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Home My WebLink About20232871.tiffUSE BY SPECIAL REVIEW (USR) APPLICATION FOR PLANNING DEPARTMENT USE: AMOUNT $ APPLICATION RECEIVED BY DATE RECEIVED: CASE # ASSIGNED: PLANNER ASSIGNED: P ROPERTY INFORMATION Is the property currently in violation? ✓ No / Parcel Number: 0 9 6 Yes Violation Case Number: 1 2 3 4 _0 0 _0 0 S ite Address: near 22543 County Road 54, Greeley, CO 80631 7 Legal Description: A portion of S2SE4 23 5 65 EXC COMM NE COR S2SE4 S89D16W 2635.44 N00D47W 21.72 N89D45E 2635.56 TO POB Section: 23 , Township 5 Within subdivision or townsite? N, Range 65 No / Yes Name: Water (well permit # or water district tap #): N/A W Zoning District: A Acreage: 79.446 Sewer (On -site wastewater treatment system permit # or sewer account #): N/A Floodplain No/ Yes Geological Hazard P ROJECT U SR Use being applied for: Solar Facilities Name of proposed business: CBEP Solar 27, LLC No/ Yes P ROPERTY OWNER(S) (Attach additional sheets if necessary.) Name: Thomas & Marjorie Brown Airport Overlay No / ✓ Yes Company: Phone #: (970) 339-3939 Email: N/A Street Address: 22509 County Road 54 City/State/Zip Code: Greeley, CO 80631 APPLICANT/AUTHORIZED AGENT (Authorization Form must be included if there is an Authorized Agent) Name: Zach Brammer Company: CBEP Solar 27, LLC Phone #: (970) 425-3175 Email: zach@cloudbreakenergy.com Street Address: PO Box 1255 City/State/Zip Code: Sterling, CO 80751 I (We) hereby depose and state under penalties of perjury that all statements, proposals, and/or plans submitted with or contained within the application are true and correct to the best of my (our) knowledge. All fee owners of the property must sign this application. If an Authorized Agent signs, an Authorization Form signed by all fee owners must be included with the application. If the fee owner is a corporation, evidence must be included indicating the signatory has the legal authority to sign for the corporation. g,..,, 'gnat e Zachary Brammer 04/29/2023 Date Signature Date Print Print 07/22 9 (Owner please print) DEPARTMENTS OF PUNNING .BUIL INC, D ENViRQNMEj HEALTH 1402 NCB TN 17 AUTH TION FORM , give permtsson to (Avi to apply for any Fu1lanning, Building, Access, Grading • r VIM perm can our beh located at (address or parcel number) below: on 12 Description: 000l 351M. NOON4110) ubdLvision dame: Rope Addces ho Owners Informati of Section Townsr Z63Lr&71, POS Auth trized Ag e nVA'ppt tea nt Contact information: Address: Phone: 31 75 orresc:ondeno to •e sent to: Additional Info: ii er _ Authorized AgenUAppitcant MEttIT V'ENUF 1 1. scie GREE.LE CC a Its,* larr- aMMENI Olt egor 4Jr a, jail 914 4. � (We) hereby cei, under p4nHai perjury and fter cartluily reading the entire contents oft d cument, that the information stated above is tree and correct to the best •f any ur) knowled Omer Signature Subscribed and bwurn to bufOr My comniivinn ox e mo this rt �r�rw��irar��iwi��,�dr��i��i��►1ii��F�Nth��unii��a��,��,��n��w 'i CiiPicTOI'ilitft MiNWTCi,1 Pr4( M11 ii %JAI It4 UI' COLURADU )40TAry wimoisposs OWfA1!iit)N I ,pIIii "„ c JO, ��,+ir�u�n�i��Ir�oii�nii�un��Ht�llll�llll�lllllll#11iN1l1141#��u�� F 7iff cr,tate aisigs.„*ra S.. Stew 4.46,„ a . .- s___ or Sigtuittiro day of tit Liu iuIiic lit f 4753381 09/07/2021 12:33 PM Total Pages: 5 Rec Fee: $33.99 Carly Koppes - Clerk and Recorder, Weld County , CO MEMORANDUM OF LEASE AND EASEMENT OPTION AGREEMENT THIS MEMORANDUM OF LEASE AND EASEMENT OPTION AGREEMENT ("Memorandum") is entered into as of 113 , 2021 by and between Thomas D. Brown and Marjorie A. Brown (together, "Owner"), and Cloudbreak Energy Partners, I...,i..LC, a Delaware limited liability company, and its successors and assigns ("Operator") RECITALS A. Owner and Operator have entered into that certain Lease and Easement Option Agreement (the "Lease Agreement"), dated cepttvi ker , 2021 (the "Effective Date"), whereby Owner has granted Operator the right to conduct due diligence on the Owner's Property and an option to lease and develop a portion of the Owner's Property (the "Option"), together with easement rights on, over, under, across, and through said Owner's Property, in the County of Weld, State of Colorado, and being more particularly described in Schedule A attached hereto and made a part hereof (the "Owner's Property"). B. This Memorandum is being executed and recorded to evidence the Lease Agreement and shall not be construed to limit, amend or modify the provisions of the Lease Agreement in any respect. MEMORANDUM 1. OWNER. The name of the Owner is Thomas D. Brown and Marjorie A. Brown, with an address of 22509 County Road 54, Greeley, CO 80631. 2. OPERATOR. The name of the Operator is Cloudbreak Energy Partners, LLC, a Delaware limited liability company, having an address of 4845 Pearl East Circle, Suite 118 #53242, Boulder, Colorado 80301, and its successors and assigns. 3. LEGAL DESCRIPTION. The specific legal description of the Owner's Property is described on Schedule A and is incorporated herein by this reference. 4. OPTION TERM. Owner has granted Operator the right to conduct due diligence on the Owner's Property to determine ifthe Operator would like to enter into a lease. The initial term of the Option Agreement is a period commencing on cc9tex'b-tr 3 , 2021 and ends on sertmkr 3, 2024. The term of the Option may be extended, at Operator's discretion, for one calendar year(s), as provided in the Lease Agreement. 5. LEASE TERM. In the event the Option is exercised under the Lease Agreement, the term of the lease will commence on the Commencement Date (as defined in the Lease Agreement) and shall expire on the twentieth (20`'') anniversary of the Commercial Operation Date (as defined in the Lease Agreement). 6. EXTENTION TERMS. Operator has the option to extend the term of the lease for three (3) additional extension terms of five (5) years each on the terms and conditions more particularly set forth in the Lease Agreement. 7. EASEMENTS. In connection with the Lease Agreement, Owner has granted or has agreed to grant Operator a number. of easements on, over, under, across and through Owner's Property, which are fully described in the Lease Agreement. 1 4845-5419-05843 4753381 09/07/2021 12:33 PM Paget of5 My Notary number is: 8. OTHER TERMS. In addition to those terms referenced herein, the Lease Agreement contains numerous other terms, covenants and conditions. and notice is hereby given that reference should be made to the Lease Agreement directly with respect to the details of such terms, covenants, and conditions. In the event of a conflict between the provisions of this instrument and the Lease Agreement, the provisions of the Lease Agreement shall control. 9. AGREEMENT TO COOPERATE. At the request of Owner after expiration of the termination of the Lease Agreement, Operator shall reasonably cooperate with Owner in all respects with obtaining the removal of the memorandum from title, including without limitation executing a termination of Memorandum in form reasonably required by Owner. EN WITNESS WHEREOF, the undersigned have caused this instrument to be executed as of the date first written above. OWNER R oel 31:12_,30a14.0.1 Thomas Brown STATE OF COLORADO COUNTY/CITY OF W di, ) ss. The foregoing instrument was acknowledged before me this bYlehcinti3 won Witness my hand and official seal My commission expires: May I I, 2(�� 201540is525 3 day of 5 12-1!! , 2021, MELISSA PINON NOTARY PUBLIC STATE OF COLORADO NOTARY ID 2015401 8525 MY COMMISSION EXPIRES MAY 11, 2023 [Remainder of page intentionally blank. Signatures continue on following pages.] 2 4845-54.19-0584.7 4753381 09/07/2021 12:33 PM Page 3of5 My commission expires' My Notary number is: 484 541 L34. 7 Marjo e Brown STATE OF coLORADO COUNTY/CITY OF ' in 'nstrument was acknowledged before me this 3 day of Thee foreg _1 • Witness my hand and official seal / 0 ot__' j�(On Notary ublic 2o%54oI3525 J maiMmlWasPENIdWMar MELISSA PINON NOTARY PUBLIC STATE OF COLORADO NOTARY ID 20154018525 MY COMMISSION EXPIRES MAY 11, 2023 k. Signatures continue on following pages.1 1 [Remainder of page intentionally blan 4753381 09/07/2021 12:33 PM Page 4of5 OPERATOR Cloudbreak Energy Partners, LLC, a Delaware limited liability company By: Nam-�. STATE OF COLORADO ) ss. COUNTY OF ) this 3day of ,2�D2l,by me �' The f'*regoing instrum nt was acknowledged before --- ,r�er Partners, LLC, a the Si of Cloudbreak gY De law limited liability company, on be if of the limited liability company. Witness my hand and official seal My commission expires: 4845-5419-0584.7 °FAA 17023 Nota Public 4aPilion MELISSA PINON NOTARY PUBLIC STATE OF COLORADO NOTARY ID 20154018525 MY COMMISSION EXPIRES MAY 11, 2023 4 4753381 09/07/2021 12:33 PM Page 5 of 5 Schedule A TO MEMORANDUM OF LEASE AND EASEMENT OPTION AGREEMENT Legal Description of Owner's Property The following real property located in the County of Weld, State of Colorado: S2SE4 23 5 65 EXC COMM NE COR S2SE4 S89D16W 2635.44 NOOD47W 21.72 N89D45E 2635.56 TO FOB 5 484544194)584,7 Al TRC January 13, 2023 Brandon Marette Energy Liaison and Land Use Coordinator Colorado Parks and Wildlife Northeast Region Office 6060 Broadway Denver, CO 80216 123 N. College Ave., Ste. 370 T 970.484.3263 Fort Collins, CO 80524 TRCcorimpanies.corn Sent via email to: brandon.marette@state.co.us RE: Cloudbreak Energy Partners, LLC — Union Colony Solar Project Review and Request for Concurrence Mr. Marette, Cloudbreak Energy Partners, LLC (Cloudbreak) is seeking assistance with identifying developmental constraints for the Union Colony Solar Project (Project, Project Area), a proposed solar photovoltaic energy development. The Project Area occupies approximately 79.4 acres located north of County Road 54 west of County Road 47 in Weld County, Colorado (Township 5N Range 65W Section 23). Figure 1 illustrates the location of the Project. TRC completed a Project -specific desktop analysis to identify critical development issues. The following biological resources were identified within the Project Area: • The Project Area consists primarily of land classified as cultivated crops, and a small amount of land in the southwestern portion of the Project Area classified as low to high intensity developed land. • TRC conducted a wetland and waterbody analysis of the Project Area using U.S. Geological Survey National Hydrography Dataset and U.S. Fish and Wildlife Service National Wetlands Inventory desktop data and identified two man-made hydrological features within the 79.4 -acre Project Area. One irrigation ditch is located in the southeastern section of the Project Area and a second irrigation ditch is located in the western portion of the Project Area (Figure 2). The Project Area does not sit within a Federal Emergency Management Agency floodplain. • The Colorado Parks and Wildlife (CPW) Threatened and Endangered Species List includes 31 state -listed threatened and endangered species including one amphibian species, eight bird species, 14 fish species, and eight mammal species. According to CPW Species Activity Maps and High Priority Habitats GIS data, the Project Area is within the breeding range of the burrowing owl and overall range of the Preble's meadow jumping mouse. See Figure 3. Based on an assessment of each species' habitat requirements, range, and distribution, it is unlikely potentially suitable habitat for any state listed threatened or endangered species other than the burrowing owl is present within the Project Area. • According to data from the CPW Wildlife Species Map Application, the Project Area lies within the golden eagle breeding range. Although foraging habitat may be present, the Project Area lacks any nesting substrate (cliffs or large trees) to support breeding golden eagles. • The Project Area does not lie within any known bald eagle ranges or foraging areas. There are two known active bald eagle nests within approximately 2.5 miles of the Brandon Marette January 13, 2023 Page 2of2 Project Area, one is approximately 1.5 miles northwest of the Project and the other is approximately 2.5 miles east of the Project. The Project Area is approximately 0.8 miles south of bald eagle summer forage, bald eagle winter forage, bald eagle winter concentration, and bald eagle winter range (Figure 3). The nearest bald eagle roost site is located at the Lower Latham Reservoir, approximately 1.7 miles southwest of the Project. • The Project Area is within mule deer overall range. The Project Area sits approximately 0.7 miles south of mule deer winter range, mule deer severe winter range, and a mule deer concentration area. There are two mule deer highway crossings within one mile of the Project Area, to the northwest along U.S. Highway 34. The Project Area is not within or near a mule deer migration corridor (Figure 3). TRC, on behalf of Cloudbreak, requests CPW's review and concurrence of the state -listed species findings. Cloudbreak will coordinate with CPW to develop applicable avoidance and minimization measures, where required. If species -specific surveys are recommended, please provide the preferred survey methodology. Project -specific shapefiles have been provided to assist in your review. If you have any questions regarding this request, please contact me at (970) 214-3338 and plorenz@trccompanies.com. Thankyou in advanceforyourpromptresponsetothisrequest. Sincerely, Patti Lorenz Senior Environmental Specialist 50,kp Ben Hall Biologist Enclosures: Figure 1 (Project Overview); Shapefiles Figure 2 (Hydrology Map) Figure 3 (CPW High Priority Habitat Overview); Shapefiles cc: Zach Brammer (Cloudbreak) Alec Shobe (Cloudbreak) Jamie Schlangen (TRC) 'T NAME: UNIONCC:' ON 1 C!i2(JRE' z C 3Y.: RLEE ON 1/9/2023, 11:36:04. AM: FILE PATH: T I 1-PROJr LAYOUT NAME UN(ONCOI ONY F(GURE2 OORDINATE SYSTEM: NAD 1983 2011 STATEPLANE COLORADO NORTH TIPS 0501 FT US: MAP ROTATION: 0 PROJECT: NWI WETLAND SITE BOUNDARY BASE MAP: GOOGLE SATELLITE (2021). DATA SOURCES: TRC, COLORADO PARKS AND WILDLIFE 200 400 FEET 1:4.800 1" = 400' CLOUDBREAK ENERGY PARTNER UNION COLONY SOLAR SITE WELD COUNTY, COLORADO NM KS TITLE: SURFACE HYDROLOGY MAP DRAWN BY: B. LEE CHECKED BY: B. TRACY APPROVED BY: B. HALL DATE: JANUARY 2023 PROJ. NO.: 516145 FIGURE 2 1526 COLE BOULEVARD BUILDING 3, SUITE 150 LAKEWOOD, CO 80401 PHONE: 303.792.0122 FILE: UNIONCOLONY •R1tN1TESYSTEM: N•! 19832111 STJTEPLINE C•L•RA • N•RTHFI',SC7509MAPR•T1Tl•N: (J LAYOUT NAME UNIONCOLONY FIGURE3 33Y::I3LEEON 1/4/2023, 09:32:59 AM: FILE PATH: T.t1-PROJF SICSEPl516145 UNIONCOLONYt2-APRX\UNIONCOLONYAPRX: J t SITE BOUNDARY BALD EAGLE ACTIVE NEST SITE HPHC MULE DEER SEVERE WINTER RANGE HPHD BALD EAGLE ACTIVE NEST SITE HPHE1 BALD EAGLE ROOST SITE HPHE1 BASE MAP: GOOGLE SATELLITE (2021). DATA SOURCES: TRC, COLORADO PARKS AND WILDLIFE PROJECT: CLOUDBREAK ENERGY PARTNER UNION COLONY SOLAR SITE WELD COUNTY, COLORADO TITLE: CPW HIGH PRIORITY HABITAT OVERVIEW PROJ. NO.: 516145 FIGURE 3 AA) TrIC 1526 COLE BOULEVARD BUILDING 3, SUITE 150 LAKEWOOD, CO 80401 PHONE: 303.792.0122 FILE: UNIONCOLONY CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Planning Questionnaire 1. Explain the proposed use and business name: o CBEP Solar 27, LLC is proposing to construct and operate the Union Colony Solar Project ("Project") in unincorporated Weld County on Parcel ID number 096123400007. The Project will be a 3.4 MWac community solar garden and will be constructed on approximately 20.96 acres of privately owned land. It will consist of solar modules mounted about 5 feet above the existing grade on single -axis trackers, which allow the panels to track the sun from east to west over the course of the day. The project will also include inverters mounted on steel posts or beams, concrete -pad mounted transformers, other electrical equipment, an access road, and a perimeter game fence with gates. 2. Explain the need for the proposed use: o Ensuring long-term energy security for the United States requires a mixture of all different types of energy production, including community solar projects like the Union Colony Solar Project. 3. Describe the current and previous use of the land. o The land is currently vacant (no existing water rights to be used for crop production) and has historically been used for oil and gas production. 4. Describe the proximity of the proposed use to residences. o The nearest residence is 200 feet from the northern side of the Project's fenceline. 5. Describe the surrounding land uses of the site and how the proposed use is compatible with them. o The surrounding land uses include oil and gas production and agricultural land. The parcel approximately 450 feet southeast of the Project site on County Road 54 is a storage yard for industrial/oil and gas equipment. The Project will not interfere with any of the nearby uses. The aesthetics of a community solar garden will fit in well with the surrounding uses. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE 2 6. Describe the hours and days of operation (i.e. Monday thru Friday 8:00 a.m. to 5:00 g,m,), o Construction activities will take place Monday through Saturday from 7:00 a.m. to 6:00 p.m. After construction is completed, occasional maintenance will occur between 7:00 a.m. and 7:00 p.m. as needed. 7. Describe the number of employees including full-time, part-time and contractors. If shift work is proposed, detail number of employees,, schedule and duration of shifts. o Construction may require up to 50 workers to be on site at one time during the peak of construction, all contractors during the day shift. Construction employees may include up to 15 civil workers, 15 electricians, 15 racking builders, and an additional 5 employees. During operations, two to four employees may be needed for maintenance, as needed, approximately twice a year. 8. Describe the maximum number of users, patrons, members, buyers or other visitors that the site will accommodate at any one time. o No users, patrons, members, buyers, or other visitors are expected to be on the site at any time. 9. List the types and maximum numbers of animals to be on the site at any one time (for dairies, livestock confinement operations, kennels, etc.). o There will be no animals on the site. 10. List the types and number of operating and processing equipment. o The Project will consist of approximately 8,268 solar modules mounted about 5 feet above the existing grade on single -axis trackers, which allow the panels to track the sun from east to west over the course of the day. The project will also include 34 inverters mounted on steel posts or beams, 2 concrete pad mounted transformers, and other electrical equipment. 11. List the types, number and uses of the existing and proposed structures. o There are no existing structures on the Project's site. o The proposed structures for the Project will include: i. Approximately 8,268 solar modules mounted about 5 feet above the existing grade on single -axis trackers, which allow the panels to track the sun from east to west over the course of the day. ii. 34 inverters mounted on steel posts or beams iii. 2 concrete pad mounted transformers iv. Approximately 5 utility poles that will connect the project to the existing Xcel Energy distribution line on the located on the south side of the parcel. of the property. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGE 3 v. One temporary construction trailer vi. Two 10' x 40' storage containers that will store parts, tools, and equipment on site during construction and operations 12. Describe the size of any stockpile, storage or waste areas. o During construction, a laydown area located within the limits of the Project area will be used to store Project facility items while facilities are installed. During operations, there will be no open stockpiling, uncovered storage, or waste areas. Up to two storage containers approximately 40 -feet in length, 10 feet in width, and 10 feet in height to store spare parts, tools, and equipment on site during construction and operations. 13. Describe the method and time schedule of removal or disposal of debris junk and other wastes associated with the proposed use. o Debris, junk, and other wastes will be stored in appropriate waste receptacles such as dumpsters during construction. CBEP Solar 27, LLC or its contractors will hire a waste management provider to regularly remove wastes associated with construction of the Project from the receptacles and bring the waste to an approved landfill or disposal site. Maintenance contractors will properly dispose of any wastes generated during operation of the Project by bringing the wastes to an approved landfill or disposal site. 14. Include a timetable showing the periods of time required for the construction of the operation. o Project construction is expected to begin in Q1 2024 and is expected to be completed in 02 2024. Construction activities would follow the estimated timetable below: Construction Phase Season/Duration Construction Begins Q1 2024 Site preparation 1-2 months Structural work 3-5 months Electrical work 2-4 months Utility work 2-4 months Construction Completion Q2 2024 15. Describe the proposed and existing lot surface type and the square footage of each type (i.e. asphalt, gravel, landscaping, dirt, grass, buildings). (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGE 4 o The existing lot surface type is all vegetated land. The proposed surface types and square footage of each type are listed below: i. Concrete: 173 sq ft ii. Gravel: 32,183 sq ft iii. Swales: 3,631 sq ft iv. Grass/Vacant: 167,302 sq ft v. Solar Racking: 759,129 sq ft 16. How many parking spaces are proposed? How many handicap -accessible parking spaces are proposed? o No parking spaces or handicap -accessible parking spaces are proposed. 17. Describe the existing and proposed fencing and screening for the site including all parking and outdoor storage areas. o There is no existing fencing or screening on the site. The Project will be surrounded by a game fence that is at least 7 feet tall. 18. Describe the existing and proposed landscaping for the site. o No existing landscaping. See landscaping/screening details for details on proposed future landscaping. 19. Describe reclamation procedures to be employed as stages of the operation are phased out or upon cessation of the Use by Special Review activity. o Decommissioning of the Project will commence within 12 months after power production has permanently ceased and be completed within 12 months of the decommissioning work commencing. Decommissioning will include the removal of: i. All non -utility owned equipment, conduits, structures, fencing, and foundations to a depth of at least three (3) feet below grade ii. All fences, graveled areas and access roads unless the property owner agrees for this to remain o The property will be restored to a condition reasonably similar to its condition prior to the development of the Project 20. Describe the proposed fire protection measures. o The Project is located within the La Salle Fire Protection District. The Project will comply with all Colorado Public Utilities Commission requirements as well as national codes and standards for construction, electrical, and fire. A supervisory control and data acquisition (SCADA) system will remotely monitor and control the Project 24 hours per day. The SCADA system will transmit Project data and control signals over the internet. (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGES 21. Explain how this proposal is consistent with the Weld County Comprehensive Plan per Chapter 22 of the Weld County Code. o The Project is consistent with the Weld County Comprehensive Plan because it: ' i. Does not interfere with any existing agricultural operations within the vicinity. ii. Respects private property rights by allowing the owner of the property to do what is in their best interest while complying with local regulations and not interfering with or infringing upon the rights of others. iii. Promotes economic growth and stability by providing a diversified source of income for the landowner, the shepherd, and the County while also offering local residents the opportunity to save money on their electricity bills through Xcel's Solar*Rewards Community Program. iv. Protects the health, safety, and general welfare of the citizens of the County by providing an emission -free source of energy. v. Is harmonious with surrounding agricultural and industrial uses. vi. Supports future mineral development by reserving space on the landowner's property where minerals can be extracted in the future. II 22. Explain how this proposal is consistent with the intent of the zone district in which it is located. (Intent statements can be found at the beginning of each zone district section in Article III of Chapter 23 of the Weld County Code.) o The landowner will continue using the water rights associated with the Project parcel on their other agricultural land. By allocating a portion of this land to the solar development, the property will be able to better allocate water to the remaining agricultural land that the landowne owns. The new solar development will also not interfere with any of the surrounding agricultural land uses. The Project's array will protect the land underneath and in turn allow the soil to revitalize over time, therefore preserving the land to be used for agricultural purposes in the future, if desired. We will be planting a native seed mixture on the property that will not require irrigation. 23. Explain how this proposal will be compatible with future development of the surrounding area or adopted master plans of affected municipalities. o The Project will be located within the Town of Kersey and the Town of Evans' Intergovernmental Agreement area. (970) 425-3175 I I N FO©a CLOU DBPEAKEN EPGY.COM I CLOU DBPEAKEN EPGY.COM CLOUDBREAK PAGE6 o The Project's area is included on the Future Land Use maps in the 2016 Town of Kersey Comprehensive Plan which identifies the land as "Undetermined Use". Therefore, the proposed solar development will not go against any established future plans. As described in the Town of Kersey Comprehensive Plan, one of the action items (R2.5.4) is "continue to explore alternative energy sources (solar, wind, etc.) and new technology for power sources and other critical infrastructure." This Project would allow the Town of Kersey to meet their clean energy exploration goals and continue pursuing more renewable initiatives such as the "Sustainable Energy City" designation also mentioned in the Comprehensive Plan. The Project's area is included in the Future Land Use maps in the 2022 City of Evans Master Community Plan which identifies the land as "Rural Residential". The document includes "energy production facilities" as a one of the secondary intended uses of the land earmarked for rural residential use. Therefore, the proposed solar development will not go against any future plans that the city has established. This project will fit in well with a future rural residential development due to the minimal noise, odor, traffic, and visibility impacts of a solar array. Additionally, this solar array will help reduce the energy burden on the local energy grid as local energy increases due to the city's growth. 24. Explain how this proposal impacts the protection of the health, safety and welfare of the inhabitants of the neighborhood and the County. o The Project is not anticipated to impact the health, safety, and welfare of Weld County citizens. Designs will comply with Colorado Public Utilities Commission requirements as well as national codes and standards for construction, electrical, and fire. A supervisory control and data acquisition (SCADA) system will remotely monitor and control the Project 24 hours per day. The SCADA system will transmit Project data and control signals over the internet. 25. Describe any irrigation features. If the proposed use is to be located in the A (Agricultural) Zone District, explain your efforts to conserve prime agricultural land in the locational decision for the proposed use. o The landowner will continue using the existing water rights on the their other prime agricultural land. By allocating a portion of this land to the solar development, the property will be able to better allocate water to the remaining agricultural land that the landowner owns. We will be planting a native seed mixture on the property and keeping the vegetation at a height of no more than 18-22 inches. 26. Explain how this proposal complies with Article V and Article XI of Chapter 23 if the proposal is located within any Overlay Zoning District (Airport, Geologic Hazard, or (970) 425-3175 I INFO©aCLOUDBPEAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGE7 Historic Townsites Overlay Districts) or a Special Flood Hazard Area identified by maps officially adopted by the County. o Flood Hazard, Geologic Hazard, and Historic Townsites: The Project is not located within the 1% Annual Chance Flood Hazard Area (Flood Zone A). According to the Colorado Geological Survey, no geologic hazards were identified within the Project Area. The Weld County property portal's Historic Townsite layer showed no presence of historic sites within the Project Area. o Airport: The Project is located within the Airport Overlay District. This District has unique height limitations as well as unique use restrictions. The use restrictions in Section 23-5-40 of the Weld County Code are defined as follows: "Notwithstanding any other provisions of this Division, no USE may be made of land or water within any zone established by this Division in such a manner as to create electrical interference with navigational signals or radio communication between the GREELEY-WELD COUNTY AIRPORT and aircraft, make it difficult for pilots to distinguish between GREELEY-WELD COUNTY AIRPORT lights and others, result in glare in the eyes of pilots using the GREELEY-WELD COUNTY AIRPORT, impair visibility in the vicinity of the GREELEY-WELD COUNTY AIRPORT, create bird strike hazards or otherwise in any way endanger or interfere with the landing, takeoff or maneuvering of aircraft intending to use the GREELEY-WELD COUNTY AIRPORT." As detailed below, the Project complies with these use restrictions as well as the height limitations: i. Electrical Interference - According to "Electro-Magnetic Interference from Solar Photovoltaic Arrays" published by the U.S. Department of the Navy, "The Federal Aviation Admiration (FAA) has indicated that EMI from PV installations is low risk. PV systems equipment such as step-up transformers and electrical cables are not sources of electromagnetic interference because of their low -frequency (60 Hz) of operation and PV panels themselves do not emit EMI. The only component of a PV array that may be capable of emitting EMI is the inverter. Inverters, however, produce extremely low frequency EMI similar to electrical appliances and at a distance of 150 feet from the inverters the EM field is at or below background levels." ii. Lights - The Project will not include any lighting, therefore there will be n o effect in distinguishing Greeley -Weld County Airport lights and others. iii. Glare - CBEP Solar 2, LLC performed a glare analysis for the Project which is included within the application package. The Project will follow all FAA regulations and utilize mitigation measures proposed by the study. iv. Visibility - The Project will not impair visibility. (970) 425-3175 I I N FO©a CLOU DBPEAKEN EPGY.COM I CLOU DBPEAKEN EPGY.COM CLOUDBREAK PAGE 8 v. Bird Strikes and Other Hazards: The Project will not create bird strike hazards or otherwise in any way endanger or interfere with the landing, takeoff or maneuvering of aircraft intending to use the Greeley -Weld County Airport. There will be no lights on the array nor anything else that would attract birds to the project area. vi. Height Limitations: Upon review of the Greeley -Weld County Airport Master Plan's Airport Layout Plan drawings, the parcel containing the Project Area was identified as a part of the Transitional Zone as well as the Horizontal Zone. The Project abides by the Airport Zone height limitations of both the Transitional Zone and the Horizontal Zone outlined in Sec. 25-5-30. 27. Detail known State or Federal permits required for your proposed use(s) and the status of each permit. Provide a copy of any application or permit. o There are no Federal permits required for the Project. o There are two State permits that may be required - the Colorado Department of Public Health and Environment Construction Stormwater Discharge Permit and the Colorado Department of Public Health and Environment Air Permit. No applications for State permits have been submitted. (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Development Review Questionnaire 1. Describe the access location and applicable use types (i.e., agricultural, residential, commercial/industrial, and/or oil and gas) of all existing and proposed accesses to the parcel. Include the approximate distance each access is (or will be if proposed) from an intersecting county road. State that no existing access is present or that no new access is proposed, if applicable: o There are 7 accesses on the Project parcel, and no new accesses are being proposed. - Access 1, the access location for Union Colony Solar Project, is an existing access point on the southern side of the parcel directly off of County Road 54. Oil and gas operations use this access road for the parcel and have agreed to an access easement for this project. The access point is approximately 900 feet west of County Road 47 and 4,335 feet east of County Road 45. - Access 2 is on the eastern side of the parcel, approximately 2,190 feet north of the Project access on County Road 47. This access is approximately 1,300 feet north of County Road 54 and 3,070 feet south of County Road 47 1/2. This is an Agricultural and Oil and Gas access. Access 3 is on the southern side of the parcel, approximately 445 feet west of the Project access on County Road 54. This access is located approximately 1,345 feet west of County Road 47 and 3,880 feet east of County Road 45. This is an Agricultural access. - Access 4 is on the southern side of the parcel, approximately 890 feet west of the Project access on County Road 54. This access is located approximately 1,790 feet west of County Road 47 and 3,420 feet east of County Road 45. This is an Agricultural access. Access 5 is on the southern side of the parcel, approximately 1,370 feet west of the Project access on County Road 54. This access is located approximately 2,260 feet west of County Road 47 and 2,960 feet east of (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE 2 County Road 45. This is a Residential access. - Access 6 is on the southern side of the parcel, approximately 1,520 feet west of the Project access on County Road 54. This access is located approximately 2,420 feet west of County Road 47 and 2,790 feet east of County Road 45. This is a Residential and Agricultural access. - Access 7 is on the southern side of the parcel, approximately 1,560 feet west of the Project access on County Road 54. This access is located approximately 2,470 feet north of County Road 47 and 2,705 feet east of County Road 45. This is a Residential and Agricultural access. 2. Describe any anticipated change(s) to an existing access, if applicable: a No accesses will be relocated but will be improved as part of the Project. 3. Describe in detail any existing or proposed access gate including its location: a There will be a 7 -foot tall perimeter fence around the Project. The access gate will be located on the southern side of the Project area. 4. Describe the location of all existing accesses on adjacent parcels and on parcels located on the opposite side of the road. Include the approximate distance each access is from an intersecting county road: o The parcel to the north of the Project parcel has 4 accesses. - Access 1 is approximately 2,190 feet north of the Project access on County Road 47. This access is approximately 1,300 feet north of County Road 54 and 3070 feet south of County Road 47 1/2. - Access 2 is approximately 2,345 feet north of the Project access. This access is approximately 1,455 feet north of County Road 54 and 2,915 feet south of County Road 47 1/2. - Access 3 is approximately 3,525 feet north of the Project access. This access is approximately 2,635 feet north of County Road 54 and 1,735 feet south of County Road 47 1/2. - Access 4 is located approximately 1.8 miles north of the Project Access on County Road 54 1/2. This access is located approximately 2,585 feet east of County Road 445 and 2,500 feet south of CO Highway 34 a The parcel to the west of the Project parcel has 7 accesses. - Access 1 is located approximately 1,730 feet to the west of the Project access on County Road 54. This access is approximately 2,640 feet west of County Road 47 and 2,600 feet east of County Road 45. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGE 3 - Access 2 is located approximately 2,375 feet to the west of the Project access on County Road 54. This access is approximately 3,285 feet west of County Road 47 and 1,955 feet east of County Road 45. - Access 3 is located approximately 2,610 feet to the west of the Project access on County Road 54. This access is located approximately 3,520 feet west of County Road 47 and 1,720 feet east of County Road 45. - Access 4 is located approximately 2,830 feet to the west of the Project access on County Road 54. This access is approximately 3,740 feet west of County Road 47 and 1,500 feet east of County Road 45. - Access 5 is approximately 1.65 miles northwest of the Project access on County Road 54 1/2. This access is approximately 1,720 feet east of County Road 45 and 3,405 feet south of CO -34. - Access 6 is approximately 1.80 miles northwest of the Project access on County Road 54 1/2. This access is located approximately 2,515 feet east of County Road 45 and 2,610 feet south of CO -34. - Access 7 is approximately 1.82 miles northwest of the Project access on County Road 54 1/2. This access is approximately 2,600 feet east of County Road 45 and 2,525 feet south of CO -34. o The parcel across County Road 54, to the southeast of the Project parcel, has 3 accesses. - The first access is located approximately 675 feet to the west of the Project access on County Road 54. This access is approximately 1,290 feet west of County Road 47 and 3,940 feet east of County Road 45. - The second access is located approximately 1,515 feet to the south of the Project access on County Road 47. This access is located approximately 600 feet south of County Road 54 and 4,520 feet north of County Road 52. The third access is located approximately 2,320 feet to the south of the project access on County Road 47. This access is located approximately 1,405 feet south of County Road 54 and 3,790 feet north of County Road 52. o The parcel across County Road 54, to the southwest of the Project parcel, has 3 accesses. - The first access is located approximately 690 feet to the west of the Project access on County Road 54. This access is approximately 1,590 feet west of County Road 47 and 3,615 feet east of County Road 45. - The second access is located approximately 840 feet to the west of the Project access on County Road 54. This access is approximately 1,745 feet west of County Road 47 and 3,420 feet east of County Road 45. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGE 4 - The third access is located approximately 1,135 feet to the west of the project access on County Road 54. This access is approximately 2,040 feet west of County Road 47 and 3,160 feet east of County Road 45. o The parcel across County Road 47 to the southeast of the Project parcel has 2 accesses. - The first access is approximately 1,020 feet east of the Project access on County Road 47. This access is approximately 100 feet north of County Road 54 and 4,260 feet south of County Road 47 1/2. - The second access for this parcel is located approximately 1,265 feet east of the Project access on County Road 54. This access is located approximately 355 feet east of County Road 54 and 5,070 feet west of County Road 49. o The parcel across County Road 47 to the northeast of the Project parcel has 5 accesses. - Access 1 is located approximately 1,060 feet to the east of the Project access on County Road 47. This access is approximately 160 feet north of County Road 54 and 4,215 feet south of County Road 47 1/2. - Access 2 is located approximately 2,010 feet to the east of the Project access on County Road 47. This access is approximately 1,105 feet north of County Road 54 and 3,240 feet south of County Road 47 1/2. - Access 3 is located approximately 2,060 feet to the east of the Project access on County Road 47. This access is approximately 1,1550 feet north of County Road 54 and 3,200 feet south of County Road 47 1/2. - Access 4 is located approximately 1,510 feet to the east of the Project access on County Road 54. This access is approximately 590 feet east of County Road 47 and 4,805 feet west of County Road 49. - Access 5 is located approximately 3,565 feet to the east of the Project access on County Road 54. This access is approximately 2,650 feet east of County Road 47 and 2,765 feet west of County Road 49. 5. Describe any difficulties seeing oncoming traffic from an existing access and any anticipated difficulties seeing oncoming traffic from a proposed access: o The existing access should not have any difficulties seeing oncoming traffic. 6. Describe any horizontal curve (using terms like mild curve, sharp curve, reverse curve, etc.) in the vicinity of an existing or proposed access: o The existing access does not have any horizontal curves in the vicinity. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK PAGES 7. Describe the topography (using terms like flat, slight hills, steep hills, etc.) of the road in the vicinity of an existing or proposed access: o The topography of the road in the vicinity of the existing access is flat. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Environmental Health Questionnaire 1. Discuss the existing and proposed potable water source. If utilizing a drinking water well, include either the well permit or well permit application that was submitted to the State Division of Water Resources. If utilizing a public water tap, include a letter from the Water District, a tap or meter number, or a copy of the water bill.: o The Project area does not have an existing potable water source. There is no proposed potable water source for the Project. Bottled water will be provided for the construction team. Any water used for dust mitigation will be brought to the property from an external source. 2. Discuss the existing and proposed sewage disposal system. What type of sewage disposal system is on the property? If utilizing an existing on -site wastewater treatment system, provide the on -site wastewater treatment permit number. (If there is no on -site wastewater treatment permit due to the age of the existing on -site wastewater treatment system, apply for a on -site wastewater treatment permit through the Department of Public Health and Environment prior to submitting this application.) If a new on -site wastewater treatment system will be installed, please state "a new on -site wastewater treatment system is proposed." (Only propose portable toilets if the use is consistent with the Department of Public Health and Environment's portable toilet p olicy.) o There is no existing on -site sewage disposal system. The operation of the Project is not anticipated to require a sewage disposal system. CBEP Solar 27, LLC or its contractors will provide portable toilets during construction. 3. If storage or warehousing is proposed, what type of items will be stored: o The Project will include up to two 10' x 40' storage containers that will store parts, tools, and equipment on site during construction and operations. 4. Describe where and how storage and/or stockpile of wastes, chemicals, and/or petroleum will occur on this site: o During construction wastes will be stored in appropriate waste receptacles such as dumpsters. CBEP Solar 27, LLC and its contractors will hire a waste management provider to regularly remove wastes associated with construction of the Project from the receptacles and bring the waste to an approved landfill (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE2 or disposal site. Maintenance contractors will properly dispose of any wastes generated during operation of the Project by bringing the wastes to an approved landfill or disposal site. During construction, up to 1,000 gallons of fuel will be stored on -site in appropriate containers. No fuel will be stored on site for operations. No other chemicals are anticipated to be stored during construction or operation of the Project. 5. If there will be fuel storage on site, indicate the gallons and the secondary containment. State the number of tanks and gallons per tank: o Up to 1,000 gallons of fuel are anticipated to be stored on one site at one time during construction. Storage of fuel will follow applicable secondary containment requirements, as applicable. There will not be fuel storage during operation of the Project. 6. If there will be washing of vehicles or equipment on site, indicate how the wash water will be contained: o There will not be vehicle washing/equipment on site during the construction and operation of the Project. 7. If there will be floor drains, indicate how the fluids will be contained: o None of the facilities constructed for the Project will contain floor drains or require wastewater treatment. 8. Indicate if there will be any air emissions (e.g. painting, oil storage, etc.): o Traffic volume, primarily in the form of passenger vehicles, would increase in and around the Project area during construction. The increased traffic would temporarily increase odors and exhaust from vehicle emissions. Odors are anticipated from the operation of heavy machinery during grading, pile driving, and other installation activities at specific time periods throughout construction. Impacts from odors during Project operation would be minimal, likely restricted to emissions from the vehicles of maintenance personnel. 9. Provide a design and operations plan if applicable (e.g. composting, landfills, etc.): o A design and operations plan is not applicable to the Project. 10. Provide a nuisance management plan if applicable (e.g. dairies, feedlots, etc.): o A nuisance management plan is not applicable to the Project. 11. Additional information may be requested depending on type of land use requested: o If any additional information is required, please don't hesitate to contact Zach Brammeratzach@cloudbreakenergy.com- (970) 425-3175. (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM FOR COMMERCIAL OR INDUSTRIAL BUILDINGS, PLEASE COMPLETE THE FOLLOWING INFORMATION: Business Name: Address: Business Owner: Home Address: CBEP Solar 27, LLC PO Box 1255 Cloudbreak Energy Partners, LLC PO Box 1255 Phone: City, state, zip: Phone: City, state, zip: List up to three persons in the order to be called in the event of an emergency: NAME Zachary Brammer TITLE COO PHONE (970) 425-3175 (970) 425-3175 Sterling, CO 80751 (970) 425-3175 Sterling, CO 80751 ADDRESS PO Box 1255, Sterling, CO 80751 Becca Gallery Partner (970) 573-6440 PO Box 1255, Sterling, CO 80751 James Cleland CEO (970) 425-3175 PO Box 1255, Sterling, CO 80751 Business Hours: 8-5 UTILITY SHUT OFF LOCATIONS: Main Electrical: Gas Shut Off: Depicted on USR Map Days: M -F N/A Exterior Water Shutoff: N/A Interior Water Shutoff: N/A 07/22 12 CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Decommissioning Plan Approach CBEP Solar 27, LLC has developed this decommissioning plan for the Union Colony Solar Project, to be implemented after the contracted lease term has ended. CBEP Solar 27, LLC, the owner of the 3.4 MW AC Solar Energy Facility (SEF) will be responsible for the decommissioning. Decommissioning of the Project will include removal of all above and below -ground infrastructure, including the arrays, inverter structures, concrete foundations and pads, and electrical infrastructure. All fences, graveled areas and access roads shall be removed unless landowner agreement to retain is presented, in writing, in which the property owner agrees for this to remain. The property shall be restored to a condition reasonably similar to its condition prior to development of the 3.4 MW AC SEE Grading and re -vegetation will comply with all applicable rules and regulations. Exclusions from the decommissioning plan include planting trees, removing internal site roads, and re -grading to previous conditions. All non -utility owned equipment, conduits, structures, fencing, and foundations to a depth of at least 3' below grade shall be removed. Decommissioning activities will follow the CDOT best management practices (BMPs) for erosion and sediment control and stormwater management that are applied during project construction, or any new BMPs relevant at the time. CBEP Solar 27, LLC will decommission the Project once the contracted lease term is over, if the lease term is not extended or renewed. Decommissioning may also be initiated if the project is no longer viable, or in the case of a force majeure event (described below). CBEP Solar 27, LLC will provide notice to Weld County prior to commencement of decommissioning the Project. Estimated Timeline and Cost Decommissioning/reclamation shall commence within 12 months after power production has permanently ceased and be completed within 12 months from the start date of the decommissioning/reclamation work. Decommissioning/reclamation cost estimates, which shall be updated every five years from the establishment and submittal of the Security, shall include all costs associated with the dismantlement, recycling, and safe disposal of facility components and site reclamation activities, including the following elements: (970) 425-3175 I INFO©aCLOUDBREAKENERGY.COM I CLOUDBREAKENERGY.COM CLOUDBREAK PAGE 2 • All labor, equipment, transportation, and disposal costs associated with the removal all facility components from the facility site • All costs associated with full reclamation of the facility site, including removal of non-native soils, fences, and constructed access roads • All costs associated with reclamation of any primary agricultural soils at the facility site to ensure each area of direct impact shall be materially similar to the condition it was before construction • All decommissioning/reclamation activity management, site supervision, and site safety costs • All other costs, including administration costs, associated with the decommissioning and reclamation of the facility site • The established date of submission of the financial assurance mechanism to Weld County Prior to construction, CBEP Solar 27, LLC will provide the County with an irrevocable standby letter of credit, bond, or alternate form of financial assurance mechanism in an amount sufficient to fund the estimated decommissioning costs required by the Code. The Security shall: • Name the Board of County Commissioners of Weld County as the sole beneficiary of the letter of credit • Be issued by an A -rated financial institution based upon a rating provided by S&P, Moody's, Fitch, AM Best, or other rating agency with similar credentials • Include an automatic extension provision or "evergreen clause" • Be "bankruptcy remote", meaning the financial assurance mechanism will be unaffected by the bankruptcy of the SEF operator Weld County, in its sole discretion, may approve alternative forms of a financial assurance mechanism such as, but not limited to bonds, letters of credit, or other securities, if it finds that such alternative forms will provide an assurance of the availability of financial resources for decommissioning/reclamation that equals or exceeds that provided by the form required herein. Furthermore, Weld County shall have the right to draw upon the irrevocable standby letter of credit, or other form of financial assurance mechanism, to pay for decommissioning in the event that the holder has not commenced decommissioning/reclamation activities within 90 days of the Board of County Commissioners order or resolution directing decommissioning/reclamation. Continued Beneficial Use If prior to decommissioning the Project, the landowner determines that any of the Project components can be beneficially used on the land after disassembly, such items would be (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBF EAKENElRGY.COM CLOUDBREAK PAGE 3 exempt from the requirements for decommissioning. If a third party acquires the Project or a portion of the Project, such third party would be responsible for providing evidence of a plan of continued beneficial use for their relevant Project components. Force Majeure An exception to these requirements will be allowed for a force majeure event, which is defined as any event or circumstance that wholly or partly prevents or delays the performance of any material obligation arising under the Project permits, but only t0 the extent: • Such event is not within the reasonable control, directly or indirectly, of CBEP Solar 27, LLC (including without limitation events such as fire, earthquake, flood, tornado, hurricane, acts of God and natural disasters; war, civil strife or other similar violence); • CBEP Solar 27, LLC has taken all reasonable precautions and measures to prevent or avoid such event or mitigate the effect of such event on CBEP Solar 27, LLC's ability to perform its obligations under the Project permits and which, by the exercise of due diligence, it has been unable to overcome; and • Such event is not the direct or indirect result of the fault or negligence of CBEP Solar 27, LLC. In the event of a force majeure event, which results in the absence of electrical generation by the Project for 12 months, CBEP Solar 27, LLC must demonstrate to Weld County by the end of the 12 months of non -operation that the Project will be substantially operational and producing electricity within 24 months of the force majeure event. If such a demonstration is not made to Weld County's satisfaction, then decommissioning of the Project must be initiated 18 months after the force majeure event. (970) 425-3175 I INFO©aCLOUDBFREAKENEPGY.COM I CLOUDBPEAKENEPGY.COM Weld County Drainage Code Certificate of Compliance Weld County Case Number: Parcel Number: USR23-0023 #096123400007 Legal Description, Section/Township/Range: THE SOUTHEAST 1/4 OF SECTION 23, TOWNSHIP 5 NORTH, RANGE 65 WEST OF THE 6TH P.M. Date: July 3, 2023 Allyson Williamson , Consultant Engineer for TRC (Applicant), understand and acknowledge that the applicant is seeking land use approval of the case and parcel in the description above. I have designed or reviewed the design for the proposed land use set for in the application. I hereby certify, on behalf of the applicant, that the design will meet all applicable drainage requirements of the Weld County Code with the exception of the variances) described on the attached exhibits. This certification is not a guarantee or warranty either expressed or implied. Engineer's Stamp: AUpo ti111iaum4140-ni Apo REGls v0 te' I��', �O 60360 -0 EXP 10/31/2023 ,Q • o�a� (SsiCNAk_ FN6 E ineer of Record Signature Variance Request (If Applicable) 1. Describe the hardship for which the variance is being requested. 2. List the design criteria of the Weld County Code of which a variance is being requested. 3. Describe the proposed alternative with engineering rationale which supports the intent of the Weld County Code. Demonstrate that granting of the variance will still adequately protect public health, safety, and general welfare and that there are no adverse impacts from stormwater runoff to the public rights -of -way and/or offsite properties as a result of the project. This drainage study was prepared to request for variance from Section 5.10 Storage requiring detention for the proposed development to comply with the Weld County Engineering and Construction Criteria (WCECC) Manual Requirements, updated January 2021. The study summarizes findings from performing a hydrologic analysis of the project site to identify the potential stormwater impact from the proposed solar project and ensures that stormwater will not be concentrated, nor wi it exceed historical f ows when it leaves the parcel to County Road 54, protecting the existing infrastructure of Weld County. Public Works Director/Designee Review (If Applicable) Public Works Director/Designee Name Date of Signature Comments: Signature Approved ❑ Denied Department of Public Works Development Review 1111 H Street, Greeley, CO 80631 I Ph: 970-304-6496 www.weldgov.com/departments/public_works/development_ review 08/02/2019 =i TRC Stormwater Drainage Study CL©UDBREAK ENERGY PARTNERS Date: To: From: Project: Subject: 3/10/2023 Cloudbreak Energy Allyson Williamson, TRC Companies 700 Highlander Blvd., Suite 210 Arlington, TX 76015 Union Colony Solar Project On -Site Drainage Study PRELIMINARY FOR INTERIM REVIEW ONLY. NOT FOR PERMITTING, BIDDING, NOR CONSTRUCTION. Prepared by or under the Direct Supervision of: Allyson Williamson, P.E. 60360 "3/10/2023" Cloudbreak Energy is pursuing the development of the Darling Ranch Project, a photovoltaic energy generation facility at a 24.8 -acre site located approximately 5.5 miles southwest of Greeley, Colorado, alongside Co Rd 47 with access from Co Rd 54 (See Appendix A -Site Plans C-301 & C-302). The existing site is currently used for agricultural purposes with approximately 1% slopes. This drainage study was prepared to summarize findings from performing a hydrologic analysis of the project site to identify the potential stormwater impact from the proposed solar project and develop appropriate drainage best management practices (BMPs) to address the impact. This drainage study was prepared to comply with the requirements from Weld County Engineering and Construction Criteria (WCECC) Manual, updated January 2021. Proposed Project The proposed solar project will consist of pole mounted photovoltaic (PV) arrays. Ground disturbance under the panels will be minimal; thus, the existing perviousness of the soil will be maintained under the solar cells allowing infiltration. Rainfall runoff from the panels will not be concentrated and flow under the pole mounted PV panels matching the pre -development flow patterns. Additional improvements associated with this project are limited to gravel drives for vehicle access and concrete pads for distribution transforms (see Appendix A - Site Plans C-301 & C- 302). No public access or utility infrastructure improvements are anticipated at this time. Site Drainage Currently, the existing site does not have any regional retention or water quality features. The soils in the area mainly consist of hydrologic soil group (HSG) B soils given by the Natural Resources Conservation Service (NRCS — Appendix B). One drainage basin labeled as Drainage Area A has been identified for the project site and is approximately 24.80 acres. Any offsite flows appear to follow the existing ditches and are not expected to affect the project site. See Appendix A for the drainage area maps and details. A hydrologic analysis was prepared using the Rational Method based upon requirements from WCECC Manual. The analysis provided estimated peak flow rates for the 100 -year storm under both pre- and post -development conditions. The design rainfall depth for a 1 -hour, 100 -year 1 Stormwater Drainage Study storm is 2.71 inches based upon NOAA Atlas 14: Precipitation -Frequency Atlas. The Rational Method equation shown below was used to determine the peak flow rates from Drainage Area A. Existing conditions were determined to be "Greenbelt, Agriculture" which correlates to a 2% impervious value according to Table 5-2, Weld County Engineering and Construction Criteria. In Table 5-5, based off the soil type and impervious percentage, the runoff calculation was 0.3600 for Drainage Area A. Proposed conditions were determined to be the weighted average of "Greenbelt, Agriculture" (2% impervious), "Solar Facilities B Soils" (2% impervious), "Packed Gravel" (40% impervious), and "Paved" (100% impervious). Using the same process as before, the runoff coefficient was weighted to be 0.3643 for Drainage Area A. The drainage area imperviousness and resulting peak flow rates from pre -and post -development conditions are summarized below. See Appendix C for the runoff coefficient calculations. Q=C*I*A Where: Q- Runoff flow rate in cubic feet per second (cfs) / Rainfall Intensity in inches per hour (in/hr) A -Area of the basin in acres (ac) Pre -development Runoff Calculation Parameters Drainage Weighted Runoff Rainfall Area Area, A (ac) Coefficient, C Intensity, (in/hr) A 24.80 0.3600 5.58 Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Intensity, Rainfall (in/hr) I % Added area ac/total (impervious Impervious ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Drainage Area development Peak Pre Flow (cfs) - Rate Post -development Peak Flow (cfs) Rate DIFFERENCE (CFS) A 49.84 50.44 0.60 Based upon the above results, the increase of impervious area would produce little increase (approximately 1.0%) in the peak flow rate. Because of this, a detention basin facility will not be proposed. Instead, a grass swale will be introduced near the north project site boundary to dissipate energy and attenuate any potential flow increase from gravel roads and concrete pads. 2 Stormwater Drainage Study Erosion Control/Stormwater Management Plan Erosion control features such as silt fences and a grass swale (also mentioned above) will be installed on the site prior to construction activities. Such measures will be included in the erosion control plan and detail sheets within the final construction documents. Grass swale sizing calculations are summarized in Appendix D. Conclusion The drainage study and attached drainage maps were produced in accordance with requirements from Weld County Engineering and Construction Criteria Manual, updated January 2021. The existing stormwater flow characteristics are expected to remain unchanged and increases in peak flow rates have been proven to be negligible. A basin type of stormwater detention would not be necessary. Improvements proposed with the project site are limited to a gravel paved drive and two small concrete distribution transformer pads. No public access or utility infrastructure improvements are anticipated at this time. The proposed development will not alter historic drainage patterns and adjacent and downstream property owners. 3 Stormwater Drainage Study References 1. Weld County, Weld County Engineering and Construction Criteria Manual, January 2021. 2. Web Soil Survey, Natural Resources Conservation Service, United States Department of Agriculture. Online at: http://websoilsurvey.nrcs.usda.gov, accessed December 2021. 3. NOAA Atlas 14, Volume 11, Version 2. ESRI Maps. USGS. Sanja Perica, Sandra Pavlovic, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Orlan Wilhite. Appendices A. Site Plans C-301& C-302 5-7 B. NRCS Soil Layer Map .8-12 C. Rational Method Calculations 13-17 D. Grass Swale Calculations 18-20 4 Stormwater Drainage Study Appendix A: SITE PLANS C-301 & C-302 5 C;lpwworking-trd\d01191951C-301 Pre -Drainage Area Map.dwg 03-10-2023 1:53:36 PM BY: pkuh DP -A Jr I FO r — — CAE' 46464'4644 J i i i 4643 4 FC OE 4641= 6431inna_ _ OE OE Pre -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Rainfall I (in/hr) Intensity, A 24.80 0.3600 5.58 WELD COUNTY ROAD 47 OE 4642 4643 S C�E r 5 - S i - 4642 OE LEGEND X.XX AC DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW S � 4644 4644 _ L i ru OE .lam FO R � 4645Ls) Ncr 1 1 \‘‘\''';11 l ti � `I 14 l I t I H 1 El II 1IliH I 111 I I :::". 1 11ll 1. Ill I '''''4\4\2,1( I iI‘\(!lil\!1.ili\,\,,i,,,' --"Jirli--77,..?...S...:::„. ,\I,I\ I I � I �1 i I I Il ll ft I H471-1.-n ll li III III ll i i LI I lb I I yot III Lb 'III' 1 11 � il,li, II( II \I .-- tlt 1 I tt\ I tl I Iiii o llIII .I ll ., t I II� l IIIll ll � il II Ill I i li , I'I I t� l .I li i III ll I ll Ilan!ILO ilj Hr u ll HIcr 'till1 'r ll ifil iI i tr) 1ii mot' IIII 7_.( If II I 4 4 . I / \/I I 4- k ar-30 l f t r i ccr 0 60 60 30 l i 0 2 (9 i i i 120 SCALE : 1" = 60' 1'2 NO. REVISION DATE INIT TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com DATE: 3/10/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" - 80' SHEET NO.: 1:53:46 PM BY: pkuh C;lpwworking-trd\dQ1191951C-302 Post Drainage Area Map.dwg 03-10-2023 m DP -A PROP GRASS SWALE OE Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Rainfall I (in/br) Intensity, % Added (impervious Impervious ac/total area ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Pre -development Post -development Drainage DIFFERENCE Area Peak Flow (cfs) Rate Peak Flow (cfs)(CFS) Rate A 49.84 50.44 0.60 — —7,---ros---rtre--r----� WELD COUNTY ROAD 47 OE 4644 1 4643 464100-- x OE •,s 4642 464114644 M i air 4643 4642 OE i C� x J I I _ I I _ S X4643 x aur _ 4642 in _ )flx FO I LEGEND OE OE PROP 26' W GRAVEL ACCESS ROAD in in PROP CONCRETE PAD i J II _ r J -x S 4644 i X J J DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW I in in in �I i i i � n _ S g / / 4644 4645 ■ I• I to d' i or I I 6F t In 1 it 4 Logs 4'I i r a t.D tzt 60 60 30 0 120 I i i i i I I o O I 0 1 CD SCALE : 1" = 60' i i 1 i i i i 1 i i • TRC TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com STAMP: INTERIM REVIEW DOCUMENTS NOT INTENDED FOR CONSTRUCTION, BIDDING, OR PERMITTING PURPOSES ALLYSON WILLIAM SON, P.E. CO LIC. # 60360 3/10/23 Z U X 1±-1 -1� O X OcLx x Z cc X OQ� ZOD In a Q 0 cC >- z D 0 U m N N GREELEY, CO 80631 PROJECT NUMBER: 516145 SHEET TITLE: POST DRAINAGE AREA MAP SHEET SIZE: ARCH "D" 24" X 36" (610 x 914) 0 2 1" ISSUED FOR PERMITTING NOT FOR CONSTRUCTION NO. REVISION DATE INIT DATE: 3/10/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" - 80' SHEET NO.: Stormwater Drainage Study Appendix B: NRCS SOIL LAYER MAP 6 104° 37' 29" W 8 40° 22' 53" N - 40° 22' 38" N O 4 1 N- 0 4 0 4 4 0 4 0 531870 531920 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) 531970 532020 532070 532120 4 i AMSSOUtlap may not be valid. at thlsssale. 104° 37 29" W 531870 531920 531970 Map Scale: 1:2,240 if printed on A portrait (8.5" x 11") sheet. Meters 0 30 60 120 180 Feet 0 100 200 400 600 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 532170 532020 5332070 532120 532170 104° 37' 14" W 8 E 40° 22' 53" N U 4 0 4 0 co 104° 3714" W 40° 22' 38" N Natural Resources Web Soil Survey all Conservation Service National Cooperative Soil Survey 1/5/2023 Page 1 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) MAP LEGEND Area of Interest (AO!) Area of Interest (A01) ) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines 0 0 A A/D B B/D C C/D D Not rated or not available Soil Rating Points II O O O A A/D B B/D MAP INFORMATION C The soil surveys that comprise your AOI were mapped at 1:24,000. C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background ,; Aerial Photography Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. 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 21, Sep 1, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2021 Jun 12, 2021 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. ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 1/5/2023 Page 2 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Altvan loam, percent slopes 0 to 1 B 24.8 100.0% Totals for Area of Interest 24.8 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, BID, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, BID, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Tie -break Rule: Higher e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 4of4 Stormwater Drainage Study Appendix C: RATIONAL METHOD CALCULATIONS 6/6/22, 11:49 AM Precipitation Frequency Data Server NOAA Atlas 14, Volume 8, Version 2 Location name: Greeley, Colorado, USA* Latitude: 40.3795°, Longitude: -104.6227° Elevation: 4642.53 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular AMS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration 5 -min 10 -min 15 -min 30 -min 60 -min 2 -hr 3 -hr Annual exceedance probability (1/years) 1/2 0.268 (0.221-0.328) 0.392 (0.323-0.480) 0.478 (0.394-0.585) 0.642 (0.529-0.786) 0.791 (0.653-0.969) 0.940 (0.781-1.14) 6 -hr 12 -hr 24 -hr 1.02 (0.854-1.24) 1.18 (0.992-1.42) 1.39 (1.17-1.65) 1.64 (1.40-1.94) 1.89 2 -day (1.63-2.22) 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day 2.06 (1.78-2.40) 2.19 (1.89-2.54) 2.50 (2.17-2.88) 2.76 (2.41-3.17) 3.51 (3.09-3.99) 4.12 (3.64-4.66) 4.86 (4.31-5.47) 5.47 (4.87-6.14) 1/25 0.378 0.476 (0.310-0.464) (0.388-0.589) 0.553 (0.454-0.679) 1 0.674 (0.554-0.828) 0.904 (0.742-1.11) 1.10 (0.903-1.35) 1.30 (1.07-1.58) 1.39 1.16-1.69) 1.62 (1.36-1.95) 1.91 (1.61-2.28) 2.20 (1.87-2.60) 0.698 (0.569-0.862) 0.851 (0.694-1.05) 1.14 (0.931-1.41) 1.39 (1.13-1.72) 1.64 (1.35-2.01) 1/50 0.628 0.758 (0.498-0.831) (0.580-1.01) 0.919 (0.728-1.22) 1.12 (0.888-1.49) 1.51 (1.20-2.00) 1.85 (1.47-2.47) 2.19 (1.77-2.92) 1.76 (1.45-2.15) 2.04 (1.69-2.47) 2.37 (1.98-2.84) 2.69 (2.26-3.19) 2.53 (2.16-2.97) 3.06 (2.60-3.60) 2.37 1.92-3.14) 2.70 (2.20-3.53) 3.06 (2.49-3.91) 3.41 (2.79-4.29) 3.81 (3.13-4.72) 2.70 3.23 3.99 (2.32-3.15) (2.76-3.79) (3.29-4.92) 2.84 (2.45-3.31) 3.25 (2.82-3.76) 3.38 (2.89-3.96) i 3.60 (3.13-4.14) 4.49 (3.93-5.12) 5.21 (4.58-5.91) 6.13 (5.42-6.92) 6.93 (6.15-7.80) 3.84 (3.31-4.46) 4.24 (3.66-4.90) 5.21 (4.54-5.97) 6.01 (5.25-6.85) 7.05 (6.19-7.99) 7.97 (7.03-9.01) 4.15 (3.43-5.09) 4.66 3.85-5.62) 5.09 4.22-6.08) 6.15 (5.12-7.25) 7.03 5.88-8.23) 8.20 (6.89-9.54) 9.26 (7.80-10.7) 1.11 (0.849-1.49) 1.35 1.04-1.81) 1.82 (1.40-2.44) 2.26 (1.73-3.04) 2.69 (2.09-3.60) 2.91 2.27-3.88) 3.29 (2.58-4.33) 3.66 (2.88-4.73) 4.01 (3.18-5.12) 4.43 (3.53-5.57) 4.61 (3.70-5.77) 4.78 (3.84-5.94) 5.29 (4.27-6.50 5.73 (4.64-6.98) 6.84 (5.57-8.22) 7.77 (6.36-9.27) 9.03 (7.42-10.7) 10.2 (8.39-12.0) 1/100 0.902 (0.659-1.24) 1.32 (0.965-1.82) 1.61 (1.18-2.22) 2.17 1.59-2.99) 2.71 (1.99-3.75) 1/200 1.06 (0.734-1.51) 1.55 (1.08-2.21) 1.89 (1.31-2.69) 2.56 (1.77-3.64) 3.22 (2.23-4.59) 1/500 1.29 (0.850-1.89) 1.89 (1.24-2.77) 2.30 (1.52-3.38) 3.11 (2.05-4.57) 3.96 (2.62-5.83) 3.25 I 3.88 4.81 (2.40-4.47) i (2.72-5.50) i (3.21-7.01) 3.53 (2.63-4.83) 3.95 (2.96-5.34) 4.23 (2.99-5.97) 4.31 (3.24-5.72) 4.67 (3.55-6.13) 5.08 (3.88-6.57) 4.69 (3.34-6.53) 5.01 (3.59-6.88) 5.39 (3.89-7.30) 5.78 (4.20-7.71) 5.28 (4.05-6.78) 5.44 (4.19-6.96) 5.98 4.37-7.93) 5.27 3.54-7.65) 5.77 (3.91-8.28) 6.04 (4.12-8.54) 6.41 (4.42-8.95) 6.75 (4.69-9.30) 6.96 (4.87-9.53) 5.95 (4.61-7.51) 6.38 (4.96-8.00) 7.52 (5.89-9.29) 6.14 (4.51-8.11) 6.62 (4.89-8.63) 7.04 (5.22-9.10) 8.18 (6.11-10.4) 8.49 (6.68-10.4) 9.82 (7.77-12.0) 11.0 (8.76-13.4) 9.19 (6.91-11.6) 10.6 I (7.99-13.3) 11.8 (8.98-14.8) 7.12 5.00-9.71) 7.54 (5.33-10.1) 7.91 (5.61-10.6) 9.04 (6.47-11.9) 10.1 (7.26-13.2) 11.5 (8.34-15.0) 12.8 (9.32-16.6) 1/1000 1.48 (0.937-2.18) 2.16 (1.37-3.19) 2.64 (1.67-3.89) 3.57 (2.27-5.27) 4.58 (2.90-6.76) 5.58 (3.58-8.16) 6.14 3.96-8.92) 6.67 (4.34-9.60) 6.88 (4.53-9.79) 7.24 (4.81-10.2) 7.53 (5.06-10.5) 7.75 (5.24-10.7) 7.91 (5.37-10.9) 8.25 (5.65-11.3) 8.57 (5.91-11.7) 9.67 (6.74-13.0) 10.7 (7.52-14.4) 12.2 (8.60-16.2) 13.5 (9.58-17.9) Precipitation frequency (PF) estimates in this table are based on frequency analysis of annual maxima series (AMS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and annual exceedance probability) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 1/4 6/6/22, 11:49 AM Precipitation Frequency Data Server C Precipitation depth 14 12 10 4 14 12 1 0 V2 AM -cased depth -duration -frequency (DDF) curves Latitude: 40.3?95', Longitude: -104.6227 C � s V5 1'10 th Duration tion re re re re to 0 -a gmo oil ) 1 N. O_ 1150 1/100 1'200 Annual e cee lance prob►abillity (1/years) NOAA Atlas 14o Volume B, Version 2 CO fo (0 '5 _ N re" igcr V500 x'1000 Created (GMT): Mon Jun 6 16.49:18 2022 Back to Top Maps & aerials Small scale terrain Annual exceecdance p robability (i!yoars) 2 5 10 25 50 100 200 500 1 000 Duration 5 -man 10 -min 15 -min 60 -min 2 -hr -hr 6-nir 12 -hr 24 -hr 2 -day 3 -day 4 -clay 7 -day 10 -day 20 -day 30 -day 45 -day 6O -day https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 2/4 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A EX I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 `- Reach 3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration __ _ `-------� overland • Reach 1 flow Reach 21- LEGEND (.) Big Flour Direr lion Ca.tc }carte nt B oundar}r NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.47 5.58 5.58 5.00 0.22 74.01 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 143.94 18.29 18.29 13.16 49.84 49.84 cfs cfs cfs Union Colony EX 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:32 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A EX Illustration Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output B Soil 24.80 I 0.36 8.93 I I sum: 2 24.80 sum: 8.93 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3600 rEr : Flow Dimon C at clam cot B MIELdElly *See sheet "Design Info" for inperviousness-based runoff coefficient values. Union Colony EX 100 Yrs.xls, Weighted C 2/2/2023, 8:32 AM CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A PR I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 Reach:3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration i Reach 2�. Reach 1 overland flow LEGEND U B eginn ng F1gtir Dire*. -don Cate lane nt Bound - NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.08 5.58 5.58 2.50 0.11 148.03 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 217.96 18.29 18.29 9.78 50.44 50.44 cfs cfs cfs Union Colony PR 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:31 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A PR Illustration LEA: Flow Direction Catchin ent BBiortindary Instructions: For each catchment subarea. enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output B SOILS 24.06 0.36 8.66 B SOIL GRAVEL ROAD 0.736 0.50 0.37 B SOIL CONCRETE PADS 0.004 0.96 0.00 Sum: 24.80 Sum: 9.03 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3643 *See sheet "Design Info" for inperviousness-based runoff coefficient values. Union Colony PR 100 Yrs.xls, Weighted C 2/2/2023, 8:31 AM Stormwater Drainage Study Appendix D: GRASS SWALE CALCULATIONS 8 T-2 Grass Swale RESIDUAL CAPACITY FOR LARGER FLOODS 1;,, • 4" (MIN) SANDY LOAM 6" MI IN _L 2-YR WSE 6" MI TRAPEZOIDAL SWALE SECTION NTS I RESIDUAL CAPACITY FOR LARGER FLOODS 2-YR WS•E 4'° MIN. SANDY LOAM 12" MIN. MIN. D 1.0' 12" MIN. (2-YR) 1.0 FPS !Y TRIANGULAR SIAN GULAR SWALE SECTION NTS CONCRETE COI I AR ENERGY DISSIPATION b ir. l' rf I PROVIDE DOUBLE CLEANOUTS WITH WATER TIGHT CAPS @150' O.O. USE 90* SWEEP OR (2) 45' BENDS (OFFSET FROM SWALE CENTERLINE TO AVOID IMPEDING FLOW WHEN USING A TRIANGULAR SECTION Design Example 1 4 MIN. GRADE CONTROL STRUCTURE BEYOND GRADE CONTROL STRUCTURE BEYOND UNDERDRAIN AND SANDY LOAM RECOMMENDED FOR LONGITUDINAL SLOPES < 2.0%. 4" SLOTTED PIPE MEETING TABLE 05-3 WITH CDOT CLASS C FILTER MATERIAL ALL AROUND OR PERFORATED HOPE PIPE WITH AASHTO #67 ALL AROUND CONTAINED WITHIN CEOTEXTILE FABRIC. ASTM D4751-AOS US STD. SIEVE #50 TO 7a, ASTM D4533 MIN. TRAPEZOIDAL TEAR STRENGTH 100 X 60 LBS, MINIMUM COE SPECIFIED OPEN AREA OF 4%. GRADE CONTROL EXTEND GRADE CTROL STRUCTURE STRUCTURES INTO ONTHE BANK A MIN. OS ABOVE THE 2-YR WSE Ii UNDERDRAIN ENSURE ACCESS TO OUTLET BY CLEAN OUT OR OTHER ACCESSIBLE STRUCTURE SWALE PROFILE NITS Figure GS -1. Grass Swale Profile and Sections The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at www.udfcd.org. This section provides a completed design form from this workbook as an example. GS -6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Hydraulic Analysis Report Project Data Project Title: Cloudbreak - Union Colony Designer: TRC (TH) Project Date: Wednesday, February 1, 2023 Project Units: U.S. Customary Units Notes: Channel Analysis: Swale A Notes: input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 3.0000 ft/ft Side Slope 2 (Z2): 3.0000 ft/ft Channel Width 1.00 ft Longitudinal Slope: 0.0020 ft/ft Manning's n: 0.0350 Depth 1.0000 ft Result Parameters Flow 5.0743 cfs Area of Flow 4.0000 ft^2 Wetted Perimeter 7.3246 ft Hydraulic Radius 0.5461 ft Average Velocity 1.2686 ft/s Top Width 7.0000 ft Froude Number: 0.2957 Critical Depth 0.5642 ft Critical Velocity 3.3402 ft/s Critical Slope: 0.0269 ft/ft Critical Top Width 4.39 ft Calculated Max Shear Stress 0.12481b/ft^2 Calculated Avg Shear Stress 0.0682 lb/ft^2 Selected Profile: FHWA Profile (read-only) Culvert Assessment Profiles Culvert Assessment Profile Name: Standard (read-only) Maximum Excavation Depth: 20.00 ft Maximum Shallow Cover: 4.00 ft Maximum Small Pipe Size: 36.00 ft Minimum Manned Entry Size: 48.00 in Riprap Classes Riprap Class Name:CLASS Riprap Class Order:1 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 304.80 mm D85: 228.60 mm D50: 165.10 mm D15: 114.30 mm Riprap Class Name:CLASS II Riprap Class Order:2 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 457.20 mm D85: 330.20 mm D50: 241.30 mm D15: 177.80 mm Riprap Class Name:CLASS III Riprap Class Order:3 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 609.60 mm D85: 431.80 mm D50: 317.50 mm D15: 228.60 mm Riprap Class Name:CLASS IV Riprap Class Order:4 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 762.00 mm D85: 533.40 mm D50: 393.70 mm D15: 266.70 mm Riprap Class Name:CLASS V Riprap Class Order:5 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 914.40 mm D85: 647.70 mm D50: 469.90 mm D15: 330.20 mm Riprap Class Name:CLASS VI Riprap Class Order:6 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1066.80 mm D85: 762.00 mm D50: 546.10 mm D15: 381.00 mm Riprap Class Name:CLASS VII Riprap Class Order:7 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1257.30 mm D85: 889.00 mm D50: 647.70 mm D15: 444.50 mm Riprap Class Name:CLASS VIII Riprap Class Order:8 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1524.00 mm D85: 1079.50 mm D50: 800.10 mm D15: 558.80 mm Riprap Class Name:CLASS IX Riprap Class Order:9 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1828.80 mm D85: 1295.40 mm D50: 965.20 mm D15: 660.40 mm Riprap Class Name:CLASS X Riprap Class Order:10 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 2133.60 mm D85: 1511.30 mm D50: 1130.30 mm D15: 787.40 mm =i TRC Stormwater Drainage Study CL©UDBREAK ENERGY PARTNERS Date: To: From: Project: Subject: 3/10/2023 Cloudbreak Energy Allyson Williamson, TRC Companies 700 Highlander Blvd., Suite 210 Arlington, TX 76015 Union Colony Solar Project On -Site Drainage Study PRELIMINARY FOR INTERIM REVIEW ONLY. NOT FOR PERMITTING, BIDDING, NOR CONSTRUCTION. Prepared by or under the Direct Supervision of: Allyson Williamson, P.E. 60360 "3/10/2023" Cloudbreak Energy is pursuing the development of the Darling Ranch Project, a photovoltaic energy generation facility at a 24.8 -acre site located approximately 5.5 miles southwest of Greeley, Colorado, alongside Co Rd 47 with access from Co Rd 54 (See Appendix A -Site Plans C-301 & C-302). The existing site is currently used for agricultural purposes with approximately 1% slopes. This drainage study was prepared to summarize findings from performing a hydrologic analysis of the project site to identify the potential stormwater impact from the proposed solar project and develop appropriate drainage best management practices (BMPs) to address the impact. This drainage study was prepared to comply with the requirements from Weld County Engineering and Construction Criteria (WCECC) Manual, updated January 2021. Proposed Project The proposed solar project will consist of pole mounted photovoltaic (PV) arrays. Ground disturbance under the panels will be minimal; thus, the existing perviousness of the soil will be maintained under the solar cells allowing infiltration. Rainfall runoff from the panels will not be concentrated and flow under the pole mounted PV panels matching the pre -development flow patterns. Additional improvements associated with this project are limited to gravel drives for vehicle access and concrete pads for distribution transforms (see Appendix A - Site Plans C-301 & C- 302). No public access or utility infrastructure improvements are anticipated at this time. Site Drainage Currently, the existing site does not have any regional retention or water quality features. The soils in the area mainly consist of hydrologic soil group (HSG) B soils given by the Natural Resources Conservation Service (NRCS — Appendix B). One drainage basin labeled as Drainage Area A has been identified for the project site and is approximately 24.80 acres. Any offsite flows appear to follow the existing ditches and are not expected to affect the project site. See Appendix A for the drainage area maps and details. A hydrologic analysis was prepared using the Rational Method based upon requirements from WCECC Manual. The analysis provided estimated peak flow rates for the 100 -year storm under both pre- and post -development conditions. The design rainfall depth for a 1 -hour, 100 -year 1 Stormwater Drainage Study storm is 2.71 inches based upon NOAA Atlas 14: Precipitation -Frequency Atlas. The Rational Method equation shown below was used to determine the peak flow rates from Drainage Area A. Existing conditions were determined to be "Greenbelt, Agriculture" which correlates to a 2% impervious value according to Table 5-2, Weld County Engineering and Construction Criteria. In Table 5-5, based off the soil type and impervious percentage, the runoff calculation was 0.3600 for Drainage Area A. Proposed conditions were determined to be the weighted average of "Greenbelt, Agriculture" (2% impervious), "Solar Facilities B Soils" (2% impervious), "Packed Gravel" (40% impervious), and "Paved" (100% impervious). Using the same process as before, the runoff coefficient was weighted to be 0.3643 for Drainage Area A. The drainage area imperviousness and resulting peak flow rates from pre -and post -development conditions are summarized below. See Appendix C for the runoff coefficient calculations. Q=C*I*A Where: Q- Runoff flow rate in cubic feet per second (cfs) / Rainfall Intensity in inches per hour (in/hr) A -Area of the basin in acres (ac) Pre -development Runoff Calculation Parameters Drainage Weighted Runoff Rainfall Area Area, A (ac) Coefficient, C Intensity, (in/hr) A 24.80 0.3600 5.58 Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Intensity, Rainfall (in/hr) I % Added area ac/total (impervious Impervious ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Drainage Area development Peak Pre Flow (cfs) - Rate Post -development Peak Flow (cfs) Rate DIFFERENCE (CFS) A 49.84 50.44 0.60 Based upon the above results, the increase of impervious area would produce little increase (approximately 1.0%) in the peak flow rate. Because of this, a detention basin facility will not be proposed. Instead, a grass swale will be introduced near the north project site boundary to dissipate energy and attenuate any potential flow increase from gravel roads and concrete pads. 2 Stormwater Drainage Study Erosion Control/Stormwater Management Plan Erosion control features such as silt fences and a grass swale (also mentioned above) will be installed on the site prior to construction activities. Such measures will be included in the erosion control plan and detail sheets within the final construction documents. Grass swale sizing calculations are summarized in Appendix D. Conclusion The drainage study and attached drainage maps were produced in accordance with requirements from Weld County Engineering and Construction Criteria Manual, updated January 2021. The existing stormwater flow characteristics are expected to remain unchanged and increases in peak flow rates have been proven to be negligible. A basin type of stormwater detention would not be necessary. Improvements proposed with the project site are limited to a gravel paved drive and two small concrete distribution transformer pads. No public access or utility infrastructure improvements are anticipated at this time. The proposed development will not alter historic drainage patterns and adjacent and downstream property owners. 3 Stormwater Drainage Study References 1. Weld County, Weld County Engineering and Construction Criteria Manual, January 2021. 2. Web Soil Survey, Natural Resources Conservation Service, United States Department of Agriculture. Online at: http://websoilsurvey.nrcs.usda.gov, accessed December 2021. 3. NOAA Atlas 14, Volume 11, Version 2. ESRI Maps. USGS. Sanja Perica, Sandra Pavlovic, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Orlan Wilhite. Appendices A. Site Plans C-301& C-302 5-7 B. NRCS Soil Layer Map .8-12 C. Rational Method Calculations 13-17 D. Grass Swale Calculations 18-20 4 Stormwater Drainage Study Appendix A: SITE PLANS C-301 & C-302 5 C;lpwworking-trd\d01191951C-301 Pre -Drainage Area Map.dwg 03-10-2023 1:53:36 PM BY: pkuh DP -A Jr I FO r — — CAE' 46464'4644 J i i i 4643 4 FC OE 4641= 6431inna_ _ OE OE Pre -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Rainfall I (in/hr) Intensity, A 24.80 0.3600 5.58 WELD COUNTY ROAD 47 OE 4642 4643 S C�E r 5 - S i - 4642 OE LEGEND X.XX AC DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW S � 4644 4644 _ L i ru OE .lam FO R � 4645Ls) Ncr 1 1 \‘‘\''';11 l ti � `I 14 l I t I H 1 El II 1IliH I 111 I I :::". 1 11ll 1. Ill I '''''4\4\2,1( I iI‘\(!lil\!1.ili\,\,,i,,,' --"Jirli--77,..?...S...:::„. ,\I,I\ I I � I �1 i I I Il ll ft I H471-1.-n ll li III III ll i i LI I lb I I yot III Lb 'III' 1 11 � il,li, II( II \I .-- tlt 1 I tt\ I tl I Iiii o llIII .I ll ., t I II� l IIIll ll � il II Ill I i li , I'I I t� l .I li i III ll I ll Ilan!ILO ilj Hr u ll HIcr 'till1 'r ll ifil iI i tr) 1ii mot' IIII 7_.( If II I 4 4 . I / \/I I 4- k ar-30 l f t r i ccr 0 60 60 30 l i 0 2 (9 i i i 120 SCALE : 1" = 60' 1'2 NO. REVISION DATE INIT TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com DATE: 3/10/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" - 80' SHEET NO.: 1:53:46 PM BY: pkuh C;lpwworking-trd\dQ1191951C-302 Post Drainage Area Map.dwg 03-10-2023 m DP -A PROP GRASS SWALE OE Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Rainfall I (in/br) Intensity, % Added (impervious Impervious ac/total area ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Pre -development Post -development Drainage DIFFERENCE Area Peak Flow (cfs) Rate Peak Flow (cfs)(CFS) Rate A 49.84 50.44 0.60 — —7,---ros---rtre--r----� WELD COUNTY ROAD 47 OE 4644 1 4643 464100-- x OE •,s 4642 464114644 M i air 4643 4642 OE i C� x J I I _ I I _ S X4643 x aur _ 4642 in _ )flx FO I LEGEND OE OE PROP 26' W GRAVEL ACCESS ROAD in in PROP CONCRETE PAD i J II _ r J -x S 4644 i X J J DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW I in in in �I i i i � n _ S g / / 4644 4645 ■ I• I to d' i or I I 6F t In 1 it 4 Logs 4'I i r a t.D tzt 60 60 30 0 120 I i i i i I I o O I 0 1 CD SCALE : 1" = 60' i i 1 i i i i 1 i i • TRC TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com STAMP: INTERIM REVIEW DOCUMENTS NOT INTENDED FOR CONSTRUCTION, BIDDING, OR PERMITTING PURPOSES ALLYSON WILLIAM SON, P.E. CO LIC. # 60360 3/10/23 Z U X 1±-1 -1� O X OcLx x Z cc X OQ� ZOD In a Q 0 cC >- z D 0 U m N N GREELEY, CO 80631 PROJECT NUMBER: 516145 SHEET TITLE: POST DRAINAGE AREA MAP SHEET SIZE: ARCH "D" 24" X 36" (610 x 914) 0 2 1" ISSUED FOR PERMITTING NOT FOR CONSTRUCTION NO. REVISION DATE INIT DATE: 3/10/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" - 80' SHEET NO.: Stormwater Drainage Study Appendix B: NRCS SOIL LAYER MAP 6 104° 37' 29" W 8 40° 22' 53" N - 40° 22' 38" N O 4 1 N- 0 4 0 4 4 0 4 0 531870 531920 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) 531970 532020 532070 532120 4 i AMSSOUtlap may not be valid. at thlsssale. 104° 37 29" W 531870 531920 531970 Map Scale: 1:2,240 if printed on A portrait (8.5" x 11") sheet. Meters 0 30 60 120 180 Feet 0 100 200 400 600 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 532170 532020 5332070 532120 532170 104° 37' 14" W 8 E 40° 22' 53" N U 4 0 4 0 co 104° 3714" W 40° 22' 38" N Natural Resources Web Soil Survey all Conservation Service National Cooperative Soil Survey 1/5/2023 Page 1 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) MAP LEGEND Area of Interest (AO!) Area of Interest (A01) ) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines 0 0 A A/D B B/D C C/D D Not rated or not available Soil Rating Points II O O O A A/D B B/D MAP INFORMATION C The soil surveys that comprise your AOI were mapped at 1:24,000. C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background ,; Aerial Photography Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. 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 21, Sep 1, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2021 Jun 12, 2021 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. ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 1/5/2023 Page 2 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Altvan loam, percent slopes 0 to 1 B 24.8 100.0% Totals for Area of Interest 24.8 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, BID, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, BID, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Tie -break Rule: Higher e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 4of4 Stormwater Drainage Study Appendix C: RATIONAL METHOD CALCULATIONS 6/6/22, 11:49 AM Precipitation Frequency Data Server NOAA Atlas 14, Volume 8, Version 2 Location name: Greeley, Colorado, USA* Latitude: 40.3795°, Longitude: -104.6227° Elevation: 4642.53 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular AMS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration 5 -min 10 -min 15 -min 30 -min 60 -min 2 -hr 3 -hr Annual exceedance probability (1/years) 1/2 0.268 (0.221-0.328) 0.392 (0.323-0.480) 0.478 (0.394-0.585) 0.642 (0.529-0.786) 0.791 (0.653-0.969) 0.940 (0.781-1.14) 6 -hr 12 -hr 24 -hr 1.02 (0.854-1.24) 1.18 (0.992-1.42) 1.39 (1.17-1.65) 1.64 (1.40-1.94) 1.89 2 -day (1.63-2.22) 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day 2.06 (1.78-2.40) 2.19 (1.89-2.54) 2.50 (2.17-2.88) 2.76 (2.41-3.17) 3.51 (3.09-3.99) 4.12 (3.64-4.66) 4.86 (4.31-5.47) 5.47 (4.87-6.14) 1/25 0.378 0.476 (0.310-0.464) (0.388-0.589) 0.553 (0.454-0.679) 1 0.674 (0.554-0.828) 0.904 (0.742-1.11) 1.10 (0.903-1.35) 1.30 (1.07-1.58) 1.39 1.16-1.69) 1.62 (1.36-1.95) 1.91 (1.61-2.28) 2.20 (1.87-2.60) 0.698 (0.569-0.862) 0.851 (0.694-1.05) 1.14 (0.931-1.41) 1.39 (1.13-1.72) 1.64 (1.35-2.01) 1/50 0.628 0.758 (0.498-0.831) (0.580-1.01) 0.919 (0.728-1.22) 1.12 (0.888-1.49) 1.51 (1.20-2.00) 1.85 (1.47-2.47) 2.19 (1.77-2.92) 1.76 (1.45-2.15) 2.04 (1.69-2.47) 2.37 (1.98-2.84) 2.69 (2.26-3.19) 2.53 (2.16-2.97) 3.06 (2.60-3.60) 2.37 1.92-3.14) 2.70 (2.20-3.53) 3.06 (2.49-3.91) 3.41 (2.79-4.29) 3.81 (3.13-4.72) 2.70 3.23 3.99 (2.32-3.15) (2.76-3.79) (3.29-4.92) 2.84 (2.45-3.31) 3.25 (2.82-3.76) 3.38 (2.89-3.96) i 3.60 (3.13-4.14) 4.49 (3.93-5.12) 5.21 (4.58-5.91) 6.13 (5.42-6.92) 6.93 (6.15-7.80) 3.84 (3.31-4.46) 4.24 (3.66-4.90) 5.21 (4.54-5.97) 6.01 (5.25-6.85) 7.05 (6.19-7.99) 7.97 (7.03-9.01) 4.15 (3.43-5.09) 4.66 3.85-5.62) 5.09 4.22-6.08) 6.15 (5.12-7.25) 7.03 5.88-8.23) 8.20 (6.89-9.54) 9.26 (7.80-10.7) 1.11 (0.849-1.49) 1.35 1.04-1.81) 1.82 (1.40-2.44) 2.26 (1.73-3.04) 2.69 (2.09-3.60) 2.91 2.27-3.88) 3.29 (2.58-4.33) 3.66 (2.88-4.73) 4.01 (3.18-5.12) 4.43 (3.53-5.57) 4.61 (3.70-5.77) 4.78 (3.84-5.94) 5.29 (4.27-6.50 5.73 (4.64-6.98) 6.84 (5.57-8.22) 7.77 (6.36-9.27) 9.03 (7.42-10.7) 10.2 (8.39-12.0) 1/100 0.902 (0.659-1.24) 1.32 (0.965-1.82) 1.61 (1.18-2.22) 2.17 1.59-2.99) 2.71 (1.99-3.75) 1/200 1.06 (0.734-1.51) 1.55 (1.08-2.21) 1.89 (1.31-2.69) 2.56 (1.77-3.64) 3.22 (2.23-4.59) 1/500 1.29 (0.850-1.89) 1.89 (1.24-2.77) 2.30 (1.52-3.38) 3.11 (2.05-4.57) 3.96 (2.62-5.83) 3.25 I 3.88 4.81 (2.40-4.47) i (2.72-5.50) i (3.21-7.01) 3.53 (2.63-4.83) 3.95 (2.96-5.34) 4.23 (2.99-5.97) 4.31 (3.24-5.72) 4.67 (3.55-6.13) 5.08 (3.88-6.57) 4.69 (3.34-6.53) 5.01 (3.59-6.88) 5.39 (3.89-7.30) 5.78 (4.20-7.71) 5.28 (4.05-6.78) 5.44 (4.19-6.96) 5.98 4.37-7.93) 5.27 3.54-7.65) 5.77 (3.91-8.28) 6.04 (4.12-8.54) 6.41 (4.42-8.95) 6.75 (4.69-9.30) 6.96 (4.87-9.53) 5.95 (4.61-7.51) 6.38 (4.96-8.00) 7.52 (5.89-9.29) 6.14 (4.51-8.11) 6.62 (4.89-8.63) 7.04 (5.22-9.10) 8.18 (6.11-10.4) 8.49 (6.68-10.4) 9.82 (7.77-12.0) 11.0 (8.76-13.4) 9.19 (6.91-11.6) 10.6 I (7.99-13.3) 11.8 (8.98-14.8) 7.12 5.00-9.71) 7.54 (5.33-10.1) 7.91 (5.61-10.6) 9.04 (6.47-11.9) 10.1 (7.26-13.2) 11.5 (8.34-15.0) 12.8 (9.32-16.6) 1/1000 1.48 (0.937-2.18) 2.16 (1.37-3.19) 2.64 (1.67-3.89) 3.57 (2.27-5.27) 4.58 (2.90-6.76) 5.58 (3.58-8.16) 6.14 3.96-8.92) 6.67 (4.34-9.60) 6.88 (4.53-9.79) 7.24 (4.81-10.2) 7.53 (5.06-10.5) 7.75 (5.24-10.7) 7.91 (5.37-10.9) 8.25 (5.65-11.3) 8.57 (5.91-11.7) 9.67 (6.74-13.0) 10.7 (7.52-14.4) 12.2 (8.60-16.2) 13.5 (9.58-17.9) Precipitation frequency (PF) estimates in this table are based on frequency analysis of annual maxima series (AMS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and annual exceedance probability) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 1/4 6/6/22, 11:49 AM Precipitation Frequency Data Server C Precipitation depth 14 12 10 4 14 12 1 0 V2 AM -cased depth -duration -frequency (DDF) curves Latitude: 40.3?95', Longitude: -104.6227 C � s V5 1'10 th Duration tion re re re re to 0 -a gmo oil ) 1 N. O_ 1150 1/100 1'200 Annual e cee lance prob►abillity (1/years) NOAA Atlas 14o Volume B, Version 2 CO fo (0 '5 _ N re" igcr V500 x'1000 Created (GMT): Mon Jun 6 16.49:18 2022 Back to Top Maps & aerials Small scale terrain Annual exceecdance p robability (i!yoars) 2 5 10 25 50 100 200 500 1 000 Duration 5 -man 10 -min 15 -min 60 -min 2 -hr -hr 6-nir 12 -hr 24 -hr 2 -day 3 -day 4 -clay 7 -day 10 -day 20 -day 30 -day 45 -day 6O -day https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 2/4 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A EX I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 `- Reach 3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration __ _ `-------� overland • Reach 1 flow Reach 21- LEGEND (.) Big Flour Direr lion Ca.tc }carte nt B oundar}r NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.47 5.58 5.58 5.00 0.22 74.01 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 143.94 18.29 18.29 13.16 49.84 49.84 cfs cfs cfs Union Colony EX 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:32 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A EX Illustration Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output B Soil 24.80 I 0.36 8.93 I I sum: 2 24.80 sum: 8.93 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3600 rEr : Flow Dimon C at clam cot B MIELdElly *See sheet "Design Info" for inperviousness-based runoff coefficient values. Union Colony EX 100 Yrs.xls, Weighted C 2/2/2023, 8:32 AM CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A PR I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 Reach:3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration i Reach 2�. Reach 1 overland flow LEGEND U B eginn ng F1gtir Dire*. -don Cate lane nt Bound - NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.08 5.58 5.58 2.50 0.11 148.03 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 217.96 18.29 18.29 9.78 50.44 50.44 cfs cfs cfs Union Colony PR 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:31 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A PR Illustration LEA: Flow Direction Catchin ent BBiortindary Instructions: For each catchment subarea. enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output B SOILS 24.06 0.36 8.66 B SOIL GRAVEL ROAD 0.736 0.50 0.37 B SOIL CONCRETE PADS 0.004 0.96 0.00 Sum: 24.80 Sum: 9.03 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3643 *See sheet "Design Info" for inperviousness-based runoff coefficient values. Union Colony PR 100 Yrs.xls, Weighted C 2/2/2023, 8:31 AM Stormwater Drainage Study Appendix D: GRASS SWALE CALCULATIONS 8 T-2 Grass Swale RESIDUAL CAPACITY FOR LARGER FLOODS 1;,, • 4" (MIN) SANDY LOAM 6" MI IN _L 2-YR WSE 6" MI TRAPEZOIDAL SWALE SECTION NTS I RESIDUAL CAPACITY FOR LARGER FLOODS 2-YR WS•E 4'° MIN. SANDY LOAM 12" MIN. MIN. D 1.0' 12" MIN. (2-YR) 1.0 FPS !Y TRIANGULAR SIAN GULAR SWALE SECTION NTS CONCRETE COI I AR ENERGY DISSIPATION b ir. l' rf I PROVIDE DOUBLE CLEANOUTS WITH WATER TIGHT CAPS @150' O.O. USE 90* SWEEP OR (2) 45' BENDS (OFFSET FROM SWALE CENTERLINE TO AVOID IMPEDING FLOW WHEN USING A TRIANGULAR SECTION Design Example 1 4 MIN. GRADE CONTROL STRUCTURE BEYOND GRADE CONTROL STRUCTURE BEYOND UNDERDRAIN AND SANDY LOAM RECOMMENDED FOR LONGITUDINAL SLOPES < 2.0%. 4" SLOTTED PIPE MEETING TABLE 05-3 WITH CDOT CLASS C FILTER MATERIAL ALL AROUND OR PERFORATED HOPE PIPE WITH AASHTO #67 ALL AROUND CONTAINED WITHIN CEOTEXTILE FABRIC. ASTM D4751-AOS US STD. SIEVE #50 TO 7a, ASTM D4533 MIN. TRAPEZOIDAL TEAR STRENGTH 100 X 60 LBS, MINIMUM COE SPECIFIED OPEN AREA OF 4%. GRADE CONTROL EXTEND GRADE CTROL STRUCTURE STRUCTURES INTO ONTHE BANK A MIN. OS ABOVE THE 2-YR WSE Ii UNDERDRAIN ENSURE ACCESS TO OUTLET BY CLEAN OUT OR OTHER ACCESSIBLE STRUCTURE SWALE PROFILE NITS Figure GS -1. Grass Swale Profile and Sections The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at www.udfcd.org. This section provides a completed design form from this workbook as an example. GS -6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Hydraulic Analysis Report Project Data Project Title: Cloudbreak - Union Colony Designer: TRC (TH) Project Date: Wednesday, February 1, 2023 Project Units: U.S. Customary Units Notes: Channel Analysis: Swale A Notes: input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 3.0000 ft/ft Side Slope 2 (Z2): 3.0000 ft/ft Channel Width 1.00 ft Longitudinal Slope: 0.0020 ft/ft Manning's n: 0.0350 Depth 1.0000 ft Result Parameters Flow 5.0743 cfs Area of Flow 4.0000 ft^2 Wetted Perimeter 7.3246 ft Hydraulic Radius 0.5461 ft Average Velocity 1.2686 ft/s Top Width 7.0000 ft Froude Number: 0.2957 Critical Depth 0.5642 ft Critical Velocity 3.3402 ft/s Critical Slope: 0.0269 ft/ft Critical Top Width 4.39 ft Calculated Max Shear Stress 0.12481b/ft^2 Calculated Avg Shear Stress 0.0682 lb/ft^2 Selected Profile: FHWA Profile (read-only) Culvert Assessment Profiles Culvert Assessment Profile Name: Standard (read-only) Maximum Excavation Depth: 20.00 ft Maximum Shallow Cover: 4.00 ft Maximum Small Pipe Size: 36.00 ft Minimum Manned Entry Size: 48.00 in Riprap Classes Riprap Class Name:CLASS Riprap Class Order:1 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 304.80 mm D85: 228.60 mm D50: 165.10 mm D15: 114.30 mm Riprap Class Name:CLASS II Riprap Class Order:2 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 457.20 mm D85: 330.20 mm D50: 241.30 mm D15: 177.80 mm Riprap Class Name:CLASS III Riprap Class Order:3 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 609.60 mm D85: 431.80 mm D50: 317.50 mm D15: 228.60 mm Riprap Class Name:CLASS IV Riprap Class Order:4 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 762.00 mm D85: 533.40 mm D50: 393.70 mm D15: 266.70 mm Riprap Class Name:CLASS V Riprap Class Order:5 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 914.40 mm D85: 647.70 mm D50: 469.90 mm D15: 330.20 mm Riprap Class Name:CLASS VI Riprap Class Order:6 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1066.80 mm D85: 762.00 mm D50: 546.10 mm D15: 381.00 mm Riprap Class Name:CLASS VII Riprap Class Order:7 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1257.30 mm D85: 889.00 mm D50: 647.70 mm D15: 444.50 mm Riprap Class Name:CLASS VIII Riprap Class Order:8 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1524.00 mm D85: 1079.50 mm D50: 800.10 mm D15: 558.80 mm Riprap Class Name:CLASS IX Riprap Class Order:9 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1828.80 mm D85: 1295.40 mm D50: 965.20 mm D15: 660.40 mm Riprap Class Name:CLASS X Riprap Class Order:10 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 2133.60 mm D85: 1511.30 mm D50: 1130.30 mm D15: 787.40 mm CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Dust Abatement Plan The purpose and intent of this Dust Abatement Plan is to ensure that the Project complies with applicable state and federal air quality standards. The Environmental Protection Agency (EPA) sets forth the National Ambient Air Quality Standards (NAAQs) pursuant to the Clean Air Act. Air quality impacts associated with construction projects generally arise from fugitive dust generation during the operation of heavy equipment. Colorado administers the NAAQS through issuance of the Air Pollutant Emission Notice (APEN). The Project will not exceed the NAAQS and will follow best management practices to ensure that the production of dust will be controlled by the regular application of water to the Project. The Project will obtain an APEN permit prior to construction. Minimal dust is expected to be generated during construction and operations due to the planned use of dust suppression best management practices and soil stabilization following construction and throughout operations. During construction, CBEP Solar 27, LLC and its contractors will control dust by applying water to disturbed soils and soil piles to control fugitive dust from blowing and impairing air quality. Once the construction phase is completed, the site will be visited 1-2 times per year for routine maintenance and as needed for emergency maintenance. Disturbed areas not covered with gravel as part of the Project design will be reseeded with native seed to revegetate disturbed areas and hold soil in place, minimizing fugitive dust impacts during operations. CBEP Solar 27, LLC would employ native revegetation methods or chemical control methods for infestations of weeds during regular maintenance if necessary. (970) 425-3175 I INFO©aCLOUDBREAKENERGY.COM I CLOUDBREAKENERGY.COM CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Dust and Weed Mitigation Plan Dust Control: • Minimal dust is expected to be generated during construction and operations due to the planned use of dust suppression best management practices and soil stabilization following construction and throughout operations. During construction, CBEP Solar 27, LLC and its contractors will control dust by applying water to disturbed soils and soil piles to control fugitive dust from blowing and impairing air quality. • During the operations of the Project, the land under and around the Project will be seeded with a native grass seed mixture, which will mitigate dust. Weed Control: • The site will be inspected annually by CBEP Solar 27, LLC or its contractors for the presence of invasive species. Minor presences will be managed by cutting and pulling in a manner to not disburse or promote spreading of weed seeds. If a major presence occurs, mowing and the potential application of herbicides will be deployed. Herbicide selection may vary depending on the time of year, the life cycle of the noxious weed species. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK CBEP SOLAR 27, LLC PO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Landscape and Screening Plan There is currently no landscaping on the Project's site. The Project will be surrounded by a 7 -foot tall game fence. Rocky Mountain Junipers will be planted along the outside of the northern fence line to provide natural screening for nearby residences. Example photos as well as a map depicting the proposed location for tree placement are provided below. Please refer to sheet C-401 of the USR Map for additional detail on the proposed security fence. EXAMPLE PHOTOS: (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Lighting Plan CBEP Solar 27, LLC is proposing to construct and operate the Union Colony Solar Project in unincorporated Weld County, Colorado. The Project includes construction of 3.4 MW of solar electric generation on a 79.54 acre parcel. This Lighting Plan describes lighting during the construction and operations phases of the Project. Temporary Construction Lighting: The need for lighting during construction is expected to be limited because the majority of construction activities will occur during daylight hours. If lighting is needed during construction, lights will be positioned and/or shielded from oncoming traffic and residences in the vicinity of the project site, as necessary. Cutoff -type luminaires would be used where practicable. Individual light sources would not exceed 150,000 lumens per light source (typical of a 1250W metal halide light) and would project 0.1 lumen or less at property lines. Unnecessary lighting will not be used. Lights would not exceed 24 feet in height. Any lighting needed for construction is not shown in the dimensioned elevation drawing of the USR Map due to its temporary nature. Project Operations Lighting: There will be no lighting on the Project after construction is completed. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM <i TRC Noise Study Report January 2023 I Union Colony Solar Project Prepared For: Cloudbreak Energy Partners, LLC 4845 Pearl East Circle,Suite 118 Boulder, Colorado 80301 Prepared By: TRC Companies, Inc. 123 North College Avenue, Suite 370 Fort Collins, Colorado 80524 i TRC Noise Study Union Colony Solar Project Weld County, Colorado NOISE STUDY Cloudbreak Energy Partners, LLC (Cloudbreak) is proposing to construct and operate the Union Colony Solar Project (Project) in unincorporated Weld County, Colorado. The Project includes construction of up to 4 direct current (DC) Megawatts (MW) of solar electric generation on a 24.08 -acre parcel. The purpose of this noise study was to determine the level of noise impact from the Project at nearby residences and to e nsure that the Project complies with state and county regulations. The level of impact has been determined based on The State of Colorado Noise Law and WCC Chapter 14 Article 9 (Noise). Fundamentals of Noise Noise can be defined as unwanted sound. When a noise is distinctly louder than the ambient noise e nvironment and reaches a certain level, it can disrupt normal activities. The magnitude of noise or the deviation from the ambient noise level is usually described by sound pressure. The magnitude of noise is u sually described by a ratio of its sound pressure to a reference sound pressure, which is usually 20 micro - Pascals. A logarithmic scale is used to relate sound pressure to a common reference pressure, yielding the sound pressure level (SPL). SPL is measured in dimensionless units of decibels (dB) and are modified by frequency response of human hearing or weighting. The commonly accepted limits of human hearing to detect sound are between the threshold of hearing at 0 dB and the threshold of pain at 140 dB. Sound frequencies are represented in units of Hertz (Hz), which correspond to the number of vibrations per second of a given tone. Sound occurs over a wide range of frequencies. Three weightings have been established for measuring sound pressure: A, B, and C. The commonly accepted audible frequency is between 20 Hz and 20,000 Hz, and human hearing is most sensitive to the frequencies between 1,000 Hz and 6,000 Hz. The A -weighted scale is adjusted to frequencies most sensitive to human ears. Sound levels that are measured using the A -weighted scale are often expressed as dB(A). All noise levels in this noise impact analysis report will be expressed in dB(A). A key concept in evaluating potential noise impacts is the perceived effect of incremental increases in existing noise levels. Changes in dB(A) are exponential; therefore, an increase of 3 dB(A) is barely perceptible, an increase of 5 dB(A) is readily perceptible, and a 10 dB(A) increase would be perceived by someone to be a doubling of the noise level (loudness). Existing Noise Environment: The subject site is located northwest of the intersection of County Road 54 and County Road 47 in an unincorporated area of Weld County, Colorado. The Project Area is surrounded by existing agricultural fields along with multiple rural residential properties. South of the Project is undeveloped land followed by an oil well. The applicable setbacks from adjacent property lines and roadways will be required, and much of the existing vegetation (if present) within the setbacks will be retained. Existing noise sources at the site occur mainly from infrequent vehicular traffic traveling on nearby roadways. 1 i TRC Noise Study Union Colony Solar Project Weld County, Colorado State of Colorado Noise Law Colorado Revised Statutes 25-12-103: Maximum Permissible Noise Levels. 1. Every activity to which this article is applicable shall be conducted in a manner so that any noise produced is not objectionable due to intermittence, beat frequency, or shrillness. Sound levels of noise radiating from a property line at a distance of twenty-five feet or more there from in excess of the dB(A) established for the following time periods and zones shall constitute prima facie evidence that such noise is a public nuisance (Table 1). 2. In the hours between 7:00 a.m. and the next 7:00 p.m., the noise levels permitted in subsection (1) of this section may be increased by ten dB(A) for a period of not to exceed fifteen minutes in any one -hour period. 3. Periodic, impulsive, or shrill noises shall be considered a public nuisance when such noises are at a sound level of five dB(A) less than those listed in subsection (1) of this section. 4. Construction projects shall be subject to the maximum permissible noise levels specified for industrial zones for the period within which construction is to be completed pursuant to any applicable construction permit issued by proper authority or, if no time limitation is imposed, for a reasonable period of time for completion of project. Table 1. State of Colorado Maximum Allowable Noise Sound Pressure Levels for Specified Premises Zone 7am to next 7pm 7pm to next 7am Residential 55 dB(A) 50 dB(A) Commercial 60 dB(A) 55 dB(A) Light Industrial 70 dB(A) 65 dB(A) Industrial 80 dB(A) 75 dB(A) Weld County Code Noise Ordinance Weld County Code (WCC) 14-9-40: Maximum Permissible Noise Levels. A. Sound levels shall be measured as provided for in Section 14-9-50 B. Sound levels are hereby established for each type of property during specific hours of the day. Any sound level which exceeds the level set for a type of property at any time of day is prohibited (Table 2). 2 i TRC Noise Study Union Colony Solar Project Weld County, Colorado C. Between the hours of 9:00 p.m. and 7:00 a.m., the noise levels set forth in Table 2 may be exceeded by up to ten (10) decibels for up to fifteen (15) minutes in a one -hour period. Table 2. Weld County Maximum Permissible Noise Levels Land Use 7am to 9pm 9pm to 7am Residential property or Commercial Area 55 dB(A) 50 dB(A) Industrial area or Construction activities 80 dB(A) 75 dB(A) Non -specified areas 55 dB(A) 50 dB(A) D. Vehicles operating in the public right-of-way are subject to the following maximum noise levels (Table 3) Table 3. Maximum Vehicular Sound Levels Vehicle Class (GVWR) Maximum 35 mph noise or less in Speed zone Limit Maximum noise over 35 mph in Speed zone Limit Over 10,000 lbs. 86 dB(A) 90 dB(A) Any other vehicle 80 dB(A) 84 dB(A) Weld County Code Exceptions Weld County Code (WCC) 14-9-60: Exceptions. The provisions of the Weld County Code do not apply to the following: N. Any noise produced at a construction site. Project Noise Construction Construction noise represents a short-term (temporary) impact on ambient noise levels. Temporary noise impacts during construction would occur during daylight hours while construction equipment is being operated including, but not limited to, passenger vehicles, earthmoving equipment, concrete mixers, water trucks, and semi-tractor/trailer trucks. The spatial distribution of construction noise emissions would vary during the day and depend upon the type of activity. Construction traffic will generate noise along the haul route. This noise would be temporary during commuting hours and when supplies are delivered over the course of construction. Operations Sources of noise during operation would only include temporary vehicle noise from maintenance personnel access and typical noise emissions from the solar array, inverters (which convert electricity from AC -to -DC, and DC -to -AC), transformers (which "step up" and "step down" the system voltage), and overhead 3 i TRC Noise Study Union Colony Solar Project Weld County, Colorado transmission. Project facilities that emit sound during operation include inverters. Noise emission from inverters depends on the inverter model and number of inverters, which will be determined based on detailed engineering to be completed during final design and approval of the site, but typical emissions from industrial photovoltaic (PV) inverters and associated supporting equipment utilized in previous solar projects within the region range from 48 to 72 dB(A) at a distance of 10 feet (Tech Environmental 2012). Within the 48 to 72 dB(A) range, inverter sound levels are generally indistinguishable from background noise levels at a distance of 150 feet from the inverter (Tech Environmental 2012). Typical equipment that is expected to be utilized for this Project includes Module Model Heliene 144M M8 530W Bifacial or similar and Inverter Model CPS SCH125KTL-DO/US-600 or similar. For comparison, a gas lawnmower can produce around 90 dB(A), a vacuum cleaner around 70 dB(A), and a dishwasher in the next room around 50 dB(A) (FAA 2022). Based on the typical sound levels from Project operation and the distance to the boundary, the Project will adhere to Weld County and State of Colorado permissible noise levels. Conclusion The purpose of this noise study was to determine the level of noise impact the Project will produce and ensure that the Project will comply with state and county regulations. The level of noise impact from the Project has been determined based on the Weld County noise regulations as well as the state of Colorado Noise Law. Based on typical solar energy facility equipment, it is expected that the noise levels from Project facilities will comply with the Weld County Noise Ordinance and state statute requirements. References Federal Aviation Administration (FAA). 2022. Fundamentals of Noise and Sound. Available https://www.faa.gov/regulations_policies/policy_ guidance/noise/basics/. Accessed March 23, 2022. Tech Environmental, Inc. 2012. Study of Acoustic and EMF Levels from Solar Photovoltaic Projects. Prepared by Tech Environmental, Inc., Waltham, MA. Prepared for Massachusetts Clean Energy Center, Boston, MA. December 2012. 4 CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Sewage Disposal Documentation No sewage disposal will be required for the operation of the Project. CBEP Solar 27, LLC or its contractor will provide portable toilets during construction. (970) 425-3175 I INFO©aCLOUDBREAKENERGY.COM I CLOUDBREAKENERGY.COM 'TRC Stormwater Drainage Study CL©UDBREAK ENERGY PARTNERS Date: To: From: Project: Subject: 8/24/2023 Cloudbreak Energy Allyson Williamson, TRC Companies 700 Highlander Blvd., Suite 210 Arlington, TX 76015 Union Colony Solar Project On -Site Drainage Study PRELIMINARY Prepared by or under the Direct Supervision of: Ally sew W illizurnisery REG/s R% 'r' 0 60360 - EXP 10/31/2023 x,\c �Fssi G N A 1• Allyson Williamson, P.E. 60360 "8/24/2023" Cloudbreak Energy is pursuing the development of the Union Colony Project, a photovoltaic energy generation facility at a 24.8 -acre site located approximately 5.5 miles southwest of Greeley, Colorado, alongside Co Rd 47 with access from Co Rd 47 (See Appendix A — Site Plan C-201 and Drainage Area Maps C-301 & C-302). The existing site is currently used for agricultural purposes with approximately 1% slopes. This drainage study was prepared to request for variance from Section 5.10 Storage requiring detention for the proposed development to comply with the Weld County Engineering and Construction Criteria (WCECC) Manual Requirements, updated January 2021. The study summarizes findings from performing a hydrologic analysis of the project site to identify the potential stormwater impact from the proposed solar project and ensures that stormwater will not be concentrated, nor will it exceed historical flows when it leaves the parcel to County Road 54, protecting the existing infrastructure of Weld County. Proposed Project The proposed solar project will consist of pole mounted photovoltaic (PV) arrays. Ground disturbance under the panels will be minimal; thus, the existing perviousness of the soil will be maintained under the solar cells allowing infiltration. Rainfall runoff from the panels will not be concentrated and flow under the pole mounted PV panels matching the pre -development flow patterns. Additional improvements associated with this project are limited to gravel drives for vehicle access and concrete pads for distribution transforms (see Appendix A — Site Plan C-201 and Drainage Area Maps C-301 & C-302). No public access or utility infrastructure improvements are anticipated at this time. Site Drainage Currently, the existing site does not have any regional retention or water quality features. The soils in the area mainly consist of hydrologic soil group (HSG) B soils given by the Natural Resources Conservation Service (NRCS — Appendix B). One drainage basin labeled as Drainage Area A has been identified for the project site and is approximately 24.80 acres. Any offsite flows appear to follow the existing ditches and are not expected to affect the project site. See Appendix A for the drainage area maps and details. 1 Stormwater Drainage Study A hydrologic analysis was prepared using the Rational Method based upon requirements from WCECC Manual. The analysis provided estimated peak flow rates for the 100 -year storm under both pre- and post -development conditions. The design rainfall depth for a 1 -hour, 100 -year storm is 2.71 inches based upon NOAA Atlas 14: Precipitation -Frequency Atlas. The Rational Method equation shown below was used to determine the peak flow rates from Drainage Area A. Existing conditions were determined to be "Greenbelt, Agriculture" which correlates to a 2% impervious value according to Table 5-2, Weld County Engineering and Construction Criteria. In Table 5-5, based off the soil type and impervious percentage, the runoff calculation was 0.3600 for Drainage Area A. Proposed conditions were determined to be the weighted average of "Greenbelt, Agriculture" (2% impervious), "Solar Facilities B Soils" (2% impervious), "Packed Gravel" (40% impervious), and "Paved" (100% impervious). Using the same process as before, the runoff coefficient was weighted to be 0.3643 for Drainage Area A. The drainage area imperviousness and resulting peak flow rates from pre -and post -development conditions are summarized below. See Appendix C for the runoff coefficient calculations. Q Q=C*I*A Where: - Runoff flow rate in cubic feet per second (cfs) / Rainfall Intensity in inches per hour (in/hr) A -Area of the basin in acres (ac) Pre -development Runoff Calculation Parameters Drainage Weighted Runoff Rainfall Area Area, A (ac) Coefficient, C Intensity/ (in/hr) A 24.80 0.3600 5.58 Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Intensity, Rainfall (in/hr) I % Added area ac/total (impervious Impervious ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Drainage Area development Peak (cfs) Pre Flow - Rate Post Peak -development Flow (cfs) Rate DIFFERENCE (CFS) A 49.84 50.44 0.60 Based upon the above results, the increase of impervious area would produce little increase 2 Stormwater Drainage Study (approximately 1.0%) in the peak flow rate. Because of this, a detention basin facility will not be proposed. Instead, a grass swale will be introduced near the north project site boundary to dissipate energy and attenuate any potential flow increase from gravel roads and concrete pads. Erosion Control/Stormwater Management Plan Erosion control features such as silt fences and a grass swale (also mentioned above) will be installed on the site prior to construction activities. Such measures will be included in the erosion control plan and detail sheets within the final construction documents. Grass swale sizing calculations are summarized in Appendix D. Conclusion The variance request and attached drainage maps were produced in accordance with requirements from Weld County Engineering and Construction Criteria Manual, updated January 2021. The existing storm water flow characteristics are expected to remain unchanged and decrease in peak flow rate. A variance from detention is reasonable because the results ensures that stormwater will not be concentrated, nor it will exceed historical flows when it leaves the parcel to County Road 54. The proposed development will not alter historic drainage patterns or adjacent and downstream property owners. 3 Stormwater Drainage Study References 1. Weld County, Weld County Engineering and Construction Criteria Manual, January 2021. 2. Web Soil Survey, Natural Resources Conservation Service, United States Department of Agriculture. Online at: http://websoilsurvey.nrcs.usda.gov, accessed December 2021. 3. NOAA Atlas 14, Volume 11, Version 2. ESRI Maps. USGS. Sanja Perica, Sandra Pavlovic, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Orlan Wilhite. Appendices A. Site Plan C-201 & Drainage Area Maps C-301 & C-302 5-8 B. NRCS Soil Layer Map 9-13 C. Rational Method Calculations 14-20 D. Grass Swale Calculations 21-27 4 Stormwater Drainage Study Appendix A: SITE PLAN C-201 AND DRAINAGE AREA MAPS C-301 & C-302 EXISTING FEATURES GARY & SUSAN ALLES PARCEL: 096124300041 RECEPTION NO.: 377224 RECORDING DATE: 6/6/2011 (NOT A PART) EX. HOUSE GARY & SUSAN ALLES PARCEL: 096123000025 RECEPTION NO.: 4304622 RECORDING DATE: 5/24/2017 (NOT A PART) PROJECT PROPERTY ADJACENT PROPERTY SOLAR LEASE AREA PROPERTY NUMBER RIGHT-OF-WAY EASEMENT/SETBACK CONCRETE ASPHALT DIRT ROAD CULVERT MAJOR CONTOURS EX. METAL PIPE BRIDGE EX. 12" CORRUGATED PIPE EX. WATER VALVE EX. FENCE 20' PROPERTY SETBACK (TYP.) EX. SWALE SOUTH EDGE OF EX. CONCRETE WALL EX. FIELD ROAD EX. DRAINAGE STRUCTURE a _rte .. = 4643 - -� -4644= -4644L4644: __. r `-�---4643 `� T 4642 -_ MINOR CONTOURS SOILS BOUNDARY LINE SOILS CLASSIFICATION UNDERGROUND ELECTRIC LINE OVERHEAD ELECTRICAL LINE UNDERGROUND GAS LINE (APPROX LOCATION) WATER LINE FIBER OPTIC LINE UTILITY POLE FENCE (3) EX. 24" CORRUGATED PIPE PROP. CLOSED WOODEN FENCE (TYP.) PROP. 7' W TRAPEZOIDAL GRASS SWALE 1 3' PANEL TO FENCE (VARIES, MIN 15') EX. BURIED PIPELINE (APPROX LOCATION) EX. 18" CORRUGATED PIPE ti t f 1 --- 7- f i a Th EX. EDGE OF ASPHALT OE 30' OE PROPOSED FEATURES MEMa S' 4641- - PROP GAME FENCE (TYP.) 1 7 4643 ---- i _ X 60' ROW BK 86, PG 273 GRAVEL ROAD GAME FENCE WITH WOODEN P05 CLOSED WOODEN FENCE SOLAR ARRAY OVERHEAD ELECTRIC LINE UNDERGROUND ELECTRIC LINE UTILITY POLE EQUIPMENT PAD TRAFFIC FLOW ARROW EX. UTILITY POLE (TYP.) - SEE NOTE 1 4,7 PROP 26' W GRAVEL ACCESS ROAD THOMAS & MARJORIE BROWN PARCEL: 096123400007 RECEPTION NO.: 4296215 RECORDING DATE: 4/24/2017 J G 4643 G -�f i 0+00 I a - EX. FIELD ROAD G O O 0 0 N a m 0 co PROPOSED EROSION CONTROL FEATURES DAVID WEINMEISTER PARCEL: 096124300036 RECEPTION NO.: 3322296 RECORDING DATE: 9/13/2005 (NOT A PART) WELD COUNTY ROAD 47 a_ f V OE mina OE GRASS SWALE NOTES EX. FIBER OPTIC X EX. OVERHEAD ELECTRIC LINE PROP. PERSONNEL GATE R28' (TYP.) 0+80 UE Or _ a a a rThf _ 1. PROPOSED MAIN ACCESS GATE TO SOLAR FARM. EMERGENCY CONTACT SIGN POSTED INCLUDING PROJECT OWNER, OPERATIONS, AND MAINTENANCE CONTRACTOR. ELECTRICAL HAZARD SIGNS POSTED SEE DETAIL SHEET C-401. 111 \` \\ \\\‘ EX. HOUSE DAVID WEINMEISTER PARCEL: 096124300033 \\‘A RECEPTION NO.: R CORDING DATE: 11/8/2011 (NOTA PART) PART) EX. ABOVE GROUND ` GAS PIPELINES J APPROX LOCATION OF PROP. PIPELINE PER REC NO. 2012585 EX. 24" CMP PIPE sr, OE dwiliNSWAS X X EX. SWALE PROP EQUIPMENT PAD (TYP.) 20' PANEL ROW SPACING (TYP.) PROP. GAME FENCE (TYP.) UE UE -x II OE �+ r X 29' PANEL TO FENCE (VARIES, MIN 15') PROP. 40' EASEMENT EX. BURIED PIPELINE (APPROX LOCATION) _� -4644 UE UE i lam EX. GUY WIRE (TYP.) i _ EX. 4' CONCRETE CHANNEL I l EX. SWALE UE CAF i _ PROP UNDERGROUND ELECTRIC m C EX. OVERHEAD ELECTRIC LINE PROP. 10'X40' TEMP CONSTRUCTION TRAILER 27' PANEL TO FENCE (VARIES, MIN 15') 4644a -- PROP. STAGING AREA PROP. 10'x40' STORAGE CONTAINER (2) EX. 24" CORRUGATED PIPE EX. 48" RCP PIPE C m J l i l \ I cc ce LL I 1 •E71 I ' 7.4ss Vc's PROP. PERSONNEL GATE /' SCALE : 1" = 60' EX. ELECTRIC BOX (TYP.) EX. WATER METER EX. FIBER OPTIC BOX (TYP.) PHYLLIS JOHNSON PARCEL: 096125200004 RECEPTION NO.: 4407883 RECORDING DATE: 6/18/2018 (NOT A PART) EX. ELECTRIC BOX (TYP.) EX. WATER LINE EX. BURIED PIPELINE (APPROX LOCATION) EX. EDGE OF ASPHALT 47 FARM LLC PARCEL: 096126100083 RECEPTION NO.: 4522458 RECORDING DATE: 9/12/2019 (NOT A PART) 30' 60' ROW BK 86, PG 273 PROP. OVERHEAD ELECTRIC • 1 EX. SIGN (TYP.) TRC TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com >- z en 0 1±-11 0 L - U ch eN 0 < FiC) Z 0 cC >- CN GREELEY, CO 80631 PROJECT NUMBER: 516145 SHEET TITLE: SITE PLAN SHEET SIZE: ARCH "D" 24" X 36" (610 x 914) 0 ISSUED FOR PERMITTING NOT FOR CONSTRUCTION NO. REVISION DATE INIT DATE: 8/23/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS SCALE: 1" 60' SHEET NO.: C 201 C;lpwworking-trd\d01191951C-301 Pre -Drainage Area Map.dwg 08-23-2023 2:49:55 PM BY: pkuh Pre -development Runoff Calculation Parameters Drainage Area A Area, A (ac) 24.80 Weighted Runoff Coefficient, C Rainfall Intensity, I (in/hr) 0.3600 5.58 WELD COUNTY ROAD 47 CE 4642 4446441 4644 -�-�-- _. LEGEND DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW I SCALE : 1" = 60' TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com NO. REVISION DATE INIT DATE: 8/23/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" - 80' SHEET NO.: C;lpwworking-trd\d01191951C-302 Post Drainage Area Map.dwg 08-23-2023 2:50:07 PM BY: pkuh Y DP —A 4642 _ 464314644 PROP 7' W TRAPEZOIDAL GRASS SWALE 1 I I _ I OE rTh OE 4644 ==4643 4641a nra-rac h M a h h to M h M h _ - 464 - 041' 7, OE 642 V G X4643 G Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Rainfall I (in/br) Intensity, % Added (impervious Impervious ac/total area ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Pre -development Post -development Drainage DIFFERENCE Area Peak Flow (cfs) Rate Peak Flow (cfs)(CFS) Rate A 49.84 50.44 0.60 -� WELD COUNTY ROAD 47 1 x aur _ FO� OE almommareras LEGEND DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW 60 60 30 0 120 SCALE : 1" = 60' \\\ \V\ \c L rC•�.l7C x H 0 E OE , eee �v - l a a =MI MIN 442 f r - 4642 PROP 26' W GRAVEL ACCESS ROAD i i n _ Vitx-sk )9x4. 1ASJO irCptitA UE UE UE PROP CONCRETE PAD UE UE 1 I _ i DAA inzaalka ot• J UE n _ i i � n _ \7ff0 AC/ _ II - - 4644 7-- _ G 4644 i C rn C m c4645 -- fr 4r CO 4r I iii)j 1 11O )111! sr 4:r LO gr i i i i i 1 i i TRC TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com >-F-- ZUrn Q w N � n O Oro U d M Z cc CN 0 Q C(5) zOD 471-' In 0 >- 0 F z D 0 U m d' N N GREELEY, CO 80631 PROJECT NUMBER: 516145 SHEET TITLE: POST DRAINAGE AREA MAP SHEET SIZE: ARCH "D" 24"X36" (610 x 914) 0 2 1" ISSUED FOR PERMITTING NOT FOR CONSTRUCTION NO. REVISION DATE INIT DATE: 8/23/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" 80' SHEET NO.: C 302 Stormwater Drainage Study Appendix B: NRCS SOIL LAYER MAP 9 104° 37' 29" W 8 40° 22' 53" N - 40° 22' 38" N O 4 1 N- 0 4 0 4 4 0 4 0 531870 531920 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) 531970 532020 532070 532120 4 i AMSSOUtlap may not be valid. at thlsssale. 104° 37 29" W 531870 531920 531970 Map Scale: 1:2,240 if printed on A portrait (8.5" x 11") sheet. Meters 0 30 60 120 180 Feet 0 100 200 400 600 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 532170 532020 5332070 532120 532170 104° 37' 14" W 8 E 40° 22' 53" N U 4 0 4 0 co 104° 3714" W 40° 22' 38" N Natural Resources Web Soil Survey all Conservation Service National Cooperative Soil Survey 1/5/2023 Page 1 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) MAP LEGEND Area of Interest (AO!) Area of Interest (A01) ) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines 0 0 A A/D B B/D C C/D D Not rated or not available Soil Rating Points II O O O A A/D B B/D MAP INFORMATION C The soil surveys that comprise your AOI were mapped at 1:24,000. C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background ,; Aerial Photography Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. 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 21, Sep 1, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2021 Jun 12, 2021 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. ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 1/5/2023 Page 2 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Altvan loam, percent slopes 0 to 1 B 24.8 100.0% Totals for Area of Interest 24.8 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, BID, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, BID, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Tie -break Rule: Higher e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 4of4 Stormwater Drainage Study Appendix C: RATIONAL METHOD CALCULATIONS 14 6/6/22, 11:49 AM Precipitation Frequency Data Server NOAA Atlas 14, Volume 8, Version 2 Location name: Greeley, Colorado, USA* Latitude: 40.3795°, Longitude: -104.6227° Elevation: 4642.53 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular AMS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration 5 -min 10 -min 15 -min 30 -min 60 -min 2 -hr 3 -hr Annual exceedance probability (1/years) 1/2 0.268 (0.221-0.328) 0.392 (0.323-0.480) 0.478 (0.394-0.585) 0.642 (0.529-0.786) 0.791 (0.653-0.969) 0.940 (0.781-1.14) 6 -hr 12 -hr 24 -hr 1.02 (0.854-1.24) 1.18 (0.992-1.42) 1.39 (1.17-1.65) 1.64 (1.40-1.94) 1.89 2 -day (1.63-2.22) 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day 2.06 (1.78-2.40) 2.19 (1.89-2.54) 2.50 (2.17-2.88) 2.76 (2.41-3.17) 3.51 (3.09-3.99) 4.12 (3.64-4.66) 4.86 (4.31-5.47) 5.47 (4.87-6.14) 1/25 0.378 0.476 (0.310-0.464) (0.388-0.589) 0.553 (0.454-0.679) 1 0.674 (0.554-0.828) 0.904 (0.742-1.11) 1.10 (0.903-1.35) 1.30 (1.07-1.58) 1.39 1.16-1.69) 1.62 (1.36-1.95) 1.91 (1.61-2.28) 2.20 (1.87-2.60) 0.698 (0.569-0.862) 0.851 (0.694-1.05) 1.14 (0.931-1.41) 1.39 (1.13-1.72) 1.64 (1.35-2.01) 1/50 0.628 0.758 (0.498-0.831) (0.580-1.01) 0.919 (0.728-1.22) 1.12 (0.888-1.49) 1.51 (1.20-2.00) 1.85 (1.47-2.47) 2.19 (1.77-2.92) 1.76 (1.45-2.15) 2.04 (1.69-2.47) 2.37 (1.98-2.84) 2.69 (2.26-3.19) 2.53 (2.16-2.97) 3.06 (2.60-3.60) 2.37 1.92-3.14) 2.70 (2.20-3.53) 3.06 (2.49-3.91) 3.41 (2.79-4.29) 3.81 (3.13-4.72) 2.70 3.23 3.99 (2.32-3.15) (2.76-3.79) (3.29-4.92) 2.84 (2.45-3.31) 3.25 (2.82-3.76) 3.38 (2.89-3.96) i 3.60 (3.13-4.14) 4.49 (3.93-5.12) 5.21 (4.58-5.91) 6.13 (5.42-6.92) 6.93 (6.15-7.80) 3.84 (3.31-4.46) 4.24 (3.66-4.90) 5.21 (4.54-5.97) 6.01 (5.25-6.85) 7.05 (6.19-7.99) 7.97 (7.03-9.01) 4.15 (3.43-5.09) 4.66 3.85-5.62) 5.09 4.22-6.08) 6.15 (5.12-7.25) 7.03 5.88-8.23) 8.20 (6.89-9.54) 9.26 (7.80-10.7) 1.11 (0.849-1.49) 1.35 1.04-1.81) 1.82 (1.40-2.44) 2.26 (1.73-3.04) 2.69 (2.09-3.60) 2.91 2.27-3.88) 3.29 (2.58-4.33) 3.66 (2.88-4.73) 4.01 (3.18-5.12) 4.43 (3.53-5.57) 4.61 (3.70-5.77) 4.78 (3.84-5.94) 5.29 (4.27-6.50 5.73 (4.64-6.98) 6.84 (5.57-8.22) 7.77 (6.36-9.27) 9.03 (7.42-10.7) 10.2 (8.39-12.0) 1/100 0.902 (0.659-1.24) 1.32 (0.965-1.82) 1.61 (1.18-2.22) 2.17 1.59-2.99) 2.71 (1.99-3.75) 1/200 1.06 (0.734-1.51) 1.55 (1.08-2.21) 1.89 (1.31-2.69) 2.56 (1.77-3.64) 3.22 (2.23-4.59) 1/500 1.29 (0.850-1.89) 1.89 (1.24-2.77) 2.30 (1.52-3.38) 3.11 (2.05-4.57) 3.96 (2.62-5.83) 3.25 I 3.88 4.81 (2.40-4.47) i (2.72-5.50) i (3.21-7.01) 3.53 (2.63-4.83) 3.95 (2.96-5.34) 4.23 (2.99-5.97) 4.31 (3.24-5.72) 4.67 (3.55-6.13) 5.08 (3.88-6.57) 4.69 (3.34-6.53) 5.01 (3.59-6.88) 5.39 (3.89-7.30) 5.78 (4.20-7.71) 5.28 (4.05-6.78) 5.44 (4.19-6.96) 5.98 4.37-7.93) 5.27 3.54-7.65) 5.77 (3.91-8.28) 6.04 (4.12-8.54) 6.41 (4.42-8.95) 6.75 (4.69-9.30) 6.96 (4.87-9.53) 5.95 (4.61-7.51) 6.38 (4.96-8.00) 7.52 (5.89-9.29) 6.14 (4.51-8.11) 6.62 (4.89-8.63) 7.04 (5.22-9.10) 8.18 (6.11-10.4) 8.49 (6.68-10.4) 9.82 (7.77-12.0) 11.0 (8.76-13.4) 9.19 (6.91-11.6) 10.6 I (7.99-13.3) 11.8 (8.98-14.8) 7.12 5.00-9.71) 7.54 (5.33-10.1) 7.91 (5.61-10.6) 9.04 (6.47-11.9) 10.1 (7.26-13.2) 11.5 (8.34-15.0) 12.8 (9.32-16.6) 1/1000 1.48 (0.937-2.18) 2.16 (1.37-3.19) 2.64 (1.67-3.89) 3.57 (2.27-5.27) 4.58 (2.90-6.76) 5.58 (3.58-8.16) 6.14 3.96-8.92) 6.67 (4.34-9.60) 6.88 (4.53-9.79) 7.24 (4.81-10.2) 7.53 (5.06-10.5) 7.75 (5.24-10.7) 7.91 (5.37-10.9) 8.25 (5.65-11.3) 8.57 (5.91-11.7) 9.67 (6.74-13.0) 10.7 (7.52-14.4) 12.2 (8.60-16.2) 13.5 (9.58-17.9) Precipitation frequency (PF) estimates in this table are based on frequency analysis of annual maxima series (AMS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and annual exceedance probability) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 1/4 6/6/22, 11:49 AM Precipitation Frequency Data Server C Precipitation depth 14 12 10 4 14 12 1 0 V2 AM -cased depth -duration -frequency (DDF) curves Latitude: 40.3?95', Longitude: -104.6227 C � s V5 1'10 th Duration tion re re re re to 0 -a gmo oil ) 1 N. O_ 1150 1/100 1'200 Annual e cee lance prob►abillity (1/years) NOAA Atlas 14o Volume B, Version 2 CO fo (0 '5 _ N re" igcr V500 x'1000 Created (GMT): Mon Jun 6 16.49:18 2022 Back to Top Maps & aerials Small scale terrain Annual exceecdance p robability (i!yoars) 2 5 10 25 50 100 200 500 1 000 Duration 5 -man 10 -min 15 -min 60 -min 2 -hr -hr 6-nir 12 -hr 24 -hr 2 -day 3 -day 4 -clay 7 -day 10 -day 20 -day 30 -day 45 -day 6O -day https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 2/4 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A EX I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 `- Reach 3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration __ _ `-------� overland • Reach 1 flow Reach 21- LEGEND (.) Big Flour Direr lion Ca.tc }carte nt B oundar}r NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.47 5.58 5.58 5.00 0.22 74.01 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 143.94 18.29 18.29 13.16 49.84 49.84 cfs cfs cfs Union Colony EX 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:32 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A EX Illustration Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output B Soil 24.80 I 0.36 8.93 I I sum: 2 24.80 sum: 8.93 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3600 rEr : Flow Dimon C at clam cot B MIELdElly *See sheet "Design Info" for inperviousness-based runoff coefficient values. Union Colony EX 100 Yrs.xls, Weighted C 2/2/2023, 8:32 AM CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A PR I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 Reach:3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration i Reach 2�. Reach 1 overland flow LEGEND U B eginn ng F1gtir Dire*. -don Cate lane nt Bound - NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.08 5.58 5.58 2.50 0.11 148.03 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 217.96 18.29 18.29 9.78 50.44 50.44 cfs cfs cfs Union Colony PR 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:31 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A PR Illustration LE : flow Direction Catch eat Bmm T L Instructions: For each catchment subarea, enter values for A and C. Subarea _ Area Runoff Product ID acres Coeff. A C* CA input input input output B SOILS 7.10 0.36 2.56 B SOIL SOLAR FACILITY 16.96 0.36 6.11 B SOIL GRAVEL ROAD 0.74 0.50 0.37 B SOIL CONCRETE PADS 0.004 0.96 0.00 sum: 24.80 sum: 9.03 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3643 *See sheet "Design Info" for inperviousness-based runoff coefficient values. 1 Stormwater Drainage Study Appendix D: GRASS SWALE CALCULATIONS 21 T-2 Grass Swale RESIDUAL CAPACITY FOR LARGER FLOODS 1;,, • 4" (MIN) SANDY LOAM 6" MI IN _L 2-YR WSE 6" MI TRAPEZOIDAL SWALE SECTION NTS I RESIDUAL CAPACITY FOR LARGER FLOODS 2-YR WS•E 4'° MIN. SANDY LOAM 12" MIN. MIN. D 1.0' 12" MIN. (2-YR) 1.0 FPS !Y TRIANGULAR SIAN GULAR SWALE SECTION NTS CONCRETE COI I AR ENERGY DISSIPATION b ir. l' rf I PROVIDE DOUBLE CLEANOUTS WITH WATER TIGHT CAPS @150' O.O. USE 90* SWEEP OR (2) 45' BENDS (OFFSET FROM SWALE CENTERLINE TO AVOID IMPEDING FLOW WHEN USING A TRIANGULAR SECTION Design Example 1 4 MIN. GRADE CONTROL STRUCTURE BEYOND GRADE CONTROL STRUCTURE BEYOND UNDERDRAIN AND SANDY LOAM RECOMMENDED FOR LONGITUDINAL SLOPES < 2.0%. 4" SLOTTED PIPE MEETING TABLE 05-3 WITH CDOT CLASS C FILTER MATERIAL ALL AROUND OR PERFORATED HOPE PIPE WITH AASHTO #67 ALL AROUND CONTAINED WITHIN CEOTEXTILE FABRIC. ASTM D4751-AOS US STD. SIEVE #50 TO 7a, ASTM D4533 MIN. TRAPEZOIDAL TEAR STRENGTH 100 X 60 LBS, MINIMUM COE SPECIFIED OPEN AREA OF 4%. GRADE CONTROL EXTEND GRADE CTROL STRUCTURE STRUCTURES INTO ONTHE BANK A MIN. OS ABOVE THE 2-YR WSE Ii UNDERDRAIN ENSURE ACCESS TO OUTLET BY CLEAN OUT OR OTHER ACCESSIBLE STRUCTURE SWALE PROFILE NITS Figure GS -1. Grass Swale Profile and Sections The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at www.udfcd.org. This section provides a completed design form from this workbook as an example. GS -6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Hydraulic Analysis Report Project Data Project Title: Cloudbreak - Union Colony Designer: TRC (TH) Project Date: Wednesday, February 1, 2023 Project Units: U.S. Customary Units Notes: Channel Analysis: Swale A Notes: input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 3.0000 ft/ft Side Slope 2 (Z2): 3.0000 ft/ft Channel Width 1.00 ft Longitudinal Slope: 0.0020 ft/ft Manning's n: 0.0350 Depth 1.0000 ft Result Parameters Flow 5.0743 cfs Area of Flow 4.0000 ft^2 Wetted Perimeter 7.3246 ft Hydraulic Radius 0.5461 ft Average Velocity 1.2686 ft/s Top Width 7.0000 ft Froude Number: 0.2957 Critical Depth 0.5642 ft Critical Velocity 3.3402 ft/s Critical Slope: 0.0269 ft/ft Critical Top Width 4.39 ft Calculated Max Shear Stress 0.12481b/ft^2 Calculated Avg Shear Stress 0.0682 lb/ft^2 Selected Profile: FHWA Profile (read-only) Culvert Assessment Profiles Culvert Assessment Profile Name: Standard (read-only) Maximum Excavation Depth: 20.00 ft Maximum Shallow Cover: 4.00 ft Maximum Small Pipe Size: 36.00 ft Minimum Manned Entry Size: 48.00 in Riprap Classes Riprap Class Name:CLASS Riprap Class Order:1 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 304.80 mm D85: 228.60 mm D50: 165.10 mm D15: 114.30 mm Riprap Class Name:CLASS II Riprap Class Order:2 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 457.20 mm D85: 330.20 mm D50: 241.30 mm D15: 177.80 mm Riprap Class Name:CLASS III Riprap Class Order:3 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 609.60 mm D85: 431.80 mm D50: 317.50 mm D15: 228.60 mm Riprap Class Name:CLASS IV Riprap Class Order:4 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 762.00 mm D85: 533.40 mm D50: 393.70 mm D15: 266.70 mm Riprap Class Name:CLASS V Riprap Class Order:5 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 914.40 mm D85: 647.70 mm D50: 469.90 mm D15: 330.20 mm Riprap Class Name:CLASS VI Riprap Class Order:6 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1066.80 mm D85: 762.00 mm D50: 546.10 mm D15: 381.00 mm Riprap Class Name:CLASS VII Riprap Class Order:7 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1257.30 mm D85: 889.00 mm D50: 647.70 mm D15: 444.50 mm Riprap Class Name:CLASS VIII Riprap Class Order:8 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1524.00 mm D85: 1079.50 mm D50: 800.10 mm D15: 558.80 mm Riprap Class Name:CLASS IX Riprap Class Order:9 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1828.80 mm D85: 1295.40 mm D50: 965.20 mm D15: 660.40 mm Riprap Class Name:CLASS X Riprap Class Order:10 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 2133.60 mm D85: 1511.30 mm D50: 1130.30 mm D15: 787.40 mm =i TRC Stormwater Drainage Study CL©UDBREAK ENERGY PARTNERS Date: To: From: Project: Subject: 3/10/2023 Cloudbreak Energy Allyson Williamson, TRC Companies 700 Highlander Blvd., Suite 210 Arlington, TX 76015 Union Colony Solar Project On -Site Drainage Study PRELIMINARY FOR INTERIM REVIEW ONLY. NOT FOR PERMITTING, BIDDING, NOR CONSTRUCTION. Prepared by or under the Direct Supervision of: Allyson Williamson, P.E. 60360 "3/10/2023" Cloudbreak Energy is pursuing the development of the Darling Ranch Project, a photovoltaic energy generation facility at a 24.8 -acre site located approximately 5.5 miles southwest of Greeley, Colorado, alongside Co Rd 47 with access from Co Rd 54 (See Appendix A -Site Plans C-301 & C-302). The existing site is currently used for agricultural purposes with approximately 1% slopes. This drainage study was prepared to summarize findings from performing a hydrologic analysis of the project site to identify the potential stormwater impact from the proposed solar project and develop appropriate drainage best management practices (BMPs) to address the impact. This drainage study was prepared to comply with the requirements from Weld County Engineering and Construction Criteria (WCECC) Manual, updated January 2021. Proposed Project The proposed solar project will consist of pole mounted photovoltaic (PV) arrays. Ground disturbance under the panels will be minimal; thus, the existing perviousness of the soil will be maintained under the solar cells allowing infiltration. Rainfall runoff from the panels will not be concentrated and flow under the pole mounted PV panels matching the pre -development flow patterns. Additional improvements associated with this project are limited to gravel drives for vehicle access and concrete pads for distribution transforms (see Appendix A - Site Plans C-301 & C- 302). No public access or utility infrastructure improvements are anticipated at this time. Site Drainage Currently, the existing site does not have any regional retention or water quality features. The soils in the area mainly consist of hydrologic soil group (HSG) B soils given by the Natural Resources Conservation Service (NRCS — Appendix B). One drainage basin labeled as Drainage Area A has been identified for the project site and is approximately 24.80 acres. Any offsite flows appear to follow the existing ditches and are not expected to affect the project site. See Appendix A for the drainage area maps and details. A hydrologic analysis was prepared using the Rational Method based upon requirements from WCECC Manual. The analysis provided estimated peak flow rates for the 100 -year storm under both pre- and post -development conditions. The design rainfall depth for a 1 -hour, 100 -year 1 Stormwater Drainage Study storm is 2.71 inches based upon NOAA Atlas 14: Precipitation -Frequency Atlas. The Rational Method equation shown below was used to determine the peak flow rates from Drainage Area A. Existing conditions were determined to be "Greenbelt, Agriculture" which correlates to a 2% impervious value according to Table 5-2, Weld County Engineering and Construction Criteria. In Table 5-5, based off the soil type and impervious percentage, the runoff calculation was 0.3600 for Drainage Area A. Proposed conditions were determined to be the weighted average of "Greenbelt, Agriculture" (2% impervious), "Solar Facilities B Soils" (2% impervious), "Packed Gravel" (40% impervious), and "Paved" (100% impervious). Using the same process as before, the runoff coefficient was weighted to be 0.3643 for Drainage Area A. The drainage area imperviousness and resulting peak flow rates from pre -and post -development conditions are summarized below. See Appendix C for the runoff coefficient calculations. Q=C*I*A Where: Q- Runoff flow rate in cubic feet per second (cfs) / Rainfall Intensity in inches per hour (in/hr) A -Area of the basin in acres (ac) Pre -development Runoff Calculation Parameters Drainage Weighted Runoff Rainfall Area Area, A (ac) Coefficient, C Intensity, (in/hr) A 24.80 0.3600 5.58 Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Intensity, Rainfall (in/hr) I % Added area ac/total (impervious Impervious ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Drainage Area development Peak Pre Flow (cfs) - Rate Post -development Peak Flow (cfs) Rate DIFFERENCE (CFS) A 49.84 50.44 0.60 Based upon the above results, the increase of impervious area would produce little increase (approximately 1.0%) in the peak flow rate. Because of this, a detention basin facility will not be proposed. Instead, a grass swale will be introduced near the north project site boundary to dissipate energy and attenuate any potential flow increase from gravel roads and concrete pads. 2 Stormwater Drainage Study Erosion Control/Stormwater Management Plan Erosion control features such as silt fences and a grass swale (also mentioned above) will be installed on the site prior to construction activities. Such measures will be included in the erosion control plan and detail sheets within the final construction documents. Grass swale sizing calculations are summarized in Appendix D. Conclusion The drainage study and attached drainage maps were produced in accordance with requirements from Weld County Engineering and Construction Criteria Manual, updated January 2021. The existing stormwater flow characteristics are expected to remain unchanged and increases in peak flow rates have been proven to be negligible. A basin type of stormwater detention would not be necessary. Improvements proposed with the project site are limited to a gravel paved drive and two small concrete distribution transformer pads. No public access or utility infrastructure improvements are anticipated at this time. The proposed development will not alter historic drainage patterns and adjacent and downstream property owners. 3 Stormwater Drainage Study References 1. Weld County, Weld County Engineering and Construction Criteria Manual, January 2021. 2. Web Soil Survey, Natural Resources Conservation Service, United States Department of Agriculture. Online at: http://websoilsurvey.nrcs.usda.gov, accessed December 2021. 3. NOAA Atlas 14, Volume 11, Version 2. ESRI Maps. USGS. Sanja Perica, Sandra Pavlovic, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Orlan Wilhite. Appendices A. Site Plans C-301& C-302 5-7 B. NRCS Soil Layer Map .8-12 C. Rational Method Calculations 13-17 D. Grass Swale Calculations 18-20 4 Stormwater Drainage Study Appendix A: SITE PLANS C-301 & C-302 5 C;lpwworking-trd\d01191951C-301 Pre -Drainage Area Map.dwg 03-10-2023 1:53:36 PM BY: pkuh DP -A Jr I FO r — — CAE' 46464'4644 J i i i 4643 4 FC OE 4641= 6431inna_ _ OE OE Pre -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Rainfall I (in/hr) Intensity, A 24.80 0.3600 5.58 WELD COUNTY ROAD 47 OE 4642 4643 S C�E r 5 - S i - 4642 OE LEGEND X.XX AC DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW S � 4644 4644 _ L i ru OE .lam FO R � 4645Ls) Ncr 1 1 \‘‘\''';11 l ti � `I 14 l I t I H 1 El II 1IliH I 111 I I :::". 1 11ll 1. Ill I '''''4\4\2,1( I iI‘\(!lil\!1.ili\,\,,i,,,' --"Jirli--77,..?...S...:::„. ,\I,I\ I I � I �1 i I I Il ll ft I H471-1.-n ll li III III ll i i LI I lb I I yot III Lb 'III' 1 11 � il,li, II( II \I .-- tlt 1 I tt\ I tl I Iiii o llIII .I ll ., t I II� l IIIll ll � il II Ill I i li , I'I I t� l .I li i III ll I ll Ilan!ILO ilj Hr u ll HIcr 'till1 'r ll ifil iI i tr) 1ii mot' IIII 7_.( If II I 4 4 . I / \/I I 4- k ar-30 l f t r i ccr 0 60 60 30 l i 0 2 (9 i i i 120 SCALE : 1" = 60' 1'2 NO. REVISION DATE INIT TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com DATE: 3/10/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" - 80' SHEET NO.: 1:53:46 PM BY: pkuh C;lpwworking-trd\dQ1191951C-302 Post Drainage Area Map.dwg 03-10-2023 m DP -A PROP GRASS SWALE OE Post -development Runoff Calculation Parameters Drainage Area Area, A (ac) Weighted Coefficient, Runoff C Rainfall I (in/br) Intensity, % Added (impervious Impervious ac/total area ac) A 24.80 0.3643 5.58 3% 100 -year Runoff Calculation Results Pre -development Post -development Drainage DIFFERENCE Area Peak Flow (cfs) Rate Peak Flow (cfs)(CFS) Rate A 49.84 50.44 0.60 — —7,---ros---rtre--r----� WELD COUNTY ROAD 47 OE 4644 1 4643 464100-- x OE •,s 4642 464114644 M i air 4643 4642 OE i C� x J I I _ I I _ S X4643 x aur _ 4642 in _ )flx FO I LEGEND OE OE PROP 26' W GRAVEL ACCESS ROAD in in PROP CONCRETE PAD i J II _ r J -x S 4644 i X J J DRAINAGE AREA DRAINAGE POINT DRAINAGE AREA BOUNDARY FLOW ARROW I in in in �I i i i � n _ S g / / 4644 4645 ■ I• I to d' i or I I 6F t In 1 it 4 Logs 4'I i r a t.D tzt 60 60 30 0 120 I i i i i I I o O I 0 1 CD SCALE : 1" = 60' i i 1 i i i i 1 i i • TRC TRC Companies, Inc. 700 Highlander Blvd. Ste. 210 Arlington, TX 76015 Tel: 817-522-1000 www.trccompanies.com STAMP: INTERIM REVIEW DOCUMENTS NOT INTENDED FOR CONSTRUCTION, BIDDING, OR PERMITTING PURPOSES ALLYSON WILLIAM SON, P.E. CO LIC. # 60360 3/10/23 Z U X 1±-1 -1� O X OcLx x Z cc X OQ� ZOD In a Q 0 cC >- z D 0 U m N N GREELEY, CO 80631 PROJECT NUMBER: 516145 SHEET TITLE: POST DRAINAGE AREA MAP SHEET SIZE: ARCH "D" 24" X 36" (610 x 914) 0 2 1" ISSUED FOR PERMITTING NOT FOR CONSTRUCTION NO. REVISION DATE INIT DATE: 3/10/23 DRAWN BY: TRC ENGINEER: AW APPROVED BY: PROJECT PHASE: USR PLANS - SCALE: 1" - 80' SHEET NO.: Stormwater Drainage Study Appendix B: NRCS SOIL LAYER MAP 6 104° 37' 29" W 8 40° 22' 53" N - 40° 22' 38" N O 4 1 N- 0 4 0 4 4 0 4 0 531870 531920 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) 531970 532020 532070 532120 4 i AMSSOUtlap may not be valid. at thlsssale. 104° 37 29" W 531870 531920 531970 Map Scale: 1:2,240 if printed on A portrait (8.5" x 11") sheet. Meters 0 30 60 120 180 Feet 0 100 200 400 600 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 532170 532020 5332070 532120 532170 104° 37' 14" W 8 E 40° 22' 53" N U 4 0 4 0 co 104° 3714" W 40° 22' 38" N Natural Resources Web Soil Survey all Conservation Service National Cooperative Soil Survey 1/5/2023 Page 1 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part (Union Colony_line) MAP LEGEND Area of Interest (AO!) Area of Interest (A01) ) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines 0 0 A A/D B B/D C C/D D Not rated or not available Soil Rating Points II O O O A A/D B B/D MAP INFORMATION C The soil surveys that comprise your AOI were mapped at 1:24,000. C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background ,; Aerial Photography Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. 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 21, Sep 1, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2021 Jun 12, 2021 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. ,b Natural Resources lain Conservation Service Web Soil Survey National Cooperative Soil Survey 1/5/2023 Page 2 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Altvan loam, percent slopes 0 to 1 B 24.8 100.0% Totals for Area of Interest 24.8 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, BID, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, BID, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 3 of 4 Hydrologic Soil Group —Weld County, Colorado, Southern Part Union Colony_line Tie -break Rule: Higher e Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/5/2023 Page 4of4 Stormwater Drainage Study Appendix C: RATIONAL METHOD CALCULATIONS 6/6/22, 11:49 AM Precipitation Frequency Data Server NOAA Atlas 14, Volume 8, Version 2 Location name: Greeley, Colorado, USA* Latitude: 40.3795°, Longitude: -104.6227° Elevation: 4642.53 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular AMS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration 5 -min 10 -min 15 -min 30 -min 60 -min 2 -hr 3 -hr Annual exceedance probability (1/years) 1/2 0.268 (0.221-0.328) 0.392 (0.323-0.480) 0.478 (0.394-0.585) 0.642 (0.529-0.786) 0.791 (0.653-0.969) 0.940 (0.781-1.14) 6 -hr 12 -hr 24 -hr 1.02 (0.854-1.24) 1.18 (0.992-1.42) 1.39 (1.17-1.65) 1.64 (1.40-1.94) 1.89 2 -day (1.63-2.22) 3 -day 4 -day 7 -day 10 -day 20 -day 30 -day 45 -day 60 -day 2.06 (1.78-2.40) 2.19 (1.89-2.54) 2.50 (2.17-2.88) 2.76 (2.41-3.17) 3.51 (3.09-3.99) 4.12 (3.64-4.66) 4.86 (4.31-5.47) 5.47 (4.87-6.14) 1/25 0.378 0.476 (0.310-0.464) (0.388-0.589) 0.553 (0.454-0.679) 1 0.674 (0.554-0.828) 0.904 (0.742-1.11) 1.10 (0.903-1.35) 1.30 (1.07-1.58) 1.39 1.16-1.69) 1.62 (1.36-1.95) 1.91 (1.61-2.28) 2.20 (1.87-2.60) 0.698 (0.569-0.862) 0.851 (0.694-1.05) 1.14 (0.931-1.41) 1.39 (1.13-1.72) 1.64 (1.35-2.01) 1/50 0.628 0.758 (0.498-0.831) (0.580-1.01) 0.919 (0.728-1.22) 1.12 (0.888-1.49) 1.51 (1.20-2.00) 1.85 (1.47-2.47) 2.19 (1.77-2.92) 1.76 (1.45-2.15) 2.04 (1.69-2.47) 2.37 (1.98-2.84) 2.69 (2.26-3.19) 2.53 (2.16-2.97) 3.06 (2.60-3.60) 2.37 1.92-3.14) 2.70 (2.20-3.53) 3.06 (2.49-3.91) 3.41 (2.79-4.29) 3.81 (3.13-4.72) 2.70 3.23 3.99 (2.32-3.15) (2.76-3.79) (3.29-4.92) 2.84 (2.45-3.31) 3.25 (2.82-3.76) 3.38 (2.89-3.96) i 3.60 (3.13-4.14) 4.49 (3.93-5.12) 5.21 (4.58-5.91) 6.13 (5.42-6.92) 6.93 (6.15-7.80) 3.84 (3.31-4.46) 4.24 (3.66-4.90) 5.21 (4.54-5.97) 6.01 (5.25-6.85) 7.05 (6.19-7.99) 7.97 (7.03-9.01) 4.15 (3.43-5.09) 4.66 3.85-5.62) 5.09 4.22-6.08) 6.15 (5.12-7.25) 7.03 5.88-8.23) 8.20 (6.89-9.54) 9.26 (7.80-10.7) 1.11 (0.849-1.49) 1.35 1.04-1.81) 1.82 (1.40-2.44) 2.26 (1.73-3.04) 2.69 (2.09-3.60) 2.91 2.27-3.88) 3.29 (2.58-4.33) 3.66 (2.88-4.73) 4.01 (3.18-5.12) 4.43 (3.53-5.57) 4.61 (3.70-5.77) 4.78 (3.84-5.94) 5.29 (4.27-6.50 5.73 (4.64-6.98) 6.84 (5.57-8.22) 7.77 (6.36-9.27) 9.03 (7.42-10.7) 10.2 (8.39-12.0) 1/100 0.902 (0.659-1.24) 1.32 (0.965-1.82) 1.61 (1.18-2.22) 2.17 1.59-2.99) 2.71 (1.99-3.75) 1/200 1.06 (0.734-1.51) 1.55 (1.08-2.21) 1.89 (1.31-2.69) 2.56 (1.77-3.64) 3.22 (2.23-4.59) 1/500 1.29 (0.850-1.89) 1.89 (1.24-2.77) 2.30 (1.52-3.38) 3.11 (2.05-4.57) 3.96 (2.62-5.83) 3.25 I 3.88 4.81 (2.40-4.47) i (2.72-5.50) i (3.21-7.01) 3.53 (2.63-4.83) 3.95 (2.96-5.34) 4.23 (2.99-5.97) 4.31 (3.24-5.72) 4.67 (3.55-6.13) 5.08 (3.88-6.57) 4.69 (3.34-6.53) 5.01 (3.59-6.88) 5.39 (3.89-7.30) 5.78 (4.20-7.71) 5.28 (4.05-6.78) 5.44 (4.19-6.96) 5.98 4.37-7.93) 5.27 3.54-7.65) 5.77 (3.91-8.28) 6.04 (4.12-8.54) 6.41 (4.42-8.95) 6.75 (4.69-9.30) 6.96 (4.87-9.53) 5.95 (4.61-7.51) 6.38 (4.96-8.00) 7.52 (5.89-9.29) 6.14 (4.51-8.11) 6.62 (4.89-8.63) 7.04 (5.22-9.10) 8.18 (6.11-10.4) 8.49 (6.68-10.4) 9.82 (7.77-12.0) 11.0 (8.76-13.4) 9.19 (6.91-11.6) 10.6 I (7.99-13.3) 11.8 (8.98-14.8) 7.12 5.00-9.71) 7.54 (5.33-10.1) 7.91 (5.61-10.6) 9.04 (6.47-11.9) 10.1 (7.26-13.2) 11.5 (8.34-15.0) 12.8 (9.32-16.6) 1/1000 1.48 (0.937-2.18) 2.16 (1.37-3.19) 2.64 (1.67-3.89) 3.57 (2.27-5.27) 4.58 (2.90-6.76) 5.58 (3.58-8.16) 6.14 3.96-8.92) 6.67 (4.34-9.60) 6.88 (4.53-9.79) 7.24 (4.81-10.2) 7.53 (5.06-10.5) 7.75 (5.24-10.7) 7.91 (5.37-10.9) 8.25 (5.65-11.3) 8.57 (5.91-11.7) 9.67 (6.74-13.0) 10.7 (7.52-14.4) 12.2 (8.60-16.2) 13.5 (9.58-17.9) Precipitation frequency (PF) estimates in this table are based on frequency analysis of annual maxima series (AMS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and annual exceedance probability) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 1/4 6/6/22, 11:49 AM Precipitation Frequency Data Server C Precipitation depth 14 12 10 4 14 12 1 0 V2 AM -cased depth -duration -frequency (DDF) curves Latitude: 40.3?95', Longitude: -104.6227 C � s V5 1'10 th Duration tion re re re re to 0 -a gmo oil ) 1 N. O_ 1150 1/100 1'200 Annual e cee lance prob►abillity (1/years) NOAA Atlas 14o Volume B, Version 2 CO fo (0 '5 _ N re" igcr V500 x'1000 Created (GMT): Mon Jun 6 16.49:18 2022 Back to Top Maps & aerials Small scale terrain Annual exceecdance p robability (i!yoars) 2 5 10 25 50 100 200 500 1 000 Duration 5 -man 10 -min 15 -min 60 -min 2 -hr -hr 6-nir 12 -hr 24 -hr 2 -day 3 -day 4 -clay 7 -day 10 -day 20 -day 30 -day 45 -day 6O -day https://hdsc. nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.3795&Ion=-104.6227&data=depth&units=english&series=ams 2/4 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A EX I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 `- Reach 3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration __ _ `-------� overland • Reach 1 flow Reach 21- LEGEND (.) Big Flour Direr lion Ca.tc }carte nt B oundar}r NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.47 5.58 5.58 5.00 0.22 74.01 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 143.94 18.29 18.29 13.16 49.84 49.84 cfs cfs cfs Union Colony EX 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:32 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A EX Illustration Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output B Soil 24.80 I 0.36 8.93 I I sum: 2 24.80 sum: 8.93 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3600 rEr : Flow Dimon C at clam cot B MIELdElly *See sheet "Design Info" for inperviousness-based runoff coefficient values. Union Colony EX 100 Yrs.xls, Weighted C 2/2/2023, 8:32 AM CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Cloudbreak Union Colony - A PR I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 24.80 2.00 B II. Rainfall Information Design Storm Return Period, Tr = 01= C2= C3= P1= Acres ok A,B,C,orD I (inch/hr) = Cl * P1 /(C2 + Td)AC3 100 28.50 10.00 0.786 2.71 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5-yr. Runoff Coefficient, C-5 = Overide 5-yr. Runoff Coefficient, C = 0.36 0.36 0.08 Reach:3 (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration i Reach 2�. Reach 1 overland flow LEGEND U B eginn ng F1gtir Dire*. -don Cate lane nt Bound - NRCS Land Type Conveyance Heavy Meadow 2.5 Tillage/ Field 5 Short Pasture/ Lawns 7 Nearly Bare Ground 10 Grassed Swales/ Waterways 15 Paved Areas & Shallow Paved Swales (Sheet Flow) 20 Calculations: Reach ID Overland Slope S ft/ft input Length L ft input 5-yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.0020 500 0.08 N/A 0.12 69.93 1 0.0020 993 2 3 4 5 Sum 1,493 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.08 5.58 5.58 2.50 0.11 148.03 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = Calculated values for Tc & Qp are based on overide values entered for C & C-5. 217.96 18.29 18.29 9.78 50.44 50.44 cfs cfs cfs Union Colony PR 100 Yrs.xls, Tc and PeakQ 2/2/2023, 8:31 AM Area -Weighting for Runoff Coefficient Calculation Project Title: Catchment ID: Cloudbreak Union Colony - A PR Illustration LEA: Flow Direction Catchin ent BBiortindary Instructions: For each catchment subarea. enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output B SOILS 24.06 0.36 8.66 B SOIL GRAVEL ROAD 0.736 0.50 0.37 B SOIL CONCRETE PADS 0.004 0.96 0.00 Sum: 24.80 Sum: 9.03 Area -Weighted Runoff Coefficient (sum CA/sum A) = 0.3643 *See sheet "Design Info" for inperviousness-based runoff coefficient values. Union Colony PR 100 Yrs.xls, Weighted C 2/2/2023, 8:31 AM Stormwater Drainage Study Appendix D: GRASS SWALE CALCULATIONS 8 T-2 Grass Swale RESIDUAL CAPACITY FOR LARGER FLOODS 1;,, • 4" (MIN) SANDY LOAM 6" MI IN _L 2-YR WSE 6" MI TRAPEZOIDAL SWALE SECTION NTS I RESIDUAL CAPACITY FOR LARGER FLOODS 2-YR WS•E 4'° MIN. SANDY LOAM 12" MIN. MIN. D 1.0' 12" MIN. (2-YR) 1.0 FPS !Y TRIANGULAR SIAN GULAR SWALE SECTION NTS CONCRETE COI I AR ENERGY DISSIPATION b ir. l' rf I PROVIDE DOUBLE CLEANOUTS WITH WATER TIGHT CAPS @150' O.O. USE 90* SWEEP OR (2) 45' BENDS (OFFSET FROM SWALE CENTERLINE TO AVOID IMPEDING FLOW WHEN USING A TRIANGULAR SECTION Design Example 1 4 MIN. GRADE CONTROL STRUCTURE BEYOND GRADE CONTROL STRUCTURE BEYOND UNDERDRAIN AND SANDY LOAM RECOMMENDED FOR LONGITUDINAL SLOPES < 2.0%. 4" SLOTTED PIPE MEETING TABLE 05-3 WITH CDOT CLASS C FILTER MATERIAL ALL AROUND OR PERFORATED HOPE PIPE WITH AASHTO #67 ALL AROUND CONTAINED WITHIN CEOTEXTILE FABRIC. ASTM D4751-AOS US STD. SIEVE #50 TO 7a, ASTM D4533 MIN. TRAPEZOIDAL TEAR STRENGTH 100 X 60 LBS, MINIMUM COE SPECIFIED OPEN AREA OF 4%. GRADE CONTROL EXTEND GRADE CTROL STRUCTURE STRUCTURES INTO ONTHE BANK A MIN. OS ABOVE THE 2-YR WSE Ii UNDERDRAIN ENSURE ACCESS TO OUTLET BY CLEAN OUT OR OTHER ACCESSIBLE STRUCTURE SWALE PROFILE NITS Figure GS -1. Grass Swale Profile and Sections The UD-BMP workbook, designed as a tool for both designer and reviewing agency is available at www.udfcd.org. This section provides a completed design form from this workbook as an example. GS -6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Hydraulic Analysis Report Project Data Project Title: Cloudbreak - Union Colony Designer: TRC (TH) Project Date: Wednesday, February 1, 2023 Project Units: U.S. Customary Units Notes: Channel Analysis: Swale A Notes: input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 3.0000 ft/ft Side Slope 2 (Z2): 3.0000 ft/ft Channel Width 1.00 ft Longitudinal Slope: 0.0020 ft/ft Manning's n: 0.0350 Depth 1.0000 ft Result Parameters Flow 5.0743 cfs Area of Flow 4.0000 ft^2 Wetted Perimeter 7.3246 ft Hydraulic Radius 0.5461 ft Average Velocity 1.2686 ft/s Top Width 7.0000 ft Froude Number: 0.2957 Critical Depth 0.5642 ft Critical Velocity 3.3402 ft/s Critical Slope: 0.0269 ft/ft Critical Top Width 4.39 ft Calculated Max Shear Stress 0.12481b/ft^2 Calculated Avg Shear Stress 0.0682 lb/ft^2 Selected Profile: FHWA Profile (read-only) Culvert Assessment Profiles Culvert Assessment Profile Name: Standard (read-only) Maximum Excavation Depth: 20.00 ft Maximum Shallow Cover: 4.00 ft Maximum Small Pipe Size: 36.00 ft Minimum Manned Entry Size: 48.00 in Riprap Classes Riprap Class Name:CLASS Riprap Class Order:1 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 304.80 mm D85: 228.60 mm D50: 165.10 mm D15: 114.30 mm Riprap Class Name:CLASS II Riprap Class Order:2 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 457.20 mm D85: 330.20 mm D50: 241.30 mm D15: 177.80 mm Riprap Class Name:CLASS III Riprap Class Order:3 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 609.60 mm D85: 431.80 mm D50: 317.50 mm D15: 228.60 mm Riprap Class Name:CLASS IV Riprap Class Order:4 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 762.00 mm D85: 533.40 mm D50: 393.70 mm D15: 266.70 mm Riprap Class Name:CLASS V Riprap Class Order:5 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 914.40 mm D85: 647.70 mm D50: 469.90 mm D15: 330.20 mm Riprap Class Name:CLASS VI Riprap Class Order:6 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1066.80 mm D85: 762.00 mm D50: 546.10 mm D15: 381.00 mm Riprap Class Name:CLASS VII Riprap Class Order:7 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1257.30 mm D85: 889.00 mm D50: 647.70 mm D15: 444.50 mm Riprap Class Name:CLASS VIII Riprap Class Order:8 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1524.00 mm D85: 1079.50 mm D50: 800.10 mm D15: 558.80 mm Riprap Class Name:CLASS IX Riprap Class Order:9 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 1828.80 mm D85: 1295.40 mm D50: 965.20 mm D15: 660.40 mm Riprap Class Name:CLASS X Riprap Class Order:10 The following values are an 'average' of the size fraction range for the selected riprap class. D100: 2133.60 mm D85: 1511.30 mm D50: 1130.30 mm D15: 787.40 mm CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Traffic Narrative 1. Describe how many roundtrips/day are expected for each vehicle type: Passenger Cars/Pickups, Tandem Trucks, Semi-Truck/Trailer/RV (Roundtrip = One (1) trip in and One (1) trip out of site). • • • Maximum anticipated number of daily trips during peak period of construction: 10 - 15 vehicles per day during peak construction 7am - 3:30pm general hours Monday - Friday. % of heavy vehicles during peak period of construction: 5 - 10% During first few months of construction. Typical anticipated number of daily trips after construction is complete: 2 - 4 trips per year depending on O&M contract details. 2. Describe the expected travel routes or haul routes for site traffic. • The primary travel/haul route will be East on Highway 34, South onto County Road 45, East onto County Road 54, and then arriving at the Southern access point on the parcel. 3. Describe the travel distribution along the routes (e.g. 50% of traffic will come from the north, 20% from the south, 30% from the east, etc.). • 100% of the expected travel will follow the primary travel/haul route detailed above. 4. Describe the time of day that you expect the highest traffic volumes. • 7:00am - 3:30pm Union Colony Solar Site Northwest Quadrant of County Road 54 and County Road 47 Weld County, Colorado Traffic Letter KE Job #2023-023 Prepared for: TRC Companies, Inc. 123 N. College Avenue, Suite 206 Fort Collins, CO 80524 Prepared by: KELLAR ENGINEERING skellar@kellarengineering.com www.kellarengineering.com 970.219.1602 phone February 28, 2023 Sean K. Kellar, PE, PTOE This document, together with the concepts and recommendations presented herein, as an instrument of service, is intended only for the specific purpose and client for which it was prepared. Reuse of and improper reliance on this document without written authorization from Kellar Engineering LLC shall be without liability to Kellar Engineering LLC. 1.0 Introduction The purpose of this Traffic Letter is to evaluate the proposed traffic generated by the proposed Union Colony Solar Site project located at the northwest quadrant of Weld County Road 54 (CR 54) and Weld County Road 47 (CR 47) in Weld County, CO. 2.0 Proposed Development The proposed project consists of a solar field land use on the property. Access to the site is proposed from a low traffic volume access off of CR 54 on the south side of the property. See Figure 1: Vicinity Map and Figure 2: Site Plan. Figure 1: Vicinity Map Union Colony Solar Site Traffic Letter -Page 2 li KELLAR ENGINEERING 3.0 Trip Generation Site generated traffic estimates are determined through a process known as trip generation. Rates and equations are applied to the proposed land use to estimate traffic generated by the development during a specific time interval. The acknowledged source for trip generation rates is the Trip Generation Report published by the Institute of Transportation Engineers (ITE). The Institute of Transportation Engineers' (ITE) Trip Generation Manual does not provide detailed data on solar field facilities. As such, KE was able to estimate the weekday peak hour trip generation for the AM and PM peak hours based upon information provided by the client and project team. The project team provided the following trip generation data: Trip Generation Data: • Maximum anticipated number of daily trips per day during peak period of construction = 10 — 15 vehicles per day during peak construction 7:00 AM - 3:30 PM general hours Monday — Friday. • % of heavy vehicles during peak period of construction = 5% - 10% during first few months of construction. • Typical anticipated number of daily trips after construction is complete = 2 — 4 trips per year depending on O&M contract details • Approximately 50% of the traffic will come from the west on CR 54 and approximately 50% of the traffic will come from the east on CR 54. Based upon the above data, the project is conservatively anticipated to generate a maximum of approximately 48 daily trips, 24 total (14 entering, 10 exiting) AM peak hour trips, and 20 total (6 entering, 14 exiting) PM peak hour trips. See Table 1: Trip Generation. Union Colony Solar Site Traffic Letter -Page 3 rica KELLAR ENGINEERING IE Figure 2: Site Plan 3 T . ic milt Lerma Den sputa IT. sltrarrenti eases;, ,..!+.: rNtmiiprrimn SYSTEM SUMMARY ICIL! WCog :MSMIIIesti.JSN nit-DHLIIC/144 'Arai •stctic PA.MMNa sov Ilonuuls Di epaolect c*aeun A toat! L Ilboutt CC1Mrr D ID2 tcTsl frit et e:YaYtS eLtt 133 1 CIENT ! A CLOUDOIRtAk n*C1gM7 Ilk+5tt$ t4 .T10.0 Ei ,S- Kra tCli Multi SP to o (iJ i s4D Ind rernuLt fill icc q mum AZIMUTH WC - Mitt urefi11 t# SOMAS stairA I ;!I, II !h..a rNo.I ! ,.. it 711 z-simnsu rnsr_-rar Dir _- a- V - - ) i _ .--- wit a i R «—L.. _ a a _� _. _. _ _ — >I of - i[_ x . II" .,_ r —1' — — 1 ii ) i _,,.....--__ _ ii I_J �'`t I _-ta Fi . I i . L J a I L ,. r� J I� .:.1 !, I I I/ I I i � 1 I I 'i 1 Im 7 iIIC I - --- -- - ______- - - ---- - I I- I. I I ' FOR C0NSTRUC1 Z Li' It I I., _ ✓I� ,.rT. 6 o ,m rI l•iiI ==='I r$ T T --- - - - - • _ I 5, u s r ti ^Y L LIrJ _ n ill _ _ _ = - - I I 1n i I - — m- - HRM 1 I I� I I M ll Int: nu ARRAY PLAN 41 tl I ---- - — J _ __ _ - _ __: __ _-__ - - __ __ ______ e� i.��_ __ _ __ _ N '^ - H mi n - •� = . *9 - —• _ L - - — era YN..-:i'_ • ini.aiti'LI:- 'z �� —cNx —# if I - FACPPOOstO MIMI or Dittlft[noir! CTURI w UN ION COLO NY WW2 al 1 - '' i•rr3-S 17-Ir, IO17TLT arm I I AA �ff A e VyPPROX L__ 'IL $'� i :CAW. ha VV- I 'I 1 ti - NORTH �r_a_ t. !' • I<xf Union Colony Solar Site Traffic Letter -Page 4 IE KELLAR ENGINEERING Table 1: Trip Generation Average Daily Trips AM Peak Hour PM Peak Hour Trips Trips Code ITE Land Use Size Rate Total Rate In Rate Out Total Rate In Rate Out Total N/A Solar Field * * 48 * 14 * 10 24 * 6 * 14 20 N/A = Not Available The Institute of Transportation Engineers' (ITE) Trip Generation Manual, 11th Edition does not provide detailed data related to the proposed use. Therefore, trip generation is based upon information obtained from the client and project team. See Section 3.0 Trip Generation for more information Union Colony Solar Site Traffic Letter Page 5 KELLAR ENGINEERING 4.0 Conclusions: The findings of the Traffic Letter are summarized below: • The proposed project is conservatively anticipated to generate a maximum of approximately 48 daily total weekday trips, 24 AM total peak hour trips, and 20 PM total peak hour trips. See Table 1: Trip Generation • The project's trip generation and site generated traffic is low. See Table 1: Trip Generation. • Due to the project's low site generated traffic, the proposed project will not create a negative traffic impact upon the local and regional traffic system and the existing roadway improvements are sufficient to accommodate the project's traffic. See Section 3.0. • The anticipated number of daily trips after construction is complete is only 2 — 4 trips per year. See Section 3.0. KELLAR ENGINEERING Union Colony Solar Site Traffic Letter -Page 6 APPENDIX Union Colony Solar Site Traffic Letter -Page 7 rica KELLAR ENGINEERING Aerial Image KELLAR ENGINEERING Union Colony Solar Site Traffic Letter -Page 8 KELLAR ENGINEERING Sean Kellar, PE, PTOE Principal Engineer Education B.S., Civil Engineering, Arizona State University — Tempe, AZ Registration Colorado, Professional Engineer (PE) Wyoming, Professional Engineer (PE) Idaho, Professional Engineer (PE) Arizona, Professional Engineer (PE) Kansas, Professional Engineer (PE) Missouri, Professional Engineer (PE) Professional Traffic Operations Engineer (PTOE) Professional Memberships Institute of Transportation Engineers (ITE) Industry Tenure 23 Years WORK EXPERIENCE: Sean's wide range of expertise includes: transportation plan- ning, traffic modeling roadway design, bike and pedestrian facili- ties, traffic impact studies, traffic signal warrant analysis, parking studies, corridor planning and access management. Sean's experience in both the private and public sectors; passion for safety and ex- cellence; and strong communication and collaboration skills can bring great value to any project. Prior to starting Kellar Engineering, Sean was employed at the Missouri Department of Transportation (MoDOT) as the District Traffic Engineer for the Kansas City District. Sean also worked for the City of Loveland, CO for over 10 years as a Senior Civil Engineer supervising a division of transportation/traffic engineers. While at the City of Loveland, Sean managed several capital improvement projects, presented several projects to the City Council and Planning Commission in public hearings, and managed the revisions to the City's Street Standards. Sean is also proficient in Highway Capacity Software, Synchro, PT Vissim, Rodel, GIS, and AutoCAD. Kellar Engineering, Principal Engineer/President - January 2016 - Present Missouri Department of Transportation, District Traffic Engineer, Kansas City District - June 2015 - January 2016 City of Loveland, Colorado, Senior Civil Engineer, Public Works Department - February 2005 June 2015 Kirkham Michael Consulting Engineers, Project Manager - February 2004 - February 2005 Dibble and Associates Consulting Engineers, Project Engineer - August 1999 - February 2004 CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Alternatives Statement Cloudbreak Energy Partners performed a rigorous search for ideal solar project locations across the State of Colorado. This search included hundreds, if not thousands, of properties within Weld County. The Brown's property was chosen due to several factors including, but not limited to: • Close proximity to high quality Xcel Energy distribution infrastructure that has the capacity for a project of this size • Close proximity to Xcel Energy's Rosedale substation • Outside of floodplains and wetlands • Relatively flat • No geotechnical constraints • Landowner participation • Limited disturbance to nearby properties and property owners Alternatives to the Brown's property were thoroughly evaluated but were ultimately dismissed due to at least one of the above factors. The proposed Project presents the most viable design and location with the least adverse impacts of all the alternatives. (970) 425-3175 I INFO©aCLOUDBREAKENERGY.COM I CLOUDBREAKENERGY.COM CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Development Standards Statement 1. Height limitation. Ground -mounted solar collectors shall not exceed twenty-five (25) feet in height, measured from the highest grade below each solar panel to the highest extent of the solar panel rotation.: o The ground -mounted solar collectors will not exceed 25' in height, as measured from the highest grade below each solar panel to the highest extent of the solar panel rotation. 2. Glare. Concentrated solar glare from solar collectors shall not be directed toward or onto nearby properties or roadways at any time of the day: o A glare study for the Project is included in the application materials. The risk of glare being directed toward or onto nearby properties or roadways will be mitigated with screening as described in the Landscape and Screening Plan. 3. Setbacks. The improved area shall conform to the setback requirements of the underlying zone. Additionally, the improved area must be at least five hundred (500) feet from existing residential buildings and residential lots of a platted subdivision or planned unit development. The residential setback requirement may be reduced if appropriate screening through landscape or an opaque fence is installed, or upon submittal to Weld County of a waiver or informed consent signed by the residence owner agreeing to the lesser setback. If landscaping or opaque fencing is substituted for setback, a landsca Ding plan or fencing plan shall first be submitted to and approved by the Department of Planning Services: o The Project conforms to the setback requirements of the Agricultural zone and will seek waivers for neighbors within 500 feet of the project or use a screening around the project near residences. 4. Dust mitigation. The operators of the SEF shall continuously employ the practices for control of fugitive dust detailed in their dust mitigation plan submitted as required by Subsection B.2., above: o The Project will continuously employ the practices for control of fugitive dust detailed in the submitted Dust Mitigation Plan. (970) 425-3175 I I N FO©a CLOU DBREAKEN ERGY.COM I CLOUDBREAKENERGY.COM ERGY.COM CLOUDBREAK PAGE 2 5. Underground cables. All electrical cables on the improved area shall be buried, except for direct current string wires that connect between solar collectors, direct current collection circuits between rows of solar arrays that are no more than four (4) feet above grade crossings, substations, switchyards, and circuit voltages greater than 34.5 kilovolts (where necessary): a All electrical cables on the improved area shall be buried, except for direct current string wires that connect between solar collectors, direct current collection circuits between rows of solar arrays that are no more than four (4) feet above grade crossings, substations, switchyards, and circuit voltages greater than 34.5 kilovolts (where necessary). 6. Fencing. The SEF shall be enclosed with a security fence as approved pursuant t0 a fencing plan submitted to the Department of Planning Services. Appropriate signage shall be placed upon such fencing that warns the public of the high voltage therein: a The Project will be enclosed by a 7 -foot tall game fence. Additional details are provided in the Landscape and Screening Plan as well as the USR Map. 7. Stormwater management. The Operator of the SEF shall submit a drainage report to comply with required Storm Drainage Criteria pursuant to Chapter 8, Article XI of this Code. Additional requirements for Municipal Separate Storm Sewer System (MS4) areas may be applicable pursuant to Chapter 8, Article IX of this Code. Ground -mounted solar collector systems shall be exempt from impervious surface calculations if the soil under the collectors is designated hydrologic A or B soil groups by the Natural Resources Conservation Service (NRCS): o A drainage report has been submitted as part of the Project's application. 8. Access permit. Prior to construction of the SEF, the applicant shall apply for and obtain an approved Access Permit from the Weld County Department of Public Works, pursuant to the provisions of Article XIV of Chapter 8 of this Code: a Prior to construction of the Project, CBEP Solar 27, LLC or its contractors shall apply for and obtain an approved Access Permit from the Weld County Department of Public Works pursuant to the provisions of Article XIV of Chapter 8 of this Code. 9. Existing irrigation systems. The nature and location or expansion of the SEF must not unreasonably interfere with any irrigation systems on or adjacent to the solar facility. a The Project will not interfere with any irrigation systems on or adjacent to the solar facility. (970) 425-3175 I INFO©aCLOUDB!REAKENEPGY.COM I CLOUDBPEAKENEPGY.COM CLOUDBREAK CBEP SOLAR 27, LLC ISO BOX 1255 STERLING, CO 80751 (970) 425-3175 INFO c©CLOUDBREAKENERGY.COM DATE: April 24, 2023 PROJECT: Union Colony Solar Project SUBJECT: Utility and Other Infrastructure Owners Infrastructure Owner Name Address Overhead utilities and underground Public Colorado Service DBA Company Xcel of Energy 1800 80202 Larimer St, Denver, CO (970) 425-3175 I INFO©aCLOUDBREAKENERGY.COM I CLOUDBREAKENERGY.COM Weld County Treasurer Statement of Taxes Due Account Number R8947307 Assessed To Parcel 096123400007 BROWN THOMAS D 22509 COUNTY ROAD 54 GREELEY. CO 80631-9764 Legal Dcscription S2SE4 23 5 65 EXC COMM NE CUR S2SE4 S89D16W 2635 44 N00D47W 21.72 N89D45E 2635.56 TO POB Si tus Address 22543 COUNTY ROAD 54 WELD Year Tax Ch arse Tax Interest 2022 $3,796.54 $0.00 Total Tax Charge Fees Payments Balance $000 $0.00 $3,796.54 $3,796 54 Grand Total Due as of 04/24/2023 Tax Billed at 2022 Rates for Tax Area 0698 - 0698 Authority WELD COUNTY SCHOOL DIST #6 NORTHERN COLORADO WATER (NC CENTRAL COLORADO WATER (CCW CENTRAL COLORADO WATER SUBD LASALLE FIRE AIMS JUNIOR COLLEGE HIGH PLAINS LIBRARY WEST GREELEY CONSERVATION Taxes Billed 2022 SENIOR Net Taxes Billed for 2022 * Credit Levy Mill Levy 15.0380000* 50 3990000 1 0000000 1 0680000 1.5820000 5.1540000 6.3070000 3.1810000 0.4140000 Amount $749.93 $2,513.40 $49 87 $53.26 $7890 $257.04 $3l4.53 $158 64 $20.65 84 I430000 $4,196.22 ($399.68) $3,796.54 Values AG -FLOOD IRRRIGATED LAND AG -WASTE LAND FARM/RANCH RESIDENCE -IMPS OTHER BLDGS - AGRICULTURAL Total $3.796.54 Actual Assessed $71,919 $18,990 $67 $20 $231,401 $16,090 $55,949 $14,770 $359,336 $49,870 ALL TAX LIEN SALE AMOUNTS ARE SUBJECT TO CHANGE DUE TO ENDORSEMENT OF CURRENT TAXES BY THE LIENHOLDER OR TO ADVERTISING AND DISTRAINT WARRANT FEES. CHANGES MAY OCCUR AND THE TREASURER'S OFFICE WILL NEED TO BE CONTACTED PRIOR TO REMITTANCE AFTER THE FOLLOWING DATES: PERSONAL PROPERTY, REAL PROPERTY, AND MOBILE HOMES - AUGUST 1 TAX LIEN SALE REDEMPTION AMOUNTS MUST BE PAID BY CASH OR CASHIER'S CHECK. POSTMARKS ARE NOT ACCEPTED ON TAX LIEN SALE REDEMPTION PAYMENTS PAYMENTS MUST BE IN OUR OFFICE AND PROCESSED BY THE LAST RI ICINFQC nnv nC Tuc nnnK1-ru IniOrnq 0000-7;p-- Weld County Treasurer's Office 1400 N 17th Avenue PO Box 458 Greeley, CO 80632 Phone: 970-400-3290 S71 tw5/4 Pursuant to the Weld County Subdivision Ordinance, the attached Statement of Taxes Due issued by the Weld County Treasurer, are evidence of the status as of this date of all property taxes, special assessments, and prior tax liens attached to this account. Current year's taxes are due but not delinquent. Signed: r Date: Mes Z4• 2-3 Hello