurring on the community include big bluestem, little bluestem, alkali cordgrass, Nebraska sedge, and Baltic rush. Key forbs and shrubs include American licorice, prairie gentian, rag sumpweed, and fourwing saltbush. The high water table supplies much of the moisture for plant growth. Plant litter is properly distributed with little movement and natural plant mortality is very low. This 5 Custom Soil Resource Report is a sustainable plant community in terms of soil stability, watershed function and biologic integrity. Total annual production ranges from 2,000 to 4,000 pounds of air-dry vegetation per acre with a Representative Value of 3,000 pounds. 6 Custom Soil Resource Report Plant Community Tables— R067BY035CO - Salt Meadow — Reference Plant Community (Two Rivers Ranch Salt Meadow Ecology) Plant Type Low Representative Value High Grass/Grasslike 1,860 2,625 3,350 Forb 85 195 325 Shrub/Vine 55 180 325 Totals 2,000 3,000 4,000 Grass/Grasslike Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 1 2400 2850 big bluestem Andropogon gerardii 90 210 Nebraska sedge Carex nebrascensis 30 90 saltgrass Distichlis spicata 30 90 Canada wildrye Elymus canadensis 30 150 slender wheatgrass Elymus trachycaulus 30 90 foxtail barley Hordeum jubatum 0 30 mountain rush Juncus arcticus ssp. littoralis 30 90 mountain rush Juncus arcticus ssp. littoralis 0 90 marsh muhly Muhlenbergia racemosa 0 30 vine mesquite Panicum obtusum 0 60 western wheatgrass Pascopyrum smithii 450 690 switchgrass Panicum virgatum 450 600 Sandberg bluegrass Poa secunda 90 300 Nuttall's alkaligrass Puccinellia nuttalliana 30 90 little bluestem Schizachyrium scoparium 30 150 Indiangrass Sorghastrum nutans 0 150 alkali sacaton Sporobolus airoides 900 1050 alkali cordgrass Spartina gracilis 30 150 prairie cordgrass Spartina pectinata 300 600 7 Custom Soil Resource Report Forb Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 2 90 300 false boneset Brickellia eupatorioides 0 30 carelessweed Cyclachaena xanthiifolia 0 90 Illinois bundleflower Desmanthus illinoensis 0 30 showy prairie gentian Eustoma exaltatum ssp. russellianum 0 60 American licorice Glycyrrhiza lepidota 30 150 leafy false goldenweed Oonopsis foliosa var. foliosa 0 30 Shrub/Vine Group Plant Common Name Plant Scientific Name Annual Production Pounds Per Acre Low High 3 60 300 fourwing saltbush Atriplex canescens 0 150 rubber rabbitbrush Ericameria nauseosa ssp. nauseosa var. nauseosa 30 60 Growth Curve Name Warm -Season Dominant, Cool -Season Subdominant; MLRA-67B; lowland water -influenced soils Growth Curve Description Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0% 0% 2% 8% 20% 30% 20% 12% 5% 3% 0% 0% 8 Pae 1 6.4.11 EXHIBIT K — Climate Provide a description of the significant climatological factors for the locality. The following climatic data is derived from text and tables extracted from the 1980 Weld County Soil Survey — Southern Part. Table 1 gives data on temperature and precipitation for the survey area, as recorded at Greeley and Ft. Lupton for the period 1951 to 1974. Table 2 shows probable dates of the first freeze in fall and the last freeze in spring. Table 3 provides data on length of the growing season. The average winter temperature is 29° F. Average summer temperature is 70° F., and the average daily maximum temperature is 87° F. Of the total annual precipitation of nine (9) inches, seventy-five percent falls between April and September, which comprise the growing season for most crops. Average seasonal snowfall is 40 inches. The prevailing winds are from the south. Average wind speed is highest at 10.4 mph. in August. 92 SOIL SURVEY TABLE 1. --TEMPERATURE AND PRECIPITATION DATA Temperature) Precipitation) Month ;Average:Average:Average: daily ; daily ; daily :maximum:minimum: January---- February--- March April may June July August SeptemberOctoberNovemberDecember 2 years in ; 12 years in 10; ! 10 will have-- I Average ; ; will have-- ; Average I I ;number of:Average: ; ;number of;Average Maximum ; Minimum ; growing ; ; Less ; More ;days with:snowfall degree ; ;than--;than--;0.10 inch; days2 f ; ; ; or more I ; ; ; ; 6F 1 °F ; OF ; °F °F 1 In ; In In ; In 1 ! 39.9 ; 10.5 1 25.3 ; 65 -19 I 37 ; .35 ; .08 ; .55 1 5.3 1 1 4 I ! k 1 ! 45.3 16.4 1 30.9 71 -11 57 ; -29 ; .15 ; .41 1 ; 4.6 51.2 22.5 1 36.8 1 78 -4 100 ; .76 ; .30 ; 1.12 1 3 ; 8.1 I I 1 ; 61.8 32.7 1 47.3 84 12 ; 248 1.36 ; .46 2.07 I 3 4.3 72.6 43.3 ; 58.0 ; 92 ; 27 558 2.16 ; .87 ; 3.20 1 5 82.8 52.0 67.4 100 ; 39 ; 822 i 1.81 ; .74 ; 2.67 ; 4 ; .0 ; ; 89.3 57.3 ; 73.4 100 ; 47 1,035 1.24 ; .47 ; 1.85 1 3 ; .0 86.9 54.9 70.9 99 43 1 '958 1.22 ; 42 1.85 3 0 77.8 44.6 61.3 94 ; 29 1 639 1.33 ; .36 2.10 3 .6 ; I 66.8 33.8 ; 50.3 85 ; 16 333 ; .91 1 .22 ; 1.46 2 ; 3.0 50.8 1 21.7 ; 36.3 ; 74 ; -1 65 1 .53 ; .14 ; .84 ; 2 I 5.4 i 42.0 13.9 28.0 67 ; -13 ; 8 ; .31 .04 ; .52 ; 1 4.1 I ; ; ; -21 ; 4,860 12.27 ; 9.55 ;14.84 ; 31 35.7 I temperature:temperature: higher lower ; than-- ; than-- ; Year ; 63.9 ; 33-6 ; 48.8 ; 101 ; .3 1Recorded in the period 1951-74 at Greeley, CO. 2A growing degree day is an index of the amount of heat available for plant growth. It can be calculated by adding the maximum and minimum daily temperatures, dividing the sum by 2, and subtracting the temperature below which growth is minimal for the principal crops in the area (400 F). WELD COUNTY, COLORADO, SOUTHERN PART 93 TABLE 2. --FREEZE DATES IN SPRING AND FALL Probability Minimum temperature) 240 F or lower 28° F or lower 320 F or lower Last freezing temperature in spring: 1 year in 10 later than-- April 28 ; May 11 2 years in 10 later than-- ; April 22 ; May 5 5 years in 1❑ later than-- ; April 11 1 April 25 First freezing temperature in fall: May 24 May 19 May 10 1 year in 10 earlier than-- October 4 ;September 25 ;September 16 2 years in 10 ; ; ; earlier than-- ; October 10 I October 1 ;September 21 5 years in 10 ; : ; earlier than-- ; October 21 ; October 11 ;September 30 'Recorded in the period 1951-74 at Greeley, GO. TABLE 3. --GROWING SEASON LENGTH Probability ❑aily minimum temperature during growing season) Higher than 240 F Higher than 28° F Higher than 32° F ➢ays ; Days 9 years in 10 166 1+17 8 years in 10 ; 175 155 ; I 5 years in 10 ; 192 ; 168 2 years in 1❑ 209 ; 132 1 year in 10 218 ; 189 Days 122 129 113 156 163 1Recorded in the period 1951-74 at Greeley, CO. Pae 1 6.4.12 EXHIBIT L - Reclamation Costs (1) All information necessary to calculate the costs of reclamation must be submitted and broken down into the various major phases of reclamation. The information provided by the Operator/Applicant must be sufficient to calculate the cost of reclamation that would be incurred by the state. (2) The Office may request the Operator/Applicant to provide additional, reasonable data to substantiate said Operator/Applicant's estimate of the cost of reclamation for all Affected Lands. Summary of Reclamation Costs: $ 9,934.08± Site Discharge $ 53,096.28±Total Grading per Extraction Front. $ 4,182.12±Total Re -soiling $ 1,141.32± Total Re -vegetation Expense $ 68,353.80± Sub -Total $ 4,322.00± Possible Mobilization and Demobilization Costs (pending OMLR estimate) $ 72,675.80± Sub -Total Direct Costs $ 17,446.20± Possible Indirect Costs Pending RMS Indirect Costs @ 24.335 % of Total Reclamation Costs $ 90,122.00± Grand Total — Financial Warranty Amount — Pending OMLR Review and estimates including estimated expenses for State of Colorado Mobilization and Demobilization and other `Indirect' cost determinations by the Office. SUMMARY OVERVIEW: Table 1 - Primary Data on Area of Affected Lands and Reclaimed Features: Entity Central Field North-West Field Combined Extraction — finished basin ( ) 180.76± 53.30± 234.06± Static Water Area — surface( ) 168.94± 48.50± 217.44± Static Water Area — elevation ( ) Basin Lands Above Static Water Level ( ) 11.82± 4.70± 16.52± Basin Area Volume ( ) 9,987,145.79± 2,405,314.58± 12,393,460.37± Static Water Level Volume ( ) 2,017,144,043.20+ 485,811,069.46± 2,502,955,112.66± Static Water Level Volume ( ) 6,190.39± 1,490.90± 7,681.83± Plant Processing Area ( ) 15.76± Wash Pond Area ( ) 5.60± Total Lands Above Static Water Level ( ) 37.98± Pae 2 6.4.12 EXHIBIT L - Reclamation Costs NOTE Well: The following estimates utilize assumptions based upon the pre -disturbed state of the application for purposes of determining estimated costs of reclamation and correlated financial warranty. Where appropriate, information is generalized and approximated from similar estimates determined by the Colorado Office of Mined Land Reclamation (OMLR), as indicated: RECLAMATION EXPOSURE: Based upon the Extraction and Reclamation Plans of this application, the status and trend of activities and affected land; and related calculations to estimate reclamation liability, are determined as follows. Please Note: Due to the difficulty of calculating heavy equipment costs similar to the Division's software program, unit costs from previous and reasonably current Division estimates of like or similar kind have been utilized to create a reasonably close estimate. The per unit basis from Division records are shown along with other sources used or referenced to determine unit costs, at the back of this exhibit. METHOD OF EXTRACTION: Before concurrent grading, resoiling, and revegetation for reclamation can commence, a perimeter keyway must first circumnavigate the area where the perimeter slopes form along the extraction limits. For Two Rivers, this includes four sequential areas of extraction: • 127.10± Acres - Central Field — Center Section • 23.19± Acres - Central Field — North-East Section • 30.47± Acres - Central Field - West Section • 53.30± Acres - North-West Field Exhibit L: Financial Warranty Map, shows Initial Extraction will begin in the yellow hatch area shown on the Exhibit L Map, comprising 16.26±. The direction of extraction will Pae I3 6.4.12 EXHIBIT L - Reclamation Costs follow the perimeter of the extraction limits over approximately 75.45± acres in order to establish the perimeter keyway for the 127.10± acre Center Section of Central Field. The perimeter extraction will leave a 51.65± acre Core, that may be extracted as needed as keyway drainage capacity allows. The initial extraction area is bordered to the South along a near 800± foot section of oil and gas line that is pending removal; along with the two oil and gas wells, also pending removal (refer to Exhibit C for ownership details). Extraction will not occur within 10 feet of these lines, or 25 feet from the wells, as indicated in the setbacks detailed under Exhibit D: Extraction Plan. Below this gas line is an existing pond and well that will be used as a Settling Basin Area, containing at present a solitary settling basin and pump as a point of discharge of groundwater. This pond may be expanded or added to below this line, and may then be extracted itself once discharge is discontinued for Central Field Operations. Perimeter Keyway Extraction will maintain a perimeter slope no steeper than 1.25H:1V, except for the perimeter shown in red along it's extraction limit, and respective toe where cut slopes will not exceed 2.OOH:1V; as indicated (refer to Exhibit S: Stability Analysis for additional information). At the toe of the cut perimeter slope is the keyway that runs below the extracted deposit of the basin, into the bedrock, which allows the subsurface waters to flow to the settling basin and discharge pumps necessary to keep the cut basin dry during a time of extraction and reclamation of the affected perimeter slopes. The keyway dimensions may vary more or less from 4± to 8± feet in depth and 4± to 16± feet in width. Extraction must be broad enough to allow equipment to safely approach the toe and exise the bed dimensions where the resulting channel is sufficient to convey the groundwaters to the settling basin for discharge. Please Note: The graphic representation of the Perimeter Keyway Extraction and Core are idealized, and may vary in shape and size presented. Annual Reports will report on the nature and extent of affected lands and more properly reflect actual conditions on the ground in a given year of operations. UNITS OF DISTURBANCE: The life of the operation is based upon a base rate of extraction approximating 8.0± acres of disturbance in a given year. This time will pulse with the market and may average 8.0± acres, but could be faster or slower. Starting out, initial warranty necessary to cover the costs of reclamation for the extent of disturbance in a given year will also vary in time and circumstance, as the initial disturbance is generally less at the onset. So, a rate of disturbance can be estimated and the warranty adjusted incrementally with time and circumstance. Starting out in the initial 2-4 years of Operations, and incrementally thereafter, necessary warranty can be estimated and adjusted in incremental Units based upon the projected Pae I4 6.4.12 EXHIBIT L - Reclamation Costs Life of the Operation. Essentially, a 30 -year Life of Operations assumes a rate of extraction of approximately 8.0± acres per year. The initial Area of Extraction is slightly over 16.0± acres of extraction — or approximately 2.0± years of operations. The initial length of slope needing graded along the near 800.0± foot South perimeter will not be required since the Settling Basin Area prevents extraction from reaching the extraction limits until the settling basin and pump are no longer needed. Still — an 800 -foot segment is a good unit to consider incrementally increasing warranty along the perimeter 2H:1V and 1.25:1V slopes — which may not be encountered until the 16.0± acres of opening extraction is completed over the first two years of Operations. So, to better assure the need to backfill such slopes, an initial 800± unit of grading for the 1.25:1V cut slope at the WCR 396 perimeter extraction limits is provided for. Additionally, two 800 -foot Units of cut slopes along the South Platte levee (1,600± feet total), will cover the potential need for the initial 800± feet along the Southern line above the Settling Basin Area; and an additional 800± feet further east along the South Platte River levee, will also be included in the initial Warranty estimate to better allow for proactive accumulation of similar Units to the Warranty over time as extraction moves forward. To this end, an additional 16± acres — estimating 8.0± acres of additional extraction to the North and South of the Core may occur, will be included in the dewatering estimate. This should provide adequate time to adjust the Warranty as Operations advance over the years in subsequent 8.0± acre units, in either or both directions around or within the Core; and as Operations eventually open new Sections for extraction. DEWATERING: Volumes per Tract: Total Gallons — Central Field = 2,017,144,043.20± gallons - 168.94 surface water acres = 11,940,002.6 gal./acre x 8.0± acres = 95,520,021.0± gallons per 8.0± acres. = Avg. = 95,520,021.0 gal./8.0 acres x $ 0.000026/gal. discharge (refer to Kurtz est. utilizing similar pump and rates.) Total Average Cost per 8.0± acres of Discharge = $ 2,483.52 per 8.0± acres — Unit Cost. 16.0± acres initial + 16.0± acres subsequent = 32/8 = 4 Units. X 4 Units $ 9,934.08 Discharge Cost for 32± acres Pae I5 6.4.12 EXHIBIT L - Reclamation Costs Please Note: The basins resulting from extraction may be reclaimed in an unlined state, since the operator retains sufficient water resources to do so. The basins may be lined or otherwise segregated from the area groundwater as an option to this approved permit, in order to liberate the water otherwise retained to supplement loss from evaporation in the unlined state. Since sufficient water resources exist, the option to line the resulting basins at an unspecified time during the life of the permit is retained under this application and as part of the approved permit. GRADING: As stated above, grading will be supported by warranty estimated in 800 -foot units for a 1.25H:1V slope along the extraction limits flanking WCR 396; and 2H:1V along the South Platte River levee, as shown on Exhibit D: Extraction Plan, and Exhibit L: Financial Warranty Map. Actual volume of fill required to grade at 3H:1V for a respective cut slope is determined in the graphics, below. Square Foot volume of backfill x 800 linear feet of slope divided by 27 will yield the required cubic feet needed. A rate per Loose Cubic Yard of fill taken from the previously approved values determined by the OMLR, is used to better insure the integrity of the resulting values. DIAGRAM depth H: 1 FINISHED GRADE FILL TO GRADE = 800 Sa FT. Continued... next page... Pae I6 6.4.12 EXHIBIT L - Reclamation Costs Assuming a mean depth of advancing cut of 1.25H:1V at the extraction limits of 40.0± feet: 800.00± lin.ft. (extraction front and side slopes) x 1,600.00± sq.ft. = 1,280,000.00± cu.ft. 27 = 47,407.40± LCY 47,407.40± LCY x $ 0.56± per LCY. $ 26,548.14± fill along an 800 -foot extraction front cut at 1.25H:1V. Assuming a mean depth of advancing cut of 2:1V at the extraction limits of 40.0± feet: 800.00± lin.ft. (extraction front and side slopes) x 800.00± sq.ft. (required fill — Diagram 1, above) = 640,000.0000± cu.ft. - 27 = 23,703.70± LCY 23,703.70± LCY x $ 0.56± per LCY. $ 13,274.07± per 800 linear foot Unit x $ 2 Units of 800 lin.ft. $ 26,548.14 Sub Total -Grading to 3H:1V along an 800 -foot extraction front cut at 2H:1V $ 26,548.14 Sub Total -Grading to 3H:1V along an 800 -foot extraction front cut at 1.25H:1V. + $ 26,548.14 Sub Total -Grading to 3H:1V along an 800 -foot extraction front cut at 2H:1V. $53,096.28 Total — Initial Grading. Pae 7 6.4.12 EXHIBIT L - Reclamation Costs Soil Demand AND Re -soiling of Affected Lands (refer to Exhibit D): Soil demand is limited to the cut basin slopes remaining above the static water level. For Central Field, the total area above the anticipated static water level of the basins is 11.82± acres. To estimate the area involved in resoiling the Center Section of Central Field — we'll use a percentage of the total perimeter length of the extraction limits involved: 15,074.72 Total perimeter length Central Field 1,633.27 Perimeter length Center —Central Field —extraction limits along WCR 396 6,243.23 Perimeter length Center —Central Field —extraction limits along S. Platte R. levee 7,876.50 Combined perimeter lengths 7,876.50 - 15,074.72 = 52% 11.82 acres x 52% = 6.15± acres requiring resoiling and revegetation (see Establishment of Vegetation over Affected Lands, below. At a depth of 0.5± feet, total volume = 6.15± acres x 0.5± feet of soil replacement, is: 6.15± acres x 43,560.0± sq.ft./acre - 27 cu.ft./cu.yd. = 9,922± cu.yds. @ 1' depth. 9,922± cu.yds. @ 1' depth soil - 2 = 4,961 cu.yds soil required at 6 inches in depth. The majority of soil placement can occur using the average placement distance of 600 ft., or less along embankments, (utilizing the same assumptions utilized at either Kurtz or Heintzelman Projects as shown at the back of this exhibit). 4,961.00± cu.yds of soil demand x $ 0.843 per LCY. $ 4,182.12 to replace 0.5± feet of soil over the existing affected lands remaining above the anticipated final water level at the Center of Central Field along the perimeter cut slopes at the extraction limits. NOTE: Total Soil Demand for the entire Central Field and the North-West Field: 11.82± Acres Central Field 4.70± Acres North-West Field 16.52± Acres Total — Combined Soil Replacement Demand 16.52± Acres x 43,560 sq.ft./acre - 27 cu.ft./cu.yd. = 26,653.27± cu.yds. @ 1' depth.26,653.27± cu.yds. @ 1' depth soil - 2 = 13,326.63± total cu.yds soil required at 6 inches in depth at Central and North-West Fields for all basin slopes remaining above the anticipated static water level and below the extraction limits. Pae I8 6.4.12 EXHIBIT L - Reclamation Costs Establishment of Vegetation over Affected Lands: The demand establishment of vegetation over the affected lands will also diminish proportionately with the planned extraction of the Tracts. For now, the total exposure is estimated as indicated above to be 6.15± acres for the Center Section of Central Field (see Soil Demand): NOTE: The cost for seed is estimated on Exhibit L - Table L-1: Primary/Preferred Re - vegetation Seed Mixture; however, the costs are known to fluctuate seasonally — and are estimates based on prior seasons. The seed mixture includes a substitute for mulch in the inclusion of a wheatgrass hybrid. The Division has historically agreed with and approved the inclusion of this hybrid as a substitute for mulch. The Optional Seed Mix will be used if the Primary Mixture fails, but costs less, so that cost is accounted for. These costs are as follows: $ 58.72± Preferred Seed Mix x 6.15± acres $ 361.13± Sub -Total Seed The cost for applying seed is based upon information derived in proximity to the Northern Colorado economy. Costs for tilling, fertilizing and seeding are based upon estimates from Longs Peak Equipment Co. These costs, including labor, are reflected as follows: $ 25.00± per acre Tilling $ 20.00± per acre Fertilizing $ 20.00± per acre Seeding $ 65.00± per acre Total Application Cost per Acre. x 6.15± acres $ 399.75± Sub -Total — Application Costs $ 760.88± Sub -Total Re -vegetation (seed + application) Costs. Assume a 50± percent failure and add half the expense back into the total for reseeding, or: $ 380.44± Sub -Total Re -seeding costs $ 1,141.32± Total Re -vegetation Expense OTHER MISCELLANEOUS COSTS: Mobilization and demobilization costs are based upon the Division's estimates, which are pending — but estimated in the summary, below. Demolition of Structures: None. Building Permits for structures will be obtain where required from the Weld County Building Department. Pae 9 6.4.12 EXHIBIT L - Reclamation Costs Please Note: The per unit cost values derived from previous OMLR determinations for heavy equipment, as applied to this exhibit, are included at the back of this exhibit. Since there is no possibility of the applicant in fully reproducing the Division's methods, utilizing similarities from past OMLR calculations is the most viable and accurate means available for the applicant to derive reasonable estimates of per unit costs and should result in estimates very reliable with that of the Division. Summary of Reclamation Costs: $ 9,934.08± Site Discharge $ 53,096.28±Total Grading per Extraction Front. $ 4,182.12±Total Re -soiling $ 1,141.32± Total Re -vegetation Expense $ 68,353.80± Sub -Total $ 4,322.00± Possible Mobilization and Demobilization Costs (pending OMLR estimate) $ 72,675.80± Sub -Total Direct Costs $ 17,446.20± Possible Indirect Costs Pending RMS Indirect Costs @ 24.335 % of Total Reclamation Costs $ 90,122.00± Grand Total — Financial Warranty Amount — Pending OMLR Review and estimates including estimated expenses for State of Colorado Mobilization and Demobilization and other `Indirect' cost determinations by the Office. Extraction of the Core following completion of the Perimeter Extraction Keyway TABEL L- PREFERRED/PRIMARY and OPTIONAL SEED MIXTURES 2022 Seed Mix Calculator Tract: ALL Application: Initial STEP 1 * STEP 2 STEP 3 # PRIMARY/PREFERRED SEED MIXTURE Species - Scientific Name Species - Common Dame Variety C/W Seeds/# pls , 43560 Seeds/sq ft Critical AREA Planting @ 40 Seeds/sq.ft. % Mix M x % of Mixture = # pls/acre ** NOTES: $/# $/Acre 1 Panicum virgatum Switchgrass Trailblazer W 389,000 8.93 4.48 0.20 0.9 $ 6.15 $ 5.51 2 Bouteloua curtipendula Sideoats grama Vaughn W 191,000 4.38 9.12 0.20 1.8 $ 5.65 $ 10.31 3 Festuca ovina Sheep fescue Covar C 680,000 15.61 2.56 0.15 0.4 $ 2.15 $ 0.83 4 Achnatherum hymenoides Indian ricegrass Paloma C 141,000 3.24 12.36 0.15 1.9 S 335 $ 6.21 5 Bouteloua gracilis Blue grama Lovington W 825,000 18.94 2.11 0.10 0.2 S -.80 $ 1.65 6 Schisachyrium scoparium Little bluestem Pastura W 260,000 5.97 6.70 0.05 0.3 $ 9.00 $ 3.02 7 Poa pratensis Kentucky bluegrass Livingston C 2,177,000 49.98 0.80 0.05 0.1 S 2.65 $ 0.27 8 Thinopyrum ponticum Tall wheatgrass Alkar C 79,000 1.81 22.06 0.05 1.1 $ 1.35 $ 1.49 9 Bromus inermis Smooth brome Manchar C 125,000 2.87 13.94 0.02 0.3 $ 1.29 $ 0.36 10 Sporobolus airoides Alkali sacaton W 1,758,000 40.36 0.99 0.01 0.1 $ 8.95 $ 0.90 11 Sporobolus cryptandrus Sand dropseed W 5,298,000 121.63 0.33 0.01 0.1 $ 4.25 $ 0.43 12 Trifolium fragiferum Strawberry clover O'Conner 300,000 6.89 5.81 0.01 0.1 $ 4.70 $ 0.27 13 see wheatgrass hybrid below for mulch TOTALS= 0 0.00 0.00 1.00 0.0 $ - S 31.22 Mulch Substitute Regreen WheatXWheatgrass *Source = Granite Seeds & NRCS ** Minimum Mix Composition = 0.10 #pls (all rounded to nearest tenth) 10 $ 2.75 $ 27.50 NOTE: Rates Shown are Drilled Rates. Where broadcasting is necessary or preferred, Rates will double. Where possible (pls) Pure Live Seed cost are determined and sourced from local seed providers. Provider and Rates shown may vary Seasonally according to seed availability and related ask prices. Since species availability may vary, the operator may substitute species of similar utility. The species described are therefore subject to change without revision to the permit. Regreen is a substitute for the use of mulch, providing live stabilization that will die out within three years as the native grasses begin to express themselves. Other options remain the discretion of the Operator. The Optional Seed Mixture is intended only in the event of seeding establishment failure of the primary/preferred mixture based upon expression at or before the end of three years following the date of seed application. STEP 1 * STEP 2 STEP 3 # OPTIONAL SEED MIXTURE Species - Common Name Species - Scientific Name Variety C/W Seeds/# pls , 43560 Seeds/sq ft Critical AREA Planting @ 40 Seeds/sq.ft. % Mix M x % of Mixture = # p1s/acre ** NOTES: $/# S 1 Agropyron cristatum Crested wheatgrass Hycrest C 265,250 6.09 6.57 0.2 1.3 2 Pascopyrumsmithii Western wheatgrass Arriba C 110,000 2.53 15.84 0.2 3.2 3 Lolium perenne Perennial ryegrass Tetraploid C 227,000 5.21 7.68 0.2 1.5 4 Psathyrostachysjuncea Russianwildrye Swift C 175,000 4.02 9.96 0.2 2.0 5 Dactylis glomerata Orchardgrass Renegade C 427,200 9.81 4.08 0.1 0.4 6 Melliotus officinalis Yellow sweetclover 260,000 5.97 6.70 0.1 0.7 8 9 10 11 12 13 TOTALS= VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT FEBRUARY 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION -COLORADO DIVISION OF RECLAMATION MIING SAFETY OFFICE OF MINED LAND RECLAMATION I I' O J—� � ee Y 9 \ N + V � — 4 LEGEND "A°"T Two Rivers Sand, Gravel and Reservoir Project D"""'": Exhibit L: Financial Warranty Map 234,06±Acres Basins Total + 5,60±Acre Wash Pond Inch = 200 feet DATE 22 February 2022 REVISION 1 OE Pae 1 6.4.13 EXHIBIT M - Other Permits and Licenses A statement identifying which of the following permits, licenses and approvals the Operator/Applicant holds or will be seeking in order to conduct the proposed mining and reclamation operations: effluent discharge permits, air quality emissions permits, radioactive source material licenses, the State Historic Preservation Office clearance, disposal of dredge and fill material (404) permits, permit to construct a dam, well permits, explosives permits, highway access permits, U.S. Forest Service permits, Bureau of Land Management permits, county zoning and land use permits, and city zoning and land use permits. • Colorado Department of Health Storm Water Permit Pending • Colorado Department of Health Emission Permit Plant. • Colorado Department of Health Emission Permit Portable Equipment — Dry Plant • Colorado Department of Health Emission Permit Wet Plant • Colorado Department of Health Emission Permit N/A — Concrete Pending Operations Pending Operations Pending Fugitive Dust — Mining Operations and related activities. Batch • Weld County Special Use Permit N/A . • Colorado Division of Water Resources Well Permit Pending • State Historic Preservation Office clearance Pending • U.S. Department of the Army Corps of Engineers No Permit Required Correspondence of 21 June 2021 . • Planned operations will not utilize or encounter materials, sources, or authorities over related lands and do not require permits for the following: radioactive source materials, construction of a dam, explosives, highway access, U.S. Forest Service, Bureau of Land Management, city zoning or land use. Refer to Approval from the City of Evans: Pending • Note: Any necessary permits for other planned or potential activities, including asphalt batch plants, recycling facilities and operations, etc., will be acquired prior to on -set of such plants, facilities or operations. All future permits will be submitted to the Division to update this list as necessary. Refer to Approval for Recycling Facilities and Operations from the City of Evans: Pending DEPARTMENT OF THE ARMY CORPS OF ENGINEERS. OMAHA DISTRICT DENVER REGULATORY OFFICE. 9307 SOUTH WADSWORTH BOULEVARD LITTLETON. COLORADO 80128-6901 July 6, 2021 SUBJECT: No Permit Required (NPR) Verification — Corps File No. NWO-2021- 01169-DEN, Two Rivers Sand Gravel Project, Weld County, Colorado Bradford Janes Varra Companies, Inc. Office of Special Projects 8120 Gage Street Frederick, Colorado 80516 Dear Mr. Janes: Reference is made to the proposed Two Rivers Sand Gravel Project located at approximate latitude 40.347835, longitude -104.774872, in Weld County, Colorado. The work as described in your submittal consists of sand and gravel extraction outside of aquatic resources. This project has been reviewed in accordance with Section 404 of the Clean Water Act (Section 404) under which the U.S. Army Corps of Engineers regulates the discharge of dredge and fill material and certain excavation activities in waters of the United States. Based on a review of the provided information, a Section 404 Department of the Army permit will not be required for the work occurring outside of aquatic resources. This NPR does not address nor include any consideration for geographic jurisdiction on aquatic resources and shall not be interpreted as such. Although a Department of the Army permit will not be required for this activity, this does not eliminate the requirements that other applicable federal, state, tribal, and local permits are obtained if needed. Please be advised that deviations from the original plans and specifications of this project could require additional authorization from this office. If there are any questions please feel free to contact Celena Cui at (303) 979-4120 or by e-mail at Celena.H.Cui@usace.army.mil, and reference Corps File No. NWO- 2021-01169-DEN. Sincerely, 1,0 Kiel Downing Chief, Denver Regulatory Offic 1 So re_ : of_ eciai �"-'� (Tht -�r� c•r�; rr•.� )-i1 j rl•F i.g it t•� O ci ciLkJi'r Uri i iC cal IG ii �: ra iii. r `cjc'ii ce Liil : II 1c1 i17 As landowner(s) to all lands to be permitted for extraction under a Colorado Division of Reclamation Mining and Safety (DRMVTS), Office of Mined Land Reclamation (OMLR) permit, signature below testify that Varra Companies, Inc., has the legal right to enter and mine with respect to all lands under this permit. Signed: Garrett C. Varra, President Varra Companies. Inc. Signed and dated this 2-S41" day of ecA^C , State oflO(adO County of d0( ) )ss The foregoing instrument was acknowledged before me this 2 g day of tit pick by----1a..'re. 2 \J 'cc of VG)((&CD r)1`p u s 1)r•,C— JESSICA HOOVER NOTARY PUBL:C STATE OF COLORADO NOTARY ID 20044035571 MY COMMISSION EXPIRES OCTOBER 4, 202 Notary Public as P(e6Lck.A--- My Commission expires: /0/LE/14 Pae 6.4.15 EXHIBIT O - Owner(s) of Record of Affected Land (Surface Area) and Owners of Substance to be Mined Owner(s) of Record of Affected Land (Surface Area): Varra Companies, Inc. 8120 Gage Street Frederick, CO 80516 Owner(s) of Substance to be Mined: Varra Companies, Inc. 8120 Gage Street Frederick, CO 80516 NOTE: Refer to Exhibit C-1: Existing Conditions Map for information regarding Other Owners of Record. Pae 1 6.4.16 EXHIBIT P - Municipalities Within Two Miles A list of any municipality(s) within two miles of the proposed mining operation and address of the general office of each municipality. Town of Milliken 1101 Broad Street Milliken, CO 80543 City of Evans 1100 37th Street Evans, Colorado 80620 5,4. 18 E.KH. 8iT 1. :cc' i Ma:!in X iotic= .:O z 7=.i •`_. _ Ccau i7'.: LJi.. 'or and Conservadoi: l'! :it -.i.. ti -I -,I!.... -..- .._i . • Ll2'_li _. [ i. .... ....:i.'ll'1 _ i!I :.,j .-..-...,. I':. .;!I!.. ,.'.I:-= �ii .1:-:1'v -ii., _..sii!cl '.h.e. E,ca;_, tri.-_ .oa:.L;.1A;i,,-...tpL!I....;,.ni io fi:.!!o Office of the Board of Weld County Commissioners c/o Weld County Clerk to the Board 1150 O Street Greeley, Colorado 80632 Subject: Colorado Division of Reclamation Mining and Safety (DRMS) Office of Mined Land Reclamation (OMLR Permit application for Varra Companies. Inc. — Two Rivers Sand. [travel and Reservoir Project. NOTICE TO THE BOARD of WELD COUNTY COMMISSIONERS Varra Companies. Inc. (the 'Applicant/Operator•) has applied for a Regular (112) reclamation permit from the Colorado Mined Land Reclamation Board (the -Board') to conduct the extraction of construction materials operations in Weld County. The attached information is being provided to notify you of the location and nature of the proposed operation. The entire application is on file with the Division of Reclamation. Mining, and Safety (the 'Division') and the Weld County Clerk to the Board. The applicant/operator proposes to reclaim the affected land to commercial Developed Water Resources and other Mixed Uses. Pursuant to Section 34-32.5-116(4)(m). C.R.S.. the Board may confer with the local Conservation Districts before approving of the post -mining land use. Accordingly. the Board would appreciate your comments on the proposed operation. Please note that. in order to preserve your right to a hearing before the Board on this application. you must submit written comments on the application within twenty (20) days of the date of last publication of notice pursuant to Section 34-32.5-112(10). CRS. fl'you would like to discuss the proposed post -mining land use, or any other issue regarding this application, please contact the Division of Reclamation. Mining, and Safety. 1313 Sherman Street. Room 215. Denver. Colorado 80203. (303) 866-3567. Your signature below acknowledges receipt of the above referenced permit application form. 1-4 Date Received: Received By: Weld County Clerk toithe BoblatiOrWeld County Commissioners 5,4. 18 E.KH. 8iT 1. :cc' i Ma:!in X iotic= .:O z 7=.i •`_. _ Ccau i7'.: LJi.. 'or and Conservadoi: l'! :it -.i.. ti -I -,I!.... -..- .._i . • Ll2'_li _. [ i. .... ....:i.'ll'1 _ i!I :.,j .-..-...,. I':. .;!I!.. ,.'.I:-= �ii .1:-:1'v -ii., _..sii!cl '.h.e. E,ca;_, tri.-_ .oa:.L;.1A;i,,-...tpL!I....;,.ni io fi:.!!o Office of the Board of Weld County Commissioners c/o Weld County Clerk to the Board 1150 O Street Greeley, Colorado 80632 Subject: Colorado Division of Reclamation Mining and Safety (DRMS) Office of Mined Land Reclamation (OMLR Permit application for Varra Companies. Inc. — Two Rivers Sand. [travel and Reservoir Project. NOTICE TO THE BOARD of WELD COUNTY COMMISSIONERS Varra Companies. Inc. (the 'Applicant/Operator•) has applied for a Regular (112) reclamation permit from the Colorado Mined Land Reclamation Board (the -Board') to conduct the extraction of construction materials operations in Weld County. The attached information is being provided to notify you of the location and nature of the proposed operation. The entire application is on file with the Division of Reclamation. Mining, and Safety (the 'Division') and the Weld County Clerk to the Board. The applicant/operator proposes to reclaim the affected land to commercial Developed Water Resources and other Mixed Uses. Pursuant to Section 34-32.5-116(4)(m). C.R.S.. the Board may confer with the local Conservation Districts before approving of the post -mining land use. Accordingly. the Board would appreciate your comments on the proposed operation. Please note that. in order to preserve your right to a hearing before the Board on this application. you must submit written comments on the application within twenty (20) days of the date of last publication of notice pursuant to Section 34-32.5-112(10). CRS. fl'you would like to discuss the proposed post -mining land use, or any other issue regarding this application, please contact the Division of Reclamation. Mining, and Safety. 1313 Sherman Street. Room 215. Denver. Colorado 80203. (303) 866-3567. Your signature below acknowledges receipt of the above referenced permit application form. 1-4 Date Received: Received By: Weld County Clerk toithe BoblatiOrWeld County Commissioners Proof of filing with the County Clerk, pursuant to Subparagraph 1.6.2(1)(c): Weld County Clerk to the Board 1150 0 Street Greeley, Colorado 80632 Subject: Colorado Division of Reclamation Mining and Safety (DBMS), Office of Mined Land Reclamation (OMLR) Permit application for Varra Companies, Inc. — Two Rivers Sand, Gravel and Reservoir Project. Your signature below acknowledges receipt of the above referenced permit application. The application will be placed for public inspection and review by your Office. The information will be made available to the public until final agency action by the OMLR Board, as defined by C.R.S. 24-4-105(14), Date Received: Received By: Office of Weld County Clerk to the Board Pae 1 6.4.19 EXHIBIT S - Permanent Man-made Structures Where the affected lands are within two hundred (200) feet of any significant, valuable and permanent man-made structure, the applicant shall: (a) (b) (c) provide a notarized agreement between the applicant and the person(s) having an interest in the structure, that the applicant is to provide compensation for any damage to the structure; or where such an agreement cannot be reached, the applicant shall provide an appropriate engineering evaluation that demonstrates that such structure shall not be damaged by activities occurring at the mining operation; or where such structure is a utility, the Applicant may supply a notarized letter, on utility letterhead, from the owner(s) of the utility that the mining and reclamation activities, as proposed, will have "no negative effect" on their utility. 6.5 GEOTECHNICAL STABILITY EXHIBIT (1) On a site -specific basis, an Applicant shall be required to provide a geotechnical evaluation of all geologic hazards that have the potential to affect any proposed impoundment, slope, embankment, highwall, or waste pile within the affected area. A geologic hazard is one of several types of adverse geologic conditions capable of causing damage or loss of property and life. The Applicant may also be required to provide a geotechnical evaluation of all geologic hazards, within or in the vicinity of the affected lands, which may be de -stabilized or exacerbated by mining or reclamation activities. (2) On a site -specific basis, an Applicant shall be required to provide engineering stability analyses for proposed final reclaimed slopes, highwalls, waste piles and embankments. An Applicant may also be required to provide engineering stability analyses for certain slopes configuration as they will occur during operations, including, but not limited to embankments. Information for slope stability analyses may include, but would not be limited to, slope angles and configurations, compaction and density, physical characteristics of earthen materials, pore pressure information, slope height, post -placement use of site, and information on structures or facilities that could be adversely affected by slope failure. (3) Where there is the potential for off -site impacts due to failure of any geologic structure or constructed earthen facility, which may be caused by mining or reclamation activities, the Applicant shall demonstrate through appropriate geotechnical and stability analyses that off -site areas will be protected with appropriate factors of safety incorporated into the Pae I2 6.4.19 EXHIBIT S - Permanent Man-made Structures analysis. The minimum acceptable safety factors will be subject to approval by the Office, on a case -by -case basis, depending upon the degree of certainty of soil or rock strength determinations utilized in the stability analysis, depending upon the consequences associated with a potential failure, and depending upon the potential for seismic activity at each site. (4) At sites where blasting is part of the proposed mining or reclamation plan, the Applicant shall demonstrate through appropriate blasting, vibration, geotechnical, and structural engineering analyses, that off -site areas will not be adversely affected by blasting. To assure the stability of any significant, valuable, and permanent man-made structures that may exist within 200 feet of planned extraction activity, a complete and thorough stability analysis was performed by American Water Engineering Services, LLC. (AWES). Their report of 23 December 2019, is based upon on -site samples collected from the intended areas of extraction. A copy of the AWES report is included at the back of this exhibit. The included AWES report verifies that the maximum planned extraction slopes of 1.25H:1V (and 2H:1V to the extend indicated by a Red Boundary along the Eastern Extraction Limit and a portion of the Southern Extraction Limit in Central Field) will not pose a hazard to such structures. The location of the extent of the 2H:1V extraction slope limits is shown in RED as indicated on the Exhibit C-2: Extraction Plan Map. To the extent practical, operational setbacks will be observed consistent with those detailed under Exhibit D: Extraction Plan. Grading and reclamation of completed areas of extraction will reduce extracted slopes to a minimum of 3H:1V, or flatter, over a majority of the extraction area, in conformance with Rule 3.1.5(7). AMERICAN WATER ENGINEERING SERVICES, LLC SLOPE STABILITY ANALYSES OMLR 112 PERMIT APPLICATION VARRA TWO RIVERS MINE AWES PROJECT # 1920-124-VARRA December 23, 2019 Problem: Two Rivers Stability Analysis - FS Min- Spencer = 1.416 7`- 70 € E. 60 SE - BO 4` 2E- 20 2E- 20 1`_ 10 0 -10 Soils Cohesion Friction Angle IMM Bed rocf: -'..,ater able Critical Surface `00.0 0.0 0.0 0.0 14.0 2E 6 `.1 10 10 20 30 40 [Scale in Feet: 70 80 50 100 110 120 Prepared for: Varra Companies, Inc. 8120 Gage Street Frederick, CO 80516 Prepared by: AWES, L.L.C. 4809 Four Star Ct. Fort Collins, CO 80524 Introduction The following report presents the results of a slope stability analysis for a proposed open cut gravel extraction operations at the Varra Pitt 124 (Two Rivers) operations between Milliken and Evans, Colorado. This analysis was performed at the request of Varra Companies, Inc., (Varra). This report is being submitted in partial fulfillment of an OMLR 112 Mine Permit Application. Background Information The proposed gravel quarry is located in portions of sections 3 and 4 of Township 4 North, Range 66 West and sections 33 and 34, Township 5 North, Range 66 West of the 6th principal meridian. The surrounding land use consists of agricultural, rural residential and natural gas and oil gathering operations. The proposed mine occupies an estimated 380 acres with an active extraction area of approximately 270 acres. The water table at the site is located in unconsolidated alluvial deposits with an average depth to water of approximately six feet below ground surface. Soil conditions generally consist of varying thicknesses of top soil underlain by sand and gravel deposits, which in turn are underlain by claystone and sandstone bedrock. Over the entire area the average saturated thickness of the sand and gravel deposits (prior to mining) is estimated at about 35 feet. It is our understanding that the sand and gravel will be dewatered during aggregate extraction. The site location is presented on Figure 1. Previous Investigations WesTest, Inc., (WesTest) conducted a sand and gravel study in January 2015. The study consisted of drilling 12 soil borings from ground surface to bedrock to determine the potential aggregate mass within the proposed mine boundary. Selected sand and gravel samples were obtained for grain size distribution determinations. The depth to bedrock over the site varied between 12 and 47 feet below ground surface. The geotechnical investigation is presented as Attachment A. Overview of Stability Analyses Soil strength testing for the sand and gravel deposits was performed as part of the WesTest study. Density testing was not performed on field samples and unit weights used by the Division of Reclamation and Mining Safety were used for bedrock and overburden clay. Unit weight values reported by Terracon Consultants, Inc., and WesTest were used for the sand and gravel deposits. Slope Stability Analysis Pit 124 — Varra 112 Permit Application Weld County, Colorado Page 2 Table 1— Soil Strength Properties Material Wet Unit Weight (lbs/cu ft.) Saturated Unit Weight (lbs/cu ft.) Cohesive Intercept (PSF) Friction Angle Overburden Clay* 114 126 50-150 28 Sand, occasional gravel 114.4***/122** 132*** 0 35.6 Sand, with gravel 114.4***/122** 132*** 0 33.2 Sand, gravelly 114.4***/122** 132*** 0 45.1 Bedrock* 124 134 500 22 Note: * Unit weight values reported by DRMS ** Unit weight values reported by Terracon Consultants *** Remolded unit weight values reported by Knight Piesold Consulting The assumptions used in the bank stability analysis include the following: • The static depth to groundwater at the distance to no pumping influence is 6 feet below ground surface and the water table will intersect the pit bank just above the mine floor (seepage face) during steady state dewatering. • The pit depth will vary between 35 and 47 feet below grade. • During extraction activities the pit bank slope will vary between 2H:1V and 1.25H:1V. The software package PC-STABL was used to evaluate slope stability. Simulations using Spencer, and Modified Bishop methods were ran to determine the most conservative safety factor. The soil strength properties used in the analysis are presented on computer generated data sheets which are presented in Attachment B. Stability analyses were ran for the following scenarios: a 40 foot mine depth with a bank cut of 1.25H:1V, a 47 foot mine depth with a bank cut of 2H:1V for the bottom 20 feet and 1.25H:1V for the remaining slope and a 37 foot mine depth with a lower 20 foot bank cut of 2H:1V with the remaining slope of 1.25H:1V. It was assumed that a safety factor of 1.3 or greater will meet regulatory approval. Slope Stability Analysis Pit 124 — Varra 112 Permit Application Weld County, Colorado Page 3 Discussion As the stratigraphy varied significantly across the study area several model runs were made to simulate the conditions encountered during drilling. A review of the model results indicate that a safety factor of slightly greater than 1.3 is achieved for a uniform slope of 1.25H:1V at a bank height of 40 feet — this safety factor is contingent on the lower sand and gravel deposits having a friction angle of 45.1 degrees. This scenario is depicted on Plate 1 in Attachment B. In other stratigraphic sequences safety factors of slightly less than 1.3 are predicted. Model results indicate that using a lower bank slope (20 feet) of 2H:1V will result in safety factors of greater than 1.4 using any stratigraphic sequence. These scenarios are depicted on Plates 2-4. Using the different wet unit weights reported in Table 1, resulted in safety factor differences of less than 2 percent. Figure 2 presents the area that should be considered for the 20 foot modified cut slopes. If any significant modifications to proposed pit wall slopes occur this analysis may not be representative of site conditions and additional simulations are recommended. Comments The discussions and recommendations in this report represent our professional opinions. Our conclusions, opinions and recommendations are based from information available at this time and we do not guarantee that undiscovered conditions will not become evident in the future. AWES' report was prepared in accordance with currently accepted engineering practices at this time and location and no other warranties, representations or certifications are implied or intended. This report was prepared by AWES, LLC. Date: December 23, 2019 Joby L. Adams, P.G. Principal/Hydrogeologist REFERENCES WesTest, Inc., 2015. Geotechnical Investigation Two Rivers Property, Weld County, Colorado. Prepared for Varra Companies, Inc., Frederick, CO, February 2015. Terracon Consultants, Inc., 2011. Geotechnical Engineering Report, Great Western Sugar, Ash Avenue, Greeley, Colorado, January 2011. FIGURES Figure 1- Site Location Map Varra Companies - Conrad Capital Group Property _ s t Mill d _ 1O.V1 FEET a ,50.] IpX,METISS Map created with TOPO!t Z20112 National Geographic (wv.- nationalgeographic.comtopol T'_ti vR GROUND=4681.02 �, �TOP PIPE=4685.07 ATTACHMENT A Geotechnical Study Results �TesT 627 Sheridan Boulevard • Lakewood, CO 80214 P: 303.975.9959 • F: 303.975.9969 office@westest.net • www.westest.net February 24, 2015 Varra Companies 8120 Gage Street Frederick, CO 80516 Attention: Mr. Garrett Varra Subject: Direct Shear Test Results G eotechn i cal Investigation Two Rivers Property Weld County, Colorado WesTest Project No. 440515 Gentlemen: Enclosed are the results of direct shear testing performed by Knight Piesold Consulting in general accordance with ASTM D 3080 on aggregate sampled during the field investigation for the Two Rivers Property between January 27 and January 30, 2015. The aggregates were tested for shear failure using a 12 inch square by 5 inch deep box to accommodate the larger sized aggregate tested. A normal load of 2,000 psf was used for the middle point of each test to simulate the midpoint of an approximate forty foot high embankment. The angle of internal friction determined for each of the materials tested is described below: Location Description Friction Angle (9) Combined borings 5 and 9 SAND, with occasional gravel 35.6° Combined borings 7 and 10 SAND, with gravel 33.2° Combined borings 4, 5 and 12 SAND, gravelly 45.1° If you have any questions on the data presented, please contact us at your convenience. Sincerely, WesTest Zachary Wheeler, EIT Reviewed by: WesTest Eric R West, RE. Cursory interpretations provided require review by a professional engineer. Knight Piesold accepts no responsibility in subsequent analyses. Shear Stress, psf 6O00 4000 2O00 0 6000 5000 4000 3000 2000 1000 0 Fall. Ult. T i . 1 .i ie' / , I _. :... _:': ' . I.I. '.. C, psf de Tan 530 87 35.6 I 40.5 0.71 0.85 I I )' - '_ i I /I j 0 2000 4000 5 10 15 20 Strain, a/a 6000 Normal Stress, psf 800O 10000 12000 Specimen No. C m Water Content, % Dry Density, pcf Saturation, % Void Ratio Side Length, in. Height, in. Water Content, % Dry Density, pcf Saturation, % Void Ratio Side Length, in. Height, in. Normal Stress, psf Fail. Stress, psf Strain, % Ult. Stress, psf Strain, % Strain rate, in./min. 1 4.0 110.0 20.3 0.5323 12.00 5.00 4.0 110.0 20.3 0.5323 12.00 5.00 1000 1328 3.3 1008 15.0 0.02 2 3 4.0 110.0 20.3 0.5323 12.00 5.00 4.0 110.0 20.3 0.5323 12.00 5.00 2000 1834 4.7 1690 15.1 0.02 4.0 110.0 20.3 0.5323 12.00 5.00 4.0 110.0 20.3 0.5323 12.00 5.00 4000 3430 6.0 3532 14.9 0.02 Sample Type: remolded Description: SAND, with occasional gravel Location: Combination of Borings 5 & 9 Assumed Specific Gravity= 2.7 Remarks: Remolding parameters provided by client. Failure tangents drawn at peak shear stress and 15% strain, Test was not inundated. Figure Client: WesTest Project: WesTest #4405 Sample Number: 44051 Proj. No.: ❑V108-198/04 Date Sampled: 2/16/15 Knight Piesold CONSULTING Tested By: DAB Checked By: JOB 6000 4000 2O00 0 6000 5000 Shear Stress, psi Fail. Utt. I .. .i... . I ..... ._..--.., I I - .... _.. . . C, psf 4i, deg Tan(o) 803 490 33.2 35.2 0.65 0.70 _�. III, II. ,i I.I. I / I _• I i.:I -rIIJ; ,I 'I, I.I ,I I' ' ; I 1 II is I I.1 . '_i f I 200O 4000 0 5 10 15 Strain, % 20 6000 Normal Stress, psf 8000 10000 12000 Specimen No. 1 2 3 C Water Content, % Dry Density, pcf Saturation, a%o Void Ratio Side Length, in. Height, in. Water Content, % Dry Density, pet Saturation, % Void Ratio Side Length, in. Height, in. Normal Stress, psf Fail. Stress, psf Strain, % Ult. Stress, psf Strain, % Strain rate, in,/min, 4.0 110.0 20.3 0.5323 12.{}0 5.00 4.0 110.0 20.3 0.5323 12.00 5.00 1000 1337 5.2 1126 14.9 0.02 4.0 110.0 20.3 0.5323 12.00 5.00 4.0 110.0 20.3 0.5323 12,00 5.00 200O 2291 6.7 2002 15,1 0.02 4.0 110.0 20.3 0.5323 12.00 5.00 4.0 110.11 20.3 0.5323 12.00 5.00 4000 3359 13.3 3275 15.0 0.02 Sample Type: remolded Description: SAND, with gravel Location: Combination of Borings 7 & 10 Assumed Specific Gravity= 2.7 Remarks: Remolding parameters provided by client. Failure tangents drawn at peak shear stress and 15% strain, Test was not inundated. Figure Client: WesTest Project: WesTest #4405 Sample Number: 44052 Proj. No.: DV 108-198/04 Date Sampled: 2/17/15 Kniahi Piesold CONSULTiNG 6O00 4000 2000 0 6000 5000 Shear Stress, psf I. - I . I . ! . i-� ji I, Fail. Ult.- , : . C, psf $, deg Tan(0) 136 47 45.1 45.3 1.00 1.01 • A { ii f , l I I : I I 0 2000 4000 - { 5 10 15 20 Strain, % 6000 Normal Stress, psf 8000 10000 12000 Specimen No. 1 2 3 Water Content, % Dry Density, pcf 75 Saturation, °Io Void Ratio Side Length, in. Height, in. Water Content, % Dry Density, pcf 2 N Saturation, % Void Ratio Side Length, in. Height, in. Normal Stress, psf Fail. Stress, psi Strain, Ult. Stress, psf Strain, % Strain rate, in./min. 4.0 4.0 4.0 110.0 110.0 H0.0 20.3 20.3 20.3 0.5323 0.5323 0.5323 12.00 12.00 12.00 5.00 5.00 5.00 4.0 4.0 4.0 110.0 110.0 110.0 20.3 20.3 20.3 0.5323 0.5323 0.5323 12.00 12.00 12.00 5.00 5.00 5.00 1000 2000 4000 1114 2187 4142 3.9 13.6 17.9 1002 2145 4055 14.9 15.0 14.9 0.02 0.02 0.02 Sample Type: remolded Description: SAND, gravelly Location: Combination of Borings 4, 5 & 12 Assumed Specific Gravity= 2.7 Remarks: Remolding criteria provided by client. Failure tangents drawn at peak shear stress and 15% strain. Test was not inundated. Figure Client: WesTest Project: WesTest #4405 Sample Number: 44053 Proj. No.: DV 108498/04 Date Sampled: 2/19/15 Knx ht Presold CONSULTING Tested By: DAB Checked By: JDB �TesT 627 Sheridan Boulevard • Lakewood, CO 80214 P: 303.975.9959 • F: 303.975.9969 office@westest.net • www.westest.net GEOTECHNICAL INVESTIGATION TWO RIVERS PROPERTY WELD COUNTY, COLORADO Prepared for: Varra Companies 8120 Gage Street Frederick, CO 80516 Attention: Mr. Garrett Varra WesTest Project No. 440515 February 12, 2015 �TesT 627 Sheridan Boulevard • Lakewood, CO 80214 P: 303.975.9959 • F: 303.975.9969 office@westest.net • www.westest.net February 12, 2015 Varra Companies 8120 Gage Street Frederick, CO 80516 Attention: Mr. Garrett Varra Subject: Geotechnical Investigation Two Rivers Property Weld County, Colorado WesTest Project No. 440515 Gentlemen: At your request we have completed the geotechnical investigation for the above - referenced project. The attached report presents the data obtained during our field and laboratory investigation. The investigation was done in general accordance with our proposal dated January 8, 2015. We appreciate the opportunity to provide our services to you on this project. We are available to discuss the details of this report with you. Please contact us if you have any questions, or if we can be of further service. Sincerely, WesTest Reviewed by: WesTest Zachary Wheeler, EIT Eric R. West, P.E. Two Rivers Property, WesTest Project No. 440515, February 12, 2015 1 TWO RIVERS PROPERTIES PROJECT NO. 440515 TABLE OF CONTENTS SCOPE 3 SITE CONDITIONS 3 FIELD INVESTIGATION AND LABORATORY TESTING 3 SUBSURFACE AND GROUNDWATER CONDITIONS 4 AGGREGATE QUALITY 7 LIMITATIONS 7 BORING LOCATION PLAN LOGS OF BORINGS LEGEND AND NOTES GRADATION TEST RESULTS FIGURE 1 ...FIGURES 2 THROUGH 5 .FIGURE 6 .FIGURES 7 THROUGH 9 SUMMARY OF TEST RESULTS TABLES 1 THROUGH 3 Two Rivers Property, WesTest Project No. 440515, February 12, 2015 2 SCOPE This report presents the results of a geotechnical investigation for Varra Companies on the Two Rivers Property located in Weld County, Colorado. The investigation was conducted to evaluate subsurface conditions relative to sand and gravel reserves. The investigation was done in general accordance with our "Proposal for Geotechnical Engineering Evaluation" dated January 8, 2015. This report includes descriptions of the subsoil and groundwater conditions found in the exploratory borings. SITE CONDITIONS The site is located west of La Salle in Weld County, Colorado. The property occupies portions of Sections 3 and 4, Township 4 North, Range 66 West, and Sections 33 and 34, Township 5 North, Range 66 West of the 6th Principal Meridian. The property is bordered to the north by W. 54th Street Road. The South Platte River flows from the west and forms the southern and eastern boundaries of the property. The Big Thompson River bisects the property in the northern half. County Road 396 continues through the property starting in the southwest corner and coming to an end at W. 54th Street Road. The area investigated contains one dwelling accompanied by one barn and one garage, but is mainly undeveloped. Natural gas and oil wells, including collection and conveyance facilities, are located throughout the site. A large portion of the site is being used for agricultural purposes. FIELD INVESTIGATION AND LABORATORY TESTING Subsurface conditions were investigated by drilling twelve exploratory geotechnical borings at the locations indicated on the Boring Location Plan, Figure 1. The borings were drilled between January 27 and January 30, 2015, with a truck -mounted hollow stem auger drill rig. A WesTest engineer was on site during drilling to log the soils encountered and obtain samples. Bulk samples of the subsurface materials and Two Rivers Property, WesTest Project No. 440515, February 12, 2015 3 undisturbed samples of the bedrock were obtained during drilling operations. Twelve shallow borings were also investigated for the presence of petroleum releases in conjunction with an engineer from AWES, LLC. Samples from the borings were returned to our laboratory, visually classified and selected for testing. Graphic logs of the soils found in the borings and some of the laboratory testing results are presented on Figures 2 through 5, Logs of Borings. The Legend and Notes to interpret these logs are included as Figure 6. Included on the gradation and summary figures are descriptions of the soils encountered. Laboratory testing included moisture content and dry density, ASTM D 2216, washed gradation analysis, ASTM C 117 and C 136, liquid limit, plastic limit and plasticity index, ASTM D 4318, and unconfined compressive strength, ASTM D 2166. These test results are presented on Tables 1 through 3, Summary of Test Results, and Logs of Borings, Figures 2 through 5. SUBSURFACE AND GROUNDWATER CONDITIONS The subsurface conditions encountered in the borings generally consisted of one-half foot of topsoil overlying overburden which varied from silty sandy clay to silty sand. Beneath the overburden we encountered SAND, occasional gravel; SAND, with gravel; SAND, gravelly; Silty clayey SAND; CLAY; Claystone-Siltstone-Sandstone Bedrock; Claystone Bedrock and Sandstone-Siltstone Bedrock. Please refer to the Log of Borings, Figures 2 through 5, and the Legend and Notes prepared to interpret these logs, Figure 6, as each material is described below. TOPSOIL One-half foot of topsoil was encountered in all of the borings except borings 10 and 11. The topsoil is dark brown to black and organic. Two Rivers Property, WesTest Project No. 440515, February 12, 2015 4 OVERBURDEN We are describing all of the material below the topsoil that cannot be used as sand or gravel for construction materials production as overburden. This material was encountered beneath the topsoil in all of our borings except boring 3. The overburden varied from low plasticity sandy silty clay to silty sand. This material extended from the topsoil to depths up to fourteen feet in boring 11. The average depth to useable sand and/or gravel beneath the surface was six feet. SAND, WITH OCCASIONAL GRAVEL We have described the material which classifies mainly as poorly graded sand (SP) as SAND, with occasional gravel. In general, this material contained a majority of sand (- No. 4 sieve size), but there was fine gravel (about 1/2" largest diameter) present in varying quantities of 5 to 30 percent. The SAND, with occasional gravel, was encountered beneath the overburden or directly beneath the topsoil in borings 1, 6, 7, 8, 9 and 11, and extends to depths from fourteen to thirty-seven feet. This material was also found intermittently above and below the SAND, with gravel; SAND, gravelly; to be described below in borings 3, 4, 5, 10 and 12. SAND, WITH GRAVEL We encountered material in most of the borings which classifies as sand but has a noticeable amount of gravel present as SAND, with gravel. In general, this material contained a majority of sand (- No. 4 sieve size), but there was gravel with particle sizes of up to 1" diameter present in varying quantities, roughly 10 to 40 percent. The SAND, with gravel, was encountered beneath the overburden or directly beneath the topsoil, as in boring 10, and extends to a depth of ten to eighteen feet. This material was also found intermittently above and below the CLAY; SAND, with occasional gravel; SAND, gravelly; to be described below in borings 3, 5, 6, 7, 9, 10, 11 and 12. SAND, GRAVELLY We have described the material which classifies mainly as poorly graded sand (SP) but has larger gravel present as SAND, gravelly. In general, this material still contained a Two Rivers Property, WesTest Project No. 440515, February 12, 2015 5 majority of sand (- No. 4 sieve size), but there was gravel with particle sizes of up to approximately 3" diameter present. While the larger particles were present we expect them to be present in quantities of 5 to 15 percent. This material was encountered directly below the topsoil or beneath the overburden in borings 2, 3, 4 and 5. This material was encountered intermittently above and below the CLAY; SAND, with occasional gravel; SAND, with gravel; to be described below in borings 2, 3, 4, 5, 6, 7, 9 and 12. SILTY CLAYEY SAND Silty clayey SAND was encountered in boring 4 at a depth of thirty-five feet. This material was loose to medium dense, moist to wet and brown. CLAY A Lense of clay was encountered in boring 9, at a depth of twenty-six feet and a thickness of one foot. This clay was soft to medium stiff, very moist to wet and brown. SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK Sandstone-claystone-siltstone bedrock was encountered in borings 1, 2, 5, 7, 9 and 12, at depths ranging from twelve feet to forty-three feet with an average depth of thirty-one feet. This interbedded material was hard to very hard and ranged in color from gray to brown. CLAYSTONE BEDROCK Claystone bedrock was encountered in borings 3, 8, 10 and 11, at depths ranging from thirty-seven to forty-seven feet with a mean depth of forty-three feet. This material was very hard and gray. SANDSTONE-SILTSTONE BEDROCK Interbedded sandstone-siltstone bedrock was encountered in boring 6 at a depth of thirty- eight feet. This material was hard to very hard and ranged from brown to gray. Two Rivers Property, WesTest Project No. 440515, February 12, 2015 6 GROUNDWATER Groundwater was encountered in all of the borings, except boring 1, at depths of six to eighteen feet beneath the surface at the time of drilling. Groundwater monitoring wells were placed in all borings at the time of drilling for future monitoring operations. Water levels will fluctuate depending on environmental conditions and seasonal flows in the rivers and irrigation ditches. AGGREGATE QUALITY As previously discussed, the material sampled during drilling operations was tested for grain size distribution (gradation analysis). The material tested is from bulk samples taken from the auger flights during drilling operations. It is not possible to retrieve all of the material being drilled so results of gradations may not be representative of the true size of the material encountered. The results of the gradation analyses, which were performed on samples we anticipate could be used to produce construction materials, indicate 28.8% of the material tested is gravel (+No. 4 sieve size). The fine portion, silt and clay, (-No. 200 sieve size) averaged 3.7% and 67.5% of the material classifies as sand. LIMITATIONS The borings were drilled at the locations and to the depths agreed upon by the client and WesTest. Variations in the subsoil conditions not indicated by our borings are possible and should be anticipated due to the distance between borings. We believe this investigation was performed in a manner consistent with the level of care and skill ordinarily used by geotechnical engineers practicing in this area at this time. No other warranty, expressed or implied, is made. If we can be of further assistance in discussing the contents of this report, please contact us at your convenience. Two Rivers Property, WesTest Project No. 440515, February 12, 2015 7 22:5TesT 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net LOGS OF BORINGS PROJECT: Two Rivers Property WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler REPORT DATE: February 12, 2015 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) I Boring 1 Depth (ft.) Boring 2 Depth (ft.) I Boring 3 0 5 10 15 20 25 30 35 40 45 50 50/4 50/5 W = 16.1 DD = 114.0 0 5 10 15 20 25 30 35 40 45 50 50/4 W = 15.9 DD = 108.8 #200 = 67.3 Qu = 11,090 0 5 10 15 20 25 30 35 40 45 50 0 o p U p o ao p oO 0o p 0 d o a,<n o9'da: o q 0 d a oao 5. O O. °,o o o p;', 0 *-'. O o9op; o a 0 o an ° q 0 d o o p; 150/5 W=14.1 DD = 118.6 Qu = 18,440 FIGURE 2 T25T 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net LOGS OF BORINGS PROJECT: Two Rivers Property WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler REPORT DATE: February 12, 2015 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) Boring 4 Depth (ft.) Boring 5 Depth (ft.) Boring 6 0 5 10 15 20 25 30 35 40 45 50 0 25/12 W = 21.1 DD = 105.2 0 5 10 15 20 25 30 35 40 45 50 #4 = 57 #10=36 #40 = 16 #200 = 5.9 #4 = 84 #10 = 60 #40 = 22 #200 = 1.9 viii/ 50/3 W = 20.1 LL = 38 PI=14 #200 = 88.4 0 5 10 15 20 25 30 35 40 45 50 0 50/5 W = 15.6 DD = 115.9 Qu = 18,050 1 50/0 FIGURE 3 22:5TesT 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net LOGS OF BORINGS PROJECT: Two Rivers Property WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler REPORT DATE: February 12, 2015 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) Boring 7 Depth (ft.) I Boring 8 Depth (ft.) Boring 9 0 5 10 15 20 25 30 35 40 45 #4 = 60 #10 = 30 #40 = 11 #200 = 3.8 50/4 0 5 10 15 20 25 30 35 40 45 0 50/3 0 5 10 15 20 25 30 35 40 45 #4 = 86 #10 = 61 #40 = 18 #200 = 4.1 50/6 W = 24.6 DD = 99.3 Qu = 4,120 50 50 FIGURE 4 Vd.j.2.5TesT 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net LOGS OF BORINGS PROJECT: Two Rivers Property WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler REPORT DATE: February 12, 2015 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) Boring 10 Depth (ft.) I Boring 11 Depth (ft.) Boring 12 0 5 10 15 20 25 30 35 40 45 50 A 150/3 0 5 10 15 20 25 30 35 40 45 50 0 7 50/3 0 5 10 15 20 25 30 35 40 45 50 #4 = 69 #10 = 55 #40 = 22 #200 = 2.7 50/4 FIGURE 5 We TesT LEGEND AND NOTES 627 Sheridan Boulevard • Lakewood. CO 80214 303.975.9959 • office@westest.net TWO RIVERS PROPERTY PROJECT NO.: 440515 1111111111 Topsoil Overburden, silty sandy CLAY to silty SAND, TRACE GRAVEL, stiff, slightly moist to moist, light brown to dark brown SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown SAND, with gravel, loose to medium dense, slightly moist to wet, tan to brown SAND, gravelly, medium dense, wet, tan to brown Silty clayey SAND, loose to medium dense, moist to wet, brown CLAY, soft to medium stiff, very moist to wet, brown SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown CLAYSTONE BEDROCK, very hard, moist to very moist, gray SANDSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, brown to gray Indicates bulk sample location Indicates 2" Modified California Barrel Sample location (ASTM D 3550) Water level at number of days indicated a Caved at number of days indicated W Indicates % moisture (ASTM D 2216) DD Indicates dry density (pcf) (ASTM D 7263) Qu Indicates unconfined compressive strength (psf) (ASTM D 2166) 50/4 Location of sample; indicates that 50 blows with a 140 pound hammer, falling 30 inches, were required to drive a 2 -inch 1. Stem Augers. 2. The stratification lines represent the approximate boundary between soil types and the transition may be gradual. The boring logs show subsurface conditions on the date and at the locations indicated. It is not warranted that they are 3. diameter sampler 4 inches. 4. purposes of this report, but should be considered as approximate for any other use. The borings were drilled on January 27, 2015 through January 30, 2015, with a Longyear 66 Drill Rig and 4 1/4 I.D. Hollow representative of subsurface conditions at other locations and times within the project area. The boring locations were staked in the field by referencing to existing landmarks. The boring locations are adequate for 5. Free water was encountered in the borings as indicated. Fluctuations in the water level should be anticipated. FIGURE 6 zgi.5,TesT GRADATION TEST RESULTS TWO RIVERS PROPERTY WESTEST PROJECT NO. 440515 FEBRUARY 12, 2015 PERCENT PASSING PERCENT PASSING 100 90 80 70 60 50 40 30 20 10 0 Boring 5, 2' to 5', SAND, gravelly, medium dense, wet, tan to brown #200 #100 #40 #10 #4 3/8"1/2" 3/4" 1"1- /2"2" 0.01 0.10 1.00 PARTICLE DIAMETER (mm) 100 90 80 70 60 50 40 30 20 10 0 10.00 100.00 Boring 5, 12' to 14', SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown #200 #100 #40 #10 #4 3/A"1/2"._4" 1'1-1/2"2" 0.01 0.10 1.00 10.00 PARTICLE DIAMETER (mm) FIGURE 7 100.00 zgi.5,TesT GRADATION TEST RESULTS TWO RIVERS PROPERTY WESTEST PROJECT NO. 440515 FEBRUARY 12, 2015 PERCENT PASSING PERCENT PASSING 100 90 80 70 60 50 40 30 20 10 0 Boring 7, 16' to 18', SAND, with gravel, loose to medium dense, slightly moist to wet, tan to brown #200 #100 #40 #10 #4 3/8" 2" 3/4" 1"1-1/2"2" 0.01 0.10 1.00 PARTICLE DIAMETER (mm) 100 90 80 70 60 50 40 30 20 10 0 10.00 100.00 Boring 9, 16' to 18', SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown #200 #100 #40 #10 #4 'I/8"1/2" . 4"1"1-1/2"2" 0.01 0.10 1.00 10.00 PARTICLE DIAMETER (mm) FIGURE 8 100.00 zgi.5,TesT GRADATION TEST RESULTS TWO RIVERS PROPERTY WESTEST PROJECT NO. 440515 FEBRUARY 12, 2015 PERCENT PASSING 100 90 80 70 60 50 40 30 20 10 0 Boring 12, 27' to 37', SAND, gravelly, medium dense, wet, tan to brown #200 #100 #40 #10 #4 3/8"1/2" 3/4" 1"1-1/2"2" y//77/ 0.01 0.10 1.00 PARTICLE DIAMETER (mm) FIGURE 9 10.00 100.00 We TesT SUMMARY OF TEST RESULTS TWO RIVERS PROPERTY WESTEST PROJECT NO. 440515 FEBRUARY 12, 2015 Boring Number Sample Depth (ft.) Soil Description and Classification Moisture Content (%) Dry Density (pcf) Atterberg Limits Gradation Analysis % Passing Swell/Consol Test Results Qu (psf)* Water Soluble Sulfates (%) LL % PI #4 #10 #40 #200 Swell % Consol % 1 13 15 SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown 1 24 N E -S I LTSTO N E SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown 1 29 LTSTON E SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown 16.1 114.0 2 3 - 5 SAND, gravelly, medium dense, wet, tan to brown 2 15 LTSTON E SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown 15.9 108.8 67.3 11,090 3 6 - 8 SAND, gravelly, medium dense, wet, tan to brown 3 45 CLAYSTONE BEDROCK, very hard, moist to very moist, gray 14.1 118.6 18,440 4 14 - 16 SAND, gravelly, medium dense, wet, tan to brown 4 25 Silty clayey SAND, loose to medium dense, moist to wet, brown 21.1 105.2 5 2 - 5 SAND, gravelly, medium dense, wet, tan to brown 57 36 16 5.9 5 12 - 14 SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown 84 60 22 1.9 5 40 LTSTON E SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown 20.1 38 14 88.4 6 11 - 14 SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown Unconfined Compressive Strength TABLE 1 We TesT SUMMARY OF TEST RESULTS TWO RIVERS PROPERTY WESTEST PROJECT NO. 440515 FEBRUARY 12, 2015 Boring Number Sample Depth (ft.) Soil Description and Classification Moisture Content (%) Dry Density (pcf) Atterberg Limits Gradation Analysis % Passing Swell/Consol Test Results Qu (psf)* Water Soluble Sulfates (%) LL % PI #4 #10 #40 #200 Swell % Consol % 6 40 SANDSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, brown to gray 15.6 115.9 18,050 6 45 SANDSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, brown to gray 7 16 18 SAND, with gravel, loose to medium dense, slightly moist to wet, tan to brown 60 30 11 3.8 7 45 LTSTON E SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown 8 11 14 SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown 8 40 CLAYSTONE BEDROCK, very hard, moist to very moist, gray 9 16 18 SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown 86 61 18 4.1 9 40 SANDSTONE-CLAYSTONE-SILTSTONE LTSTON E BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown 24.6 99.3 4,120 10 12 - 15 SAND, with gravel, loose to medium dense, slightly moist to wet, tan to brown 10 50 CLAYSTONE BEDROCK, very hard, moist to very moist, gray 11 26 29 SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown 11 45 CLAYSTONE BEDROCK, very hard, moist to very moist, gray 12 21 24 SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown Unconfined Compressive Strength TABLE 2 We TesT SUMMARY OF TEST RESULTS TWO RIVERS PROPERTY WESTEST PROJECT NO. 440515 FEBRUARY 12, 2015 Boring Number Sample Depth (ft.) Soil Description and Classification Moisture Content (%) Dry Density (pcf) Atterberg Limits Gradation Analysis % Passing Swell/Consol Test Results Qu (psf)* Water Soluble Sulfates (%) LL % PI #4 #10 #40 #200 Swell % Consol % 12 28 38 SAND, gravelly, medium dense, wet, tan to brown 69 55 22 2.7 12 40 SANDSTONE-CLAYSTONE-SILTSTONE N E -S I LTSTO N E BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown Unconfined Compressive Strength TABLE 3 ATTACHMENT B PC-STABL Results Plate 1 Problem: Two Rivers Stability Analysis - EslI]- Bishop = 1.303 70 6E 60 as EO #` 40 30 25 20 ]5 10 -10 Soils Cohesion Friction Angle eMir Bedrock 500.0 1.t.0 End,grl 0.0 4E] End w gravel 0.0 33.2 Sand 0.0 2S. ' ater —able CrKicalSurface -10 -5- 0 10 ]5 20 2E 30 3E §0 45 50 E.E. 60 6E 70 75 SO S5 DO §E 100 105 110 (Scale in Feet Plate 2 Problem: Two Rivers Stability Analysis - FS Min- Spencer = 1.407 Soils Cohesion Friction I Angle Bedrock 500.0 14.0 Sand v. Gr l 0.0 :2.2 Sand 0.0 End, Or; Iy 0.0 45.1 Clay E0.0 2S.0 V. ate r —able Critical Surface 0 10 20 30 .0 F•0 (Scale in Feet; TO 80 D0 100 110 120 -10 Plate 3 Problem: Two Rivers Stability Analysis - FS Min- Bishop = 1.533 70 CC 50 45 C 30 2E 20 1E- 10 0 0 10 20 30 40 E.0 50 (Scale in Feet; TO 80 D0 100 110 120 Clay 'A'ate r able Critical Surface Plate 4 Problem: Two Rivers Stability Analysis - FS Min- Spencer = 1.41 70 CC 50 45 40 C 30 2E 20 1E- 10 0 0 10 20 30 40 E.0 50 (Scale in Feet; TO 80 D0 100 110 120 Clay 'A'ate r able Critical Surface Hello