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Home My WebLink About20203412.tiffUSE BY SPECIAL REVIEW (USR) APPLICATION FOR PLANNING DEPARTMENT USE: AMOUNT APPLICATION RECEIVED BY DATE RECEIVED: CASE #i ASSIGNED: PLANNER ASSIGNED: USR2o-0017 PROPERTY INFORMATION (Attach additional sheets if necessary.) Is the property currently in violation' Site Address: No /L Yes Violation Case Number: Xfl•FR CR 50 \NQflJQU, CC) Parcel Number: t 0 -n Legal Description: __E,.Q k RC, ((A-6 yThit) Section: 3, Township N, Range t w Zoning District: Acreage:Within subdivision?No /Yes Townsrte?No /nYes If yes, subdivision or townsite name: Floodplainli,No / Yes Geological HazardIr5t1No ! lYes Airport Overlay No /DYes PROPERTY OWNER(S) (Attach additional sheets if necessary) Name: ±ar„AitracK ‘uuk1/4\.Q,C Company: Cr I d s otl& Name of proposed business: Phone #: Email. Street Address: Cluni-N1/4.04 City/State/Zip Code: fir-► 1 `�'ti nit Name: Company: Phone #: Email: Street Address: City/State/Zip Code: APPLICANT/AUTHORIZED AGENT (Authorization must be included if there is an Authorized Agent.) Name: Company: Vsair, -A \as - t Phone #: hien ..)5j o Street Address: City/State/Zip Code: leu 0 3O 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, evide r e must br included indicating the signatory has the legal authority toign for the corporation. Si. nature tiak. frillier Print 01/01/2020 /9 4-(16:_-2,02,D Date Signature Ma r'/< Print 6'4174,20 Date A@ LEEY Q STOCK 11---!clARM coTrAm 0c0 REGISTERED AGENT ENGAGMENT LETTER Bailey Stock I Harmon I Cottam P.C., (hereinafter "BSHC") hereby agrees to serve as a Wyoming registered agent, pursuant to Wyo. Stat. §17-28401 et seq., for Ten Sleep Investment Group LLC (hereinafter "Entity"). BSHC has met the applicable requirements and is registered with the Wyoming Secretary of State as a commercial registered agent. The annual fee for serving as registered agent shall be $75.00 per year and is non- refundable. Additionally, Entity shall reimburse BSHC for any and all costs incurred when accepting and forwarding any service of process, including, but not limited to telephone, telefax, copy and postage charges. For any mail forwarding requirements, an additional contract needs to be executed. The fees and costs set forth herein may be modified annually by BSHC upon providing 30 days written notice to Entity. Pursuant to Wyo. Stat. §17-28-104(d), Entity shall provide to BSHC the name, business address and business telephone number of a natural person who is an officer, director, employee or designated agent of Entity who is authorized to receive communications from BSHC and is deemed the designated communications contact for Entity. The current designated communications contact for Entity is: Name: l?' Slew? 7mesvnien* thz?.te lzat Business Address/Designated Contact: cellq 11 a 0 i it 4 big ZZ3 10103 i eff CO Business Telephone Number: � 36--daq/Uwell . . Title: The of address process of is to record be delivered to which to all Entity service is: Email Address: !� Q• ' i, e , ar/�,,� I, d MI ibninacialen Will Mail Forwarding Be Needed: (yes/n) Registered Agent Engagement Letter Page 1of3 4073890 01/08/2015 02:39 PM Total Pages: 1 Rec Fee: $11.00 Carly Koppes - Clerk and Recorder, Weld County, CO After Recording Return To: Ten Sleep Investment Group LLC 4295 East CR 16 Loveland, CO 80537 STATEMENT El ENT OF AUTHORITY I. This Statement of Authority relates to an entity named: Ten Sleep Investment Group LLC The Entity is a: limited liability company 3. The Entity is formed under the laws of: Wyoming 4. The mailing address for the entity is: 4295 East CR 16 Loveland, CO 80537 5. The name and position of each person authorized to execute instruments conveying, encumbering, or otherwise affecting title to real property on behalf of the entity is: Julie M. Flillyard, Member or Fred J. Miller, Member or Richard B. Miller, Member. 6. The authority of the foregoing person(s) to bind the entity is not limited as follows: NONE. 7. Other matters concerning the manner in which the entity deals with interests in real property: NONE 8. This Statement of Authority is executed on behalf of the Entity pursuant to the provisions of C.R.S. Section §38-30-172. Executed this: December 31, 2014 Ten Sleep Investment Group LLC, a Wyoming limited liability company By: hte I. Iii llyard, Member STATE OF: Colorado COUNTY OF: WELD The foregoing instrument was acknowledged before me this 31st day of December, 2014, by Julie M. Hillyard, Member of Ten Sleep Investment Group LW Witness my hand and seal. My commission expires: /RI751( Leah PA Langford Notary Public State of Colorado Notary ID 2D1224078054 My Commission Expires December 3, 2016 Notary Public vt, original or the same counterpart. Further, a facsimile copy of this Agreement or any signature hereon shall be deemed an original for all purposes. IN WITNESS WHEREOF, the parties hereto have executed this Engagement Letter as of the 01 clay ofJul,2016. Ten Sleep Investment Group LLC By: 0 elk resiaent Bailey I Stock I Harmon I Cottam P.C. By: Lance T. Harmon Registered Agent Engagement Letter Page3of3 3990986 Pages: 1 of 1 01/20/2014 12:23 PM R Fee:$11.00 11 .00 Steve Moreno. Clerk and Recorder: Weld County, CO III IIl�1�SRP�+r:l�h'h4,fi4 i��kdrlill'+�41hti W�J Yl��k II III STATEMENT OF AUTHORITY 1. This Statement of Authority relates to an entity? named Superior Oilfield Set-yr'Ltd., and is executed on behalf of the entity pursuant to the provisions of Section 38-30-172, C.R.S. 2. The type of entity is a: • corporation O nonprofit corporation limited liability company El general partnership limited partnership [] other: E] registered limited liability partnership registered limited liability limited partnership limited partnership association government or governmental subdivision or agency trust (Section 38-30-108.5, C.Q.S.) 3. The entity is formed under the laws of : State of Colorado 4. The mailing address for the entity is: 1011 116 Avenue, Greeley, CO 80631 The Z name position of each person authorized to execute instruments conveying, encumbering, or otherwise affecting title to real property on behalf of the entity is: any one of Julie M. Hillyard, Member; Fred J. Miller, Member; or Richard B. Miller, Member 6.2 The authority of the foregoing person(s) to bind the entity is V not limited C] limited as follows: 7. Other ratters concerning the manner in which the entity deals with interests in real property: Executed this — day of January, 2014. STATE OF COLORADO County of Weld Ri hard B. Miller, Member in instrument was acknowledged before me this7C day of January, 2014, by Julie The foregoingg Hillyard, Fred J. Miller and Richard B. Miller as Members of Superior Oilfield Services Co. Ltd. Witness my hand and official seal. My commission expires: OS/0 7/02 .O t_ _ MAS2355‘002kStmt.Authority.doe 'This form should not be used unless the entity is capable of holding title to real property. 2The absence of any limitation shall be prima facie evidence that no such limitation exists, line statement of authority must be recorded to obtain the benefits of the statute. No.1112. Rev. 8-01. STATE NT OF AUTHORITY l'AILY is. 4 C6k Sti{• , Co ale M. J0DY M DODON Notary Public State of Colorado Notary 10 20094022943 My Commission Expires Aye 7, 2017 DEPARTMENT OF PLANNING AND BUILDING DEPARTMENT OF PUBLIC HEALTH AND ENVIRONNMENT 1555 NORTH 17TH AVENUE GREELEY, CO 80631 AUTHORIZATION FORM FOR BUILDING, PLANNING AND HEALTH DEPARTMENT PERMITS AND SERVICES 11 (We), CL\C \MTC\, (Owner — please print) , give permission to k1 \Lo C- ATI) (ApplicanUAgent =please print) to apply for any Planning, Building or Health Department permits or services on our behalf, for the property located at: aalw3. cam, Kktewsa C_D PT Nte4 Klieg 3 4- (ck! Legal Description: ,15P4f Section 3 , Township -T N, Range W Subdivision Name: Lot Block Property Owners Information: Phone: 1�2),Fsk-ipk E-mail: Applicant/Agent Contact Information: Phone:Wn) ��- (5?f)?) _._ E -Mail: ci\A.R_Se \6(•-__ta Email correspondence to be sent to: Owner _EL, Applicant/Agent _Both Postal service correspondence to be sent to: (choose only one) Owner Applicant/Agent _IL Additional Info: US9, bc\-iL\ Owner Signature: Owner Signature: Date: bt .,, -,� Date: 7/29/2019 9 USR Questionnaire - Richard Miller 19-112 27808 COUNTY ROAD 50 Planning Questions: Planner on Call 970-400-6100 1. Explain, in detail, the proposed use of the property. Include, at a minimum, the following: a. Type of use for which the application is being made. Laser Oilfield is proposing to locate their equipment storage yard (dozers, road graders, ect..), up to 4 Conex containers in the future and maintenance shop on site. By definition "Equipment and storage yards for STREET/ROAD and pipeline construction contractors, and production unit set-up and maintenance contractors." Is gas and oil support. This company does well pad setups for the oil and gas. The existing house will be used as a Caretakers Residence only, no offices will be on this site. Mr. Miller has 2 roustabout trucks, that currently do not run, however as the oil field picks back up, he will run those crews. In the Future he will have a max of 5 trucks on his roustabout crew. This is a gas/ oil support business. b. Current or previous use of the land, if any. The current land use: To grow and harvest Alfalfa and hay as well as other Ag uses. There is one existing home on the property. This structure will be utilized as the caretaker's residence. . Include a statement delineating the need for the proposed use. Gas and Oil is large part of jobs here in Weld County, oil and gas support is necessary to keep and maintain the oil and gas services in the Weld County area. With the current state of the gas and oil, a site is needed to store equipment when not in use. d. Describe the uses surrounding the site and explain how the proposed use is compatible with them. There is multiple USR's in the area including one adjacent to the property to the East for a Helipad- USR -879. The other properties adjacent to the site are used for Ag. One to the North for a natural gas line — USR 13-0064. As well as USR 14-0064 to the south for Truck parking and a shop. e. Describe the proximity of the proposed use to residential structures. The property to the Northeast is 940'±. The property to the Southeast is approx. 715'±, The property to the southwest is approx.. 4600'±, and the house to the Northwest is approx. 1,200'±. f. Describe the hours and days of operation (e.g. Monday thru Friday 8:00 a.m. to 5:00 p.m.). Monday through Friday form 6 a.m. to 5 p.m. g. Describe the number of shifts and the maximum number of employees per shift. 4 full time employees, 1 shift 6 a.m. — 5 p.m. h. Describe the maximum number of users, patrons, members, buyers or other visitors that the use by special review facility is designed to accommodate at any one time. 2 Mechanics, 10 Drivers/ 1 Buyer (once per week), 1 Vendor and the 0►wner Page 1 of 7 USR Questionnaire - Richard Miller 19-112 27808 COUNTY ROAD 50 i. List the types and maximum numbers of animals to be on the site at any► one time (for dairies, livestock confinement operations, kennels, etc.). Livestock on the property (8 personal horses) and chickens. j. List the types and numbers of operating and processing equipment to be utilized. 6 Semi trucks and up to 3 trailers as well as up to 10 pieces of large equipment for gas and oil services (scrapers, dozers, etc.), gravel mining equipment, screen -decks, and conveyors as well as company pickup trucks. k. List the types, number and uses of the proposed structures to be erected. (3) 40'x 60' Pole barns to be used as storage and maintenance facility for trucks and equipment owned and operated by Laser Oilfield Services. These additional buildings will be constructed a needed. Building permits will be obtained before the construction of the proposed buildings. I. Describe the size of stockpile, storage or waste areas to be utilized, if any. Recycled Asphalt maybe stockpiled for drive surface on property for construction. m. Describe the method and time schedule of removal or disposal of debris, junk and other wastes associated with the proposed use. There will be a trash dumpster located Northwest side of the largest barn/sho p. Waste oils will be stored in 500 -gallon, double walled oil tanks used for heat. Anti -freeze will be stored in 55 -gallon barrels. Old and new tires as well as new and old batteries and old parts will be stored inside the building until adequate amount acquired for removal. n. Include a timetable showing the periods of time required for the construction of the operation. Site grading will occur at the completion of the USR process. First Pole barn will more than likely be constructed within the first year. The second and third Pull barn will be constructed as needed in the future. o. Describe the type of lot surface proposed and the square footage of each type (e.g. asphalt, gravel, landscaping, dirt, grass, buildings). Gravel: 172,910 Sq. Ft. Landscaping: 887089 Sq. Ft. Buildings: 23,117 Sq. Ft. Concrete: 8,264 Sq. Ft. p. How many parking spaces are proposed? How many handicapped (ADA) parking spaces are proposed? 1 ADA Space is proposed in front of the existing shop. 10 Addition parking stalls for company trucks and employees as well as 10 spaces for Tractor Trailers. Page 2 of 7 USR Questionnaire - Richard Miller 19-112 27808 COUNTY ROAD 50 q. Describe the proposed screening for all parking and outdoor storage areas. Drill pipe fence, screening trees and L.S. berms are proposed to screen the equipment and outdoor storage from the adjacent public ROW and residential housing surrounding the site. r. Describe the existing and proposed landscaping for the site. Screening trees along the Northern and Eastern sides with landscape berms and the North Fm ntage/ROW s. Describe the type of fence or other screening proposed for the site. No existing screening on site Proposed is Pipe fence and screening trees. Screening trees to be placed to screen ROW and adjacent residential structures. t. Describe reclamation procedures to be employed as stages of the operation are phased out or upon cessation of the Use by Special Review activity. All buildings will remain, all gravel areas will be removed and planted with native vegetation or planted with Alfalfa or other Ag crop. u. Describe the proposed fire protection measures. None Proposed 2. Explain how this proposal is consistent with the Weld County Comprehensive Plan. "Sec. 22-2-20. A. Goal 7. County land use regulations should protect the individual property owner's right to request a land use change." Which is why Mr. Miller is requesting a USR and only planning to change a portion of his parcel. He is still utilizing a large portion of his land as Ag to grow alfalfa. 3. 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.) Sec. 23-3-40. - Uses by special review outside of subdivisions and historic townsites. 23-3-40.w OIL AND GAS SUPPORT AND SERVICE. This USR is for an Oil and Gas support company's storage yard and shop. Especially at this time, with the gas and oil prices, a lot of oil and gas support is slowing down, and they need a place to store their equipment when not in operation. 4. Explain how this proposal will be compatible with future development of the surrounding area or Adopted master plans of affected municipalities. This is Ag land, with the right to request a land change, Mr. Miller is only changing a portion of his land to help support oil and gas. There is multiple USR's in the area including one adjacent to the property to the East for a Helipad- USR -879. The other properties adjacent to the site are used for Ag. One to the North for a natural gas line — USR 13-0064. As well as USR 14-0064 to the south for Truck parking and a maintenance shop. Page 3 of 7 USR Questionnaire - Richard Miller 19-112 27808 COUNTY ROAD 50 S. Explain how this proposal complies with Article V and Article Xl of Chapter 23 if the proposal is located within any Overlay Zoning District (Airport, Geologic Hazard, or Historic Townsites Overlay Districts) or a Special Flood Hazard Area identified by maps officially adopted by the County. Kersey IGA Overlay - Does not fall within the AP, Geologic or Historic townsite Overlay Districts. 6. 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. Out of the 21+ acres of Ag land only a small portion (3.88 ac) will be used for truck parking, equipment parking, detention pond and berm. The Western piece and a portion of the East will remain grasses/alfalfa and will continue to be farmed. 7. Explain whether this proposal interferes with the protection of the health, safety and welfare of the inhabitants of the neighborhood and the County. Oil and gas support are here to help with the protection, health and welfare of its neighbors and the County. Oil and gas support is important in the economic health of Weld County. Environmental Health Questions: 970-400-2702 1. What is the drinking water source on the property? 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. Central Weld Water District- please see attached water Bill 2. What type of sewage disposal system is on the property? If utilizing an existing septic system provide the septic permit number. if there is no septic permit due to the age of the existing septic system, apply for a septic permit through the Department of Public Health and Environment prior to submitting this application. If a new septic system will be installed, please state "a new septic system is proposed." only propose portable toilets if the use is consistent with the Department of Public Health and Environment's portable toilet policy. Septic # SP -9700185, If additional Commercial OWTS is required for office and site employees, a design of the OWTS will be obtained form an engineer licensed in the State of Colorado. 3. If storage or warehousing is proposed, what type of items will be stored? Vehicles and heavy equipment such as Semi's, Scrapers, gravel mining equipment, up to 4 Conex containers etc. As well as new and used batteries, new and used tires, as well as parts will be stored inside. 4. Describe where and how storage and/or stockpile of wastes, chemicals, and/or petroleum will occur on this site. Waste oil will be stored in 500 -gallon, double walled self-contained oil tanks used for heat. Anti -freeze and motor oil will be stored in containment systems at least 150% larger than the largest tank in the containment system itself. Page 4 of 7 USR Questionnaire - Richard Miller 19-112 27808 COUNTY ROAD 50 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. 1000 -gallon diesel tank, double walled self-contained oil tanks used for heating. 6. If there will be washing of vehicles or equipment on site, indicate how the wash water will be contained. No on -site vehicle or equipment washing will be performed on site. 7. If there will be floor drains, indicate how the fluids will be contained. No floor drains proposed, one drain exists and will be abandoned. The pipe at the drain will be plugged. 8. Indicate if there will be any air emissions (e.g. painting, oil storage, etc.). Antifreeze and motor oil new and used, no painting or sandblasting of equipment is proposed on site. 9. Provide a design and operations plan if applicable (e.g. composting, landfills, etc.). N/A 10. Provide a nuisance management plan if applicable (e.g. dairies, feedlots, etc.). Will provide a Dust Abatement Plan. Noise will be limited to the hours of operation. 11. Additional information may be requested depending on type of land use requested. Public Works Questions: 970-400-3767 1. Include a traffic narrative with the information below. A traffic impact study may be required. Improvements to adjacent streets/roads may be necessary to provide adequate safe and efficient transportation to and from the site. An Improvements Agreement may be required. a. The projected number of vehicle trips (average per day, maximum per day, peak hour data) to and from the site and the type of vehicles (passenger, semi -truck, etc.). b. Describe how many roundtrips/day are expected for each vehicle type: Passenger Cars/Pickups, Tandem Trucks, Semi-Truck/Trailer/RV (Roundtrip = 1 trip in and 1 trip out of site) c. Describe the expected travel routes for site traffic. d. 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.) Page 5 of 7 USR Questionnaire - Richard Miller 19-112 27808 COUNTY ROAD 50 e. Describe the time of day that you expect the highest traffic volumes to and from the site. 2. Describe where the access to the site is planned. Center of property, off of County Road 50, approx. 900 feet west of County Road 57. This is an existing access point. This access will be upgraded for large commercial vehicles. 3. Drainage Design: Design and construction of a detention pond as described in an approved Drainage Report is required unless the project falls under an exception to stormwater detention requirements per code. (See below.) Does your site qualify for an exception to stormwater detention? If so, describe in a drainage narrative the following: This site does not qualify for exemption from storm water detention. Grading and drainage will be provided with final drainage report with this application. a. Which exception is being applied for? Include supporting documentation. b. Does the water flow onto the property from an offsite source? If so, from where? c. Describe where the water flows to as it leaves the property. d. Describe the direction of flow across the property. e. Describe the location of any irrigation facilities adjacent to or near the property. f. Describe any previous drainage problems with the property. 4. If your site does not qualify for an exception, the following applies: a. A Drainage Report summarizing the detention pond design with construction drawings and maintenance plan shall be completed by a Colorado Licensed Professional Engineer and adhere to the drainage related sections of the Weld County Code. A final drainage report will be provided with the USR application. b. The Drainage Report must include a certification of compliance, which can be found on the Public Works website, stamped and signed by the PE. C. See the attached Drainage Report Review Checklist. Page 6 of 7 USR Questionnaire - Richard Miller 19-112 27808 COUNTY ROAD 50 Exceptions to stormwater detention requirements: 1. A second dwelling permit in the A (Agricultural) Zone District. 2. Towers including, but not limited to, wind and telecommunication towers. 3. Pipelines or transmission lines, excluding laydown yards, metering sites, substations, and any other above ground appurtenances. 4. Gravel pits if the stormwater drains into the gravel pit. Releases from the site shall comply with the Weld County Storm Drainage Criteria, including dewatering. Topographical information shall be provided. 5. Development of sites where the change of use does not increase the imperviousness of the site. 6. Non -Urbanizing areas where the total pre-existing and post development impervious area produces stormwater runoff of less than, or equal to, 5 cfs for the 1 -hour, 100 -year, storm event. This exception shall be supported by calculations signed and stamped by a Colorado Licensed Professional Engineer. 7. Parcels with total area less than, or equal to, 1.0 gross acre. 8. An individual parcel with an unobstructed flow path and no other parcel(s) between the Federal Emergency Management Administration (FEMA) regulatory floodplain channel and the project. 9. A parcel greater than 1 gross acre and less than, or equal to, 5 gross acres in size is allowed a onetime exception for a new 2,00O sq. ft. building or equivalent imperviousness. 10. A parcel greater than S gross acres in size is allowed a one-time exception for a new 4,500 sq. ft. building or equivalent imperviousness. 11. Concentrated Animal Feeding Operation (CAFO), Animal Feeding Operations (AFO) and Housed Commercial Swine Feeding Operation (HCSFO) which are covered and approved by the Colorado Discharge Permit System (CDPS) regulations. Portions of the site not included or covered by the CDPS permit shall comply with the Weld County Storm Drainage Criteria. Building Questions: 970-4004100 1. List the type, size (square footage), and number of existing and proposed structures. Show and label all existing and proposed structures on the USR drawing. Label the use of the building and the square footage. Existing: 481)(100' 5 -bay Building will remain and be utilized as a shop for maintenance of vehicles. House will remain ascaretaker residence. If required, a building permit for achange of use from Ag building to a commercial building will be obtained. Proposed: (1) 40'x 60' Pole Barn built rather quickly, the other two (same size) are proposed for the future as needed. 2. Explain how the existing structures will be used for this USR. 48)(10015 -bay Building will remain and be utilized as a shop for maintenance of vehicles. House will remain as a caretaker residence 3. List the proposed use(s) of each structure. Proposed: (1) 40'x 60' Pole Barn built rather quickly, the other two (same size) are proposed for the future. All Used for storage and maintenance of equipment and trucks. Page 7 of 7 Decommissioning Plan t. Describe reclamation procedures to be employed as stages of the operation are phased out or upon cessation of the Use by Special Review activity. All buildings will remain, all gravel areas will be removed and planted with native vegetation or planted with Alfalfa or other Ag crop. Dust Mitigation Plan Unpaved roads will be watered for dust control, as necessary. On -site vehicle speeds will be restricted to 10 mph to reduce the amount of dust generated. Haul trucks leaving the site WI cover loads. Landscape andScreening Plan q. Describe the proposed screening for all parking and outdoor storage areas. Drill pipe fence, screening trees and Ls4 berms are proposed to screen the equipment and outdoor storage from the adjacent public ROW and residential housing surrounding the site on the North ROW. r. Describe the existing and proposed landscaping for the site. There will be screening trees along the Northern Roland Eastern side between the property and the neighbor. Landscape berms and Trees on the North Frontage/ROW s. Describe the type of fence or other screening proposed for the site. No existing screening on site Proposed is Pipe fence and screening trees. Screening trees to be placed to screen ROW and adjacent residential structures. Nuisance Abatement Plan Screening and Landscaping will be upheld. Trash Containers will be contained within the property, inside of a trash enclosure, near the buildings and away from the road. Traffic will adhere to the business timeframes stated to help reduce noise. ` V f €467, i' ALLES TAYLOR & DUKE, LLC 3610 35TH AVE . UNIT #6 t1 LICENSED PROFESSIONAL ENGINEERS EVANS, 80634 LICENSED PROFESSIONAL LAND SURVEYORS 970-330-0308 xr June 12, 2020 Weld County Department of Planning, Engineering Review 1555 North 17th Avenue Greeley, Colorado 80631 RE: Traffic Narrative Laser Oil Field Services Richard Miller 27808 CR 50 Kersey CO 80644 Lot "B" RE -683 Dear Madam/Sir: Using the information as provided by the site Tenant, Alles Taylor 86 Duke, LLC (ATE)) is generating the following traffic narrative. The following is a copy of when a Traffic Impact Study is required on Weld County Roads. "A Traffic impact Study can be waived, and a detailed Traffic Narrative submitted if the applicant agrees to traffic triggers. Any triggers based upon the traffic narrative or the traffic study will be included within the improvements and road maintenance agreement. The Traffic Narrative must include at the minimum: 1. The type (i. a Trucks/passenger vehicles etc...) and number of vehicles per day 2. Peak hour traffic numbers 3. Expected routes 4. Trip distribution along the routes (i.e. 50% of traffic will come from the north, 20% from the south, 30% from the east) 5. Specifically agree in writing to the below improvements triggers. a. 10 vph during peak hour turning left into the facility -left deceleration lane b. 25 vph during peak hour turning right into the facility -right deceleration lane c. 50 vph during peak hour turning right out of the facility -right acceleration lane." The access point is located on CR 50. A Weld County Access Permit Application is being submitted with this Use by Special Review (USR). The proposed site is for the main office space for Laser Oil Field Services, maintenance facilities for company equipment, the storage of heavy equipment and gravel pit mining equipment when it is not in use. 2019-112 ;C; fl� c≥. i 67Yt flai°O3Y '7'i 'S.z V:. —It ast ALLES TAYLOR & DUKE, LLC 3610 35TH AVE. UNIT #6 LICENSED PROFESSIONAL ENGINEERS EVANS, 80634 LICENSED PROFESSIONAL LAND SURVEYORS 970-330-0308 All employee parking occurs on the property, the total maximum number of employees 4 (on -site) full time, the hours of operation are from 6:00 A.M. to 5:00 P.M. and assumes that there is a 2 -hour window for employees coming to and leaving the site at peak travel times. 6 semi -trucks will also operate from this site, it is assumed that not all trucks will be used on a daily basis, however for the purposes of this traffic narrative it will be assumed that all 6 trucks will make 2 round -trips to and from the site on any given day whereas 1 truck trip will during the morning peak travel time and returning to the site during the evening peak travel time. 1) Trucks: Assume that there will be up to 6 trucks on any given day for business operations, 1 truck per week for fuel deliveries, 2 parts delivery per week. Passenger Cars and Pickups: The number of employees is up to 14 at any given time on site. 2 company supervisor trucks will access the site throughout the day. 2) The peak hours are from 6:00 A.M. to 8:00 A.M. and 4:00 P.M. to 6:00 P.M. The maximum peak hour trip generation for employee traffic is 7 vehicles per hour. It is assumed that there will be truck traffic during peak hours for a total trip count of 3 trucks per peak hour. 3/4) It is assumed that 80% of employee traffic will access site from / to WCR 53 which is located 2 miles to the west the remaining 20% would use WCR 57 which is located 2 miles to the east. It is assumed that 60% of the truck traffic will access site from/to WCR 53 which is located 2 miles to the west and the remaining 40% will travel on WCR 50 to the east a distance of 2 miles to the east to WCR 57. Traffic/Turning Direction Brake down. Peak Hour 6-7, 7-8 AM and 4-5, 5-6 P.M. Trucks = Truck Traffic (100% from/to west) Turning in LH Turning in RH Turning out LH Turning out RH 1 2 2 1 Employee Traffic (Auto) (80% from/to west) 2019-112 Turning in LH ALLES TAYLOR 86 DUKE, LLC 3610 35TH AVE. UNIT #6 ,O ri LICENSED PROFESSIONAL ENGINEERS EVANS, 80634 LICENSED PROFESSIONAL LAND SURVEYORS 970-330-0308 Turning in RH Turning out LH Turning out RH 1.4 5.6 5.6 1.4 5) Richatd. Miller, Laser Oilfield Services Total If you hye questions, please contact me. Respectfully submitted. 4, Mark Taylor Colorado P.R. 46065 2019-112 FOR COMMERCIAL SITES, PLEASE COMPLETE THE FOLLOWING INFORMATION BUSINESS EMERGENCY INFORMATION: Business Name:Le cLpisie ` \ v Address:_ c7 Sine talc sero Business Owner IS LeAle 1 ce.5 Phone: 9 7th —3P5 2 _ 91( li <ie City, ST, Zip:Ver 0 got:ALI Phone: Home Address: City, ST, Z'ip: List three persons in the order to be called in the event of an emergency: NAME ticJc Nii(Lst _es TITLE PrarZ A' ADDRESS PHONE 2.7sTse cieR„lb q7E) -34517 -(spizt( Business Hours: Type of Alarm: A one 1-1 Burglar 0 Holdup El Fire ntSilent Audible Name and address of Alarm Company: Location of Safe: Int Inirnintinntalnitirit *Mink*** it** Ilrlfnlr***** **#t ** ************ **** ** MISCELLANEOUS INFORMATION: Number of entry/exit doors in this building: Location(s): v rt' e .: . ealooteMada Is alcohol stored In building? O Location(s): Are drugs stored in building? tUc Location(s): Are weapons stored in building? Puy Location(s): The following programs are offere s a public service of the Weld County.. heriffs Office. Please indicate the programs of interest, Physical Security Check UTILITY SHUT OFF LOCATIONS: Main Electrical: Gas Shut Off: le , for --%4---\< Exterior Water Shutoff: Interior Water Shutoff: y Grime Prevention Presentation 4k, Notice of Inquiry Weld County Pre -application Case # PRE19-0174 Date of Inquiry 6/28/19 Municipality Kersey CPA Name of Person Inquiring Rick Miller Property Owner McNutt taut Trust Planner Diana Aungst Planner Phone Number 970-400-3524 Planner Email Address daungst@weidgovo m Legal Description Lot B of RE -863 S4, T3N, R64W Parcel Number 1053-0300-0020 Nearest Intersection CR 50 and CR 57 Type of Inquiry USR for field office The above person met with County Planning staff about developing a parcel of land inside your designated Intergovernmental Agreement/Coordinated Planning Agreement Boundary. it,)_ I \ )(,/q- \ County Planner's signature j \:\ would you like to pursue annexation of this property? NO X YES Date of Contact 7 eizti "r Comments: r PLathirt_,K(t s,4h&v `-'-- ` approprial e2 ac_4 r-Q,� i R c or cA `t (AO door Sior-okii;k-Lt orAyto L Jlet ti � `-F 4 "� � ! J ni /y�� •�7 ,�+� ++/'�� /jcJ Signature of Municipality Representative Title Date ` Please sign and date to acknowledge that the applicant has contacted you and return this signed form to Weld County Department of Planning Services. Weld County Planning Department 1555 N 17th Ave, Greeley, CO 80631 ^- (970) 400-6100 ^• (970) 304-6498 Fax 20181107 Property Owner Name Weld County Public Works Dept. 1111 H Street P.O. Box 758 Greeley, CO 80632 Phone: (970)304-6496 Fax: (970)304-6497 Zepp‘naca \\sue Company Address gal leo& estaii � City V\QJCSQJ4 State 113 Zip Phone (q10) to\ E-mail aolket44 Information The access is on CR 60 Nearest intersection: CR C•30 & CR gall Distance from intersection: tsf;16.3 Parcel number: tbE%o?�cco2L Section/Township/Range: 3-��-caul Total number of existing accesses to parcel: Total number of proposed accesses: Latitude Longitude ACCESS PERMIT APPLICATION FORM Authorized Agent/Applicant (if different from Owner) Name t%-krac �01/4\A‘ty' Company AV,OsITAm‘bc- C. Zettikt, L1.,.G Address ?Qfl hats vrnOt,es (p City Euctn.s State Qa Zip aOtpao Phone fnth �j3b' CMCAS E-mail QMQS-A(3WOC— k..R,.Q*LItl•COM Proposed Access Information Culvert size & type (15" CMP/RCP min.) Materials used to construct access 12004 &rise ft. Access construction scheriuleagon peiz000.SL a�' OSQ„ Approx. width of access 2 1 Planning/building case number 1 Proposed Access Count —.Residential Commercial Oil and Gas Agricultural Description of Work Temporary 2.00CQSS2S (3.ce-Vrt‘S �n� rivk , Win a r J0h.t. as kank. t s Y P.YYt&PLA i i Existing Access Count Residential Commercial Oil and Gas Agricultural kSnat SA_ r1/4A a.t_C,2SS O oist. U4. L1. :ctija:a:VVVOLI Q a . At' cflSd 'Tha. 42.,s4 4c auc ctS S Um � 11 Ices vQ -aan CC�m�.CCW�.w� (9.0:), ro�..c�t oS Required Attached 'Documents Property map or sketch (template available on pg. 2) indicating all proposed and existing accesses Access Pictures (N, S, E, & W at the location where the access meets a county maintained road) Access Authorization Form (Not required if the application is signed by the property owner) Additional application materials may be required by the Public Works Department Fee schedule $150 - Temporary, Small Commercial & Residential $300 - Industrial & Large Commercial Submit application to accesspermits@weldgov.com By accepting this permit, the undersigned Property Owner/Authorized Agent, under penalty of perjury, verifies they have received all pages of the permit application; they have read and understand all the permit requirements and provisions set forth on all pages. By virtue of their signature the Property Owner/Authorized Agent is bound by and agrees to comply with all said permit requirements and provisions, all Weld County ordinances, and state laws regarding access construction. Signature -- Printed Name Signature Printed Name In case of rnultip Property Owners/Authorized Agents} kosik Milder Date (52 '-zoo Date6/5-0406;?e) Accesses must be constructed within 1 year of issuance. An extension can be requested from the Weld County Public Works Department. Accesses must be in accordance to Chapter 12, Article V and Appendix 12-A of County Code Page 1of2 Parcel Sketch A = Existing Access /1= Proposed Access qs is‘ N ,0k ca ¶oe4%A lac ce.tvk+ -- kaaki. ts nakesciv CR 5O e1AJ fric ,4% ,012„ o '$i r cCI r�, CRL{B L% U Page 2 of 2 Property Report https://propertyreport.co.weld.co.usl?account=84257186 Weld County PROPERTY PORTAL Account Parcel 84257186 I 105303000020 r Legal Property information (970) 400-3650 Technical Support (970) 400-4357 Account: 84257/86 September 17, 2019 Account Information Space Account Type t- Agricultural Tax —F Year 2019 Buildings 4 PT NE4NE4 3-4-64 LOT B REC EXEMPT RE -683 (.75R) Subdivision Block Lot Actual Value 425,763 Land Economic Area 6201 KERSEY Property Address Property City 27808 COUNTY ROAD 50 -r WELD Zip Section Township Range 03 04 64 A Assessed Value 42,790 Owner(s) Account Owner Name TEN SLEEP R4257186 INVESTMENT GROUP LLC Address 2986 W 29TH ST UNIT B-12 GREELEY, CO 806318547 V Document History Copyright ® 2019 Weld County/ Colorado. All rights reserved. Privacy Policy & Disclaimer I Accessibility Information 1 of 6 911712019, 4:35 PM Property Report https://propertyreport.ca.we1d.co.us/account=84257186 Reception Rec Date 01867074 08-21-1981 1972686 1972686 Type Grantor WDN 07-03-1984 07-03-1984 2454890 09-11-1995 2900980 3024609 t RE RE -683 RE RECORDED EXEMPTION WD 11-15-2001 01-16-2003 OCN r BRANCH LLOYD & JEAN I Grantee RE -683 RE -683 MC NUTT RONALD J & KAREN F MC MUTT MCNUTT RONALD J & RONALD J KAREN F OCN MCNUTT RONALD J & 3035304 02-24-2003 4517100 I 08-23-2019 MCNUTT QCN RONALD J & KAREN F SWD 7 MCNUTT KAREN F TRUST NO 1; MCNUTT RONALD J & KAREN F TRUSTEES OF; MCNUTT et. al. TRUST NO 1 MCNUTT RONALD J & 4 - Doc Fee Sale Date Sale Price 0.00 01-01-1900 0 0.00 I 07-03-1984 0.00 MCNUTT RONALD J & KAREN F TRUSTEES OF TEN SLEEP INVESTMENT GROUP LLC 37.50 09-08-1995 o.ao 11-07-2001 0.00 01-10-2003 t 0.00 01.10-2003 0 375,000 0 0 91.95 08-16-2019 Building Information Building I Acco u ntN o T Building ID Occupancy R4257186 _ 1 Single Family Residential on Ag V 919,500 2 of 6 9/1712019,4:35 PM Property Report https://propertyrcport.ce.weld.co.us/`account=R4257186 ID Type NBHD Occupancy 1 Residential 6201 Single Family Residential on Ag ID Exterior Roof Interior HVAC Cover Frame 1 Masonry Veneer 1D Square Condo Ft SF 1 3,156 0 r 4 a!0 Complete 100 Drywall Electric I Baseboard Bedrooms Baths Rooms 3 Perimeter Units 0 0 3 0 Unit Make Type Total I Finished Garage Carport Balcony Porch Basement Basement SF SF SF SF SF SF j 0 0 880 0 0 490 1 Built As Details for Building ° ID Built Square Year As Ft Built 1.00 2 Story 3,156 1975 Additional Details for Building AI ID 1 1 1 1 1 Detail Type Add On Appliance Fixture Fixture Fixture 1 ' Garage 1 Porch 1 Porch 1 Porch Stories ! Length Width Description Fireplace Wood Allowance Allowance Bath 2 Bath 3 Detached - - Open Slab Slab Roof Cell Slab Roof Cell 0 Units 880 360 350 140 3 of 6 9/17/2019, 4:35 PM Property Report https://properryreport.co.weld.co.usnaccount=R4257186 Building 2 AccountNo R4257186 Building ID Occupancy 2 Utility Building ID Type NBHD Occupancy Yp Complete 2 Out Building Utility Building Bedrooms Baths Rooms 100 0 0 0 ID Exterior !Roof Interior HVAC Perimeter Units UnitMake Cover Type 2 ID Square Ft t ID r. 2,00 L -- 1,500 Condo SF 4 Total Basement SF None 170 Finished Basement SF 0 1 I Garage Carport Balcony Porch SF SF SF SF 0 0 0 0 0 1 0 0 Built As Details for Building 2 Square ' Year Ft I Built Built As Utility Building 1,500 Stories Length r 1976 0 60 No Additional Details for Building 2 AccountNo R4257186 Building 6 Building ID Occupancy 6 Equipment Building Width 25 4 of 6 9117/2019, 4:35 PM Property Report https ://propertyreport. co. weld, co.usi account=RR42 5 .l 186 ID Type NBHD Occupancy Complete Out Equipment Building Building 100 Bedrooms Baths Rooms ID ExteriorRoof Interior HVAC Perimeter Units Unit Cover Type IDSquare Condo Ft SF None 288 0 Total Finished Basement Basement SF SF 6 4,608 0 0 0 ID Built As Details for Building 6 ID Built As t 6.90 Equipment Building Square Year Ft Built 0 Make Garage Carport Balcony Porch SF SF SF SF Stories Length Width 4,608 1986 0 No Additional Details for Building 6 Building 7 AccountNo Building ID R4257186 7 [D L7 96 48 Occupancy 7 I Shed - Equipment Type NBHD Occupancy Out Building Exterior Shed - Equipment Complete 100 Roof Interior HVAC Cover Bedrooms Baths Rooms 0 0 Perimeter Units None 100 0 Unit Make Type 0 5 of 6 9/17/2019, 4:35 PM Property Report https://propertyreport.co.weld.co.us/?account=84257186 ID Square Ft 7 1,200 Condo SF 0 Total Basement SF 0 Finished Garage Basement SF SF 0 4 Built As Details for Building 7 ID 7.00 Built As Shed - Equipment Square Ft 1,200 Year Built 1986 No Additional Details for Building 7 Stories 0 Carport SF Length 40 Balcony SF 0 Width 30 Porch SF 0 Type Improvement improvement Land Code 4277 4279 4117 Totals Valuation Information Description FARM/RANCH RESIDENCE - IMPS FARM RANCH SUPPORT BLDGS FLOOD IRRIGATED LAND - AGRICULTURAL MO Actual Value 369,239 35,921 20,603 Assessed Value 26,400 1 0, 420 5,970 425,763 42,790 • Comparable sales for your Residential property may be found using our SALES SEARCH TOOL Acres 0.000 0.000 21.250 21.250 V Land SqFt 0 925,650 925,650 6 of 6 9/17/201974:35 PM N .., I" WELD COUNTY ihrim NL.INE. NAAP['lNU 5,074.7 0 2,537.35 U SR -1749 ChM M U I C.ATi I ON TOW E € 5 S13 0611 !N Nl041 16NAT tLJSR•iOO64•.. _._ AM3 RI CULTURAL SERVICES WGS_1 984 Web_Mercator Auxiliary_Sphere O Weld County Colorado 5,074.7 Feet This map is a user generated static output from, an Int;rnet t rnapding site and is for reference onl,'. Data la., ers that appnr on this map ma.' or rip/ r . ; bra . .:orate, current, or .other\ rise r?liabl THIS MAP IS NOT TO BE USED FOR NAVIGATION ran r% fl• t1lck-v Denver S Legend D Li Parcels USR - Uses by Special Reviev% Floodplain - 500 Year Floodplain - `l00 Year Zone A Floodplain - 100 Year Floodwa Floodplain - 100 Year Zone AE Floodplain - 100 Year Zone Al-- Floodplain - 100 Year Zone AC Highway Road Road Highway County Boundary Notes Surrounding USR's t.�•r en!1r 4,468.5 0 2,234,23 4,468.5 Feet F, WELD COUNTY ithr ONLINE MA r P I NC; r F.7 7`t r`r.\°'r�tr�.;.Ain L■ a� 1 l% %Vitt it 7ar.'+r-t an V47�°'!. FJ ti� 4 Rd 100 Year A WGS_1964_Web_Mercato►r Auxiliary_Sphere 0 Weld County Colorado This map is a user generated static output from an Internet mappin3 site and is for reference only: Data layers that appeir on this map may or may not be accurate, current, or othenf,:ise reliable. THIS MAP IS NOT TO BE USED FOR NAVIGATION Fort Collin:, U Boultla:r Denver . Legend Parcels Floodplain - Floodplain - Floodplain Floodplain - Floodplain - Floodplain Highway Road Road Highway 500 Year 100 Year Zone A 100 Year Floodwa 100 Year Zone AE 100 Year Zone AI - 100 Year Zone AC LI County Boundary Notes Please 1. Verify that consistent acreage is used in all calcs. Circled. 2. See comments about ROW use and setback requirements. Please address each redlined comment and highlight any changes in the document. Based on the revised submittal there may be additional comments/concerns. Call with any questions: Melissa King 9704003762 Final Drainage Report ATD Job #2019-112 Richard Miller Lot "B" of Recorded Exemption No. 1053 -3 -1 -RE -683 Located Within the Northeast Quarter of the Northeast Quarter of Section 3, Township 4 North, Range 64 West of the 6`h Principal Meridian, County of Weld, State of Colorado lbe by Special Review No. USR Review of the grading plan and erosion sediment control plan is associated with the submittal of a grading permit request. Please find the application form and cklist at this link: https://www.weldgov.com/ departments/public_works/ development_review Include certificate of compliance: https://www.weldgov.com/ UserFiles/Servers/Server_6/File/ Departments/Public° o20Works/ DevelopmentReview/Certificate% 20of%20Compliance% 2008022019.pdf Richard Miller 27808 County Road 50 Weld County, Colorado June 8, 2020 Prepared by Dan Campbell El -1;7,4322 A MI Include drainage checklist:https:// www.weldgov.com/UserFiles/ Servers/Server_6/File/ Departments/Public%20Works/ DevelopmentReview/Drainage %20Report%20Checklist% 200802019. pdf "1 hereby attest that this report for the Final drainage design for Richard Miller was prepared by me, or under my direct supervision, in accordance with the provisions of the Weld County Storm Drainage Design Criteria for the responsible parties thereof I understand that Weld County does not and shall not assume liability for drainage facilities designed by others." Mark A. Taylor Registered Professional Engineer State of Colorado No. 46065 Table of Contents General Location and Description Location Description of Property Drainage Basins and Sub -Basins Major Basin Description Sub -Basin Description Drainage Design Criteria Development Cntena Reference and Constraints Hydrological Cntena Hydraulic Cntena Drainage Facility Design General Concept Specific Details Conclusions Compliance with the Weld County CODE Drainage Concept References Appendices 2 4 4 4 5 5 6 7 7 8 11 12 12 13 14 14 14 14 15 Appendix A Page Data Al -6 Property Information A7-] 0 Aenal Maps A11-35 Web Soil Survey Data A36 FIRM A37-44 Drainage Calculations (Historic and Developed) A45-50 IDF Tables/Curves A51-52 Interpolations for Rainfall Intensity Values A53-54 Interpolations for Runoff Coefficient, C A55 Table R0-5 — Runoff Coefficients, C A56-57 Modified FAA Method for Detention Pond Volume A58 Detention Pond Volume Calculations A59 WQCV Calculations A60-61 Detention Pond Release Time A62-76 Riprap Design Data A77 Weir Wall Sizing Calculations A78 Culvert Outlet Protection A79-90 Memorandum, Water Rights in Colorado A91-100 CDPHE — Stormwater Fact Sheet — Construction 3 I. General Location and Description A. Location 1. The subject property, Parcel No. 105303000020, described as Lot "B" of Recorded Exemption No. 1053 -3 -1 -RE -683, recorded July 03, 1984 as Reception No. 01972686, is located in the Northeast Quarter (NE 1/4) of the Northeast Quarter (NE 1/4) of Section 3, Township 4 North, Range 64 West of the P.M., County of Weld, State of Colorado. 2. The subject property is zoned Agricultural. Currently, the agricultural land area for crop production is 18.13 +1- acres. The proposed development of the site will reduce the agricultural land area by 3.98 +/- acres, leaving 14.15 +/- acres for future agricultural production. 3. The subject property does not lie within the Weld County MS4 Zone per Weld County Property Portal Website. 4. The subject property is approximately 2.6 miles southeast of the Town of Kersey limits and is considered non -urbanizing. Weld County Code Sec. 8-11-20 defines non -urbanizing as an area farther than '/ mile from municipal boundaries. 5. Weld County Road (WCR) 50 borders the property on the north. WCR 57 is 0.08 +/- miles east of the property. WCR 55 is 0.70 +/- miles west of the property. WCR 48 is 0.80 +/- miles south of the property. 6. No major open channels, lakes, streams, irrigation or other water resource facilities lie within and/or adjacent to the project site. The Latham Ditch is located 0.33 +/- miles east of the site. The Loloff Reservoir is located 0.27 +/- miles northeast of the site. Ownership information for the Latham ditch was researched and could not be determined. 7. To the north of the subject property, adjacent to WCR 50, is an Agricultural property owned by James & Sally Eckhardt. Adjacent to the cast of the site is a Residential property owned by David Ohlendorf. Adjacent to the southeast of the site is a Residential property owned by Gary & Valeen Jackson. Adjacent to the south of the site is an Agricultural property owned by Roberto & Raquel Lara. Adjacent to the west of the site is an Agricultural property owned by David & Dorothy Bates. The properties surrounding the subject property are either zoned Agricultural or Residential. B. Description of Property 1. The total area of the subject property is 21.84 +/- acres (Gross) and 21.01 +/- acres (Net). The Net area equals the Gross area minus the 30' existin_ R.O.W. and the 10' reserved R.O.W. on the north. The proposed development s 6.71 - acres. 4 2 The existing ground cover is a mix of native vegetation and prairie grass as well as agricultural crops According to the United States Department of Agriculture's (USDA) WebSoil Survey, the entire site is made up of approximately 92% Olney fine sandy loam (Hydrologic soil group Type B) and 8% Vona sandy loam (Hydrologic soil group Type A) The majority of the site is Olney fine sandy loam (Soil map unit symbol 47), all drainage calculations will use Type B Soils 3 The proposed development includes • a 40' x 40' agriculture storage building o three 50' x 80' equipment maintenance shops (phased, built as needed) o a packed gravel parking/dnving surface for equipment storage and tractor trailer parking • a detention pond with weir wall and release structuie o an emergency overflow spillway for the detention pond • a landscaping berm for screening • a modified access entrance with 60' radius curves • an RCP culvert below the access entrance to convey stormwater in the WCR 50 borrow ditch • a cattle guard for permanent hacking control o removal of the existing oil tank batteries located near the entrance • removal of the eastern entrance into the oil tank battery area 4 From the Web Soils Survey, the depth to ground water is 6 5 feet or deeper The onsite OWTS permit records, Permit# SP -9700185, indicates that groundwater was observed at 7 0 +/- feet below grade in the soil profile Alles, Taylor & Duke (ATD) did not perform any observations or testing of on -site soils or groundwater II Drainage Basins and Sub -Basins A Major Bairn Description 1 Weld County Public Works was contacted in regards to existing drainage reports and master drainage plans in the area No information was available 2 The subject property is located in the South Platte Drainage basin The South Platte Drainage Basin includes much of the populated region of the Front Range extending outward to the eastern plains of Colorado The South Platte River Corridor has experienced a trend of increased urbanization in recent years 3 Floodplain the site is located in Zone X (area of minimal flood hazard) per Firm Panel 08123C1775E, effective date January 20, 2016 Please see the attached map 4 A topographical survey was conducted by ATD and 1 ft contours on the existing and proposed surfaces are provided on the grading plan 5 B. Sub -Basin Description 1. Historic drainage patterns on the site are as follows: Stormwater runoff on the subject property sheet flows in a northeast direction at approximately 1% to 3% slopes. Stormwater runoff ultimately reaches the borrow ditch along WCR 50 and flows east. Historic Basin -1 (HB-1) 6.40 - Acres with the boundaries shown on sheet C-2 of the drawing set. An impervious value of 2% was used for historic drainage analysis. The 10-yr runoff coefficient is 0.17 and the 100-yr runoff coefficient is 0.36. The allowable release rate for the detention pond is based on the historic site conditions for a non -urbanized area, for the 10-yr storm event, which is 1.74 cfs (0.272 cfs/acre) Surrounding and adjacent properties in the area have similar historic drainage patterns as the project site; stormwater runoff flows in a northeast direction at approximately 1% to 3% slopes. With the proposed development, there are six drainage Sub -Basins (SB-A through SB-E and B-1). All proposed drainage basin boundaries are shown on sheet C-4 of the drawing set. The developed Sub -Basin descriptions are as follows: Sub -Basin A (SB-A) is 4.68 +1- acres with a calculated impervious value of 39%. SB-A comprises most of the proposed development including: the existing structures and residence area, some landscaped areas, the proposed structures, and a large portion of the proposed packed gravel surface. The 10-yr runoff coefficient is 0.36 and the 100-yr runoff coefficient is 0.50. Stormwater runoff from SB-A sheet flows to Design Point 1. Sub -Basin B (SB-B) is 0.84 +/- acres with a calculated impervious value of 40%. SB-B consists of a large portion of the proposed packed gravel surface. The 10-yr runoff coefficient is 0.36 and the 100-yr runoff coefficient is 0.50. Stormwater runoff from SB-B sheet flows to Design Point 2. Sub -Basin C (SB-C) is 0.54 +/- acres with a calculated impervious value of 64%. SB-C consists of a small portion of the proposed packed gravel surface, some landscaped areas, and the detention pond. The 10-yr runoff coefficient is 0.48 and the 100-yr runoff coefficient is 0.58. Stormwater runoff from SB-C sheet flows into the detention pond. The detention pond was analyzed with an impervious value of 100%. Sub -Basin D (SB-D) is 0.34 4 /- acres with a calculated impervious value of 19%. SB-D consists of packed gravel surface near the site entrance and landscaped areas east of the entrance. The 10-yr runoff coefficient is 0.27 and the 100-yr runoff coefficient is 0.44. Stormwater runoff from SB-D does not contribute to the detention pond and sheet flows into the WCR 50 borrow ditch. Sub -Basin E (SB-E) is 0.47 +/- acres with a calculated impervious value of 2%. SB-E consists of a portion of land that will remain as agricultural use. The 10-yr runoff coefficient is 0.17 and the 100-yr runoff coefficient is 0.36. Stormwater runoff from SB-E sheet flows to the detention pond and is accounted for at the overflow weir but not for sizing the detention pond. Basin -1 (B-1) is 6.06 +1- acres with a calculated impervious value of 42%. B-1 consists of SB-A, SB-B, and SB-C and is the basin that contributes stonnwater runoff to the detention pond. Thal 0-yr runoff coefficient is 0.37 and the 100-yr runoff coefficient is 0.50. 2. Offsite stonnwater flows from the west and south are intercepted by an irrigation ditch that runs along the perimeter and will not enter the site. Offsite stormwater flows from the north and east flow away from the site and will not enter the site. There are no offsite flows from the neighboring properties affecting this site. III. Drainage Design Criteria A. Development Criteria Reference and Constraints Was this interpolated using the 42%. Please recheck. I. No foreseeable site constraints such as slopes, streets, adjacent properties, utilities, existing structures, will negatively impact the proposed drainage plan. The historic drainage patterns on the site will be maintained in such a manner that it will reasonably preserve the natural character of the area as much as possible while mitigating increased runoff to the surrounding properties. 2. Methodologies used in preparing this report are as follows: • The Rational Method was used to determine stonnwater runoff rates for historic and developed flows; equation (RO-1) found in Urban Storm Drainage Criteria Manual, Volume 1, Revised April 2008 (USDCM Vol. 1) • Time of concentration values for historic and developed conditions were determined using equations (RO-2), (RO-3), (RO-4), and (RO-5) found in (USDCM Vol. 1) • Rainfall curves/tables were determined using NOAA Atlas 14, Volume 8, Version 2, and the rainfall intensity equation (RA -3) provided in (USDCM Vol. 1). • The runoff Coefficients, C were obtained from Table R0-5 found in (USDCM Vol. 1). • The Water Quality Capture Volume (WQCV) was calculated using equations 3-1 and 3-3 found in Chapter 3 of the (USDCM Vol. 3), Best Management Practices, Updated November 2010. • The required detention pond volume was calculated using the Modified FAA Method spreadsheet found in the Urban Drainage & Flood Control District (UDFCD) Detention Basin Volume Estimating Workbook Version 2.34, Released November 2013. o The designed detention pond volume was calculated using the average area method with 0 1' contours around the detention pond (Average Area Method = ((Al + A2)/2) x Stage Depth = Stage Volume (CF) - The restnctor plate onfice sizing used to control the WQCV release was calculated using Orifice Flow equation 11 4 3 B found in the City of Greeley Design Criteria and Construction Specifications Manual, Storm Drainage Volume II, Addendum June 2008 (COG Vol 2) a The orifice plate orifice sizing used to control the 100-yr volume release was calculated using Orifice Flow equation 11 4 3 B found in COG Vol 2 a The nprap emergency overflow spillway and detention pond rundowns were designed using the Rock Chute Design Data Spreadsheet, Version WI -July - 2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998 The sizing of the emergency overflow weir wall in the detention pond was calculated using Equation 11 4 3 A(1) found in COG Vol 2 A spreadsheet is included that shows the stormwater release time of the entire pond (WQCV and 100-yr volume) a A spreadsheet is included that shows the designed detention pond volume using the average area method o A spreadsheet is included that shows all drainage calculations using the Rational Method o Spreadsheets are included that show interpolated values for Runoff coefficients and Storm Intensity values o Soil information from NRCS Web Soil Survey Website is included in this report Aerial maps from Weld County Property Portal are included this report B Hydrological Criteria 1 The calculated Time of Concentration values for historic and developed stormwater flows are as follows a Historic Basin To iii: = 51 minutes a Sub -Basin A T. Dew=16 minutes a Sub -Basin B T, Dev= 13 minutes a Sub -Basin C Dev=11 minutes a Sub -Basin D = 11 minutes a Sub -Basin E T, ixv.= 16 minutes a Basin -1 TT Dev= 16 minutes 2 The Historic Basin rainfall intensity values calculated with a time concentration of 51 minutes are as follows a lio Hie 1 60 in/hr 0 IWO H,s 3 03 rn/hr 8 The Sub -Basin A rainfall intensity values calculated with a time of concentration of 16 minutes are as follows o lio Dev 3 13 in/hr o 1100 Dev 5 95 in/hr The Sub -Basin B rainfall intensity values calculated with a time of concentration of 13 minutes are as follows O 110 ox.v 3 47 in/hr O 1100 my 6 58 in/hr The Sub -Basin C rainfall intensity values calculated with a tune of concentration of 11 minutes are as follows o 110 Dev 3 72 mihr o I1oo Dev 7 05 in/hr The Sub -Basin D rainfall intensity values calculated with a time of concentration of I I minutes are as follows o lie Dev 3 72 m/hr o I100 Dev 7 05 in/hr The Sub -Basin E rainfall intensity values calculated with a time of concentration of 16 minutes are as follows o I10 Dev 3 13 in/hr o Lou Dev 5 95 in/hr The Basin -I rainfall intensity values calculated with a time of concentration of 16 minutes are as follows o 110 Dev 3 13 in/hr o 1100 Dev 5 95 in/hr 3 The runoff coefficients, C for Historic Basin Flows (Type B Soils at 2% imperviousness) are as follows o Cto H. 0 17 o C1oo w. 0 36 The runoff coefficients, C for Sub -Basin A Flows (Type B soils at 39% imperviousness) are as follows O CIO Dev 0 36 o C1o0 Dev 0 50 The runoff coefficients, C for Sub -Basin B Flows (Type B Soils at 40% imperviousness) are as follows ▪ Cie oev 036 o CIO Dv., 0 50 9 The runoff coefficients, C for Sub -Basin C Flou s (Type B Soils at 64% imperviousness) are as follows • Cu) pc, 048 • Cioo oev 0 58 The runoff coefficients, C for Sub -Basin D Flows (Type B Soils at 19% imperviousness) are as follows • Cio Dcv 0 27 o Cio0 De, 044 The runoff coefficients, C for Sub -Basin E Flows (Type B Soils at 2% imperviousness) are as follows • GO Dev 0 17 e Cioo Dcv 0 36 The runoff coefficients, C for Basin -1 Flows (Type B Soils at 42% imperviousness) are as follows • CIO Dew 0 37 O Goa Dcv 0 50 4 The design storm recunence intervals used in this drainage report are the ten (10) year, and one hundred (100) year storm events The detention pond will hold slightly mole than the 100-yr storm volume and will be released at the maximum 10-yr hrstonc flow rate for the non -urbanized site The maximum discharge rate for releasing the detained stormwater is Q = 1 74 cfs (0 272 cfs/acre) 5 The Rational Method was used to calculate stormwater runoff rates, equation (RO-1) found in USDCM Vol 1 The Rational Method is based on the Rational Formula Q = CIA, in which • Q = the maximum rate of runoff (cfs) m C = a runoff coefficient that is the ratio between the runoff volume from an area and the average rate of rainfall depth over a given duration for that area o I = average intensity of rainfall in inches per hour for a duration equal to the time of concentration, Tc • A = area (acres) The Historic Basin peak flow values are as follows • Qio Ms= 1 74 cfs (0 272 cfs/acre) • Qioo H,s= 6 99 cfs (1 091 cfs/acre) The Sub -Basin A peak flow values (Design Point 1) are as follows • Qio Dcv= 5 27 cfs (1 127 cfs/acre) • Qioo D,v= 13 91 cfs (2 975 cfs/acre) 10 The Sub -Basin B peak flow values (Design Point 2) are as follows o Qui Dcv= 1 05 cfs (1 249 cfs/acre) o Quo ix, =2 77 cfs (3 290 cfs/acre) The Sub -Basin C peak flow values are as follows o Qio ocv= 0 97 cfs (1 786 cfs/acre) c Qioo Dcv= 2 23 cfs (4 089 cfs/acre) The Sub -Basin D peak flow values are as follows o Quo ocv= 0 34 cfs (1 004 cfs/acre) o Quo ix -v= 1 05 cfs (3 102 cfs/acre) The Sub -Basin E peak flow values are as follows o Quo Dcv= 0 25 cfs (0 610 cfs/acre) o Quo Dcv= 1 02 cfs (2 452 cfs/acre) The Basin -1 peak flow values are as follows o Qio Dcv=7 02 cfs (1 158 cfs/acre) c Qice Dcv= 18 04 cfs (2 975 cfs/acre) 6 The required 100-yr detention volume was calculated as 30,806 cubic feet (cf) The WQCV was calculated as 4,072 cf The total required storage volume is 30,806 cf+ 4,072 cf= 34,878 cf The designed detention pond volume was calculated as approximately 40,071 cf The detention pond is oversized by approximately 5,193 cf (14 9%) C Hydraulic Criteria 1 The designed detention outlet is a two -stage release The first stage is for WQCV, which is designed to release in approximately 44 4 hours The second stage is designed to release the rest of the pond at the maximum rate of 1 74 cfs (0 272 cfs/acre) in approximately 7 0 hours The entire pond is designed to be released within approximately 51 5 hours, which is under the 72 hours required per Colorado State Legislation Please see attached spreadsheet for release time calculations 2 The WQCV outlet structure will consist of a concrete box with inner wall dimensions of 3 0' x 3 7' The box will have a centered straight notch opening 1 5" in width from bottom to top A restnctor plate (10 5" x 23 5" x 0 25") will be placed centered over the straight notch opening 0 5" from the bottom of the concrete box (elevation of 4636 04') The orifice sizing to control the WQCV flows will be 1 5" x 0 5", which will be released m approximately 44 4 hours Please see sheet C-5 in the drawing set for further details 3 The release of the 100-yr volume will be controlled with an orifice plate centered over the 12 0" diameter corrugated metal pipe (CMP) opening in the weir wall The 11 I orifice plate will have a 3.0" x 6.7" rectangle orifice centered at the bottom of the plate. The 100-yr volume down to the top of the WQCV structure will drain in approximately 7.0 hours. Please see sheet C-5 in the drawing set for further details. 4. All criteria and calculation methods used in this report are presented in either Weld County Code, or in compliance with Urban Storm Drainage Criteria Manuals Volumes I, II, and ill dated June 2001 (revised in April 2008). IV. Drainage Facility Design A. General Concept 1. The historic drainage patterns on the site will 1 will reasonably preserve the natural character mitigating increased runoff to the surrounding Per Sheet C-5, portions of the outlet structure and the emergency spillway are in the ROW and within the minimum setback of 20 feet from future ROW. Relocate/obtain ROW Use Permit. Applicant will be responsible for any future relocation. Historic drainage patterns on the site are as follows: Stormwater runoff on the subject property sheet flows in a northeast direction at approximately 1% to 3% slopes. Storniwater runoff ultimately reaches the borrow ditch along WCR 50 and flows east. The proposed drainage plan is as follows: All stormwater runoff will flow away from structures at minimum 2% slopes and will sheet flow in a northern direction at approximate 1% to 3% slopes until reaching the detention pond. The detained stormwater in the detention pond will be released into the WCR 50 borrow ditch through the outlet structure with a 12" CMP. 2. The anticipated hydraulic structures for this drainage design includes: two detention pond rundowns, a weir wall, an emergency spillway with cutoff wall, a concrete outlet structure with a restrictor plate to control the release of the WQCV, an orifice plate on the weir wall to control the release of the 100-yr volume, a 12" CMP release pipe from the outlet structure to the WCR 50 borrow ditch, an 18" RCP culvert to be placed under the modified entrance. Has the volume associated with these two rundowns Detention Pond Rundowns: been addressed wrt required basin storage volume. Two detention pond rundowns will be utilized to convey stormwater into the detention pond. Both rundowns will have soil riprap type "VL" for erosion protection. Please see Sheet C-6 in the drawing set and the attached Rock Chute sheets for further detail. Weir Wall: The calculated horizontal length of the weir is 23.0'. Using a weir length of 23.0' resulted in a flow rate of 21.1 cfs. The stormwater flows contributing to the weir include: Basin -1 + Sub -Basin E (18.04 + 1.02) cfs = 19.06 cfs. The weir wall is adequately sized. The width of the weir wall is 0.67'. The weir wall is to extend 3.0' into undisturbed soil. #4 rebar will be used for durability purposes (not for structural) 12 in the weir wall. Please see Sheet C-5 in the drawing set and the attached spreadsheet for further detail. Please consider relocating such that it is not aligned with primary outfall. Emergency Overflow Spillway: The length of the spillway from the weir wall to the stilling basin is approximately 29.9' with a slope of 21.5%. The width of the spillway is 27' at the weir wall and 23' at the stilling basin. The side slopes of the spillway are 4:1. Type "VL" soil riprap will he used for the spillway, D50 = 6.0" with a rock chute thickness of 12.0" for erosion protection. Please see Sheets C-5 and C-6 in the drawing set and the attached Rock Chute sheets for further detail. Cutoff Wall: The cutoff wall for the 12" CMP will of the future ROW. The cutoff will be centered in the spillway and will be 11' in length and 0.67' in width. The cutoff wall will extend 3' into undisturbed soil. Please see sheets C-5 and C-6 in the drawing set for further detail. Sec 8-11-100.A.5 - Two cutoff walls are required. Provide info on pipe bedding material. Detention Pond Release Pipe: The outlet pipe extends from the release structure to the emergency spillway stilling basin, which is where the pipe ends. The outlet pipe is a 12.0" CMP with a Length of approximately 30.6' and a slope of 1.44%. Please see sheets C-5 and C-6 for further details. WCR 50 Borrow Ditch Culvert: An 18" RCP culvert located under the site entrance will be used to convey stonnwater through the WCR 50 borrow ditch. The length of the culvert including the flared end sections is approximately 123.3' with a slope of 0.81%. A minimum of 1' of cover over the culvert is required. Type "VL" soil riprap will be used on both the inlet and outlet ends for erosion protection. Please see sheet C-6 in the drawing set for further details. B. Specific Details Maintenance should be a "stand alone document" such that it can be distributed to the applicant. S 1. Maintenance will b Sec.8-11-140.B. •ond. The side slopes of the detention pond will not be greater than 3:1, so traditional maintenance equipment will be adequate to ensure the pond is utilized as designed. After a storm event that produces stormwater runoff into the detention pond, the detention pond shall be checked for erosion; if erosion is found at this time or any time within the life of the pond, it shall be repaired in a timely manner. All vegetation across the site shall be kept at less than one foot tall per Weld County Code; the pond shall be mowed and maintained on a regular basis to ensure its optimal function. After any storm event that results in water flowing through the release structure and pipe; the release structure and pipe should be checked for blockage of any kind. If a storm event results in storm water going over the overflow weir, the weir and riprap shall be checked for erosion; if there is any erosion it shall be repaired in a timely manner. Ensure that trash rack maintenance is called out. 13 i Include only the frequency associated with this site. Detention pond cleaning, silt removal, can be performed using small equipment such as a skid -steer loader. The detention pond shall be visually inspected one year after closing of the grading permit to check for sediments and general integrity of the pond. If heavy silting is observed at this time, an as -built with a survey of the pond may be required. Sediment build up is likely influenced by the overall imperviousness of the site. The lower the I value, the more often the ponds need to be checked for sediment build up. For example, I= 80%, most of the site is paved and stormwater runoff is relatively clean (pond should be inspected every 5 years). For example, I = 40%, sediments from gravel surfaces are prone to movement into low laying areas such as the detention pond (pond should be inspected more frequently, every l to 3 years). 2. Necessary copies of Draft CDPHE, CAFO, DRMS, or State Engineer's permit applications will be included for this project; the site is larger than 1.0 acre. V. Conclusions A. Compliance with the Weld County CODE 1. The stormwater drainage design is in compliance with the Weld County Code. The drainage design will adequately protect public health, safety, and general welfare and have no adverse impacts on public rights -of -way or offsite properties. B. Drainage Concept 1. The drainage design will mitigate site stormwater runoff form the higher storm events. The detention pond will hold up to the 100-yr storm volume and will be released at the maximum 10-yr historic flow rate (Non -urbanized site). The maximum discharge rate for releasing the detained stormwater is Q= 1.74 cfs (0.272 cfs/acre). 2. There are no foreseeable influences of the proposed development on any Weld County Master Drainage Plan recommendations. VI. References a. Urban Storm Drainage Criteria Manual, Volumes I and II, (Revised April 2008). b. Urban Storm Drainage Criteria Manual, Volume Ill, (Revised November 2010). c. City of Greeley Design Criteria and Construction Specifications, Storm Drainage Volume II, (Addendum June 2008). d. UDFCI) Detention Basin Volume Estimating Workbook Version 2.34, Released November 2013. c. USDA Natural Resource Conservation Service, Web Soil Survey, Website f Rock Chute Design Data Spreadsheet, Version WI -July -2010, Based on Design of Rock Chutes by Robinson. Rice, Dadavy, ASAE, 1998. g. Weld County Engineering and Construction Criteria, April 2012, Draft Copy. 14 h NOAA Atlas 14, Volume 8, Version 2, Website i Weld County Online Mapping Website www weldgov coin/departments/assessor VII Appendices Appendix A Page Data Al -6 Property Information A7-10 Aenal Maps All -35 Web Soil Survey Data A36 FIRM A37-44 Drainage Calculations (Historic and Developed) A45-50 IDF Tables/Curves A51-52 Interpolations for Rainfall Intensity Values A53-54 Interpolations for Runoff Coefficient, C A55 Table R0-5 — Runoff Coefficients, C A56-57 Modified FAA Method for Detention Pond Volume A58 Detention Pond Volume Calculations A59 WQCV Calculations A60-61 Detention Pond Release Time A62-76 Riprap Design Data A77 Weir Wall Sizing Calculations A78 Culvert Outlet Protection A79-90 Memorandum, Water Rights in Colorado A91-100 CDPHE — Stormwater Fact Sheet — Construction 15 4/8/2020 Property Report alIMSWeld County PROPERTY PORTAL Property Information (970) 400-3650 Technical Support (970) 400-4357 Account: R4257186 April 8, 2020 Account Information Account Parcel Space p Account Type Tax Year Buildings Actual Value Assessed Value R4257186 105303000020 Agricultural 2020 4 425,763 42,790 Legal PT NE4NE4 3-4-64 LOT B REC EXEMPT RE -683 (.75R) Subdivision Block Lot Land Economic Area KERSEY RURAL J Property Address PropCif arty Zip Section Township Range 27808 COUNTY ROAD 50 WELD 03 04 1 64 Owner(s) Account i Owner Name Address R4257186 TEN SLEEP INVESTMENT GROUP LLC 2986 W 29TH ST UNIT B-12 GREELEY, CO 806318547 Document History https://propertyreportco.weld.co.us/?accountr-R4257186 1/10 418/2020 Property Report Reception Rec Date Type j Grantor J Grantee Doc Fee Sale Date Sale Price 01867074 08-21-1981 WDN 0.00 01-01-1900 0 1972686 07-03-1984 RE RE -683 RE -683 0.00 07-03-1984 0 1 1972686 07-03-1984 RE RECORDED EXEMPTION RE -683 0.00 0 2454890 09-11-1995 WD BRANCH LLOYD & JEAN MC NUTT RONALD J & KAREN F 37.50 09-08-1995 375,000 2900980 11-15-2001 QCN MC NUTT RONALD J & KAREN F 0.00 11-07-2001 0 MCNUTT RONALD J TRUST NO 1 & 3024609 01-16-2003 QCN 0.00 01-10-2003 0 MCNUTT RONALD J & MCNUTT RONALD J & 3035304 02-24-2003 QCN 0.00 01-10-2003 0 MCNUTT RONALD J & KAREN F TRUSTEES OF MCNUTT RONALD J & KAREN F 4517100 08-23-2019 SWD TEN SLEEP INVESTMENT GROUP LLC 91.95 08-16-2019 919,500 MCNUTT KAREN F TRUST NO 1; MCNUTT RONALD J & KAREN F TRUSTEES OF; MCNUTT et al. Building Information Building 1 AccountNo 1 Building ID Occupancy R4257186 1 Single Family Residential on Ag https://propertyreport.co.weld.co.us/?account=R4257186 2/10 4/312020 Property Report ID Type NBHD Occupancy Complete Bedrooms Baths Rooms 1 Residential 6201 Single Family Residential on Ag 100 3 3 0 ID Exterior Roof Cover Interior HVAC Perimeter Units Type Make 1 Frame Masonry Veneer Drywall Electnc Baseboard 364 0 ID Square Ft Condo SF Total Basement SF Finished Basement SF Garage SF Carport SF Balcony SF Porch SF 1 3 156 0 0 0 880 0 0 490 Built As Details for Bulldina 1 ID Built As Square Ft Year Built Stories Length Width 1 00 2 Story 3 156 I 1975 2 0 0 Additional Details for Buildin ID DetailType Description Units 1 Add On Fireplace Wood 1 1 Add On Swimming Pools 1 1 Appliance Allowance 1 1 Fixture Allowance 1 1 Fixture Bath 2 1 1 Fixture Bath 3 2 1 Garage Detached 880 1 Porch Open Slab 360 1 Porch Slab Roof Carl 350 1 Porch Slab Roof Cell 140 httpsllpropertyreportco weld co usl?account=R4257186 3/10 4/812020 Properly Report Building 2 AccountNo Building ID Occupancy R4257186 2 Utility Building ID Typo NBHD Occupancy Complete Bedrooms Baths Rooms 2 Out Building Utility Building 100 0 0 0 ID ExteriorRoof Cover interior HVAC Perimeter Units Unit Make 2 None 170 0 ID Square Ft Condo SF Total Basement SF Finished Basement SF Garage SF Carport SF Balcony SF Porch SF 2 1500 0 0 0 0 0 0 0 Built As Details for Building 2 ID Built As Square Ft Year Built Stones Length Width 2 00 Utility Building 1 500 1976 0 60 25 No Additional Details for Building 2 Building 6 AccountNo Building ID Occupancy R4257186 6 Equipment Building httpsf(propertyreportco weld co uslaccount=84257186 4/10 4/8/2020 Property Report ID Type NBHD Occupancy Complete Bedrooms Baths Rooms 6 Out Building Equipment Building 100 0 0 0 ID Exterior Roof Cover Interior HVAC Perimeter Units Type Make 6 None 320 0 ID Square Ft Condo SF Total Basement SF Finished Basement SF Garage SF Carport SF Balcony SF Porch SF 6 5 376 0 0 0 0 0 0 0 Built As Details for Building 6 ID Built As Square Ft Year Built Stories Length g Width 600 Equipment Building 5 376 1986 0 112 48 No Additional Details for Building 6 Building 7 AccountNo Building ID Occupancy R4257186 7 Shed - Equipment ID Type NBHD Occupancy Complete Bedrooms Baths Rooms 7 Out Building Shed- Equipment 100 0 0 0 ID Exterior Roof Cover Interior HVAC Perimeter Units Unit Type Make 7 None 100 0 https.//proportyreportco weld so usfaccount=84257188 5/10 4/8/2020 Property Report ID Square Ft 7 I 1,200 Condo Total SF Basement SF 0 Finished Basement SF f. 0 Garage Carport Balcony Porch SF SF Built As Details for Building 7 ID Built As Square Ft 7.00 Shed - Equipment 1,200 Year Built 1986 No Additional Details for Building 7 SF SF Stories 0 0 Length 40 Width 30 Valuation Information Type Code Description Actual Value Assessed Value Acres Land SqFt Improvement 4277 FARM/RANCH RESIDENCE- IMPS 369,239 26,400 0.000 0 Improvement I 4279 FARM RANCH SUPPORT BLDGS 35,921 10,420 0.000 0 Land - 4117 FLOOD 20,603 5,970 , 21.250 ! 925,650 IRRIGATED LAND - AGRICULTURAL Totals - { - 425,763 42,790 21.250 925,650 Comparable sales for your Residential property may be found using our SALES SEARCH TOOL Tax Authorities https.//propertyreport.co.weld.co.us/?account=R4257186 6/10 'Tab. WELD COUNTY m.\I'I'IN6 ECKHARDT Calculated Acres 22.111 GIS Calculated Acres TEN SLEEP INVESTMENT GROUP LLC 27:306 GIS Calculated Acres LARA ROBERTO Y JACKSON GARY D Notes WGS_1984 Weo_Mercator_Auxiliary_Sphere 279.28 558.6 Feet J This no .p is • u• !r cme+ated _tahc output frr rn ar Int n:t m .fin n' s,; refe. ,::rp onl• r 4a '.r, -vc that , u n •hr n, ... ..,•1?tM 1.' Weld County Cobrado THIS MAP IS NOT TO BE USED FOR NAVIGATION 1,117.12 2,234 .2 Feet t WGS_1934_Web_Mercator Auxiliary _Sphere C Weld County Colorado Ths rrit0 it a . -neat- t _tat _ :cp,t, t. _ art h• - r . T, x ::e r t .r WU':•rce Gill. Dj". } rrrt ItIA : xr rat m.,). rr , r r. t t 3 x:urat _utr''+C r -tr..•.. . r.) ,ri. THIS MAP IS NOT TO BE USED FOR NAVIGATION Legend connect, Pipet ne tk'deryftrd CsbdL': River - Large Scale Area of Complex Gnomes area tc be S:.Pmerged Bay: rnet Braga CanaiD't ■ Cain,Wor r Flame r- Fcresttre ■ Hazard Zone Inundation Area ■ Lod( Chamber - Rapids n Miter!), 1. ill. r •r4 _tUISk, r.r.P c'rt. t-.t',,.uratu. u" -r t. (V c,t►rr .4 -. r,?t,HE 0 [U' 4 N rn i A Hydrologic Soil Group —Weld County. Colorado. Southern Part cp " & nut. td. C: fkii5 E^!'i' t9, Map Crak?' 1:2,1501 pined on A I:ca at (8S" x 11") sheet — — Meters 0 30 60 13) 18D . Feet 0 100 200 403 8 Map projection: Web Mercator Comer aooninetes: W S84 Edge tics: UTM Zone 13N WC3584 alNatural Resources Web Soil Survey 3� Conservation Service National Cooperative Soil Survey 100 31 4 W 1/28/2020 Page 1 of 4 40° 20' 5(. -. 406 20' 47 N Hydrologic Soil Group —Weld County. Colorado Southern Part MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AO!, Soils Soil Rating Polygons A AD B B'") C/D n Not rated or not available Soil Rating Lines .0%/ A N A/D D • • Not rated or not available Soil Rating Points ■ A ▪ AID ■ B ▪ BlD 0 O C C/D D Not rated or not ava table Water Features Strearns a -d Canals Transportation 1-x4 Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AUI were mapped at 1 24,000 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 mere detailed scale Please rely on the bar scale on each map sheet `or 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 18, Sep 13 2019 Soil map units are labeled (as space allows) for map scales 1 50.000 or larger Date(s) aerial images were photographed Jul 17. 2015 —Oct 2, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident USDA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 of 4 Hydrologic Sot Group —Weld County Colorado Southern Pan Hydrologic Soil Group Map unit symbol I Map unit name I Rating I Acres in AOl I Percent of AO1 47 78 Olney fine sandy loam B 1 l0 3 percent slopes Vona sandy loam 1 to 3 A percent slopes Totals for Area of Interest Description 20 1 17 218 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 (AID B/D 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 (AID B/D 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 82 0% 80% 100 0% 0Natural Resources Web Soli Survey Conservation Service National Cooperative Soil Survey 1128O020 Page 3014 Hydrologic Soil Group —Weld County Colorado Southern Part Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more components A component is either some type of soil or some nonsoil entity e g , rock outcrop For the attribute being aggregated the first step of the aggregation process is to denve one attnbute value for each of a map units components From this set of component attributes the next step of the aggregation process derives a single value that represents the map unit as a whole Once a single value for each map unit is derived a thematic map for soil map units can be rendered Aggregation must be done because on any soil map, map units are delineated but components are not For each of a map unit's components a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a critical factor in some, but not all, aggregation methods The aggregation method Dominant Condition ' first groups like attribute values for the components in a map unit For each group, percent composition is set to the sum of the percent composition of all components participating in that group These groups now represent 'conditions" rather than components The attribute value associated with the group with the highest cumulative percent composition is returned If more than one group shares the highest cumulative percent composition the corresponding 'tie break' rule determines which value should be returned The 'tie break" rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified all components in the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered Tie break Rule Higher The tie break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie prlA Natural Resources Web Soli Survey Conservation Service National Cooperative Soil Survey 12&2020 Page 4 of 4 Map Und Description Olney fine sandy loam 1 to 3 percent slopes —Weld County Colorado Southern Part Weld County, Colorado, Southern Part 47 —Olney fine sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol 382v Elevation 4 600 to 5 200 feet Mean annual precipitation 11 to 15 inches Mean annual air temperature 46 to 54 degrees F Frost -free penod 125 to 175 days Farmland classification Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Map Unit Composition Olney and similar soils 85 percent Minor components 15 percent Estimates are based on observations, descriptions and transects of the mapunit Description of Olney Setting Landform Plains Down slope shape Linear Across -slope shape Linear Parent material Mixed deposit outwash Typical profile H1 - 0 to 10 inches fine sandy loam H2 -10 to 20 inches sandy clay loam H3 - 20 to 25 inches sandy clay loam H4 25 to 60 inches fine sandy loam Properties and qualities Slope 1 to 3 percent Depth to restnctwe feature More than 80 inches Natural drainage class Well drained Runoff class Low Capacity of the most limiting layer to transmit water (Ksat) Moderately high to high (0 57 to 2 00 in/hr) Depth to water table More than BO inches Frequency of flooding None Frequency of ponding None Calcium carbonate maximum in profile 15 percent Salinity maximum in profile Nonsaline to very slightly saline (0 0 to 2 0 mmhos/cm) Available water storage in profile Moderate (about 7 0 inches) Interpretive groups Land capability classification (irrigated) 3e Land capability classification (nonimgated) 4c Hydrologic Soil Group B Natural Resources Conservation Service Web Soil Survey 112812020 National Cooperative Soli Survey Page 1 of 2 Map Unit Description Olney fine sandy loam 1 l0 3 percent slopes— Weld County Colorado Southern Part Ecological site Sandy Plains (R067BY024CO) Hydnc soil rating No Minor Components Zlgweld Percent of map unit 10 percent Hydnc soil rating No Vona Percent of map unit 5 percent Hydnc soil rating No Data Source Information Soil Survey Area Weld County Colorado Southern Part Survey Area Data Version 18, Sep 13 2019 QSD Natural Resources Conservation Service Web Soil Survey 1/2812020 National Cooperative Soli Survey Page 2 of 2 Map Unit Description Vona sandy loam 1 to 3 percent slopes— Weld County Colorado Southern Part Weld County, Colorado, Southern Part 76 —Vona sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol 363w Elevation 4 600 to 5 200 feet Mean annual precipitation 13 to 15 inches Mean annual air temperature 48 to 55 degrees F Frost free penod 130 to 160 days Farmland classification Farmland of statewide importance Map Unit Composition Vona and similar soils 85 percent Minor components 15 percent Estimates are based on observations descnptions and transects of the mapunit Description of Vona Setting Landform Terraces plains Down slope shape Linear Across slope shape Linear Parent matenal Alluvium and/or eolian deposits Typical profile H1 - 0 to 6 inches sandy loam H2 - 6 to 28 inches fine sandy loam H3 - 28 to 60 Inches sandy loam Properties and qualities Slope 1 to 3 percent Depth to restnchve feature More than 80 inches Natural drainage class Well drained Runoff class Very low Capacity of the most limiting layer to transmit water (Ksat) High (1 98 to 6 00 In/hr) Depth to water table More than 80 Inches Frequency of flooding None Frequency of ponding None Calcium carbonate, maximum in profile 15 percent Salinity maximum in profile Nonsaline to slightly saline (0 0 to 4 0 mmhos/cm) Available water storage in profile Moderate (about 6 8 inches) interpretive groups Land capability classification (imgated) 3e Land capability classification (nonimgated) 4e Hydrologic Soil Group A Ecological site Sandy Plains (R067BY024CO) Hydnc soil rating No USDA Natural Resources c� Conservation Service Web Soli Survey 1f28/2020 National Cooperative Soil Survey Page 1 of 2 Map Unit Description Vona sandy loam 1 to 3 percent slopes —Weld County Colorado Southern Part Minor Components Remmlt Percent of map unit 9 percent Hydnc soil rating No Olney Percent of map unit 3 percent Hydnc soil rating No Julesburg Percent of map unit 3 percent Hydnc soil rating No Data Source Information Soil Survey Area Weld County Colorado, Southern Part Survey Area Data Version 18, Sep 13 2019 USgn Natural Resources Conservation Service Web Soil Survey 112812020 National Cooperative Soil Survey Pape 2 012 400 20.56- N 4U" 20 4F N 1340 31 55'w 3 r v A Depth to Water Table —Weld County, Colorado, Southern Part 510010 County Road 50 n r. - I r'cci I I I 5381110 5311910 5100'10 SALM/ Map Scale: 1:2,150 f prated on A porbait (8.5" x 11") street 0 3o ea 120 MIeten 180 Feet 0 10D XO 40D COO Rip 1xtjecbt rr: VNe)Mercator Caner itadinates: WK£84 Edge as. URA Zone 13N W684 USDA Natural Resources Web Soil Survey -r Conservation Service National Cooperative Soil Survey 1940 11 41' w a 1/28/2020 Page 1 of 4 40' 7C SB u Depth to Water Table —Weld County, Colorado. Southern Part MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Solis Soil Rating Polygons l 0-25 25 - 50 50 - 100 100 - 150 150-200 200 Not rated or not available Soil Rating Lines .1/400 0-25 a i 25-50 a • 50 - 100 100-150 & 150 - 200 200 a i Not rated or not evadable Soil Rating Points • • O 0-25 25 - 50 50- 100 100-150 150 200 > 20C Not rated or rot available Water Features Streams and Canals Transportation F++ Rails ti Interstate Highways US Routes Manx Roads Local Roads Background Aerial Ptotograpry The soh surveys that comprise your AOI were mapped at 1 24.000 blaming- Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of Me 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 18. Sep 13. 2019 Soil map units are labeled (as space allows) for map scales 1:50,000 or !anger Date(s) aerial images were photographed Jul 17, 2015- -Oct 2. 20'7 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 USIA Natural Resources Web Sot Survey a Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 cf 4 Depth to Water Table —Weld County Colorado Southern Pon Depth to Water Table Map unit symbol I Map unit name I Rating (centimeters) I Acres In AOI I Percent of AO! 47 76 Olney One sandy loam >200 1 to 3 percent slopes Vona sandy loam 110 3 >200 percent slopes Totals for Area of Interest Description 20 1 92 0% 17 80% 21 8 100 0% Water table" refers to a saturated zone in the soil It occurs dunng specified months Estimates of the upper limit are based mainly on observations of the water table at selected sites and on evidence of a saturated zone namely grayish colors (redoximorphic features) in the soil A saturated zone that lasts for less than a month is not considered a water table This attribute is actually recorded as three separate values in the database A low value and a high value indicate the range of this attribute for the soil component A representative' value indicates the expected value of this attribute for the component For this soil property only the representative value is used Rating Options Units of Measure centimeters Aggregation Method Dominant Component Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map and as a whole A map unit is typically composed of one or more components' A component is either some type of soil or some nonsoil entity e g rock outcrop For the attribute being aggregated the first step of the aggregation process is to denve one attribute value for each of a map units components From this set of component attnbutes the next step of the aggregation process derives a single value that represents the map unit as a whole Once a single value for each map unit is derived a thematic map for soil map units can be rendered Aggregation must be done because on any soil map map units are delineated but components are not. For each of a map units components a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a critical factor in some but not all aggregation methods (bgq Natural Resources Conservation Service Web Soil Survey 1/28/2020 National Cooperative Soil Survey Page 3 014 Depth to Water Table —Weld County Colorado Southern Part The aggregation method' Dominant Component' returns the attribute value associated with the component with the highest percent composition in the map unit If more than one component shares the highest percent composition the corresponding lie break rule determines which value should be returned The tie -break rule indicates whether the lower or higher attribute value should be returned in the case of a percent composition tie The result returned by this aggregation method may or may not represent the dominant condition throughout the map unit Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified all components in the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered Tie break Rule Lower The tie -break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie Interpret Nulls as Zero No This option indicates if a null value for a component should be converted to zero before aggregation occurs This will be done only if a map unit has at least one component where this value is not null Beginning Month January Ending Month December pp Natural Resources �i Conservation Service Web Soil Survey 1/25/2020 National Cooperative SW Survey Page 4 of 4 40° 20' 56 N 40° 20' 42' N 3 rn Y1 53aoen 1 Small Commercial Buildings —Weld County, Colorado, Southern Part 538810 Map Scale: 1:2,150 Y printed rn A portrait (8.5"x 11`) sheet. Meters N 0 30 e0 120 180 IO iQJ 200 4 800 Feet Mao pro edict : Wpb Mercator Corner 000rdnates: WGS84 Edge Ucs.11TM Zone 13N WGS84 (1�St� i Natural Resources Web Soil Survey i� Conservation Service National Cooperative Soil Survey 10e 31'41' w Sc 1/28/2020 Page 1 of 5 40° 20' Y ti 40' ?Cr 42' N Small Commercial Buildings —Weld County. Colorado, Southern Part MAP LEGEND Area of Interest (AOI) Area of Interest (AO' Soils Soil Rafting Polygons fal Very, limited in Somewhat limited 1E� Not limited ri Not rated or not ava !able Soil Rating Lines Very limited • • Somewhat limited MVO Not 'milted • • Not rated or not ava table Soil Rating Points MI Very limited O Somewhat limited ▪ Not limited • Not rated or not available Water Features St -earns and Cana!s Transportation Rails ay Interstate Higinvays oleo US Routes Major Roads Local Roads Background Aerial Photograpny MAP INFORMATION The soil surveys that comprise your AO: were mapped at 1 24,000 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 protection 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 -MRCS certified data as of the version dates) listed below Soil Survey Area. Weld County. Colorado, Southern Part Survey Area Data Version 18. Sep 13, 2019 Soil map units are labeled (as space allows) for map scales 1.50,000 or larger Date(s) aerial images were photographed' Jul 17. 2015- -Oct 2. 2017 The orthophoto or other base map on which the soil lines were compiled and d.gibzed probably differs from the background imagery displayed on these maps. As a result some minor shifting of map unit boundaries may be evident. USDA Natural Resources a Conservation Service Web Soil Survey National Cooperative Soil Survey 1/28/2020 Page 2 of 5 Small Commercial Buildings —Weld County Colorado Southern Pan Small Commercial Buildings Map unit symbol Map unit name Rating Component name (percent) Rating reasons (numeric values) Acres in AO1 Percent of AOI 47 Olney fine sandy loam 1 to 3 percent slopes Not limited Olney (85%) 78 Vona sandy Not limited Vona (85%) loam 1 to 3 percent slopes Totals for Area of Interest Rating Acres in AOI Per Not limited Totals for Area of Interest 21 8 21 8 201 820% 17 80% 21 8 100 0% root of AOI 100 0% 100 0% USDA Natural Resources Conservation Service Web Sol Survey 1/28/2020 National Cooperative Soli Survey Page 3 of 5 Small Commercial Buildings —Weld County Colorado Southern Part Description Small commercial buildings are structures that are less than three stories high and do not have basements The foundation is assumed to consist of spread footings of reinforced concrete built on undisturbed soil at a depth of 2 feet or at the depth of maximum frost penetration whichever is deeper The ratings are based on the soil properties that affect the capacity of the soil to support a load without movement and on the properties that affect excavation and construction costs The properties that affect the load supporting capacity include depth to a water table ponding, flooding subsidence linear extensibility (shrink -swell potential), and compressibility (which Is inferred from the Unified classification of the soil) The properties that affect the ease and amount of excavation Include flooding depth to a water table, ponding slope depth to bedrock or a cemented pan hardness of bedrock or a cemented pan, and the amount and size of rock fragments The ratings are both verbal and numencal Rating class terms indicate the extent to which the soils are limited by all of the soil features that affect the specified use 'Not limited" indicates that the soil has features that are very favorable for the specified use Good performance and very low maintenance can be expected "Somewhat limited' indicates that the soil has features that are moderately favorable for the specified use The limitations can be overcome or minimized by special planning, design or installation Fair performance and moderate maintenance can be expected 'Very limited' indicates that the soil has one or more features that are unfavorable for the specified use The limitations generally cannot be overcome without major soil reclamation special design or expensive installation procedures Poor performance and high maintenance can be expected Numerical ratings indicate the seventy of individual limitations The ratings are shown as decimal fractions ranging from 0 01 to 1 00 They indicate gradations between the point at which a soil feature has the greatest negative impact on the use (1 00) and the point at which the soil feature is not a limitation (0 00) The map unit components listed for each map unit in the accompanying Summary by Map Unit table in Web Soil Survey or the Aggregation Report in Soil Data Viewer are determined by the aggregation method chosen An aggregated rating class is shown for each map unit The components listed for each map unit are only those that have the same rating class as listed for the map unit The percent composition of each component in a particular map unit is presented to help the user better understand the percentage of each map unit that has the rating presented Other components with different ratings may be present in each map unit The ratings for all components regardless of the map unit aggregated rating, can be viewed by generating the equivalent report from the Soil Reports tab in Web Soil Survey or from the Soil Data Mart site Onsite Investigation may be needed to validate these interpretations and to confirm the identity of the soil on a given site qA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 125/2020 Page 4 015 Small Commerual Buildings —Weld County Colorado Southern Pan Rating Options Aggregation Method Dominant Condition Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more components" A component is either some type of soil or some nonsoil entity e g rock outcrop For the attnbute being aggregated, the first step of the aggregation process is to denve one attribute value for each of a map unit's components From this set of component attributes the next step of the aggregation process derives a single value that represents the map unit as a whole Once a single value for each map unit is derived a thematic map for soil map units can be rendered Aggregation must be done because on any soil map, map units are delineated but components are not For each of a map units components a corresponding percent composition is recorded A percent composition of 60 Indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a cntical factor in some but not all aggregation methods The aggregation method' Dominant Condition first groups like attribute values for the components in a map unit For each group percent composition is set to the sum of the percent composition of all components participating in that group These groups now represent "conditions rather than components The attnbute value associated with the group with the highest cumulative percent composition is returned If more than one group shares the highest cumulative percent composition the corresponding 'tie break" rule determines which value should be returned The 'tie break' rule Indicates whether the lower or higher group value should be returned in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified all components in the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered Tie -break Rule Higher The tie -break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie tmNatural Resources Conservation Service Web Soil Survey 1/28/2020 National Cooperative Sol Survey Page 5 of 5 40' 20' 56'N 40' 20'4rN 53371:0 u Corrosion of Concrete Weld County. Colorado. Southern Part 3 tLeci `tUi1 J t'i,i nv Mat ?5:( : Cf'zd'f (J hit: tjSt is f;YONtt r Map Scale: 1:2,150 if printed on A portrait (8.5"x 111 street. Meters 0 30 ®0 120 183 Feet 0 100 200 400 gp0 yap inlcctun: Wpb Mercator Comer cuordinetes: WGS84 Edge tics: 11114 Zone 13N WGS84 pq Natural Resources �i Conservation Service Web Soil Survey National Cooperative Soil Survey 3 A 10e 31'41 W 1/28/2020 Page 1 of 4 40° 20' 56 N 40° 20' 4r N Corrosion Concrete Veld County oicraco Souihr_rn Part MAP LEGEND MAP INFORMATION Area of Interest (AOij Area of interest (AO) Soils Soil Rating Polygons a 0 High Moderate Low Not rated or not available Soil Rating Lines a High • • Moderate ••••••Low . • Not ra•ed or not available Soil Rating Points ® High ▪ Modesto O Low • Not rated or not available Water Features Streams and Canals Transportation Its Rails ort-e.t interstate Highways US Routes Major Roads _oca Roads Background The soil surveys that comprise your AOI were mapoed at ® Acne ?rotcgraphy 1:24.000 \Naming• 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 snail 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 18. Sep 13. 2019 Soil map units are labeled (as space allows) for map scales 1'50.000 or larger Date(s) aerial images were photographed Jul 17, 2015 —Oct 2. 2017 The orthophote 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. USDA Natural Resources Web Soil Survey +oll. Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 of 4 Corrosion of Concrete —Weld County Colorado Southern Part Corrosion of Concrete Map unit symbol I Map unit name I Rating I Auras In AOl I Percent of AOl 47 76 Olney fine sandy loam Low 1 to 3 percent elopes Vona sandy loam 1 to 3 Moderate percent slopes Totals far Area of Interest Description 201 17 92 0% 80% 218 1000% Risk of corrosion pertains to potential soil -induced electrochemical or chemical action that corrodes or weakens concrete The rate of corrosion of concrete is based mainly on the sulfate and sodium content texture, moisture content and acidity of the soil Special site examination and design may be needed if the combination of factors results In a severe hazard of corrosion The concrete in installations that intersect soil boundaries or soil layers is more susceptible to corrosion than the concrete m installations that are entirely within one kind of soil or within one soil layer The nsk of corrosion is expressed as low "moderate or "high " Rating Options Aggregation Method Dominant Condition Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more "components' A component is either some type of soil or some nonsoil entity, e g rock outcrop For the attribute being aggregated, the first step of the aggregation process Is to denve one attribute value for each of a map unit's components From this set of component attributes, the next step of the aggregation process denves a single value that represents the map unit as a whole Once a single value for each map unit is denved a thematic map for soil map units can be rendered Aggregation must be done because on any soil map map units are delineated but components are not For each of a map unit's components, a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a critical factor in some but not all, aggregation methods tJANatural Resources Conservation Service Web Soil Survey 1/28/2020 National Cooperative Soil Survey Page 3 014 Corrosion of Concrete —Weld County Colorado Southern Part The aggregation method Dominant Condition first groups like attribute values for the components in a map unit. For each group percent composition is set to the sum of the percent composition of all components participating in that group These groups now represent conditions rather than components The attribute value associated with the group with the highest cumulative percent composition is returned If more than one group shams the highest cumulative percent composition the corresponding lie -break' rule determines which value should be returned The tie break rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified, all components In the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered 77e -break Rule Higher The tie break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie USDA Natural Resources Conservation Service Web Solt Survey 1/28/2020 National Cooperative Soil Survey Page 4 of 4 C 2O47N ti Corrosion of Steel —Weld County, Colorado, Southern Part MEMO 5w10 Map Scale: 1:2,150 If printed on Amtrak (8.5"x 11") sheet. Meters 0 30 80 1Z0 180 Feet 0 163 2A0 400 800 Map projection: Vreb Memtor Comer wadinata WGS84 Edge Ws: IBM Zone 13N WGS84 S36P'0 539400) 11SDA Natural Resources VVIeb Soil Survey National Cooperative Soil Survey a Conservation Service County Road 50 1O+"3141 ECM 3 1/28/2020 Page 1of4 40° 2G Ss N 40 Corrosion of Stee—Weld County Colorado. Southern Part Transportation *44 Rails A/ Interstate Hghways szvs US Routes Major Roans Local Roads MAP LEGEND MAP INFORMATION Area of Interest (AO') Background Area of Interest (AOI) Aera rotcgrao' Soils Soil Rating Polygons High I Moderate Low Not rated or not available Soil Rating Unes — High • i Moderate ..••• Low • i Not rated or not avalable Soil Rating Points High o Mocerate • Low • Not rated or not available Water Features The soil surveys that comprise your AOI were mapped at 1:24,000 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 riot 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. Natura. 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 18 Sep 13. 2019 Streams and Canals Soil map units are labeled (as space allows) for map scales 1 50,000 or larger Date(s) aerial images were photographed. Jul 17. 2015 —Oct 2, 2017 The orthophoto or other base map on which the so l 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 J USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 of 4 Corrosion of Steel —Weld County Colorado Southern Part Corrosion of Steel Map unit symbol I Map unit name I Rating I Acres In AOl I Percent of AOI 47 76 Olney fine sandy loam High 1 l0 3 percent slopes Vona sandy loam 1 l0 3 High percent slopes Totals for Area of Interest Description 201 17 218 ' Risk of corrosion" pertains to potential soil induced electrochemical or chemical action that corrodes or weakens uncoated steel The rate of corrosion of uncoated steel is related to such factors as soil moisture particle size distribution acidity and electrical conductivity of the soil Special site examination and design may be needed if the combination of factors results In a severe hazard of corrosion The steel in installations that intersect soil boundaries or soil layers is more susceptible to corrosion than the steel in installations that are entirely within one kind of soil or within one soil layer The nsk of corrosion is expressed as ' low moderate' or ' high' Rating Options Aggregation Method Dominant Condition Aggregation Is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more 'components' A component is either some type of soil or some nonsoil entity e g rock outcrop For the attribute being aggregated the first step of the aggregation process is to derive one attnbute value for each of a map unit s components From this set of component attributes the next step of the aggregation process derives a single value that represents the map unit as a whole Once a single value for each map unit is denved a thematic map for soil map units can be rendered Aggregation must be done because on any soil map map units are delineated but components are not For each of a map unit's components a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a critical factor in some but not all, aggregation methods 02 0% 80% 100 0% Natural Resources Conservation Service Web Soli Survey 1/28/2020 National Cooperative Soil Survey Page 3 014 Corrosion of Steel —Weld County Colorado Southern Pall The aggregation method' Dominant Condition first groups like attribute values for the components in a map unit For each group percent composition is set to the sum of the percent composition of all components participating in that group These groups now represent 'conditions' rather than components The attribute value associated with the group with the highest cumulative percent composition is returned If more than one group shams the highest cumulative percent composition the corresponding tie break rule determines which value should be returned The tie break rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified, all components in the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered lie break Rule Higher The tie break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie c� m Natural Resources Conservation Service Web Sad Survey 1128/2020 National CooperaWe Soil Survey Page 4 014 National Flood Hazard Layer FiRMette 40°21'0.29"N 104°32'8_43'W 40°20'32.87"N 0 250 500 1,000 1,500 081230.775E 6ff7/ O/2016.,` Feet 2,000 1:6,000 Sl FEMA Legend SEE EIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS OTHER AREAS OF FLOOD HAZARD M,,86'0£,LC 701. OTHER AREAS Without Base Flood Elevation (BFE) Zon0 A V, A99 With BFE or Depth Zone AE AO, AH VE. AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Zone x Future Conditions 1% Annual Chance Flood Hazard Zone X Area with Reduced Flood Risk due to Levee. See Notes. Zone X Area with Flood Risk due to Leveezone o 0 SCREEN Area of Minimal Flood Hazard zone x Effective LOMRs Area of Undetermined Flood Hazard emit. V GENERAL - - - - STRUCTURES lililii 20.2 Channel, Culvert, or Storm Sewer Levee. Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation OTHER _ FEATURES MAP PANELS 9 Coastal Transect Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary --- Coastal Transect Baseline Profile Baseline Hydrographic Feature Digital Data Available N No Digital Data Available Unmapped The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 4/8/2020 at 6:07:28 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear basemap imagery, flood zone labels, legend. scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. DRAINAGE CALCULATIONS Job Name Richard Milt Job No. 19.112 Otte 1/3O/2020 PERCENT IMPERVIOUS Site Area Existing Site Conditions 'evoe Packed Gravel liGolslCax role BASIN 0 0 0 278961 H' fY ft' A' CAonslant ur Iifiked from boxes above Input value or note Co.G;ated Nue Value that seldom changes Percent Imperviousness from Table HO -s Paved Gravel Routs/Cum:I eire 13'eunbe3sLandscap,ny :_snoscapng/.;ndeveioped AC Percent in' perrviousness Existing (Catcusted) • i Cs • runoff coefficient for 5 -year frequency (learn Table RO-5) ('Note Soli Type) C•0 - runoff niece"' Ice ID -year frequency (from Table RO•S)('Note Soil Type) C -a' curd? coeflicient for 100 -year frequency (from Table RO-5)('Note Soli Type) 6.40 0.02 009 0.17 016 1IME OF CONCEN(RATION t, HISTORIC l ,,, - t+l Equator) RO-2 tr • computeC tune of concentration (minutes) <<ovanoro(tribal tow time (minutes) t.= channeIzed flow hme (minutes) I, • (0396(1 1.CjL.ehyS.e" Equation RO 3 1, ■ Waal or overland flow time (minutes) C. = runoff coefficient for 5 -year frequency (from Table HO 5) C'rote Sal Typo) 1, • lengrn of oveitend flew I ft). not greater ran 300' (urban) or 500' (rule So - average slope ninny ;wetland Ikwv path (tuft) l- stonc Dna nags Patn 1 L.= Delta = 500 47 1.00 0 40 090 0 02 Son Type 8 ft. rot greater than 33O (urban) or 500 (rural) n t • 41 62 minutes t = ; y((fa'C.f'(S_ ‘It = L;63Y, Equeborh RO-a t - chshpeiizoC flow line (minutes) L, z length of chamekzeo flow (II) S,. - average slope along cbannetiereo Mow path (fVf1) Tha Sole Sa e 0.009 0.09 - 7169 ft Delta - 12 3 ft 6= S._ K• 0.0172 10 9.12 5014 HISTORIC FLOW VALUE FOR 5 -YEAR C=CIA Equation 120- minutes MI Table RO-6 C, • Conveyance Coefficient (Table R O 21 fytt Table RO- 2 min tes ' Use Tc a 51 Minutes U = peak rote of runoff (CFS) C • Rumfl coefficient I = eV9 hntaturly Of rainfall for a duatuin equal to gsvrni I. (rnrhr ) A O area (Arne) Ct= _ Ir • A 0".• Illnd 0.09 1 28 0.74 HISTORIC FLOW VALUE FOR 10•YEAR O=CIA Equation HO -- 6 40 Imperviousness = 2% iNhrusing linear ugerpalabon hum Rainier IOF Tables lc it SI Minutes its O115 CFS/AC O • peak rate of n.nofl (CFS) C r, Runoff weff:uent I - aver in ten siy of randier Ion a rkialcn equal to given t (.rvhr) A = area (Acres _ CI() - n• 1 0 Imperviousness • 2'. u1Rv using bnew Interpolation from Rainfall IDF Tables. Tc = 51 Minutes 6 40 1 74 CFS Pee 0272 CFS/AC HISTORIC FLOW VALUE FOR 100 -YEAR O=CIA Equation RC -1 O a peak rate of runoff (CFS) C = Runoff coefficient I = avg intensity of rainfall for a Ouralon equal to given I, (inrhr) A = area (Acrd) 0100 = 036 Imperviousness - I,00 �ayty using knew ntorpolauon from Rainfall ICE TaDlos IC = 51 Minutes A 6 40 cros 0,,,,1«..,.. tI 6 99 -Err: 1 091 PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN A Sie Area = Proposed Site Conditions Paved/Ponds Gravel Roofs/Concrete Landscapinga 4.648 I:C Percent Imperviousness Developed (Calculated) 0.38 c C, - t volt coefficient kr 5-yeai lregsncy (from Table RO-51 (*Note Sod Type) C1° a runoff coeffic.ent for 10 -year frequency (from Table RO-5) CHOW Soil Type) C,.o' runoff coefficient fur 100-yeer Iregaency (from Table RO-5) ('Note Sal Type) TIME OF CONCENTRATION t, DEVELOPED l ant Ili 203707 It' 123174 f? 49152 1Y 31381 fe C FS&AC Percent imperviousness from Table RO.3 Equation RO-2 Pavet)iPonag Gravel Roofs/Concrete I andscapvrg 029 0.3E (1 5C a,,, a computed time of concentration (minutes) t = overlarxl (inivat) now trne (minutes) 11= channeftzed flow time (minutes) r (0 395(1 1-C3XL.45yS °" Equation RO-3 overland (rasa!) flow time (minutes) off C. = runcoefficient for 5 -year frequency (from Table RO-5) ('Note Sod Type) L r length of overland row (It). not greater Von 3O0' (urban) or 600 (rural) 1) Si, = average slope along overland flow pain (M Oovetoped Penn L.= Delta 500 440 1 00 0 40 090 002 Soil Type B 11 not greater than 300' (wean) or 500' (rural) It S. - C, a 0009 029 flift Table RD. 5 _ 34.11 minutes t = Ld(l6C'C.)'(a.J1)) a 1160V, Equation RO-4 t, = channetized flow time (minutes) C, = Conveyance Coenic'enl ( Table RD It l _ le.'gln of cnmiaacd flow (ft) S. = average slope along chant-ell:eft flow pat (putt) Therefor. L. a - Delta' 603.5 9.6 it ft S. Cv' 00191 10 1 606 40 19 TIME Of CONCENTRATION CHECK t ore a (1./180)+10 l a. minutes minutes hitt Table RO-2 Equality' RO.5 T� not to exceed equation RO-5 al lust design pf tit) ` computed true o' concentration (minutes) I., =length of lint pate (11) i = imperviousness in decimal S = average slope along channe:ized few path (Ml) C 39 r= • 100350 11 Delta = 14 Il 1558 s= G0'4 Mt minutes Use 4.. _ ' Use Tc ' 16 Minutes for Sub Basin A Drainage Calculations DEVELOPED FLOW VALUE FOR 5 -YEAR - DESIGN POINT 1 G=CIA Equation 50.1 0s 16 O = peak rate el runof (CFS 1 C = Runoff COcfhCeent I = evg intensity of rainiest for a duration squat lr given 1 A:area (AC) Cs = 0.29 Imperviousness = 39% Is 2.(a-2 sVhr using knew interpolation horn Ftatilati OF Tables. Tc = 16 Minutes A = 4.88 Acres (Net) 3.42 CFS 0.731 I CFS/AC DEVELOPED FLOW VALUE FOR 10 -YEAR • DESIGN POINT 1 Oi-CIA Equatxsi RO.1 O = peak rate of rump (CFS) L = Runoff coefficient = avg intensity of rainfall fore duration equal to gr,-.n t A=area (AC) Cw - 0.36 Impernsress = 39'. iw = 3.13 •n/hr using kncm interpolation from Rar dail IDF Tab es, 'C = 16 Minutes A • 4 G8 Acre's (NM) Oar .=•.r' I 527 CFS = DEVELOPED FLOW VALUE FOR 100 -YEAR • DESIGN POINT 1 O=CIA Equatkri RO- I Q.1.0 c•. t 127 I C FSIAC O • peak rate of runoff (CFS) C r RUM n Met'cteenl I - avg intensity of nonfat; for a duration equal to given L A - area (AC) C,,. = 0.50 imperv,nusnees = 39% - 5-95 g l using linear interpolation from Rainfall IDF Tables. Tc = 16 Minutes A - 4.68 Acres (Net) 1391 CFS ; 2.975 ICFSIAC PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN B Sic Arca 36711 ft' Proposed Sife Conditions Paved,Poruls o M Gtaoei 36311 ft' Roofa/Concrete 0 h' Lenascap>7 370 nit • 081 �C Percent I npecvtcusness Developed (Calculated)0.40 = t G, = rurgff coef ioent ler 5 -year frequency (from Tao* RO.5) ('Note Soil ' ype 030 Percent Imperviousness from Table RO.3 PavecVPonda Gravel Roets/Coraete Landscaping Co a runoff cutlfiu t lot •(-ynar frog ;marl (final Table RO-5) ('Note Soil Type) 035 C„ rump rucoca clam for 100 year Iraq,ar,cy (freer, obit RO-5) (*Note Sat ypyou.050 TIME OF CONCENTRATION I. DEVELOPED Lao- N4 Ir •„ = computed time of concentration (minutes) t • overland (initial) flow time (minutes) 0" channelmed how time (minutes) L (0 395(1 1-C;)(t ))/S,„' •' Fltria(onRO.3 t = overland (mural) flow time (minutes) C., = runoff coefficient for 5 -year frequency (from Table RO.5) ('Note Soil Type) L, = angel of oveneid flow (fl). not greater man 3OT (urban) or 500' meal) S. • average slope Song overland flow path (flitl) Developed Path 1 Eguebon RO-2 L.` Delta = 473 5 8.60 1.00 040 090 002 Soil Type B ft. not greeter tttan 30Y (urban) a 500 (rural) ft Se= C,• 0017 030 tvn Tabus RO-5 t 2&44 minutes t' L,/((t0•C.r(Sp'')) • L 0'v, Equation RO.4 = cliercelized flow time (minutes) C a Conveyance Coefficient (Table RO-2) 4 = engtn of channelled flew (ft) S. r average slope along channekzed flow path (Mt) Thereto* ow• TIME OF CONCENTRATION CHECK t c.. • (U180)t10 a.. L ` De!le = t- 0 0 It ft Sw C.• 00030 0 000 nUIOW. minutes IVu Table RO-2 Equation RO-5 T, not to exceed equation RO-S at first desyn of t1,, • Computed time of amines:arn (r.,in;Rns) L, = length of flow path (ft) = lmpervioulmoss in decimal S a overage slope along ctwnne.tzeJ low path (fVt1) i= 040 L, = 47350 h Deta = 0 12 6! m inutes 0017 jfllfl Use t, ii 13 ' Use Ta, - 13 Minutes ter Sub -Basin B D,ainage Calculations DEVELOPED FLOW VALUE FOR S -YEAR - DESIGN POINT 2 O=CIA Equation RO 1 O • peak rate of runoff (CFS) C a Runoff coel'icrent - avg intensity of rainfall for a diation equal to given L A = area ;AC) C. = 0.30 Imperviousness - 40% 16 = 2 79 uety rsinig knew nierpola:to r from Rainfall ID( Tables Tc • 13 Mimeos A = 0134 Acres (Net I 0%C termini** 071 CFS • DEVELOPED FLOW VALUE FOR 10 -YEAR - DESIGN POINT 2 O•CIA Equation RO-1 0 837 1 C2 SIAC Q = peak rate of runoff (CFS) C = Rio cif coefficient I = avg intensity Cf rniitfali 1[x a d;xatxxr e)e:al to yivrn I, A r area (AC) C„ = 0.36 imperviousness • 40'. L16 - A" 1 OS 34' 0 NA CFS Mn usu10 lanai n:erpofauon from Rsnfst IDF Tables. Tc • 13 Mmuies Acres (Nett 249 ,CFSAAC DEVELOPED FLOW VALUE FOR 100YEAR DESIGN POINT 2 OCR :quiLonRO-1 Ci .:o a ..n .inn O - peat rate of runoff (CFS) C = Runoff ooelhcienl I = avg intensity of rainfall for a drauon equal :o given L A = wee (AC) C.r = A• 0.50 6.58 0.84 !mpennotaness • 4C% atr ti5iry tartar in;erpotatr:rn. from Rainfall IDF Tables, , Tc 4. 13 M.ixrtns Anus (Net) 277 CFS - 3 290 IC PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN C 5 to Area' Proposed Site Conditions Prir:d Grave Roots/Cantata landscaping 23730 12216 7201 0 4313 tt' h' ft) 117 ft' Percent Imperviousness Developed (Calculated) 0 be 0.6.4 FS,AC Percent Impefviousress horn Table RU -3 Pore Gravel Roofs/Concrete Landscaping AC C. a r,rrrAf coefficient for 5 -year frequency (from Table MI5) ('Note Soil Type) C,,, • runoff coe licerll for 10- year frequency (from table RO 5) (-Note Soil Typo) C,°6 = runoff coefficient for '(10 -year 'requency (from Table RO-b) ('Note Soil Type) TIME OF CONCENTRATION t, DEVELOPED ! --•t EcuauanP0-2 : computed time of cun;entrauon (minutes) c = overland I inrbal) ffoN lime (minutes) t = channelized now bme (mvgne') l• (0 395(1 1•CsxL,D4)yS•°in Equation RO-3 = overlent (credal) (tow time (minutes) C, ' runoff coeifit enl for fryear frequency f from Table RO-5; (-Note Sod Type) L • lenctr of overland flow (1) not greater than 3(10 ( unbar ) or 50(1 (rtx.4? = average slope eking overtand flow path (felt! Developed Path 044 0.48 0,8 = Delta = 1228 300 1 00 0.40 0.90 0 02 Soil Type Et It not greater than 300 (urban) or 500 (rural h S. Cs = 0 024 0 44 left Ia*kR0-5 l = 9 83 n notes t, = Li((60•C,1'(S:' 6)) . LJBOV, Equabue R0-4 - charvieitzed flow time (minutes) C-. - Conveyance Coefficient (Table R0.2) L = Iergth of charmer zed flow (hl S. = average slope along dnarvierlred flow path (left) La 0 ft Delta = 0 h Therefore. La C. 0 0000 1 000 9 83 rfInutos minutes VIM table RO-1 TIME. OF CONCEI'TRA7TON CHECK Eq abo'i RO.5 lc ow _ (11180)' 10 T, not to euaitio aquatnn RO.5 ru rust design pt 4 ir=. = computed time Of concentration (minutes) L. _ length Of low pain ; ft) i = imperviousness in decimal S = average slope along channeled flow path (lift) 0,64 t,= 12280 h Delta = 1 ft =O. 1068 minutes SI 0 024 full Use Ica 11 Minutes for Sub -Basin C °fainage Calculations DEVELOPED FLOW VALUE FOR 5 -YEAR O -CIA EquatonRO-1 Use 11 C:- peat( rwe of runoff (CFS) C = Runoff coefficient _ avg iMeY'saty of rainfall Mr a du ration equal to given I. A = area (AC) C, = 0 44 Imperviousness = 64'. l> = 2.98 iNhr. using sneer interpolation from Rainfall IDF tables. 1c' 11 Minutes A - 054 Acre* (Net) Oso«.rw- °I 071 DEVELOPED FLOW VALUE FOR 10 -YEAR O=CIA Equsbon RO-1 O., CFS ■ 311 CFS/AC O = pea* rate of runoff (CFS) C - Runoff coefficient I = avg intensity O1 rainfall for a duration equal to raven I. A=erea(AC) C.= a 0 48 Imperviousness = 64`• I 097 lie - 3.72 in/hr using linear n terpolaticn Ihvn Rainfall OF Tables. Tc = 11 Minutes A - 0.54 Auw (Net DEVELOPED FLOW VALUE FOR 100 -YEAR O=CIA Equation RO-1 O• P, (Hw�w pJ CFS ■ 1786 1 CFS,'AC C = peas rate of runoff (CI -S) C = Run-off coefficient I = evg intensity of rainfall fore duration equal to given t, A = area (AC) 0 58 Imperviousness r ti4% lino ° 7.05 utfr using linear interpolation from Rainfall or Tables. Tc = 11 Minutes A= 054 Acres(Nil) I 2.23 CI -S = 4,089 ICFS'AC PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN 0 54c Area Proposed Site Conditions Pond Caravel Roofs/Concrete Landscaping Percent Imperviousness Developed (Calculated) 0.19 = I Ca = runoff coefficient for 5-yeer frequency (from Table RO.6)('Note Son Type) C,(, a smolt coefficient fur ' 0 -year frequency (from Table RO.5) ('Note Sod Type) C,,x - runoff coefficient to' 103 year frequency ( from Table RU• 5) ('Note Soil 1 ype) 14813 0 66X2 0 8181 f1' ft ft' Per;eni mper.rousres% from Term RO 3 Pond Graved Roots/Cencrete Landscaping 019 0.27 0 44 1 00 040 090 002 Sad Type E PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN E Site Area • Proposed Site Condulons Pond Gravel Roofs/Conaele Landscapny 20087 0 0 0 20067 ft' It' re re rt' S Percent tmpe-vr=Ar ess Developed (Cacvlaled; 47 C02 Percent Imperviousness from Table RO.3 P,y,d Gravel Roofs/Concrete Landscaping =r C, a runoff coefficient br blear ',gurney (Aron Tab a RO.51('Nole Sod Type) C,u = rtxurt wdfenen( kw 10 -year IregctncyMom retie RO'5) ('Note Sul Type C,,, = runoff ccethoenr lot •03 -year fragtency ( from Tao a RO St 1•Nrna Sod Type) DEVELOPED FLOW VALUF FOR 5 -YEAR OrCIA EQuatro,' RO.1 Os 006 017 036 1 00 040 090 002 Soil Type G - teak rats of runoff (CFS) C - Runotf coefficient evg u(ansty cf reintaA for a dur.hon equal b given L A - weal ;AC.) C. = 0.09 imperviousness = 2'. 252 indv using blear wterpole'xn from Rarnfelt IDF Tables T c • 113 Iambs A - 0 47 Aues (Nall I o'1 DEVELOPED FLOW VALUE FOR 10 -YEAR O=Cu eq aOon RO-I CFS = 0227 IC FS/AC O - peak rele of runts (CFS) C = Runef Poem:K g I • avg intensity of ranfad for a drabon.gust to given I. A = area;AC) C,, = 0.17 Imperviousness = 21. I.. = 3.13 rte- using Wear mlerpolatt n from Rainfall IDF Table+. Tc • 16 Unites A - 017 Auer, (Nei) I _ on DEVELOPED FLOW VALUE FOR 100 -YEAR O•CIA Equafron RO 1 O,...r. -a•.. _ CFS- Li-S/AC 0 • pea< rate of runoff (CFS) C • Runoff coefficient I • evg dteraity of ramlafl for a duration equal b given l A • arm (AC) C I„ti • A= I _ 0.36 £95 0 47 1 02 CFS a Inporvuynness 23. d✓hr rn ng hnnar nterpa.ahon fmm Randall 1DF Tables. Tc a 16 Unites Aces (Net) _ 2 142 ICFS/AC PERCENT IMPERVIOUS DEVELOPED • BASIN -1 • Basin -1 is Comprised of Sus -Basins A.B.C. Which Contributes Stoneater Runoff to the Detention Pond Silt, Area = Proposed Site Conditions Pork) Graver Roofs/Canaeta Landscaping 2641481ft' t' 12216 166716 31381 53835 M 11' rt' ft' r erce't irtpe v ou%ncas from 1101. RO-3 Pond Gravel Roofs/Concrelo Landscaping Percent Imperviousness Developed (Calculated) C1, - tunruerkN.t (7g Steer frequency (from Table RO-5) ('Not- Sod -ype) C = runoff overheat -M. lot 10 -yew frequency (from Table R0-5) ('Nob Sod 'roe) C,.- - troll coeffwoenl for 100 -year frequency (frota Table RO-6) (*No* Sod 'ante) 606 A' 0.31 037 0.50 100 040 090 007 Sod Type B DEVELOPED FLOW VALUE FOR }YEAR ()re (A Epuahon NU.1 G ' peak rate o' runoff (CFS) C • Rurw'l coeffnuoni 1 a avg rnlertsity of rainfall k,r a duratarn equal to given 6 A r area(AC) C, ` 0 31 Impemasnoss = 42% I, = 252 rrytr .nu>6 brew intorpotahcn ('urn Rainfall IOF Tables. Tc a 16 Minutes Aa 606 ACAS (Net) OS DaMliervi'` 4 74 CFS 0 781 CFSIAC DEVELOPED FLOW VALUE FOR 10.YEAR O CIA Equabon RO.1 O • peak rate o' liner (CF 5) C • R,no' coeruent I s an intensity of raglan bra &raw equal b given L A r are 1(AC) Cw037 Impervovances • 42% lo = 3 13 Irunr sky knew rdapnlabun from Rating IDF 'able. Tc - 16 Mtnulea Ltrrspan* ell al 702 A • 606 Acres (NM) 115E Icrshic DEVELOPED FLOW VALUE FON 106 -YEAR O•CIA Eguoton RC 1 CFS= O • peak rate of runoff (CFS) C - Rumor p,ef(rcmnl I : avg intensity of rataall lot a dlrrahkli i equal to given L A • area(AC) Cur,' lux= A• O.uu Unteplel 1804 0.50 Imperviousness c 42% Iryt,r using brew interpolation from Rainfall OF Tables. Tc _ 18 ;Amain (Net) 2.975 CrS'AC 1/28/2020 Precipitation Frequency Data Server NOAA Atlas 14, Volume 8, Version 2 Location name: Kersey, Colorado, USA' Latitude: 40.3463', Longitude: -104.5305' Elevation: 4655.77 ft" source: ESRI Maps " source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sonja Pence, Deborah Martin, Sandra Peviovic, tshani Roy, Michael St Laurent, Carl Trypaluk, Dale Unruh. Michael Yekte, Geoffery Bonnin NOM, National Weather Service. Sitver Spring, Maryland pF tabular I PF JrQplicaI I Maps _A aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour) i Average recurrence Interval (years) Duration 1 2 I 5 IL 10 JI 25._.._ 4 50 100�j 200 JL 500 loon J - -_� _JL_ 5 -min 2.94 (2.39-3.66) 3.56 (2.88-4.43) 4.72 (3.80-5.89) 5.83 (4.68-7.32) 7.57 (5.93-10.1) 9.08 (6.88-12.2) 10.8 (7.81-14.9) 12.6 (8.70-17.9) 15.3 (10.1-22.3) 17.4 (11.1-25.6) 10 -min 2.15 51.75-2.68)J 2.60 (2.11-3.24) 3.46 (2.79.4.31) 4.27 (3.42-5.36) 5.54 (4.34-7.41) 8.65 (5.04-8.96) 7.87 (5.72-10.9) 9.22 (6.37-13.1) 11.2 (7.37-16.3) 12.8 (8.14-18.7) 15-min1.75 (1.42-2.18) 2.12 (1.72-2.64) 2.81 (2.27-3.61) 3.47 (2.78-4.35) 4.51 6 (3.53-6.02) 5.41 4.10-7.291 8.40 (4.65-8.84) 7.50 5.18-10.B� 9.08 (8.00.13.3) I 10.4 (6.61.15.2) I 30-min1.18 (0.954-1.46) 1.42 (1.15-1.77) 1.88 (1.52-2.35) 2.33 (1.86-2.92) 3.03 (2.37-4.05) 3.63 (2.75-4.90) 4.30 (3.13-5.95) 5.05' (3.49-7.17) 6.12 (4.044.94) 7.01 (4.46-10.3) 60 -min 0.731 (0.593-0.909) 0.870 (0.705-1.08) 1.14 (0.924-1.43) 1.42 (1.14-1.78) 1.86 (1.46-2.50) 2.25 (1.71-3.04) 2.69 (1.96-3.73) 3.18 (2.20-4.53) 3.89 (2.58-5.70) 4.49 (2.86-6.59) 2 -hr 0.437 (0.357-0.538) 0.515 (0.420-0.836) 0.674 (0.548-0.834) 0.835 (0.674-1.04) 1.10 (0.878-1.47) 1.34 (1.03-1.80) 1.61 (1.18-2.22) 1.91 (1.34-2.71) 2.36 (1.58-3.43) 2.74 (1.76-3.98) 1 3 -hr 0.319 (0.282-0.391) 0.372 0.305-0.456) 0.482 (0.394-0.594) 0.597 (0.485-0.739) 0.790 1(0.833-1.06)J 0.965 (0.745-1.30) 1.17 (0.882-1.60) 1.39 (0.980.1.96) 1.73 (1.16-2.50) 2.01 (1.30-2.90) 6 -hr 0.183 (0.152-0.223) 0.216 (0.178-0.262) 0.280 (0.231-0.342) 0.345 (0.282-0.423) 0.452 (0.384-0.595) 0.547 (0.425-0.724) 0.654 0.775 (0.550-1.08) 0.952 (0.848-1.38) 1.10 (0.719-1.57) ,(0.487-0.887) 12 -hr 0.106 (0.088-0.128) 0.126 (0.105-0.152) 0.163 (0.136-0.198) 0.199 (0.164-0.242) 0.254 (0.205-0.328) 0.302 (0.235-0.393) 0.354 (0.286-0.472) 0.412 (0.294-0.564) 0.495 (0.339-0.697) 0.564 (0.372-0.798) 24 -hr 0.063 (0.053-0.075) 0.074 (0.062-0.089) 0.094 (0.079-0.113) 0.113 (0.094-0.138) 0.142 (0.115-0.180) 0.166 (0.131-0.214) 0.193 (0.148-0.254) 0.222 (0.160-0.301) 0.264 (0.182-0.367) 0.298 (0.199-0.417) 2 -day 0.036 (0.031-0.043) 0.043 (0.036-0.051) 0.054 (0.046-0.064) 0.064 (0.054-0.077 0.079 (0.064-0.099)11(0.072-0.116)ll(0.080-0.136) 0.092 0.105 0.119 (0 086-0.159)) 0.139 (0.097-0.191) 0.155 (0.104-0.215) 3 -day (0.023-0.031) (0.023-0.031) 0.031 (0.026-0.038) 0.038 (0.033-0.045) 0.045 (0.038-0.054) 0.055 (0.045-0.069) 0.084 (0.051-0.080) 0.073 (0.056-0.094) 0.082 (0.060-0.109) 0.096 (0.067-0.130) 0.106 (0.072-0.147) may 0.021 (0.018-0.025) 0.025 (0.021-0.029) 0.030 (0.026-0.036) 0.035 (0.030-0.042) 0.043 (0.035-0.053) 0.049 (0.039-0.082) 0.056 (0.043-0.072) 0.063 (0.048-0.083) 0.073 (0.051-0.100) 0.081 (0.055.0.112) 7 -day 0.014 (0.012-0.016) 0.016 (0.014-0.019) 0.020 (0.017-0.023) 0.023 (0.020-0.027) 0.027 (0.023-0.033) 0.031 (0.025-0.038) 0.035 (0.027-0.044) 0.039 (0.029-0.051) 0.044 (0.031-0.059) 0.048 (0.033-0.066) 10 -day 0.011 (0.009-0.012) 0.012 (0.011.0.014) 0.015 (0.013-0.018) 0.018 (0.015-0.021) 0.021 (0.017-0.025) 0.024 (0.019-0.029) 0.026 (0.020-0.033) 0.029 (0.021-0.037) 0.032 (0.023-0.043) 0.035 (0.024-0.048) 20 -day [(0.006-0.000.0078 .80.010.0110. 0.007-0.000009 (0.008-0) (0.009011-0.013) 0. (0.011-0013.015) 0.014 (0.011-0.017) 0.015 (0.012-0.019) 0.017 (0.013-0.021) 0.019 (0.013-0.024) ((0.014-0.027)1 0.020 30 -day 0.005 (0.005-0.006) 0.006 (0 005-0.007) 0.007 (0.006-0.008) 0.008 (0.007-0.010)_ 0.010 (0.008-0.011) 0.011 (0.009-0.013). 0.012 0.009.0.0141 0.013 0.009-0.016 0.014 (0.010-0.018) ((0.010-0.020) 0.015 I 45 -day 0.004 (0.004-0.005) 0.005 (0.004-0.006) 0.006 (0.005-0.007) 0.007 (0.006-0.008) 0.008 (0.006-0.009) 0.008 (0.007-0.010) 0.009 (0.007-0.011) 0.010 {0.007-0.012) 0.011 (0.008-0.014) 0.011 (0.008-0.015) 60 -day 0.004 (0.003-0.004) 0.004 (0.004-0.005) 0.005 (0.004-0.008) 0.006 (0.005-0.006) 0.006 (0.005-0.008) 0.007 (0.006-0.008) 0.008 (0.006-0.009) 0.008 (0.008-0.010) 0.009 (0.006-0.011) 0.009 (0.007-0.012) 1 Precipltatlon frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). 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 average recurrence interval) wil 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 Tog PF graphical httpsilidsc.nws.noaa.goo/hdsc/pfds/pfds_printpage.html?iat=40.3463&Ion=104.5305&data=intensity&units=engiish&series=pds 1/4 1/28/2020 Precipitation Frequency Data Senior PDS-based intensity -duration -frequency (IDF) curves Latitude: 40.3463°. Longitude: -104.5305' 100 000 10.000 1.000 0.100 0.010 0.001 c c c IA intensity (in/hr) c 0.100 ro y 'a 1:: 0.010 O � c c A t N L IeS Duration I- N T CM N K1 �pro ro N O 5 10 25 50 100 200 Average recurrence interval (years) NOAA Atlas 14, Volume 8, Version 2 >. !. !. J. 1 S ro N O � p 500 1000 Created (GMT)• The Jan 28 23:00:43 2020 Back to Top Maps & aerials Small scale terrain Average recurrence interval (years) MINIM 1 2 — 5 — 10 — 25 50 100 200 — 500 1000 Duration 5 -mm — 2 -day 10 -min -- 3 -day 15 -min — 4 -day 30-mn — 7 -day — 50 -mm — 10 -day — 2fir — 20 -day 3-nr — 30 -day SIMS boar — 48 -day 12 -hr — 50 -day — 24 -hr httpsilhdec.nws.noaa.govthdsdpfds/pfds_printpage.html?lat--40.3463&ion=-104.5305&data=intensity&un ts=english&serlesapds 2/4 1128/2020 Precipitation Frequency Data Server Large scale terrain 1 Large scale map Longs Peal - 4345in #Boulder Vrett 6 t 1 Fort Collins Cheyenne Oteley Longmon' rBoulder —€t"e` J1 100km 6bmi } Large scale aerial https://hdsc.nws.nose.gov/hdsc/pfds/pfds_printpage.html?let--40.3463&Ion=104.5305&data=intensity&units=english&series=pds 3/4 1/28/2020 Precipitation Frequency Data Server gack to ToQ US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions? HDSCQuestions@nnaa.gov Disclaimer httpsJ/hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.htmI?lat=40.3463&Ion=-104.5305&data=intensity&units=english&series=pds 4/4 Intensity -Duration Curves for Rational Method From NOAA Atlas 14 1 -HOUR POINT RAINFALL DEPTHS 2 -YEAR 0.870 5 -YEAR 1.140 10 -YEAR 1.420 25 -YEAR 1.860 50 -YEAR 2.250 100 -YEAR 2.690 Equation 5-1 1= = Input Fields 28.5 P, (I0 4 T',d )0's6 I = rainfall intensity (inches per hour) P, = 1 -hour point rainfall depth (inches) Ti= storm duration (minutes) Time (minutes) i Intensity -Duration (inches per hour) 2 -year 5 -year 10 -year 25 -year 50 -year 100 -year 5 2.95 3.87 4.82 6.31 7.63 9.12 10 2.35 3.08 3.84 5.03 6.09 7 28 15 1.98 2.59 3.22 4.22 5.11 6.11 20 1.71 2.24 2.79 3.66 4.43 5.29 25 1.52 1.99 2.47 3.24 3.92 4 69 30 1 37 1.79 2.23 2.92 3.53 422 35 1.24 1.63 2.03 2.66 3.22 3.85 40 1.15 1.50 1.87 2.45 2.96 3.54 45 1.06 1.39 1.73 2 27 2.75 3.29 50 0.99 1.30 1.62 2.12 2.57 3.07 55 0.93 1.22 1.52 1.99 2.41 2.88 60 0.88 115 144 1.88 2.27 2.72 65 0.83 109 1 36 1.78 2.15 2.58 70 0.79 1.04 1.29 1.69 2.05 2.45 75 0.75 0.99 123 1.61 1.95 2.33 80 0.72 0.95 118 1.54 1.87 2.23 85 0 69 0.91 1 13 1.48 1.19 2.14 90 0.66 0.87 1.08 1.42 1.72 2.05 95 0.64 084 1 04 1.37 1.65 1.98 100 0.62 0.81 1 01 1.32 1.59 1.91 105 060 0.78 0 97 1.27 1.54 1.84 110 0.58 0.75 094 1.23 1.49 1.78 115 0.56 0.73 0.91 1.19 1.44 1.72 120 0.54 0.71 0.88 1.16 1.40 1.67 125 0.52 0.69 0.86 1.12 1.36 1.62 130 0.51 0.67 0.83 1.09 1.32 1.58 135 0.50 0.65 0.81 1.06 128 153 140 0.48 0.63 0.79 1.03 1.25 1.49 145 0.47 0.62 0.77 101 1.22 1.46 150 0.46 0.60 0.75 0.98 1.19 1.42 155 0.45 0.59 0.13 096 1.16 1 39 160 0.44 0.57 0.71 094 1.13 1.35 165 0.43 0.56 070 0.94 1.11 1.32 170 0.42 0.55 0.68 0.89 1.08 1.29 175 0.41 0.54 0.67 0.88 1.08 1.27 180 0.4C 0 53 0 65 0.86 1.04 1.24 Intensity -Duration Curves for Rational Method inches per hoer (in/hr) 10.39 9.00 8.00 :'3 6.33 5.90 &D0 333 2.033 1.03 0.00 car —o—:C• •a 2S•• ea. :ea* — : ,].._4_1. — � 1� -� i _lc P7.-- _1_1_2_1-- a t i i f 1 i • ._ •- _ 4 . . . . . . • . - _ , " ..• - - - - ___,._...1 - - . . • I _ . -. ♦. . _. ...._" . — - • . r. 1 • • . . r -4. �. •. . � •. t' ........4...................-r _ .. • , • ..- -. .....• - }w ..•_ -• 1 a . _ -. y-- -I.- , --• _.., •.. _. -.-_. + . -- .- . . ♦ • • . • -- .- . ... .. ' . . _ .... -- +-. •� _ �.. ♦. _. .._� . .. .•_ .. 1 ._ • i. _. ..-1 -• • . • ♦ __. I - -4...4 ' -` -r -- r r •t _ T .. _ _l_...1 f .1 - I t 1 _ -----t .: 1 I 1 • • -}- -Y �-•---� • -.$ _I -_4 ♦ -.• +- 4.--i _.- ... ♦ . 1 :} _ •-• 4.....- . 4_6_4...w._.•• ._ •._.. • .. - 0 IC 43 5C 80 :00 123 Sto-•-1 D;rat•on ^$es) ar C 2CC Interpolated I Values from Intensity Duration Curves (5-yr, 10-yr, 100-yr) Historic (Tc = 51 Minutes) Sub -Basin A Developed (Tc = 16 Minutes) 5 -Year 50 1 30 51 15 55 1 22 15 = 1 28 10 -Year 50 1 62 51 110 55 1 52 110= 160 100 -Year 50 3 07 51 lloo 55 2 88 11a5= 3 03 5 -Year 15 2 59 16 15 20 2 24 15= 252 10 -Year 15 3 22 16 110 20 2 79 110= 313 100 -Year 15 6 11 16 1100 20 5 29 1100 = 5 95 Sub -Basin B (Tc = 13 Minutes) Sub -Basin C (Tc = 11 Minuted 5 -Year 10 3 08 13 15 15 2 59 15= 279 5 -Year 10 308 11 15 15 2 59 15= 298 10 -Year 10 -Year 10 3 84 10 3 84 13 110 11 110 15 3 22 15 3 22 110= 347 110= 372 100 -Year 100 -Year 10 728 10 728 13 1100 11 Iioo 15 6 11 15 6 11 1100 = 6 58 1100 = 7 05 Sub -Basin D (Tc = 11 Minutes) Sub -Basin E (Tc = 16 Minutes) 5 -Year 10 3 08 11 15 15 2 59 15= 298 10 -Year 10 3 84 11 110 15 3 22 110 = 3 72 100 -Year 10 7 28 11 1100 15 6 11 1100 = 7 05 Basin -1 (Tc = 16 Minutes) 5 -Year 15 2 59 16 15 20 2 24 15= 252 10 -Year 15 3 22 16 110 20 2 79 115= 313 100 -Year 15 611 16 1100 20 5 29 Iwo = 5 95 5 -Year 15 2 59 16 15 20 2 24 i5 = 2 52 10 -Year 15 3 22 16 110 20 2 79 Ito= 313 100 -Year 15 6 11 16 1100 20 5 29 1100 = 5 95 Interpolations of Runoff Coefficients, C for Historic and Developed Flows (5-yr, 10 yr, 100 yr) Historic (Type B Soils - Table R0 5, I = 2%) Developed (Type B Soils - Table R0 5, I = 39%) Historic Basin 5 -Year O 0 08 2 C5 5 01 C5= 0 09 10 -Year O 015 2 Cm 5 019 Cio= 017 100 Year O 0 35 2 O100 5 0 38 Cm = 0 36 Sub Basin A 5 -Year 35 0 27 39 C5 40 0 30 C5= 0 29 10 Year 35 034 39 C10 40 0 36 Cu,= 036 100 Year 35 0 48 39 C100 40 0 50 Cioo = 0 50 Developed (Type B Soils - Table R0 5, l= 40%) Developed (Type B Soils Table R0 5, I = 64%) (Interpolations not needed) Sub Basin B 5 Year C5= 0 30 10 -Year Cio= 036 100 Year Cioo = 0 50 Sub Basin C 5 Year 60 0 41 64 C5 65 0 45 C5= 044 10 Year 60 0 46 64 C10 65 0 49 C10= 048 100 -Year 60 0 56 64 C100 65 0 59 C500 = 0 58 Developed (Type B Soils Table RO-5, I = 19%1 Developed (Type B Soils Table RO 5.1= 2%1 Sub Basin D 5 -Year 15 017 19 C5 20 0 20 C5= 019 10 Year 15 0 25 19 Cio 20 0 27 Cio= 027 100 Year 15 0 42 19 Cwo 20 0 44 C+oo = 044 Developed (Type B Soils - Table RO 5. I= 42%1 Bas n 1 5 Year 40 0 30 42 Cb 45 0 32 C5= 031 10 -Year 40 0 36 42 C,0 45 0 38 Coo= 037 100 Year 40 0 50 42 C100 45 0 51 C,00= 050 Sub -Basin E 5 Year 0 0 08 2 C5 5 01 Cs= 0 09 10 Year 0 015 2 Cio 5 0 19 Cio = 0 17 100 -Year 0 0 35 2 Cioo 5 0 38 Cioo= 036 DRAINAGE CRITERIA MANUAL (V. 1) U� - C�,1107• 7fr2� 314'. Table RO-5 Runoff Coefficients, C o�G:3 Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0:39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0 30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 -• 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 + 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 ` 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 • 0.41 0.46 0.51 0.54 0.56 65% 0.41 1 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0 53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 _ 0.90 _ 0.92 0.94 0.95 0.96 RUNOFF 2007-01 RO-11 Urban Drainage and Flood Control District DETENTION VOLUME BY THE MODIFIED FAA METHOD Project Richard Miller 2019.112 basin ICY (For catchments less than 160 acres only- For larger catchments. use hydrograph routing method) (NOTE for catch:n.4715 fargor tlas 9C acres, CUHP hydrograpn and routing are recommended) Determination of 64 NOR Detention Volume Using Mod fled FAA Method Determ nation of MAJOR Detention Volume Using Modified FAA Method Design Information (Inoutl Desion Information tlflout', noon,* 1k..nan. Im vrv...,an..s ,. • C.Icssm.rl Orea49. Aro. 4 • 42 03 p.lc.n4 CNrnm•nt 0. 144.94 In.per.lou.n.-I I. • 47 00 {n' -sr -1 Ca$chnsat Dra'noq.r. Ae A • Clip:Iscacs Pcc.. PunknW{ntwrn NRCS S%4 Gimp to A. B. C or U Pr.de1•.bpm.nl NW S Sc. Group Typo • A 0 C D Ravin Renee for Oalart.on Corttca 1 • 10 pin (2 5 .0 25 50 or 1[5. i Roan Pentad lot D$:aenbjn r ware t • 100 or hoots 6 I o ;5 60 '00i (2 0' limo of Conca rflron or' ' A•nfled 1c • 16 molutea fano of Cont•a,calwl., .d Watershed Tc • 15 mrulat AO: wag.. UM R.4as. 8614 r. 0 272 do aces Al. rota, UM Rattan Polo • 0 772 dvcre how Pros:34406w q On. P • 1 44 trees Ono AO.r- Nrac.plttnn P. • 272 04sicrl A. Mall IX Formula ••C/►,1(Cr•'J•0, Dsegn Ke MNf 1D► Fcimuls Ill 0/►.10,•TJ•C, raw 0.640.9.4.• Oro C • 26 SO 0.:614 tarn rt., C. • I860 Coot Iwo cuen•t C + 10 :6aalttenl two C; - t0 Cn.6u:% Inns - - - c • _ 0.789 :o.rt r•n Tfre. • 0 7i3� Determination of Avereae Outflow from the Basin (Catculatadl: fDetorminnlon of Avoraae Outflow Iron the Basin (Cof Outflow Iron the basin (Calculandi• RwruN Co•ft.;4m 0 37 lair er1 Coalf.cr.n, 010 Inflow Pee. Runoff Op -r. • 7 04 cis .4Awr r'aall Rum,' ...p.m . 17 91 J. _ __ _ Alts«.fll. S.•s C utlbw Ra4 4 Op .A • 1 68 c1• lb A. at* Posh 04.10. • Fs < Qv -caw a ^ :,Is Mod FAA Maroc Storage Vs um. • 7 93ie cunt foci Moo FAA. M Motor !toper Volum• • 30 A00 ;IA* fowl Mort FAA MI&wogs V um. • 0 182 acre•A Moa Major Monti Vohaw. • -Mimif M al 0.707 Mn-h - - 10 4. E Ma: Racial O.a.7o;, ,n3wpwortol •5.9..µw VMve Here -•y S la' 5.1.4nu5s) Raada4 Dawn mmu:.c Lana II Ratio trier.•. ,lot inches, IV b %pilot) Ina. ' sire 6cr.Jn1 fo.4pu't A-1011LIT.rf Facia (ouapull ' . .rage Outlb•, C4 toulpult Outflow ohm* a9re-fool 10.0.13 • tons,. Volun. eat -lot (output) Rainfall D.a'r'.ton mnUlos 4101701) Rlrfea Mangy litotes rN Output) crib.. Aaiun. •UO.loi LOutet4i 1 luprrori F saw •n t9VIDul) A .row. winos. de (0.4994 131A1ba an sus -lost (0s4ciat) 54'1 1• .loan. 4cr•.1... tuuIo ) 0 000 0 000 000 0.00 0 00C 0 000 0 000 0 ono 1 0.00 000 I ) 10 ` 1 40 50 00 7o 80 90 100 110 Ito lap 140 160 ' 60 110 ISO 100 200 210 1X 730 710 :50 280 710 200 200 300 310 370 330 340 350 380 370 3$0 300 400 410 420 450 440 850 4/4 4'0 4811 490 '.00 610 • to 310 540 560 MC 670 680 500 fa7: 3 136 71p` 2 73 162 1 62 144 176 1 18 1 0• 1 01 C'4 ca. 063 079 075 0 71 068 0 45 043 0 60 O N 060 054 0 63 0 551 060 046 3 47 046 3 44 3 43 0 42 041 040 039 0 '9 0 31 0 37 0+0 036 0 3' 014 034 033 033 032 031 041 0.30 030 030 029 029 076 028 0 27 027 027 026 020 0 119 0111 0 207 0231 0 251 0286 0 280 0 791 0 301 0 311 0319 0327 0134 034% 0347 0163 o;', O 363 0 WA 0 373 0 378 9 3Cl 0 300 0 390 0 .44 0 195 040' 0 406 0 408 0 412 0 415 0 116 0 421 0424 0427 0 429 V 422 0 436 0436 0 440 0 443 0 449 0447 046C 0467 0 454 049` 0 450 0461 0463 0 466 0 461 u 46V 047. 0 473 0 415 0177 U47. 0 481 3 462 100 090 077 070 0 6c o t3 0 61 060 0 56 0 58 057 067 055 056 055 055 056 054 064 064 0 54 064 0 63 063 053 0 51 n r - 0' 053 01. 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C 061 0050 0 651 0.646 0641 04'8 0633 0616 0 S I G 0614 0.008 0602 0196 0 800 U5411 9 518 0577 0 566 O IF 3 0662 0!1411 0 539 0 537 Mod F 701 g-' 12 1bdl.ad (Few. 1 (Fe. 4 s Madison 14A M Minor S•.aeq. Volcano (cuo,c kf • 1 038 . V od FAA Maier Storage Vaasa (cubic fl.( . Mod. rM Minot Swope Volume (.er•Jt ) • 0.1622 Mod. FAA Major Slangs Volcano. (atr.•6 ) a UOFCD DETENTION BASIN VOLUME ESTIMATING WOKKBJOK Verslor 2 34 Released Novenloe' 2013 30,606 0 /1373 5. t' 070 12 41 01) r Project: Richard Miller 2019-112 Basin D. DETENTION VOLUME BY THE MODIFIED FAA METHOD Volume (acre-feet 1 1.2 1 0.8 0.6 04 02 0 Inflow and Outflow Volumes vs. Rainfall Duration e�bJ•o••000• °oeoos°•o•�•••••••..•• woe • • .•••°°°o OOOOOOOO O -o OOor)O O 0 100 200 300 400 Duration (Minutes) 500 600 ._....a......_ . r awn Wimp•.rte S ••••••••••••• *Owe -lip- •IF. r— vs Gears .ate • NISEI Vag. See •••••• 700 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34. Relssseo November 2013 7014.1 f7 1tAd1. CAA tfUral) id* MOSred FAA F !6x1070 12 47 rti! POND VOLUME CALCULATIONS Average Area Method = ((Al + A2)/2) Stage Depth = Stage Volume (CF) Elevation (NAVD 29) Contour Area (ft) Volume of Stage (93) Accumulative Volume (fe) 4642 0 13992 56 1383 9 40071 4 4641 9 13685 55 1354 5 38687 5 4641 8 13403 75 1326 4 373331 4641 7 13123 31 1298 4 36008 7 4641 6 12844 22 1270 5 34708 3 4641 5 12568 48 1242 8 33437 8 4641 4 12290 11 1215 3 32185 0 4641 3 12015 08 1187 8 30979 7 4641 2 11741 41 1180 5 29791 9 4641 1 11469 10 1133 4 28631 4 4641 0 11198 14 1106 3 27498 0 4640 9 10928 11 1079 5 26391 7 4640 8 10661 27 1052 9 25312 2 4640 7 10397 61 1026 7 24259 3 4640 6 10137 13 1000 8 23232 5 4640 5 9879 83 975 3 22231 7 4640 4 9625 72 950 0 21258 4 4640 3 9374 79 925 1 20306 4 4640 2 9127 05 900 5 19381 3 4640 1 8882 49 876 2 18480 8 4640 0 8641 11 852 2 17604 6 4639 9 8402 84 828 5 16752 4 4839 8 8167 79 805 2 15923 9 4638 7 7935 96 782 2 15118 7 4639 6 7707 35 750 5 14338 5 4839 5 7481 95 737 1 135771 4639 4 7259 78 715 0 12840 0 4639 3 7040 82 i 693 3 12125 0 4639 2 6825 08 671 9 11431 7 46391 6612 56 650 8 10759 8 4039 0 6403 25 630 0 10109 0 4638 9 6196 94 609 5 9479 0 4638 8 5993 73 589 4 8869 5 4638 7 5793 60 569 5 8280 1 4638 6 5596 66 550 0 7710 6 4838 5 5402 61 530 7 7160 6 4638 4 5211 76 511 8 6629 9 4638 3 5023 99 493 2 81181 4638 2 4839 31 474 9 5624 9 4638 1 4657 73 458 8 51501 4638 0 4479 23 437 4 4693 2 4637 9 4289 43 418 4 4255 8 4837 8 4097 61 401 3 3837 5 4637 7 392919 384 7 34381 4637 6 3764 17 368 3 3051 5 4637 5 3602 53 352 3 26831 4637 4 3444 30 336 7 2330 8 4837 3 3289 48 321 4 1894 1 4637 2 3138 01 3084 1672 7 46371 2989 95 291 8 1368 3 4837 0 2845 30 258 1 1074 6 4838 9 2315 89 209 8 818 5 4636 8 1880 83 170 3 606 7 4636 7 1524 49 138 3 436 4 4636 6 1241 95 109 8 298 1 4636 5 95418 81 4 188 3 4638 4 87415 54 8 106 8 46363 42226 322 520 46362 22214 155 198 48381 87 02 4 4 4 4 4636 0 0 00 0 0 0 0 Top of Pond/Weir Elevation = 4642 0 100-yr v WOCV Water Surface Elevation = 4641 6 (Calculated 100 yr Volume * WOCV 34 878 CF) 100-yr Water Surface Elevation = 4641 3 (Calculated 100-yr Volume 30806 CF) Required Detention Pond Volume = 34,878 CF (WOCV (4 072 CF). 100,, Vol (30 806 CF) = 34 878 CF) Designed Detention Pond Volume = 40 071 CF Detention Pond Is oversized by 5 193 CF (14 9%) ' Designed WOCV Water Surface Elevation = 4638 0 (Calculated WCICV 4 072 CF) Lowest Pond Elevation = 4638 0 2019-112 Water Quality Capture Volume (WQCV) Calculations WQCV Calculations WQCV = a(0.9113-1.1912+0.781) For 40 hr Release a = 1 Required Storage = (WQCV/12)`Area Required WQCV Storage = FAA Method 100 YR = WQCV = Total Detention Pond Volume = Area (AC 0.093 Page SQ-24 Page SQ-24 30826 4072 34898 0.42 6.06 AC -ft = ft' ft' 4072 Detention Pond Release Time WS Devotion (8) Invert Vey (It) C °Initial (CFS) °final (CFS) °Avg (CFS) Volume of Stage (CF) Time to Empty Stage (hr) Accumal8lve Time (hr) 4642.0 46350 0.65 174 173 173 13839 022 5145 46419 46360 065 173 171 172 13543 022 5122 4641.8 463613 065 171 170 170 13264 022 5101 46417 4636 0 0 65 1 70 168 169 1298.4 0 21 50 79 46416 46360 065 168 166 167 127D5 021 50.58 46415 46360 065 166 165 166 12428 021 5036 46414 46360 065 165 163 164 12153 021 5016 4641.3 46360 065 163 162 162 11878 020 4995 46412 46360 065 162 160 161 116D5 020 4975 46411 46360 065 160 158 159 11334 020 4955 46410 46360 065 158 137 157 11063 020 4935 4640.9 46360 065 1.57 155 156 10795 019 4915 46408 46360 055 155 153 1.54 10529 019 4896 46407 46360 065 153 151 152 10267 019 4877 46406 46360 065 151 1SD 150 10008 018 4858 46405 46360 065 150 148 149 9753 018 48.40 4640.4 4631.0 065 148 1.46 147 9500 018 4822 46403 46360 0.65 146 144 145 9251 018 4804 46402 46360 065 144 142 143 9005 017 4786 46401 46360 065 142 140 141 8762 017 4768 4640 0 4636.0 065 140 1.39 139 852 2 017 47 51 4639 9 4636.0 0 65 139 137 138 828 5 017 47 34 4639.8 4636.0 0 65 137 135 136 805 2 016 4718 46397 46360 065 135 133 1 34 782 2 016 4701 46396 46360 065 133 131 132 7595 016 4685 46395 46360 065 131 129 130 7371 016 4669 46394 46360 065 129 127 128 7150 016 4653 46393 46360 0.65 127 124 125 6933 015 4637 4639.2 46360 065 124 122 123 6719 015 4622 46391 46360 065 122 120 121 6508 015 4607 4639.0 4636.0 065 120 118 119 630 0 015 45 92 4638.9 46360 025 118 116 117 6095 015 4577 46388 46363 065 116 113 114 5894 014 4563 4638 7 4636 0 0.65 113 111 112 669.5 014 45 48 46386 46360 065 111 109 1.10 9500 014 4534 46385 4631 0 0 65 109 106 107 530 7 014 45 20 4638A 46360 065 106 104 1.05 5118 014 4507 4638.3 46360 065 104 101 102 493.2 013 4493 46382 46360 065 101 098 1.00 4749 013 4480 46381 46360 065 098 004 051 456.8 025 4466 46380 46360 065 004 004 004 4374 3.22 4442 46379 46360 065 004 004 004 4184 316 4120 46378 4636A 065 004 004 004 4013 312 3803 46377 46360 065 004 003 003 3847 308 3491 46376 46360 065 003 003 003 3683 305 3183 46375 4636.0 065 003 003 003 3523 301 2879 46374 46360 065 003 003 003 3367 299 2577 4637.3 46360 065 003 003 003 3214 296 2279 46372 46360 065 003 003 003 3064 295 1982 46371 46360 065 003 003 003 291.8 294 1687 46370 4636A 065 003 D03 003 2581 274 1393 46369 46360 065 003 002 002 2098 236 1119 4636.8 46360 065 002 002 002 1703 204 884 46367 46360 065 002 002 002 1383 178 68D 46366 4636.0 065 002 002 002 1098 154 501 46365 46360 065 002 002 002 814 127 347 4636.4 46360 065 002 001 002 548 098 219 4636.3 46360 065 001 001 001 322 069 121 46362 46360 015 001 001 001 155 045 052 46361 46360 065 001 003 002 26 004 007 4636.04 46360 340 003 000 001 1.8 003 003 46360 46360 000 0.00 000 0.0 000 000 • 100yr♦ WQCV WaterSurface Dev 4641 6 • 11W -Or Water Surface Elea 46413' ••• Designed WOCV Water Surface Elea 4638 0 •••• Flow Sw4ches from Orifice to Weir Top of Pond to Water Quality (hr) Water Quality to Bottom of Pond (hr) Total (hr)e 7 03 44 42 5145 A= area (ft') = g = gravitational constant (ftlsec')= h = head on entice measured from centerline (ft) - Q= Orifice Flow Calculations (From water surface elev. 4642.0' to water surface elev. 4638.0') Q = CA(2gh)'' City of Greeley Eq. 11.4.3.5 Rectangle Orifice C„ • Orifice Coefficient = A = area (f?) _ g = gravitational consla•it (fuse(')= h = head on orifice measured from centerfne (ft) Q 065 0 14 32.2 572 1.74 CFS Base Height Water Depth 0.250 0.558 6 ft ft ft Orifice Flow Calculations (From water surface elev. 4638.0' to water surface elev. 4636.04') Q = CA(2gh)"' City of Greeley Eq. 11 4.3.B Rectangle Orifice Cr. Orifice Coefficient = Base ft Height ft 0.65 0.005 32.2 1 98 0.04 CFS Weir Flow Calculations (from water surface Q = CLH City of Greeley Eq. 11.4.3.A(1 C= L = Length (ft) _ H = Depth of Flow (ft) Water Depth 0.125 0.012 2 elev. 4636.04' to invert elev. 4636.0') 3.400 0.125 0.042 0.03 CFS ft From table 11 1 City of Greeley manual Rock Chute.xls Rock Chute Design Data (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Emergency Spillway County: Weld Designer: Dan Campbell Date: March 4. 2020 Input Geometry: Upstream Channel Bw = 23.0 ft. Side slopes = 1.0 (m:1) Velocity n -value = 0.013 Bed slope = 0.0010 ft./ft. Chute Checked by: Mark Taylor Date: 03/04/20 Bw = 23.0 ft. Factor of safety = 1.50 (Fs) 1.2 Mln Side slopes = 4.0 (m:1) - . 2.0:1 max. Bed slope (4.7:1) = 0.214 ft./ft 3.0:1 max. Noten value = a) velocity n from waterway program Freeboard = 0.5 ft. - -> orb) computed mannings n for channel Outlet apron depth d = 1.0 ft. Page 1 of 3 Downstream Channel Bw = 23.0 ft. Side slopes = 3.0 (m:1) Velocity n -value = 0.022 Bed slope = 0.0010 ft./ft. Design Storm Data (Table 2, FOTGJ WI-NRCS Grade Stabilization Structure No. 410): Base flow = 19.2 cfs Apron elev. -- Inlet =42.0 ft. Outlet 35.6 ft. -- (.�t,rc,r, 5.4 ft. 0 „,g„ = Runoff from design storm capacity from Table 2, FO TG Standard 410 Q , = Runofff from a 5 -year, 24 -hour storm. Oho= 19.2 cfs High flow storm through chute O5 = 0.1 cfs Low flow storm through chute Note : The total required capacity is routed through the chute (principal spillway) or in combination with an auxiliary spillway. Input tailwater (Tw) : Tw (ft.) = Program Tw (ft.) = Program Profile and Cross Section (Output): Starting Station = 0+QQ,Q man h0 = 0.08 ff. (0 ft.) Hp, = 0.44 ft. Energy Grade Line .. Inlet Channel Slops: = 0.001 ft.M = 0.42 R. (0.02 ft) Hp = 0.36 ft. (0.01 ft.) = 0.27 if (0.01 ft.) hn, = 0.14 ft. (0 ft.) HNC = 0.41 ft. Inlet A ---10yc run r • • 0.715ye = 0.2 ft. NN(0.01 t) • • • 40(D50)= 10 ft. Velocityin1et = 1.97 fps radius at normal depth Critical Slope check upstream is OK 1 Note: When the normal depth (y„) in the inlet channel is less than the weir head (He), ie., the weir capacity is less than the channel capacity, restricted flow or pondin5 will occur. This reduces velocity and prevents erosion upstream of the inlet apron. • • Typical Cross Section r Freeboard = (r 5 ft. 7 • • . S. 1 Geotexti le-' • Notes: 1) Output given as High Flow (t ow Flow) values. 2) Tailwater depth plus d must be at or above the hydraulic jump height for the chute to function 3) Critical depth occurs 2yc - 4y, upstream of crest. 4) Use WI Const. Spec. 13, Class I non -woven geotextile under rock. = 0.17 h. Hydraulic Jump (0.01 ft.) �- Height, z2 = 0.41 ft. (0 01 ft.) Hdiap = 5 11 It . • S. • • • Rock Chute Bedding • • r I A Y 6 ft 15(O50)(F,) Profile Along Centerline of Chute Berm Geotextile Rock Chute Bedding F--• 2.3 ft. ---1 ' Rock t ckness = 9.3 In. Use Hp along chute but not less than z2. c **Y. Fs = zt = n -value = Dso(Fs) = 2(D50)(F5) _ Tw+d= z2 _ The outlet 0.81 cfs#`R. VelocityOt111et = Tw+d = 1.84 ft - Tw o. k. (1.56 ft.) - rw a. k. 084 ft (0.56 ft.) 2.5 Outlet Channel Slope = 0.001 ft.Jft. t ft. (1 ft. minimum suggestad) 1 7R fps at normal depth Equivalent unit discharge 1 50 Factor of safety (multiplier) 0.17 Ft Normal depth in chute 0.044 Manning's roughness coefficient 4 6 in, Minimum Design D50' Rock chute thickness 1.84 ft. Tailwater above outlet apron 0 -11 ft. Hydraulic jump height will function adequately 9.3 in. High Flow Storm Information Rock _Chute .xls Page 2 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Emergency Spillway Designer: Dan Campbell Date: 3/4/2020 I. Calculate the normal depth in the inlet channel High Flow Low Flow Y = Area _ ()high = 0.42 ft. 9.7 ft2 19.2 cfs Scupstrearnchannel = 0.003 ft/ft II. Calculate the critical depth in the chute High Flow Yc = 0.27 ft. Area = 6.6 ft2 Qhigi = 19.2 cfs Hce = 0.41 ft h„ = 0.14 ft. 10y, = 2.74 ft. 0.715, = 0.20 ft. Yn Area = QIO',N County: Weld Checked by: Date: 0.02 ft. (Normal depth) 0.5 ft2 (Flow area in channel) 0.1 cfs (Capacity in channel) Low Flow Yc Area Qiow = HCe = 0.715, = III. Calculate the tailwater depth in the outlet channel 0.01 ft. (Critical depth in chute) 0.2 ft2 (Flow area in channel) 0.1 cfs (Capacity in channel) 0.01 ft. (Total minimum specific energy head) 0.00 ft. (Velocity head corresponding to yz) (Required inlet apron length) 0.01 ft. (Depth of flow over the weir crest or brink) High Flow Low Flow Tw = Area = ()kip = H2 = 0.84 ft. 21.5 ft2 384 cfs 0.00 ft Tw = 0.56 ft. (Tailwater depth) Area = 13.9 ft2 (Flow area in channel) ()low = 19.3 cfs (Capacity in channel) H2 = 0.00 ft. (Downstream head above weir crest, H2 = 0, if H2 < 0.715*yc) IV. Calculate the head for a trapezoidal shaped broadcrested weir Cd -- High Flow Hp = 0.42 ft. Area = 9.8 ft2 0.00 fps 0.00 ft. 19.2 cfs 1.00 (Coefficient of discharge for broadcrested weirs) 0.36 ft. 8 4 ft2 2.28 fps 0.08 ft. 19.2 cfs (Weir head) (Flow area in channel) (Approach velocity) (Velocity head corresponding to Hp) (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Low Flow Hr, = 0.01 ft. Area = 0.3 ft2 V. = 0.00 fps hp„ = 0.00 ft. Qlow - 0 1 cfs 0.01 ft. 0.3 ft2 0.44 fps 0 00 ft. 0.1 cfs (Weir head) (Flow area in channel) (Approach velocity) (Velocity head corresponding to Hp) (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Rock Chute .xls Page 3 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Emergency Spillway Designer: Dan Campbell Date: 3/4/2020 County: Weld Checked by: Date: V. Calculate the rock chute parameters (wlo a factor of safety applied) High Flow q, = 0.08 cms/m DS0 (mm) = 78.74 > (3.1 in.) n = 0.044 z, _ = Velocity = Zrnean = F, _ Lrodc apron = 0.17 ft. 4.0 ft2 4.76 fps 0.17 ft. 2.06 3.87 ft Low Flow D50 n= z, _ A, _ Velocity = Znean — F1_ 0.00 cros/m (Equivalent unit discharge) 5.68 0.030 0.01 ft 0.2 ft? 0.82 fps 0.01 ft. 1.75 VI. Calculate the height of hydraulic jump height (conjugate depth) High Flow Z2 _ Qhlgh A2 = 0.41 ft. 19.2 cfs 10.2 ft2 mm (Median angular rock size) (Manning's roughness coefficient) (Normal depth in the chute) (Area associated with normal depth) (Velocity in chute slope) (Mean depth) (Froude number) (Length of rock outlet apron = 15'D50) Low Flow zz = 0.01 ft. (Hydraulic jump height) high = A2 = 0 1 cfs (Capacity in channel) 0.3 ft2 (Flow area in channel) VII. Calculate the energy lost through the jump (absorbed by the rock) High Flow E, _ E2 = RE _ 0.52 ft. 0.47 ft. 10.31 % Calculate Quantities for Rock Chute Rock Riprap Volume Area Calculations h = 0.41 x, = 4.12 L = 1.69 As = 1.69 x2= 4.00 At) = 27.25 Ab+2*A6 = 30.63 ft2 Length Rock CL. Inlet = 9.95 Outlet = 6.15 Slope = 30.77 2.5:1 Lip = 2.59 Total = 49.46 ft. Rock Volume 56.10 yd3 Geotextile Quantity Width Length (d Bot. Rock 2*Slope = 11.63 Bottom = 23.25 Total = 34.87 ft. rota; = 49.45 ft. Geotextile Area 191.62 yd2 Low Flow E,= E2 = RE - 0.02 ft. 0.02 ft. 5.23 % (Total energy before the jump) (Total energy after the jump) (Relative loss of energy) Bedding Volume Area Calculations h = 1.41 x, = 0.00 L = 5.81 AS = 0.00 x2 = 0.00 Ab = 0.00 Ab+2*A& = 0.00 Bedding Thickness t,, t2 = 0.00 in. Length (a Bed CL Total = 49.45 ft. BeddingVolume ft2 0 00 yd3 Note 1) The radius is not considered when calculating quantities of riprap, bedding, or geotextile. 2) The geotextile quantity does not include over - overlapping (18 -in. min.) or anchoring material (18 -in. min. along sides. 24 -in min. on ends). 0+00.0 0+08.2 0+10.0 0+11.7 0+40.1 0+46.1 0+48.6 Rock Chute Design - Plan Sheet (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Minimum Project: Miller 19-112 Emergency Spillway Designer: Dan Campbell Date: 3/4!2020 Enter • County: ''Ve,d Checked by: Date: " Design Values 4 6 in. D.,c dia. _ 9.3 in. 3 ft Rutk,h„1 thickness = Inlet apron length - 6 ft outlet apron engirt 10 ft. Radius . Plan Values 6 00 in. 12.00in. 10 00ft. 6 00 ft 17 It _ Rock Gradation Envelope % Passing D 10 086 050 010 Diameter, in (weight, Ihs ) 9-12(52-122) 8 - 11 (34 - 89) 6-9(15-52) 5-8(8-34) Will bedding be used? No Notes: ° Rock, bedding, and geotextile quantities are determined from the x -section below (neglect radius) ° Geotextile Class 1 (non -woven) shall be overlapped and anchored (18-inmin. along sides and 24 -in minon the ends). Upstream Channel Stip,=0.0oittm Rock Chute Stakeout Notes Sta. Elev. (Pnt) 4211 (1) 42 ft (2) 41.9 ft (3) 41.6 ft. (4) 35.56 ft (5) 35 56 ft (8) 3656 ft (7) Class I non -woven C O 4 (—Inlet apron elev. = 42 ft 3 Rock thlcluless = 1 ? in - --• 10t? --- 7 Radius = 17 ft. -" Geotextile Rock gradation envelope can be met vnth DOT Light riprap Gradation • 1 / 30 ft • • 1 L� 4.67'% Quantities e Rock = 57 yd3 Geotextile (WCS-13)° = 192 yd` Bedding = 0 Excavation = 0 Earthfill = 0 yda yd3 yd3 Seeding = 0.0 acres Degree of angularity = 1 50% angular, 50% rounded 2 100 % rounded Outlet apron elev. = 35 56 tr-) S en. all On Profile Along Centerline of Rock Chute Freeboard =0 5 ft 1 Rock Chute Cost Estimate Unit Unit Cost Cost Rock Geotextile Bedding Excavation Earthfill Seeding $ 10.00 /yda $570.00 $12.OOlyd2 $2,304.00 $12.00 /yd3 $0.00 $12.00/yd3 $0.00 $1.00 lyd3 $0.00 $2.00 /ac. $0.00 Total $2,874.00 4 i v Downstream Channel Slope 0 0o' 6 f -~ 2,1�-d- 1ft. "Note. The outlet will function adequately Top width = 2 .. ft = 041 ft Geotextile Rock Chute Bedding Rock thickness = 12 in. • Use H throughout chute F5' - It but not less than zz Rock Chute Cross Section Profile, Cross Sections, and Quantities 4NRCS ti... ,.«..i., LI.-w • I' .... 'O4,1 tom: GM••••• . n a,. Miller 19-112 Emergency Spillway Weld County Page 1 of I ous c,mbat pateitaed a pa Weir N Rock Chute.xls for construction plan Rock Chute Design - Cut/Paste Plan (Version WI -July -2010, Based on Design of Rock Chutes by Robinson. Rice, Kadavy. ASAE, 1998) Project: Miller 19-112 Emergency Spillway County: Weld Designer: Dan Campbell Date: 3/4/2020 Checked by: Date: Design Values Dyj dia. - 6.0 in. RockChWe thickness = 12.0 in. Inlet apron length = 10 ft. Outlet apron length = 6 ft. Radius - 17 ft. Will bedding be used? No Rock Gradation Envelope % Passing Diameter, in. (weight. lbs.) D, ap Des Dsa Dip 9-12(52-122) 8-11 (34 - 89) 6-9(15-52) 5-8(8-34) Coefficient of Uniformity, (D 60)/(D ,0) < 1.7 Quantities' Rock = 57 Yd3 Geotextile (WCS-13)° = 192 yd2 Bedding = 0 Yd3 Excavation = 0 yd3 Larthfill = 0 Yd3 Seeding = 0.0 acres Noe.: " Rock, bedding, and geotextile quantities are determined from x -section below (neglect radius). h Geotextile Class I (Non -woven) shall be overlapped and anchored (18 -in. minimum along sides and 24 -in. minimum on the ends) -- Quantity not included. Upstream Channel slope = o Got tuft Stakeout Notes ta. Elev. (Pnt) 0+00.0 42 ft. (1) 0+08.2 42 ft (2) 0+10.0 41.9 ft (3) 0+11.7 41.6 ft. (4) 0+40.1 35.56 ft. (5) 0+46.1 35.56 ft. (6) 0+48.6 36.56 ft. (7) Notes: c O to r— Inlet apron elev. 42 ft. Inlet apron Rock thckness = 12 in 10 ft. ---- • Radius = 16.68+t---/ Geotextile • • • • • • • • • • • Point No. 2 3 4 Outlet apron elev. - 35.56 ft ) 4.67 Outlet a • • y 30 ft __--- 6 ft. Profile Along Centerline of Rock Chute Description Point of curvature (PC) Point of intersection (PI) Point of tangency (PT) Downstream Channel ron Slope = 0.001 ft./It. Rock Chute Bedding ;Top width - 26 ft. Freeboard = 0 5 ft Rock gradation envelope can be met with DOT Light riprap Gradation 1 4' Berm Geotextile 0.41 ft. / � Rock Chute Bedding Rock thickness = `t 23 ft r B'=233ft Rock Chute Cross Section Profile, Cross Sections, and Quantities 12 in Use Hr, throughout cnute but not less than z7. ANRCS palsy Ratans Cori na.» mine :irw0 Slats UeiaDwrw e, squats* I Miller 19-112 Emergency Spillway Weld County sw. Ce Cantr Slier d Rock_Chute.xls Page 1 of 3 Rock Chute Design Data (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE Designer: Dan Campbell Date: March 28, 2020 Input Geometry: County: Checked by: Date: Weld Mark Taylor 03/28/20 Upstream Channel Chute Downstream Channel Bw = 15.0 ft. Bw = 4.0 ft. Bw = 8.0 ft. Side slopes = 35.0(m:1) Factor of safety = 1.50 (Fs) 1.2 Min Side slopes = 50.0(m:1) Velocity n -value = 0.022 Side slopes = 5.0 (m:1) ' 2.0:1 max. Velocity n -value = 0.025 Bed slope = 0.0320 ft./ft. Bed slope (16.3:1) = 0.061 ft./ft > 3.0:1 max. Bed slope = 0.0100 ft./ft. Jote: n value = a) velocity n from waterway program Freeboard = 0.5 ft. - or b) computed mannings n for channel Outlet apron depth, d = 0.5 ft. Base flow = 13.9 cfs Design Storm Data (Table 2, FOTG, WI-NRCS Grade Stabilization Structure No. 410): Apron elev -- Inlet =42.0 ft. Outlet 36 5 ft. --- (Hd:op = 5 ft. Q nph = Runoff from design storm capacity from Table 2. FOTG Standard 410 Q; = Runoff from a 5-year,24-hour storm. Qhueh= 13.9 cfs High flow storm through chute _ Qs = 0.1 cfs Low flow storm through chute Note : The total required capacity is routed through the chute (principal spillway) or in combination with an auxiliary spillway. Input tailwater (Tw) : Tw (ft.) = Program -- Tw (ft.) = Program Profile and Cross Section O utout Starling Station =i0+00.0 hp„ =Oft (0 h.) Hpe= 107 ft Energy Grade Line Hp= ).071t. Inlet Channel Slor.'e It 0.032 ft 'ft. = 0.19 ft. (0.01 ft.) Quo (0 05 ft.) yc = 0 57 f1 {0.03 it -10yc = ci ft - h„= 0.2 ft. (0.02 ft.) Hu = 0.77 ft. 40(D5o) = 10 ft. Velocity1Nef = 3.36 fps radius at normal depth Crlical Slope check upstream is unstable 1 Note: When the normal depth (y„) in the inlet channel is less than the weir head (Hp), ie., the weir capacity is less than the channel capacity, restricted flow or ponding wilt occur. [his reduces velocity and prevents erosion upstream of the inlet apron. i-- 0.715yc = 0.41 ft. N.. 10.02 ft.) . • • • • • • Typical Cross Section r- Freeboard = 0.5 ft 1 m * Use H, along chute but not less than z2. 4 _ A Geotextile S. Profile Along • • !. • S. S. S. S. *41 Notes: 1) Output given as High Flow (Low Flow) values 2) Tailwater depth plus d must be at or above the hydraulic jump height for the chute to function. 3) Critical depth occurs 2yc - 4yc upstream of crest 4) Use WI Const. Spec. 13, Class I non -woven geotextile under rock. = 0.43 tt. (0.03 ft ) l'N. Hdrop = `i f( ;'s% `` •. ''.. ;b.3, Rock Chute 15(D50)(FS) Bedding Centerline of Chute Geotextile Rock Chute N Bedding 4 ft. - - - Rock thickness = l3 8 rr'r *A* Fs_ z,= n -value = Dsu(Fs) = 2(Dso)(Fs) Tw+d= 22 = The outlet 2.42 cfs/ft. Hydraulic Jump Height, z2 = 0.73 ft. (0.04 ft.) Tw+d = 0.92 ff. - Tw o.k. (0.81 ft) - Tv, o.k. 0 42 P. (0.31 ft) Outlet 2.5 r Channel 1 — Slope = 0.01 ft./ft. 0 5 ft {1 ft rninimor, suggested) Velocityouue, = 2 31 fps at normal depth Equivalent unit discharge I 5u Factor of safety (multiplier) 0.43 ft 0 037 4 4 tn. 8ein. 0.92 ft. 073 h. Normal depth in chute Manning's roughness coefficient Minimum Design D50' Rock chute thickness Tailwater above outlet apron Hydraulic jump height will function adequately High Flow Storm Information Rock_Chute.xls Page 2 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE Designer: Dan Campbell Date: 3/28/2020 I. Calculate the normal depth in the inlet channel High Flow yr, '- Area Qh;yr, Scupstreamchannel 0.19 ft. 41 ft2 13.9 cfs 0.013 ft/ft II. Calculate the critical depth in the chute County: Weld Checked by: Date Low Flow y„ = 0.01 ft. (Normal depth) Area = 0.2 ft2 (Flow area in channel) Q;,.,, = 0.1 cfs (Capacity in channel) High Flow Low Flow Yc _ Area = Qr,yr, = Hte= _ 10yc = 0.715yc = 0.57 ft. 3.9 ft2 13.9 cfs 0.77 ft. 0 20 ft. 5.67 ft. 0.41 ft. Yc Area Qiow Hce hey 0.715yc = III. Calculate the tailwater depth in the outlet channel 0.03 ft. 0.1 ft2 0.1 cfs 0.05 ft. 0.02 ft. 0.02 High Flow Low Flow Tw = Area = Qhigh = H2 = 0.42 ft. 12.0 ft2 27.8 cfs 0.00 ft Tw = Area cw H,= ft. (Critical depth in chute) (Flow area in channel) (Capacity in channel) (Total minimum specific energy head) (Velocity head corresponding to yi (Required inlet apron length) (Depth of flow over the weir crest or brink) 0.31 ft. (Tailwater depth) 7.2 ft2 (Flow area in channel) 14.0 cfs (Capacity in channel) 0.00 ft. (Downstream head above weir crest, H2 = 0, if H2 < 0 715`yc) IV. Calculate the head for a trapezoidal shaped broadcrested weir Co = High Flow Hp = 1.07 ft. Area = 55.8 ft2 Vo = 0.00 fps hp„ = 0.00 ft. Qh,gh = 13.9 cfs Low Flow Hp = Area = Vo = h„ = (Coefficient of discharge for broadcrested weirs) 1.07 ft. 55.8 ft2 0.25 fps 0.00 ft. 13.9 cfs (Weir head) (Flow area in channel) (Approach velocity) (Velocity head corresponding to Hp) (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head 0.05 ft. 0.8 ft2 0.00 fps 0.00 ft 0.1 cfs 0.05 ft. 0.8 ft2 0.16 fps 0.00 ft. 0.1 cfs (Weir head) (Flow area in channel) (Approach velocity) (Velocity head corresponding to H`) (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Rock_Chute.xls Page 3 of 3 Rock Chute Design Calculations (Version WI -July -2010. Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE Designer: Dan Campbell Date: 3/28.2020 County: Weld Checked by: Date: V. Calculate the rock chute parameters (w/o a factor of safety applied) High Flow q, = 0.22 cros/m D50 (mm) = 74.85 -> (2.95 in) n = 0.037 z1_ A1= Velocity = Zmean F1 _ Lock apron = 0.43 ft. 2.6 ft2 5.34 fps 0.32 ft. 1.67 3.68 ft Low Flow qc = D5_ n= z1_ _ Velocity = zmean F1 = 0.00 cms/m 7.60 mm 0.026 0.03 ft. 0.1 ft2 1.21 fps 0.03 ft. 1.35 VI. Calculate the height of hydraulic jump height (conjugate depth) High Flow Li = gh = 0.73 ft. 13.9 cfs 5.6 ft2 (Equivalent unit discharge) (Median angular rock size) (Manning's roughness coefficient) (Normal depth in the chute) (Area associated with normal depth) (Velocity in chute slope) (Mean depth) (Froude number) (Length of rock outlet apron = 15`D&,) Low Flow z2 = 0.04 ft. (Hydraulic jump height) ()high A2 _ 0.1 cfs (Capacity in channel) 0.2 ft' (Flow area in channel) VII. Calculate the energy lost through the jump (absorbed by the rock) High Flow E1 = E2 = RE _ 0.87 ft. 0.83 ft. 4.65 Calculate Quantities for Rock Chute Rock Riprap Volume Area Calculations h = 1.07 x1 = 5.10 L = 5.46 AS = 5.46 x2 = 5.00 At, = 9.20 Ab+2'As = 20.11 ft2 Length a Rock CL Inlet = 9.98 Outlet = 6.11 Slope = 90.07 2.5:1 Lip = 1.24 Total = 107.41 ft. Rock Volume 80.00 yd3 Geotextile Quantity --- Width Length (&_ Bot. Rock 2`Slope = 21.11 Bottom = 4.20 Total = 25.31 ft, Total = 107.40 ft. Geotextile Area 302.01 yd2 Low Flow E, E2_ RE = 0.05 ft 0.05 ft. 0.99 % (1 otal energy before the jump) ( i otal energy after the jump) (Relative loss of energy) Bedding Volume Area Calculations h= 2.07 xi = 0.00 L = 10.55 As = 0.00 x2 = 0.00 Ab = 0.00 At,+2'Ati = 0.00 ft2 Bedding Thickness t1, 12 = 0.00 in. Length a Bed CL Total = 107.40 ft. Bedding Volume 0.00 yd3 Note: 1) The radius is not considered when calculating quantities of riprap, bedding, or geotextile. 2) The geotextile quantity does not include over - overlapping (18 -in. min.) or anchoring material (18 -in. min, along sides. 24 -in. min. on ends). 0+00.0 0+09.5 0+10.0 0+10.5 0+99.9 1 +05.9 1+07.2 Rock Chute Design - Plan Sheet (Version WI -July -2010. Based on Design of Rock Chutes by Robinson. Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE County: Weed Minimum Designer: Dan Campbell Checked by: Date: 3/28/2020 Date: IEnter I Design Values Plan Values 10 ft. Radius = X17 ft D,U 4.4 in Dso, dia. = 6.00 in. % Passing R« 8.8 in Fir... th,cknes:. 12.00 in DtoD 6 ft, Inlet apron length - 10 00 ft D55 6 ft. Outlet apron length = 6.00 ft, D50 Rock Gradation Envelope Diameter, in (weight. lbs.) 9-12(52-122) 8 - 11 (34 - 89) 6-9(15-52) 5-8(8-34) Will bedding be used? No Notes: a Rock, bedding, and geotextile quantities arc determined from the x -section below (neglect radius) " Geotextile Class I (non -woven) shall be overlapped and anchored (18 -in. min along sides and 24 -in. min. on the ends) Upstream Channel Slope = 0 032 ft eft Rock Chute Stakeout Notes Sta. Elev. (Pnt) 42 It (1) 42 ft. (2) 42 ft (3) 42 ft (4) 36.5 ft (5) 365h (6) 37 ft (7) Class I non -woven if"? Radius = 17 ft --"/ Geotextile Rock gradation envelope can be met Wm DOT Light nnrap Gradation Inlet apron elev. = 4 t: Rock thi ;tress = • K • 1 : • Quantities a Rock = 's`,i Yd3 Geotextile (WCS-13)° = 303 yd2 Bedding = 0 Yd3 Excavation = t1 yd3 Earthfill = 0 yd'' Seeding = 0 0 acres Degree of angularity 1 50% angular, 50% rounded 2 100 % rounded Outlet apron elev = 36 5 ft Downstream Channel SIopta _ U t ft ''t. --- h f;----r'J1 Ld= 05tt - *- 2.5 q x Uu et at)ro i Profile Along Centerline of Rock Chute "Note: The outlet will function adequately Freeboard =0.5 ft. Rock Chute Cost Estimate Unit Unit Cost Cost Rock Geotextile Bedding Excavation Earthfill Seeding $10.00/yd3 $12.001yd2 $12.00 /yd3 $12.00/yd3 $1.00 /yd3 $2.00 lac. Total $800 00 $3,636.00 $0.00 $0.00 $0.00 $0.00 $4,436.00 V ToD width = It 4 ft. Geotextile 4 Rock Chute 'N Bedding -- Rock thickness = 12 in. Sir 4.21t ' Use lip throughout chute but not less than zl Rock Chute Cross Section Profile, Cross Sections, and Quantities 4NRCS Nita COOev... L. ,., Av.,.• U IMO albeit IkH On.r,/ A,", iA.. I Miller 19-112 Pond Rundown SE Weld County Page 1 of 1 Upstream Channel Rock Chute.xls for construction plan Rock Chute Design - Cut/Paste Plan (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE Designer: Dan Campbell Date: 3/28/2020 County: VVeld Checked by: Date: Design Values D50 dia = 6.0 in. Rockchute thickness = 12.0 in. Inlet apron length = 10 ft. Outlet apron length = 6 ft. Radius = 17 ft, Will bedding be used? No Rock Gradation Envelope % Passing Diameter, in. (weight, lbs.) D103 -------- 9 - 12 (52 - 122) Das 8-11 (34 - 89) Dsu 6-9(15-52) D,o 5-8(8-34) Coefficient of Uniformity, (Der,)/(D 70) < 1.7 Quantities a Rock = 80 Geotextile (WCS-13)r' = 303 Bedding = 0 Excavation = 0 Earthfill = 0 yd3 yd2 yd3 yd3 yd3 Seeding = 0.0 acres Notes • d Rock, bedding, and geotextile quantities are determined from x -section below (neglect radius). c Geotextile Class l (Non -woven) shall be overlapped and anchored (18 -in. minimum along sides and 24 -in. minimum on the ends) --- quantity not included. C O 'V V/ Slope = 0.032 ftitt Stakeout Notes Sta. Elev. (Pnt) 0+00.0 0+09.5 0+10.0 0+ 10.5 0+99.9 14059 1+07.2 Notes: 42 ft. (1) 42 ft. (2) 42 ft. (3) 42 ft. (4) 36.5 ft. (5) 36.5 ft. (6) 37 ft. (7) Inlet apron elev. = 42 ft. 2 Inlet apron* j,; Rock thickness= 12 in. 10 ft. ---- Radius = 16.68 ft -Y Geotextile 90 ft. 1 • Point No. 2 3 4 Outlet apron elev. = 36.5 ft. 1 16.35' - - Profile Along Centerline of Rock Chute Description Point of curvature (PC) Point of intersection (PI) Point of tangency (PT) Downstream Channel Slope = 0.01 ft./ft et a•ron�� ,� t 6ft - 15 1 d- 0.5 ft • Rock Chute Bedding 4Top width _= 15 ft. Berm Geotextile Freeboard = 0.5 ft. Rock gradation envelope can be met with DOT Light nprap Gradation 1 5� • 1.07 ft. 4M 4 Rock Chute �..N Bedding Rock thickness = B'= 4.2 ft. Rock Chute Cross Section 12 in. • Use Hp throughout chute hut not less than z2. Profile, Cross Sections, and Quantities �NRCS I Miller 19-112 Pond Rundown SE Weld County Cstact J.pOwtC ,.' • , , o ',Axel pie •4n. Inlet Channel Slope = 0.02 ft 'ft. =0.11 ft. (0.02 ft.) Rock_Chute.xls Page 1 of 3 Rock Chute Design Data (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West County: Weld Designer: Dan Campbell Checked by: Mark Taylor Date: March 28, 2020 Date: 03/28/20 Input Geometry: Upstream Channel Bw = 10.0 ft. Side slopes = 20.0(m:1) Velocity n -value = 0.022 Bed slope = 0.0200 ft./ft. > Chute —> Downstream Channel Bw = 4.0 ft. Bw = 5.0 ft. Factor of safety = 1.50 (F5) 1.2 Min Side slopes = 50.0(m:1) Side slopes = 8.0 (m:1) > 2.0:1 max. velocity n -value = 0.025 Bed slope (13.9:1) = 0.072 ft./ft - ' 3.0:1 max. Bed slope = 0.0100 ft./ft Note: n value = a) velocity n from waterway program Freeboard = 0.5 ft. --o- ar b) computed mannings n for channel Outlet apron depth, d = 0 5 ft. Base flow = 2.8 cfs Design Storm Data (Table 2, FOTG, WI-NRCS Grade Stabilization Structure No. 410): Apron elev. -- Inlet =42.0 ft. Outlet 36.5 Q r„qh O5 t -- (HdrDP 5 ft.) = Runoff from design storm capacity from Table 2, FOTG Standard 410 = Runoff! from a 5-year,24-hour storm. ()high= 2.8 Qb= 0.1 cfs High flow storm through chute cfs Low flow storm through chute Note. The total required capacity is routed through the chute (principal spillway) or in combination with an auxiliary spillway. Input tallwater fTw) : > 7w (ft.) = Program -> Tw (ft.) = Program Profile and Cross Section (Output): starting Station = 0+00 0 hp = 0 f (0 ft ) Hpe r 0.37 ft. Energy Grade Line _------=_'4- Oft low 7.4 414 geo = 0.09 ft. (0.02 ft.) Hee = 0.3 ft. Hp= 037fr T ----- ___ (005ft) yc= 0.21 ft. (0.03 ft.) _ r • 40(Dx)_ 5 ft 9 Velocity,1iet = 2 01 fps radius at normal depth Critical Slope check upstream :s unstable 1 Note- When the normal depth (yn) in the inlet Geotextil channel is less than the weir head (H„), ie , the weir capacity is less than the channel capacity, restricted flow or ponding will occur. This reduces velocity and prevents erosion upstream of the inlet apron. • 0.715yc= 0.15 ft • Typical Cross Section Freeboard = 0.5 ft Y B M= Use Hr, along chute but not less than z2. N -.N(0 02 ft) . . • • Notes 1) Output given as High Flow (Low Flow) values. 2) Tailwater depth plus , must be at or above the hydraulic jump height for the chute to function. 3) Cntical depth occurs 2yc - 4y,_ upstream of crest. 4) Use WI Const. Spec 13, Class I non -woven geotextile under rock zt = 0 16 1t Hydraulic Jump Height, z2 = 0.27 ft. (0 04 ft.) (0.03 ft N • Hemp = bit. 4 13'q., -- 3 ft. --- Rock Chute 15(Dso)(F,) Bedding • Profile Along Centerline of Chute Rock Chute Bedding •Rt Tw+d = 0,72 ft, - Tw (0.67 ft.) - Tv: o.k. (1.22 ft. (0.17 ft.) 2.5 Outlet Channel Slope = 0.01 ft Hi d = 0.5 ft (1 ft minimum suggested) Veiocitycuue: = 1 55 fps at normal depth 0.56 cfs/ft Equivalent unit discharge Fs = 1.50 Factor of safety (multiplier) = 0.1C'? Normal depth in chute n -value = 0.0.14 Manning's roughness coefficient D3(F5) = 2.3 in. Minimum Design D50* 2(D50)(F5) = 4.6 in. Rock chute thickness Tw + d = 0.72 ft Tailwater above outlet apron z2 = 0.27 ft. Hydraulic jump height The outlet will function adequately High Flow Storm Information Rock_Chute.xls Page 2 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West Designer: Dan Campbell Date: 3/28/2020 I. Calculate the normal depth in the inlet channel High Flow Yn - Area = ()high = 0.11 ft. 1.4 ft2 2.8 cfs Scupstreamchannel = 0.015 ft/ft II. Calculate the critical depth in the chute High Flow yc _ Area = Qing- _ HCe _ 10y, = 0.715yC = 0.21 ft. 1.2 ft2 2.8 cfs 0.30 ft. 0.09 ft. 2.13 ft. 0.15 ft. Low Flow Yr = Area = County: Weld Checked by: Date: 0.02 ft. (Normal depth) 0.2 ft2 (Flow area in channel) gob, = 0.1 cfs (Capacity in channel) Low Flow yr = 0.03 ft. Area = 0.1 ft2 Qlow = 0.1 cfs Hce hr:,, 0.715y, _ III. Calculate the tailwater depth in the outlet channel High Flow Tw = Area Qhgh H.2 0.22 ft. 3.6 ft2 5.6 cfs 0.00 ft. 0.05 ft. 0.02 ft. 0.02 ft. Low Flow Tw = Area = Qlow H2= 0.17 ft. 2.2 ft2 2 9 cfs (Critical depth in chute) (Flow area in channel) (Capacity in channel) (Total minimum specific energy head) (Velocity head corresponding to ye) (Required inlet apron length) (Depth of flow over the weir crest or brink) (Tailwater depth) (Flow area in channel) (Capacity in channel) 0.00 ft (Downstream head above weir crest, H2 - 0, if H2 < 0.715'yc) IV. Calculate the head for a trapezoidal shaped broadcrested weir Cd = High Flow Hp = Area = Vo = hp„= ()high 0.37 6.5 0.00 0.00 2.8 Low Flow Hp = Area = V. = hp, = Q:.0w = ft ft2 fps ft. cfs 00 (Coefficient of discharge for broadcrested weirs) 0.37 ft. (Weir head) 6.4 ft2 (Flow area in channel) 0.44 fps (Approach velocity) 0.00 ft. (Velocity head corresponding to Hp) 2.8 cfs (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head 0.05 ft. 0.5 ft2 0.00 fps 0.00 ft 0.1 cfs 0.05 0.5 0.25 0.00 0.1 ft. ft2 fps ft. cfs (Weir head) (Flow area in channel) (Approach velocity) (Velocity head corresponding to Hp) (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Rock_Chute.xls Page 3 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West Designer: Dan Campbell Date: 3/28/2020 County: Weld Checked by: Date: V. Calculate the rock chute parameters (w/o a factor of safety applied) High Flow Low Flow q, D50 (mm) = n� z1 _ A1_ Velocity = Z,nean F1 Lrock apron 0.05 cros/rn 39.24 - (1.54 in.) 0.034 0.16 ft. 0 9 ft2 3.29 fps 0.13 ft. 1.61 1.93 ft. q,= D50 = 8.58 mm (Median angular rock size) n = 0.027 (Manning's roughness coefficient) z1 - 0 03 ft. (Normal depth in the chute) A, = 0.1 ft2 (Area associated with normal depth) Velocity = 1.23 fps (Velocity in chute slope) zmean = 0.02 ft (Mean depth) F1 - 1.40 (Froude number) (Length of rock outlet apron = 15*D53) 0.00 cros/m (Equivalent unit discharge) VI. Calculate the height of hydraulic jump height (conjugate depth) High Flow 22 r- °h,qh A, 0.27 ft. 2 8 cfs 1 7 ft/ Low How 22 = ()high A2 _ 0.04 ft. 0.1 cfs 02 ft2 (Hydraulic jump height) (Capacity in channel) (Flow area in channel) VII. Calculate the energy lost through the jump (absorbed by the rock) High Flow E, = 0.33 ft. E2 = 0.32 ft. RE = 3 74 % Calculate Quantities for Rock Chute Rock Riprap Volume Area Calculations Lenqth (W. Rock CL h 0.3/ 8.06 L = 2.98 A5 = 2.98 x2 = 8.00 Ab = 12 12 Ah,+2'A, = 18,09 ft2 Inlet = 9.98 Outlet = 4.11 Slope = 76.59 2.5:1 Lip = 1.24 Total = 91.93 ft. Rock Volume 61.59 yd3 Geotextile Quantity Width Length (d Bot. Rock 2'Slope - 22.09 Bottom = 4.12 Total = 26.22 ft. Total = 91.92 ft. Geotextile Area 26774 yd2 Low Flow E1 E2 RF = 0.05 ft. 0.05 ft. 0.84 % (Total energy before the jump) (Total energy after the jump) (Relative loss of energy) Bedding Volume Area Calculations h 1.31 x,=0.00 L = 11.05 As = 0.00 x2 = 0.00 Ab = 0.00 Ab+2'A% = 0.00 ft2 Bedding Thickness ti, t2 = 0.00 in. Length (@ Bed CL Total = 91.92 ft. Bedding Volume 0.00 yd3 Note. 1) The radius is not considered when calculating quantities of riprap, bedding, or geotextile. 2) The geotextile quantity does not include over - overlapping (18 -in. min.) or anchoring material (18 -in min. along sides, 24 -in. min. on ends). 0*00.0 0+09.4 0+1a a 0+10.6 0+86.4 0+90.4 n+91.6 Rock Chute Design - Plan Sheet (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West Designer: Dan Campbell Date: 3128/2020 Minimum L I Enter County: Weir, Checked by: Date: Design Values Plan Values 2.3 in. 4.6 in. 2 ft. 3 ft 5 ft D5,3 dia = Reckon thickness Inlet apron length o Outlet apron length - Rat his = 8.00 in. 12.00 in. 10ooft_ 4.00 ft. 17 ft. Rock Gradation Envelope % Passing Diameter, in. (weight, lbs.) 9 - 12 (52 - 122) 8 - 11 (34 - 89) 6-9(15-52) 5-8(8-34) Will bedding be used? No Notes: a Rock; bedding, and geotextile quantities are determined from the x -section below (neglect tadius). ° Geotextile Class I (non -woven) shall be overlapped and anchored (18 -in. min. along sides and 24-rn min on the ends). Upstream Channel Slope - 0.02 rut:. Rock Chute Stakeout Notes Sta. Elev. (Pot) 42 it. (1) 42 ft (2) 42ft (3) 42 ft (4) 36.5 ft (5) 36.5 ft (6) 37 ft (7) Class I non -woven C 0 Ct C Inlet apron elev. = 42 ft Rock Ihicknesa = 12 in. Radius = 17 ft Geotextile Rock gradation envempe can be met with DOT Light riprap Gradation • • • • • • • 1 • Quantities a Rock = 62 Yd3 Geotextile (WCS-13)° = 268 yd2 Bedding = 0 Yd3 Excavation = 0 yd3 Earthfill = 0 yd3 Seeding = 0.0 acres Degree of angularity _ 1 50% angular, 50% rounded 2 100 % rounded Outlet apron elev. _ 36 5 't fl 2.5 r Downstream Channel Slope I) 01 lit d— 0.5 ft. Profile Along Centerline of Rock Chute "Note: The outlet will function adequately Freeboard =0.5 ft. Rock Chute Cost Estimate Unit Unit Cost Cost Rock $10.00 /Yd3 $620.00 Geotextile $12.00/yd2 $3,216.00 Bedding $12.001yd3 $0.00 Excavation $12.001yd3 $0.00 Earthfill $1.00 /yd3 $0.00 Seeding $2.00 /ac. $0.00 Total $3.836.00 1 4Z4p width = 10 tr 1(1. 4 ft. Geotextile Rock Chute Bedding Rock Ihx:kness = 12 In. • Use Hp throughout chute n'=4.1ft. Rock Chute Cross Section but not less than z2. Profile, Cross Sections, and Quantities 4NRCS Plat ...,...,..(a..,..n t. Uri! a... O.rn, wiles Miller 19-112 Pond Rundown West Weld County Page loll •••a•.• Jaw , Rock Chute xls for construction plan Rock Chute Design - Cut/Paste Plan (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West Designer: Dan Campbell Date: 312872020 Design Values Rock Gradation Envelope D50 dia = 6 0 in. RockehL.e thickness = 12 0 in. Inlet apron length = 10 ft. Outlet apron length = 4 ft. Radius = 17 ft Will bedding be used? No % Passing Diameter, in. Al/eight, lbs.) DEW - 9-12(52-122) D85 — 8 - 11 (34 - 89) Dbo 6-9(15-52) D,o ------ 5-8(8-34) Coefficient of Uniformity, (D60)/(D ,o) < 1.7 County: Weld Checked by: Date: Quantities a Rock = 62 Yd3 Geotextile (WCS-13)° = 268 Yd2 Bedding = 0 yd3 Excavation = 0 yd3 Earthfill = 0 yd3 Seeding = 0.0 acres Notes . ' Rock. bedding, and geotextile quantities are determined from x -section below (neglect radius) ° Geotextile Class I (Non -woven) shall be overlapped and anchored (18 -in. minimum along sides and 24 -in. minimum on the ends) -- quantity not included . Upstream O Channel cn Slope = 0 02 ft /ft Stakeout Notes ta. Elev.IPnt) 0+00 0 42 ft. (1) 0+09 4 42 ft. (2) 0+10.0 42 ft. (3) 0+10.6 42 ft (4) 0+86.4 36.5 ft. (5) 0+90.4 36.5 ft. (6) 0+91.6 37 ft. (7) Notes: Inlet apron elev. = 42 ft Point No. Description 2 Point of curvature (PC) a Rock thwkness = 12 in. 3 Point of intersection (PI) f�lltt� 4 Point of tangency (PT) Outlet apron elev = 36 5 ft. Geotextile- Profile Along Centerline of Rock Chute 0.37 ft. DOT Light riprap Gradation 4 ft. Rock Chute Cross Section Profile, Cross Sections, and Quantities Rock gradation envelope can be met with Downstream Channel Geotextile 4iV• 4f10.Ri Su la inxl Sen Ut GYM NAM* v d ArMV. Rock thickness = 12 in. B' = 4.1 ft. * Use Hp throughout chute but not less than 12. 2019-112 Weir Wall Sizing Emergency Overflow Weir Calculations Q = CLH° City of Greeley Eq 11 4 3 A(1 C= L = Length (ft) _ H = Depth of Flow (ft) = Q= 26 23 05 21 14 CFS > From table 11-1 City of Greeley manual ,19 O6 Basin -1 Q.0= 18 04 CFS Sub -Basin E Q100 = 102 CFS Q100Total= Basin 1+Sub Basin E Q 100 Total = 18 04 + 102 (CFS) Q 300 Total = 19 06 CFS CFS "Note Basin -1 and Sub -Basin E flows are accounted for at the Overflow Weir Sub Basin D flows are not accounted for at the Overflow Weir Determination of Culvert Headwater and Outlet Protection Protect: Miller 19-112 Basin ID: Culvert Check V I } F w Z 7 — Solt Type. r Craose One IO Non-Ssno, Desi•n Infor -tion I •u : Design Descharge C ircuiar Culvert: Barrel Diameter in inches inlet Edge Type (Choose from pull -down 1st) Box Culvert: Barrel Height (Rise) .n Feet Barrel Width (Span) in Feet Inlet Edge Type (Choose from pull -dawn fist) Number of Barrels inlet Elevation Outlet Elevation Q$ Slope Culvert Length Manning's Roughness Bend Loss Coefficient Exit :.ors Coefficient l atiwater Surface Elevation Max Allowable Chorine Velocity O= I n �•j SQUMO End WgM'on Height (Rise) -� Width (Sean) - No , Llev IN - Elev OUT - n= kp= k, - Elev Y, V- OR 1 4638 4637 123 0013 hi I 5/ cfs rches h ft ft ft ft ft fVs Required Protection (Output): I ailwnter Surface Height Flow Area al Max Channel Ve outy Culvert Cross Sectional Area Available Entrance Loss Coefficient Friction Loss Coefficient Sum of AI Losses Coefficients Culvert Normal Depth Culvert Critical Depth Tailwater Depth for Design Artusted Diameter QR Adjusted Rise Expansion Factor Flow/Dtameterl5 Qft Flow/(Span ' Rise'') Froude Number Tailwater/Adru stud Diameter QR Tailwater/Adjusted Rise net Control Headwater Outlet Control I leadwater Design Headwater Elevation Headwater/Dlarneter Qfl Headwater/Rise Ratio Minimum Thoaretical Riprap Size Nominal Riprap Size UDFCD Riprap Type Length of Protection Width of Protection "I A, _ A= n k, Y - Y, - d= D•= 1/(2'tan(0)) O/D"2.5 = Fr = YUD= HW, HWo= HW-. HWID = Type LP T= 0-6C 1.58 1 77 0.50 2.23 3.73 1 16 1.16 1 33 4 18 3.27 0.99 0 40 206 83 4,840.06 1.37 4 8 VL S 3 ft If ft ft f1 ft ft ft fe .7s ft ft m in ft ft URBAN DRAINAGE AND FLOOD CONTROL DISTRICT Paul A. Hindman Executive Director 2480 W 26th Avenue Suite 156B Denver CO 80211 5304 MEMORANDUM FROM Ken MacKenzie, P C Master Planning Program Manager Telephone 303 455 8277 Fax 303 455-7880 www udlcd org SUBJECT New Colorado Revised Statute §37-92-602 (8) "Concerning a Determination that Water Detention Facilities Designed to Mitigate the Adverse Effects of Storm Water Runoff Do Not Materially Injure Water Rights DATE March 9, 2016 (Original July 7, 2015) Senate Bill 15-212 was signed into law by Governor Hickenlooper in May 2015 and became effective on August 5, 2015 as Colorado Revised Statute (CRS) §37-92-602 (8) This statute provides legal protection for any regional or individual site stormwater detention and infiltration facility in Colorado, provided the facility meets the following criteria 1 It is owned or operated by a governmental entity or is subject to oversight by a governmental entity (e g required under an MS4 permit) 2 It continuously releases or infiltrates at least 97% of all of the runoff from a rainfall event that is less than or equal to a 5 -year storm within 72 hours after the end of the event 3 It continuously releases or infiltrates as quickly as practicable, but in all cases releases or infiltrates at least 99% of the runoff within 120 hours after the end of events greater than a 5 -year storm 4 it operates passively and does not subject the stormwater runoff to any active treatment process (e g , coagulation, flocculation, disinfection, etc ) 5 If it is in the Fountain Creek (tributary to the Arkansas River) watershed it must be required by or operated in compliance with an MS4 permit The statute specifies that runoff treated in stonnwater detention and infiltration facilities shall not be used for any other purpose by the owner/operator/overseer (or that entity's assignees), shall not be released for subsequent diversion or storage by the owner/operator/overseer (or that entity's assignees), and shall not be the basis for a water right or credit plan\kenlCRS 37 92 6028) memo update 20)51015 There are specific notification requirements that apply to all new stormwater detention and infiltration facilities, including individual site facilities built by pnvate parties as a development requirement For any stormwater detention and infiltration facility constructed after August 5, 2015 and seeking protection under the new statute, the "entity that owns, operates, or has oversight for" shall, prior to operation of the facility, provide notice to all parties on the substitute water supply plan notification email list maintained by the State Engineer This notice must include the following I The location 2 The approximate surface area at design volume 3 Data that demonstrate that the facility has been designed to comply with the release rates described in Items 2 and 3 above 1 he Colorado Division of Water Resources (DWR) maintains seven email lists, one for each of the seven major watersheds in Colorado (these coincide with the seven DWR Divisions) UDFCD worked with DWR and the Colorado Stormwater Council to develop a simple data sheet and an online map -based compliance portal website that will allow all municipalities and counties in Colorado to easily upload this required notification information The website application will then automatically send email notifications to the proper recipients, relieving public works staff of the emailing burden while also minimizing the volume of email going out to the email list recipients Please note that the notification requirement applies only to new stormwater facilities (constructed after August 5, 2015), which the statute provides a 'rebuttable presumption' of non - injury to water rights This rebuttable presumption is contestable but only by comparison to the runoff that would have been generated from the undeveloped land condition prior to the development necessitating the stormwater facility Stormwater facilities in existence before August 5, 2015 are defined in the statute as materially non -injurious to water rights and do not require notification Additionally, the State issued a memorandum on February 11, 2016 indicating that construction BMPs and non -retention BMPs do not require notice pursuant to SB-212 and are allowed at the discretion of the Division Engineer, and that green roofs are allowable as Jong as they intercept only precipitation that falls within the perimeter of the vegetated area and do not intercept or consume concentrated flow nor store water below the root zone The DWR Statement can be found here http //water state co us/DWRIPub/Documents/DWR%20Storm%20Water%20Statement pdf The compliance portal can be found here https //maperture dieitaldataservices com/gvh/?viewer=cswdif A tutorial YouTube video can also be accessed from that website or found here UDFCD YouTube Video planikenICRS 37 92-602(5) memo update 20151015 We also have a list of frequently asked questions with answers which is attached to this memorandum Please email me at kmackenzie(atudfcd org with any questions pinnkkenlCRS 37 92603(8) memo update 70151015 Frequently Asked Questions related to Colorado Revised Statute 37-92-602(8) Statute Related Questions Where can I find out more information on the statute? A memorandum can be found at http //udfcd ore/guidance-documents Does this statute apply only to facilities within MS4s or government owned facilities? Would a private facility located In a rural area need to be uploaded? The statute protects only those stormwater detention and infiltration facilities that are operated solely for stormwater management and are owned or operated by a governmental entity or are subject to oversight by a governmental entity (e g , required under other statutes for flood protection or water quality) Additionally, to be covered, these facilities must meet the drain time limitations and other criteria specified in the statute and UDFCD memorandum if a hypothetical private facility located in a rural area was voluntarily built (not as an imposed development requirement), it is not protected under the statute and no notification is required, but it may be considered a water diversion out of priority by the State How do these new regulations apply to micropool designs since they typically will exceed the 120 hour release time period? The volume of the micropool is typically 0 0006 times the 5 year Inflow volume (0 06%) and 0 0002 times the 100 year Inflow volume (0 02%), which is well within the allowable criteria The statute says 'no other beneficial use" is allowed Define "beneficial " As a municipal corporation, detention is beneficial to reduce pipe sizes Beneficial use refers to uses for which you would otherwise need a water right, like replacement water or irrigation water Why is Fountain Creek excluded from legislation and what are the requirements to build a detention basin in the Fountain Creek watershed? Facilities in Fountain Creek that meet the other criteria specified in the statute are protected only if they are required by or operated in compliance with a Colorado Issued MS4 permit Those facilities in the Fountain Creek watershed that do not meet this criterion are more susceptible to a claim of water right injury, but they do not otherwise require a water right The exclusion of the Fountain Creek watershed was a necessary concession in order to get the backing of the Colorado Farm Bureau Will existing facilities need to be retrofitted to meet the 72/120 hour drain time requirement? if your existing facility meets the drain time criteria specified In the statute, then the facility meets the compliance criteria if your existing facility Is a retention pond and you don't have a water right, then yes, you should retrofit (or get a water right) CSR 37 92 607(6( FAQ UDFCD 2015-06 26 How should retention facilities be handled? Neither retention facilities nor constructed wetlands are protected under 37 92 602(8) CRS These facilities expressly require a water right Does the bill require that operation and maintenance demonstrate on going compliance? What happens if a facility does not function as designed (e g, lack of maintenance, poor infiltration)? The statute protects only those facilities that meet the drain time criteria If a facility does not operate as designed, or if the design proves to be flawed, not only is it not protected under 37 92 602(8) CRS, it also likely violates a CDPS issued permit and corrective measures are responsibly warranted What about regional facilities that are designed for a future condition but operate in an interim mode that does not comply with the statute? Those constructed after August 5, 2015 should be designed to comply with the statute in their interim condition as well as in the final configuration If they do not comply, they will not be protected under the statute, and no notification is required Those already in operation on August 5, 2015 do not require notification, but are not protected unless they comply with the drain time criteria Are facilities designed to protect areas less than one acre subject to this legislation? Yes There is no size threshold for the notification requirement All stormwater detention and infiltration facilities that meet the definition in the statute and are made operable after August 5, 2015 are subject to the statute Could a water rights holder contest a facility even without any real basis just to tie up a development or make it more difficult to develop a property? What ability do irrigation companies, farmers, etc have to Impact a project when these notices go out? The water rights holder must show that the facility has caused injury (not will cause injury) The injury must be further with respect to the water the complainant would have received in the watershed condition that existed as of the water right's pnority date absent the urbanization necessitating the facility in the case of redevelopment is the calculation from the existing developed condition to the proposed developed condition or from the assumed "predeveloped condition' Any challenge must be with respect to the water the plaintiff would have received in the watershed condition that existed as of the water right's priority date, absent the urbanization necessitating the facility CSR 37 92-602181 FAQ UDFCD 2015 08 26 What liability and/or responsibility does a contractor have while working on a stormwater detention facility that the responsible party (government entity operator design engineer, etc ) failed to comply with the notification requirements? If the facility Is designed to drain in the time specified In the statute and proper notification is made, a claim of injury is not likely, since the claim must be in comparison to the water available before any of the land development that necessitated the detention in the first place Statute does not apply to the following Flow through devices (e g, media filter drains, hydrodynamic separators, baffle vaults without storage) o Process water holding ponds for the oil and gas industry o Stock ponds and irrigation ponds o Construction BMPs (e g , sediment traps, etc ) o Any facility not meeting the following criteria o is owned or operated by a governmental entity or is subject to oversight by a governmental entity, o continuously releases or infiltrates at least 97% of the 5 year storm within 72 hours, o continuously releases or Infiltrates at least 99% of the 100 -year storm within 120 hours, o operates passively and does not subject the stormwater runoff to any active treatment process CSR 37 92 602(8) FAQ UDFCD 2015 08 26 Procedure and Compliance Workbook Related Questions Is the SDI workbook required or can a different PDF documenting drain times be uploaded? (e g, UD Detention) The user can upload any PDF that provides data that demonstrates compliance (i e , drain times) UD Detention would be adequate as it also calculates drain times for various events In the design data spreadsheet do we use the 60 minute 1 year storm value (at basin location) for the WQCV design storm? Is the water quality capture volume drainage time a maximum or minimum of 40 hours? The Urban Storm Drainage Criteria Manual Vol 3, Chap 3 (http //www udfcd org/index html) gives detailed information on sizing the water quality capture volume anywhere in Colorado and guidance on recommended drain times (e g 40 hours for extended detention, 12 hours for rain gardens) Can we route our own inflow hydrographs through the spreadsheet to show compliance? Yes, there is a table to the right of the printable area that allows you to input your own storm hydrographs In fact, this will be necessary for unusually large watersheds as the largest embedded Inflow storm hydrograph in the workbook is 675 56 acre feet in volume (the smallest Is 0 001 acre feet) The workbook has been tested successfully for watersheds as small as 01 acres in area Define an operational' detention facility A detention facility is operational when stormwater is flowing into it and flowing out of it (either on the surface or infiltrating into the soil below it), while experiencing a change in the detained volume over time (first increasing in volume and then decreasing) Does the design engineer upload the notification or does the government entity with jurisdiction (MS4) upload it? Would it be the City or the property owner? Anyone can upload a site Local Jurisdictions have administrative privileges to create, modify, accept, or delete any record within their Jurisdiction This is to allow those jurisdictions to monitor for errant activity Those with administrative privileges will also receive an email immediately whenever a record is created or modified within their jurisdiction What is the recourse or plan of action against the detention facility owner If they do not comply with the notification compliance? If the facility is designed to drain in the time specified in the statute and proper notification is made, a claim of injury is not likely, since the claim must be in comparison to the water available before any of the land development that necessitated the detention in the first place After notification, if a downstream water right user objects, what then? The downstream user can't object to a facility before It is operable but they can rebut the presumption of non injury if they can prove they have been (not will be) injured after the facility is in place (and only then in respect to water they would have received at their priority date) C55 57 92 602(8) FAD UDFCD 2015 08 26 What type of feedback do you expect to get from the people receiving a notification? Each record created will have two email addresses, one for the record creator and one for the community having jurisdiction over the site You may anticipate inquiries as to the need for the facility and details about how It operates Would it be acceptable to notify at the time of plan approval and prior to construction? Yes, as long as notification occurs before the facility becomes operable, you are in compliance with the statute We often use future detention basins as temporary sedimentation basins during construction When do we provide notification? Construction sedimentation basins should not be uploaded the portal If you are using the facility Ina modified and temporary form during construction, wait until the final detention configuration is complete before entering the record CSR 37 92 602181 FAQ UDFCD 2015-08 26 Portal & Notification (Noted The compliance portal is located at httns //maperture dinitaldataservlces com/Rvh/?viewer=cswdif The compliance portal was developed to streamline the notification requirement of the new statute Anyone can place a pin on the map to create a new stormwater detention/infiltration facility The portal recognizes counties, cities, and towns as "Jurisdictions" and has assigned to each Jurisdiction administrative privileges Jurisdictions can create, modify, or delete any record within their own jurisdiction, and must accept into the database a record created by anyone else within their Jurisdiction When a jurisdiction creates a new record it is automatically accepted into the database and its information is put into the queue for the email notification The icon on the map interface will be blue When anyone who is not a Jurisdiction creates a new record in the portal database the icon will remain green and no notification will go out until the jurisdiction accepts the record into the database which will turn the icon blue and place it in the queue for notification The entity creating a record will be able to later edit that record using the edit password emailed to them by the portal The password is specific to the record Note that the jurisdiction accepting the record does not indicate approval of the facility it is simply a necessary database quality assurance measure to prevent vandalism and errant records If the jurisdiction believes the record to be In this class, they may delete the record or contact the creator of the record to verify it If a record Is not accepted or deleted by the Jurisdiction with 30 days of its creation, it will automatically be accepted by the system, turn blue, and notifications will go out within a week of that event Records are perpetually viewable by those with administrative privileges but are removed from the map 30 days after being accepted into the database Portal & Notification Related Questions If you have multiple facilities in series is it appropriate to upload each separately? For example, four water quality rain gardens in a parking lot drain to a downstream flood control facility How If the facilities are Intended for water quality only, they do not require notification (with the exception of extended detention basins) An extended detention basin designed to treat only the water quality capture volume followed by a flood control facility can be entered as two separate facilities or one facility accommodating for the effective stage/storage and drain times of the two facilities in the stated example, only the downstream flood control facility need be uploaded If there are multiple flood control facilities in series, appropriate drain CSR 37 92 602181 FAQ UDFCD 2315-08 26 many facilities should be uploaded to the site? times should be demonstrated UDFCD recommends documentation outside of the compliance portal workbook for this purpose, (e g, attach SWMM output) Does notification need to take place for modifications to existing detention facilities already in the portal? If the facility is already operable on August 5, 2015, it is defined in the statute as non injurious to water rights, provided it meets the other drain time criteria specified in the statute if your modifications are going to make the downstream water rights holders condition better (e g, smaller stored volume or faster drain time), then no notification is required if the opposite is true, handle it as a new facility and provide notification of the new configuration Are State agencies and RTD to be given usernames and passwords? Those agencies will be treated in the same manner as jurisdictions, and will have editorial privileges necessary to create, modify, and delete only their own records The cities, towns, and counties of Colorado will have administrative privileges to create, modify or delete any record within their jurisdiction Who will be auditing the statewide notification compliance portal for correct data? There is no statutory enforcement mechanism Those communities having administrative privileges will receive an email notice every time a record is created, edited, or deleted within their jurisdiction and should review these records for accuracy The DWR does react to complaints If the community uploads the data for the developers, does it appear that the community is the owner? Each record will have two contact email addresses as part of the public record, one for the engineer of record and one for the community having jurisdiction over the facility Why do I have to print a pdf to upload, and not Just upload my spreadsheet? Can't this feature be built into the portal? For reasons of consistency and storage limitations the design data sheet can only be In pdf format This also minimizes the risk of document altering by others Where is the compliance portal? https //maperture digitaldataservices com/gvh/?viewer=cswdlf What resources are available to help navigate the compliance portal? A webinar recording is available at UDFCD YouTube Video Do existing facilities need to be entered? No, if the facility was operable on August 5, 2015, notification is not required These facilities are defined in the statute as non -injurious to water rights, provided they meet the other criteria specified in the statute How will interested parties be notified of newly uploaded facilities? CSR 37 92 602(8) FAQ UDFCO 2015-08-26 A weekly digest email will be sent out to the recipients in each of the DWR's seven divisions Each division will receive an email on a different day of the week to minimize traffic loading on the compliance portal Only those posted since the previous email will be included Additionally, those facilities in existence for more than 90 days will no longer be visible to the general audience, only to those with editorial or administrative privileges This is to reduce clutter on the portal and ease navigation for the end user Is there a backup of the site's data somewhere? The site has robust security features and automatic backups are produced and stored offsite at regular frequent time intervals If a detention facility is below grade, is that apparent to users of the portal? Is water surface area needed? The statute applies to facilities above and below grade, and there is no requirement to distinguish which type the facility is The water surface at design volume is one of three pieces of information mandated under the statute's notification requirement Do not enter zero for this value, instead enter the area of the vault Do we need to input an address, a latitude and longitude, what are the criteria to place a facility in the portal correctly? The map feature offers a number of ways to zoom to the correct location, including "zoom to address' and "zoom to map " Any of these methods should enable you to place a marker within 100 feet of the exact location This meets the Intent of the notification requirement Once you place the pin, the latitude, longitude, DWR division, and local Jurisdiction will all be automatically populated In the database How do you prevent duplicate entries? What if two separate entitles report compliance for the same facility The map interface feature should eliminate this problem When placing a marker Icon, If there Is already a marker icon at your location, click on that icon to retrieve the specific data for comparison The local government will receive an email notice immediately when a new record is created within their jurisdiction What types of facilities require notification per SB-212? Water Quality Only Flood Control Included BMPs Grass Buffers Not Required Not Required Grass Swales Not Required Not Required Bioretentlon (with or without an underdrain) Not Required Required Green Roof Not Required N/A Extended Detention Basin Required Required Sand Filter Not Required Required Permeable Pavement Systems Not Required Required Media Filter Drain Not Required Not Required Underground Detention Vaults Required Required Constructed Wetland Pond N/A, SUBJECT TO WATER RIGHTS Constructed Wetland Channel N/A, SUBJECT TO WATER RIGHTS CSR 37 92 602(8) FAQ UDFCD 2015 08 26 Retention Pond N/A, SUBJECT TO WATER RIGHTS CSR 37 92 602(8) FAQ UDFCD 2015-08 26 COLORADO Department of Public Health 8 Environment Dedicated to protecting and Improving the health and an ,ronment of the people of Colorado STORM WATER FACT SHEET — CONSTRUCTION Contents A Introduction 1 B Obtaining Regulatory Coverage 2 1 Do you need a Permit? 2 a Applying for a Permit 3 b Options Small Construction Sites 3 i Qualifying Local Programs 3 11 R Factor Waiver 3 2 Who May Apply' 4 C Permit Requirements 4 D Local Stormwater Requirements 5 E Amending Your Permit Certification 5 F Ending Your Permit Coverage 6 G Multiple Owner/Developer Sites 7 1 Permit Coverage 7 2 Permit Compliance 8 H Sale of Residence to Homeowners 10 I Construction Dewatenng 10 J Concrete Washout 10 A INTRODUCTION Look for this symbol throughout this guide for brief summanes of the most important information you need to know about stormwater permitting for construction activities Then read further if you want more details In 1992, the State of Colorado stormwater regulation went into effect to control municipal and industnal stormwater discharges, based on EPA regulations The regulation is meant to reduce the amount of pollutants entenng streams, rivers, lakes, and wetlands as a result of runoff from residential, commercial and industnal areas The State regulation (5 CCR 1002 61) covers discharges from specific types of industries including construction sites, and storm sewer systems for certain municipalities In Colorado, the program is under the Colorado Department of Public Health Et Environment, Water Quality Control Division (the Division) The Colorado program is referred to as the Colorado Discharge Permit System (CDPS), and regulated stormwater discharges from construction activities are covered under the CDPS General Permit for Stormwater Discharges Associated with Construction Activities (the Stormwater Construction Permit) Construction activities produce many different kinds of pollutants which may cause stormwater contamination problems The main pollutant of concern at construction sites is sediment Grading activities remove grass, rocks, pavement and other protective ground covers, resulting in the exposure of underlying soil to the elements The soil is then easily picked up by wind and/or washed away by rain or snowmelt Sediment runoff rates from construction sites are typically 10 to 20 times greater than those from agricultural lands, and 1,000 to 2,000 times greater than those from forest lands During a short penod of time, construction activity can contnbute more sediment to streams than would normally be deposited over several decades, causing physical, chemical, and biological harm to our State's waters The added sediment chokes the river channel and covers the areas where fish spawn and plants grow Excess sediment can cause a number of other problems for water bodies, such as Increased difficulty in filtering drinking water, and clouding the waters, which can kill plants growing in the river and suffocate fish A number of pollutants, such as nutrients, are absorbed onto sediment particles and also are a source of pollution associated with sediment discharged from construction sites Page 1 of 1O Revised 7 2O15 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 vowcolorado gov/cdphe Caueurr r1/ John W Hlckenlooper Governor I Larry Wolk MD, MSPH Executive Director and Chief Medical Officer O � In addition, construction activities often require the use of toxic or hazardous materials such as fuel, fertilizers, pesticides and herbicides, and building materials such as asphalt, sealants and concrete, which may also pollute stormwater These materials can be harmful to humans, plants and aquatic life This Fact Sheet provides general guidance for compliance with the CDPS permitting requirements for stormwater discharges from construction activities The Division reserves the right to interpret the permitting requirements on a case by case basis, as necessary B OBTAINING REGULATORY COVERAGE FOR CONSTRUCTION SITES A You must obtain permit coverage (or an R -Factor waiver) to discharge stormwater from any construction activity that disturbs at least 1 acre of land (or is part of a larger common plan of development or sale that will disturb at least 1 acre) The owner or operator must apply for coverage under the Stormwater Construction Permit at least 10 days prior to the start of construction activities The application Is available from the Division's web page 1) Do you need to obtain coverage under the Stormwater Construction Permit? Construction Sites that disturb one acre or greater, or are part of a larger common plan of development disturbing one acre or greater, are covered under Colorado's stormwater permitting requirements Generally, permit coverage is required, as discussed in Part B 1 a below However, additional options may exist if your project or plan of development will disturb less than 5 acres (Small Construction Site), as discussed in Part B 1 b, below If permit coverage is required, or a waiver applied for, it must be maintained until the site is finally stabilized Is it part of a larger common plan of development or sale, "A common plan of development or sale" is a site where multiple separate and distinct construction activities may be taking place at different times on different schedules Examples include 1) phased projects and projects with multiple filings or lots, even if the separate phases or filings/lots will be constructed under separate contracts or by separate owners (e g , a project where developed lots are sold to separate builders), 2) a development plan that may be phased over multiple years, but is still under a consistent plan for long term development, and 3) projects in a contiguous area that may be unrelated but still under the same contract, such as construction of a building extension and a new parking lot at the same facility If the project is part of a common plan of development or sale, the disturbed area of the entire plan must be used in determining permit requirements Disturbance associated with utilities, pipelines, or roads that are constructed for the purpose of serving a facility, are considered together with that facility to be part of a common plan of development However, adjacent construction of trunk lines or roads that are part of a regional network and not directly associated with the facility construction, are not usually considered to be part of the common plan for that facility Note that permit coverage or an R Factor waiver is still required for each individual project (facility or adjacent construction activity) that disturbs one or more acres What is the total estimated area of disturbance? The area of disturbance is the total area at the site where any construction activity is expected to result in disturbance of the ground surface This includes any activity that could increase the rate of erosion, including, but not limited to, cleanng, grading, excavation, and demolition activities, installation of new or improved haul roads and access roads, staging areas, heavy vehicle traffic areas, stockpiling of fill materials, and borrow areas Construction does not include routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of the facility "Finally Stabilized" means that all ground surface disturbing activities at the site have been completed, and all disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed Re seeding alone does not qualify Page 2 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 worm colorado govlcdphe John W Hickenlooper Governor I Larry Wolk, MD MSPH, Executive Director and Chief Medical Officer What are the requirements for recommencing construction activities at a later date at a site that has been completely stabilized and the permit terminated? If a common plan of development is completely stabilized such that the entire common plan of development meets the definition of finally stabilized and permit coverage for that common plan of development has been terminated (the permittee has submitted a notice of termination to the division and the division has confirmed that the certification has been inactivated), then a new determination of 'common plan of development' shall be made for any future construction activities conducted by a different owner(s)/developer(s) that occur within the previously permitted area to determine if permit coverage is needed However, if the original owner/developer of a common plan of development, that achieved final stabilization and terminated permit coverage, is the one who is restarting construction activities within that development, then any construction activity they are engaged in would be considered part of the original larger common plan of development and therefore require permit coverage if one acre or greater Note that if the site has never been finally stabilized, then this does not apply as the original development is considered ongoing a) Applying for a permit Application for coverage under the Stormwater Construction Permit must be made at least 10 days pnor to the start of construction activities, unless the site is a Small Construction Site that qualifies for an alternative option discussed in B 1 b, below An application, which includes guidance on developing a Stormwater Management Plan (SWMP), is available from the Division The SWMP must be completed prior to application See Section C, "Permit Requirements,' for further information If your application is complete, it will be processed and your permit certification mailed to you The Stormwater Construction Permit certification must be inactivated once the site has been finally stabilized, in order to end permit coverage and billing An inactivation form is supplied with the permit certification b) Additional Options for Small Construction Sites (at least 1 acre, but less than 5 acres of disturbance) The following options may apply to Small Construction Sites that disturb less than 5 acres, and are not part of a larger common plan of development exceeding 5 acres (Regardless of which option applies at the State level, all local requirements must still be met as discussed in Section D, below ) The options discussed under Parts b i and b ti below are not available for Large Construction Sites i) Obtain coverage under a State -designated Qualifying Local Program (For Small Construction Sites Only) The Division may designate a local municipality's stormwater quality control program as a Qualifying Local Program This means that the local program's requirements are at least as stnngent as the State permit In this case, it is not required for the owner or operator to apply for permit coverage under the Stormwater Construction Permit The local municipality will be responsible for notifying you that you do not need to apply for State coverage, if this is an option You can also view a list of the few municipalities with Qualifying Local Programs at the Division's web page (see first page for web address) The local program must have been formally designated by the Division to qualify Most municipalities have some type of local program and may require permits and fees However, simply having a local program in place does not necessanly mean that it is a qualifying program and that the Division's Stormwater Construction Permit application is not required The current designated Qualifying Local Programs in Colorado are the Cities of Durango, Golden, and Lakewood ii) Apply for coverage under the R -Factor Waiver (Available for Small Construction Sites only) The R Factor waiver allows a site owner or operator to apply for a waiver from coverage under the Division's Stormwater Construction Permit, if the R Factor, calculated using the State approved method, is less than 5 during the penod of construction The R Factor is a way to measure erosion potential based on the length of the project and time of year An application with instructions for using the State approved method is available from the Division's web page (see first page for web address) In general, the only projects that will qualify for the waiver are projects that are completely stabilized within a month or two after the start of construction That means that projects relying on seeding for revegetation will usually not qualify for the waiver, because the vegetation must be established before the Page 3 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 www Colorado gov/cdphe I John W Hickenlooper Governor I Larry Wolk MD MSPH, Executive Director and Chief Medical Officer iJi"^ Chi C Cn site is considered stabilized During the spring and summer months, when Colorado experiences the bulk of its rainfall, many projects will not qualify at all for the waiver In addition, the Division will not grant waivers for construction sites located in areas where snow cover exists at, or up gradient of, the site for extended periods of time, if the construction site will potentially remain active and unstabilized during spring runoff This waiver does not relieve the operator or owner from complying with the requirements of local agencies, such as meeting local stormwater quality requirements, including those required by a Qualifying Local Program as discussed in Section B 1 b i, above 2) Who may apply for permit coverage? The Permit applicant must be a legal entity that meets the definition of the owner and/or operator of the construction site, in order for this application to legally cover the activities occurring at the site The applicant must have day to day supervision and control over activities at the site and implementation of the SWMP Although it is acceptable for the applicant to meet this requirement through the actions of a contractor, as discussed in the examples below, the applicant remains liable for violations resulting from the actions of their contractor and/or subcontractors Examples of acceptable applicants include Owner or Developer An owner or developer who is operating as the site manager or otherwise has supervision and control over the site, either directly or through a contract with an entity such as those listed below General Contractor or Subcontractor A contractor with contractual responsibility and operational control (including SWMP implementation) to address the impacts construction activities may have on stormwater quality Other Designated Agents/Contractors Other agents, such as a consultant acting as construction manager under contract with the owner or developer, with contractual responsibility and operational control (including SWMP implementation) to address the impacts construction activities may have on stormwater quality An entity conducting construction activities at a site may be held liable for operating without the necessary permit coverage if the site does not have a permit certification in place that is issued to an owner and/or operator For example, if a site (or portion of a site) is sold or the contractor conducting construction activities changes, the site's permit certification may end up being held by a permittee (e g , the previous owner or contractor) who is no longer the current owner and/or operator In this case, the existing permit certification will no longer cover the new operator's activities, and a new certification must be issued, or the current certification transferred See Section F, below, for additional guidance on scenarios with multiple owners and/or operators Utilities, Other Subcontractors, etc A separate permit certification is not needed for subcontractors, such as utility service line installers, where the permittee or their contractor is identified as having the operational control to address any impacts the subcontractor's activities may have on stormwater quality Although separate permit coverage may not be needed in some cases, these entities are not exempt from the stormwater regulations for all of their projects and may still be held liable if their activities result in the discharge of pollutants Leases When dealing with leased land or facilities, the lessee shall be considered the "owner" for the purposes of stormwater permitting if they are responsible for the activities occurnng at the site C PERMIT REQUIREMENTS The pnmary requirement of the Stormwater Construction Permit is the development and Implementation of a Stormwater Management Plan (SWMP) The permit application includes guidance that must be followed for development and implementation of the SWMP Permit requirements are the same for both Small and Large Construction Sites The Stormwater Construction Permit requires dischargers to control and eliminate the sources of pollutants in stormwater through the development and implementation of a Stormwater Management Plan (SWMP) The purpose of a SWMP is to identify possible pollutant sources that may contnbute pollutants to stormwater, and identify Best Management Practices (BMPs) that, when implemented, will reduce or eliminate any possible water quality impacts For construction activities, the most common pollutant source m sediment Other pollutant sources include fuels, fueling practices and chemicals/materials stored on site, concrete washout, etc BMPs encompass a wide range of practices, both structural and non structural in nature, and may include silt fence, sediment ponds, vehicle tracking Page 4 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 www coloredo gov/cdphe John W Hickenlooper Governor I Larry Wolk MD MSPH, Executive Director and Chief Medical Officer Al tj controls, good housekeeping, inspection and maintenance schedules, training, etc The SWMP is not submitted with the permit application unless requested An up to date copy of the SWMP must be kept on site, for use by the operator, and so that Division, EPA, or local inspectors can review it during an inspection If an office location 1s not available at the site, the SWMP must be managed so that it is available at the site when construction activities are occurring (e g , by keeping the SWMP in a supenntendent's vehicle ) Further information concerning the contents of the SWMP can be found in Appendix A of the application, "Preparing a Stormwater Management Plan " This document and others can be obtained from the Division's web site or by contacting the Division (see first page for address information) D LOCAL STORMWATER REQUIREMENTS FOR CONSTRUCTION Where local requirements exist for stormwater management, an owner/operator must comply with both the Division's and the local agency's requirements In addition to the requirement to obtain and comply with the Division's Stormwater Construction Permit, it is possible that additional government agencies (I e , cities, counties, and special districts) may impose local requirements to control the discharge of pollutants from construction activities An owner or operator of a construction activity must comply with the Stormwater Construction Permit requirements discussed in this Fact Sheet, even if they are also covered by a local program's requirements (However, in the case of a Qualifying Local Program, as discussed in Section B 1 b ii, some administrative requirements for the Stormwater Construction Permit may be simplified ) Likewise, the Stormwater Construction Permit does not pre empt or supersede the authority of local agencies to prohibit, restrict, or control discharges of stormwater Where a local program places additional restrictions on stormwater management at a construction site within its jurisdiction, the owner/operator must comply with those stricter requirements in addition to the Division's permitting requirements For example, although the Division allows several options for permitting at multiple owner/operator sites, a local authority may restnct these options and require specific procedures to be followed for who maintains permit coverage and authority for stormwater discharges MS4 Permits Many cities, counties, and special districts are covered by a Municipal Separate Storm Sewer System (MS4) permit These permits require the governmental entity to implement venous programs to improve stormwater quality in their junsdiction Included in these permits is the requirement to implement a program to manage the discharge of pollutants from construction sites within their junsdiction Therefore, if a construction site located within the jurisdiction of one of these government entities does not properly manage stormwater at that site, the government entity may be in violation of their permit in addition to the construction site owner and operator E AMENDING YOUR PERMIT CERTIFICATION This section is only applicable if the limited information on the construction project submitted in the two - page application form changes In such case, it may be necessary to provide the Division with revised information If the information provided by the permittee in their two page application form is no longer accurate, the permittee must provide the revised information to the Division This includes such items as the planned total disturbed acreage, and the project legal descnption or map originally submitted with the application (Note it is not necessary to revise the anticipated final stabilization date, since the information provided was only an estimate) To revise this information, provide a letter to the Division's Stormwater Program (see the contact information on page 1) that includes the revised information The Division will not respond to this letter, so you are advised to obtain delivery confirmation from your postal service to confirm receipt When the Stormwater Management Plan is revised, as required by the Stormwater Construction Permit, it is not necessary to notify the Water Quality Control Division When BMPs or other site details discussed in the SWMP are modified, the SWMP must be updated to accurately reflect the actual field conditions Examples include, but are not Page 5 of 10 Revised 7 2015 4300 Cherry Creek Dnve S Denver CO 80246 1530 P 303 692 2000 www coloredo Bow/cdphe John W Hickenlooper Governor I Larry Wolk MD MSPH Executive Director and Chief Medical Officer "Cu , LCO limited to, removal of BMPs, addition of BMPs, modification of BMP design specifications, and changes in items included in the site map and/or descnption However, this information Is not submitted to the Division, unless requested F ENDING YOUR PERMIT COVERAGE _b A Stormwater Construction Permit certification remains active until inactivatedor transferred or reassigned to a new responsible party Forms for inactivation, transfer or reassignment of a permit certification can be obtained from the Division's web site or by contacting the Division (see first page for address information) 1) Inactivation notice Permit coverage for a site that has been finally stabilized in accordance with the 5WMP (see definition in Section B 1, above), may be inactivated by submitting a completed Inactivation Notice form This form contains a certification statement that must be signed in accordance with the General Requirements of the permit Also, the permittee may inactivate permit coverage at sites where all areas have been removed from their permit coverage, by one or more of the methods below reassignment of permit coverage (see Section F 3), sale to homeowner(s) (see Section H), and/or amendment by the permittee, as discussed in Section E, above for areas where permit coverage has been obtained by a new operator (see Part G 1, below) or the area is returned to agricultural use (see the Division's Oil and Gas Construction Fact Sheet) In these cases the permittee would no longer have any land covered under their permit certification, and therefore there would be no areas remaining to finally stabilize Submittal of an Inactivation Notice is still required and must discuss how the above conditions have been met 2) Transfer of permit Permit coverage for a construction site may be transferred to a new entity when responsibility for stormwater discharges at the site changes from the permittee to the new entity To transfer permit coverage, the permittee must submit a completed Notice of Transfer and Acceptance of Terms form that is signed in accordance with the General Requirements of the permit If the new entity will not complete their portion of the transfer form, the permit certification may be inactivated if the permittee has no legal responsibility for the construction activities at the site, requests inactivation in wntten correspondence to the Division, and submits a completed Inactivation Notice form 3) Reassignment of permit Permit coverage for a specific portion of a permitted site may be reassigned to a new entity when a permittee no longer has control of that portion of the site, and wishes to transfer coverage of that portion to a second party To reassign permit coverage for a specific portion of a permitted site, the permittee must submit a completed Notice of Reassignment of Permit Coverage form that is signed in accordance with the General Requirements of the permit If the new entity will not complete their portion of the reassignment form, the specific portion of the site may be removed from permit coverage if the permittee has no legal responsibility for the construction activities at the portion of the site, and a wntten request (including contact information for the new entity) is submitted to the Division G PERMITTING FOR DEVELOPMENTS WITH MULTIPLE OWNERS AND/OR OPERATORS A For situations where multiple entities meet the definition of owners and/or operators for different portions of a development (e g , a single development with multiple lots being owned and operated by separate entities), extra care must be taken to ensure that proper permit coverage is maintained and that stormwater management practices are correctly documented and Implemented Local stormwater quality programs may have diffenng requirements for who must maintain permit coverage, and what actions must occur when permitted areas and/or activities change Construction site owners and operators must ensure Page 6 of 10 Revised 7 2015 4300 Cherry Creek DrumS Denver CO 80246 1530 P 303 692 2000 WON., colorado gov/cdphe I beta eu c.. John W Hickenloaper, Governor I Larry Wolk, MD MSPH, Executive Director and Chief Medical Officer that their actions do not result in violations of local program requirements Refer to Section D for additional information 1) Permit Coverage for Multiple Owner/Operator Development When a portion of a permitted site is sold'to a new owner, a permit certification must be in place that is held by an entity meeting the definition of owner and/or operator of the sold area (see the discussion in Section B 2, above) This may be accomplished in one of the following ways a) Coverage Under the Existing Certification Activities at the sold area may continue to be covered under an existing permit certification for the project if the current permittee meets the definition of operator for the sold area To meet the definition of operator, the current permittee must have contractual responsibility and operational control to address the impacts that construction activities at the sold area may have on stormwater runoff (including implementation of the SWMP for the sold area) Therefore, a legally binding agreement must exist assigning this responsibility to the current permit holder on behalf of the new owner and/or operator for the sold area It is not necessary to notify the Division in such case However, documentation of the agreement must be available upon request, and the SWMP must be maintained to include all activities covered by the Stormwater Construction Permit Example Developer Dan sells a lot to Builder Bob Developer Dan is currently covered by a permit certification that covers a larger area, which includes the sold lot Developer Dan and Builder Bob may enter into a contract that assigns the responsibility for permit coverage and stormwater management to Developer Dan for Builder Bob's lot Developer Dan is also responsible for making sure his SWMP includes the activities on the sold lot Developer Dan's permit certification will continue to cover construction activities on Builder Bob's lot b) New Certification Issued - Reassignment A new permit certification may be issued to the new owner and/or operator of the sold area The existing permittee and the new owner and/or operator must complete the Reassignment Form (available from the Division's web page, see page 1) to remove the sold area from the existing permit certification and cover it under a certification issued to the owner and/or operator of the sold area Both entities must have 5WMPs in place that accurately reflect their current covered areas and activities Example Developer Dan sells a lot to Builder Bob Developer Dan is currently covered by a permit certification that covers a larger area, which includes the sold lot For this example, Developer Dan and Builder Bob must jointly submit the Reassignment Form Builder Bob will be issued a new permit certification for his lot and the lot will be removed from Developer Dan's permit coverage Pnor to submittal of the Reassignment Form, Developer Dan must revise his SWMP to reflect the changes in his covered area and activities, and Builder Bob must develop his own SWMP to cover the area and activities he will obtain coverage for c) Amend Existing Permit Certifications - In some cases, both parties (the onginal owner/operator and the new owner/operator of an area undergoing transfer of ownership or operation) will already both be permit holders for their portions of the overall project (i e , at least two permit certifications are issued for the project and cover both the party wishing to reassign coverage and the party wishing to accept coverage) When an additional area is transferred between the two parties, the permittees may simply amend their permit certifications instead of completing the Reassignment Form Both parties must separately complete the procedures discussed in Section E to amend their permit coverage, removing the applicable area(s) from the original owner/operator's permit coverage, and adding the area(s) to the new owner/operator's permit coverage The requests must cite both permit certification numbers (Note this request may be submitted jointly if it is signed by both entities) This option will likely be used in cases where a developer and an owner have already submitted a Reassignment Form, as discussed in Part b, above, where an initial transfer of lots has occurred, and then additional lots are transferred at a later date Both entities must have 5WMPs in place that accurately reflect their current covered areas and activities Example Developer Dan sells a lot to Builder Bob Developer Dan is currently covered by a permit certification that covers a Larger area, which includes the sold lot In addition, Builder Bob also holds a permit certification for other portions of the development which he already owns, and Builder Bob wishes to cover his new lot under this certification Developer Dan submits a request to remove the lot from his permit certification and provides Builder Bob's permit certification number that the lot will now be covered under Builder Bob also submits a request to modify his permit certification to add the lot, and provides Developer Dan's permit Page 7 of 10 Revised 7 2015 4300 Cherry Creek Drive 5 Denver CO 80246 1530 P 303 692 2000 www, coloredo gov/cdphe John W Hlckenlooper Governor I Larry Wolk, MD MSPH Executive Director end Chief Medical Officer rr t7 certification number under which the lot was previously covered Developer Dan and Builder Bob must revise their SWMPs to reflect the changes in their covered area and activities 2) Permit Compliance for Multiple Owner/Operator Development As a permittee, the most important concept for projects where multiple entities are involved is if activities within your permitted area result in pollution of stormwater, yai are the entity responsible for ensuring that those pollutants are properly managed Permittees are responsible for complying with the Stormwater Construction Permit requirements for the areas and activities for which they have permit coverage, and for all BMPs they are relying on to comply with the permit Properly addressing and documenting the responsibility of various parties at a construction site will help protect an entity from liability in the case where another party's actions result in failure of BMPs a) Pollutants from Outside the Permitted Area 9:A permittee may be held liable for pollutants that pass into and are then discharged from their permitted \ area or that result from another entity's activities Specifically, a permittee may have responsibility to ensure proper implementation of BMPs to control stormwater discharges from their permitted area, even if another entity is contributing pollutants The Stormwater Construction Permit requires the permittee to ensure the implementation of BMPs which will be used to control the pollutants in stormwater discharges associated with construction activity from their permitted area Therefore, a permittee may be responsible for adequately implementing and maintaining BMPs that are providing treatment for pollutants onginating outside of their permitted area or from another entity's activities An example is when a permittee's property is being used by a separate entity for construction activities (e g , loading and unloading, site access, materials storage, etc ), or BMPs located on the permittee's property are being relied on to treat stormwater runoff from another site This scenario is common when a developer sells off lots to a builder As a practical matter, what most often occurs is that the developer must allow the builder to use the developer's infrastructure (e g , roads, storm drains, ponds, etc ) for activities and BMPs that cannot realistically be limited to the builder's property In this case, the developer remains a liable party (in addition to the builder) to ensure that proper stormwater management is implemented for the project Permit coverage may instead be assigned to the builder for this infrastructure, if the builder has been designated as the operator of the area for stormwater quality purposes (See Section B 2) However, this may not always be practical when multiple builders are operating in an area or when the developer is still performing their own construction activities Refer to the Liability and Example sections, below, for further guidance b) BMPs Located Outside the Permitted Area J\ If a permlttee will be relying on BMPs that are outside of the area they own and/or operate, the specific actions listed below must be taken to ensure compliance with the Stormwater Construction Permit The permittee is responsible for ensunng the proper managment all pollutants from their permitted area Even if the BMP are implemented by another party, the permittee may still be liable if their pollutants are eventually discharged The permittee is responsible for ensuring the operation and maintenance of all BMPs that are used to control pollutants that originate from their activities, even if the BMPs are located outside of the area owned and/or operated by the permittee For example, a builder may only have ownership of a single lot, but may have to rely on BMPs that are located off of their lot and on a developer's property to adequately manage stormwater runoff, such as inlet protection that is on the developer's streets If a permlttee will rely on BMPs that are outside the area that they own and/or operate, the following measures must be taken I) Any off site BMPs must be documented in the permittee's SWMP This includes structural BMPs (e g , inlet protection and sediment ponds) and non structural BMPs (e g , concrete wash out areas and street sweeping) By including the BMPs In the SWMP, the permittee can effectively include the practices under Page 8 of 1O Revised 7 2015 4300 Cherry Creek Drive S , Denver CO 80246-1530 P 303 692 2000 vnavr colorado gov/cdphe John W Hickenlooper Governor I Larry Wolk, MD MSPH Executive Director and Chief Medical Officer fit Of F/ IF7 their permit coverage In such cases, the same off site BMPs may actually be included in two or more parties' SWMPs u) The permittee must have adequate permission from the land and/or BMP owner(s) to utilize the off site conveyances and BMPs and to ensure proper maintenance and operation The permittee must be able to provide evidence of this agreement upon request iii) The off site BMPs must be operated and maintained in accordance with the SWMP(s) and must control the discharge of pollutants It may be necessary to enter into agreements with other parties to ensure operation and maintenance of these BMPs Regardless of who actually comes out the operation and maintenance of a BMP, all permittees who make use of the BMP to control pollutants from their construction activities remain liable if the BMP is not adequately operated and maintained Iv) All BMPs must be located pnor to discharge to surface waters or municipally owned storm sewer systems Liability In the above examples, to reduce liability, the developer and builder should communicate on stormwater management issues and document who will be responsible for specific BMPs (e g , who will maintain inlet protection and implement street sweeping) If BMPs are not being adequately implemented by the party defined as responsible, the other party should take the necessary action to ensure pollutants originating from, or passing through, their permitted area are properly controlled It is recommended that stormwater management responsibilities be addressed in contracts or other legal agreements between applicable owners and operators for construction sites where one party's actions may impact another party's permit compliance These legal agreements will both help define roles and responsibilities at a multi owner/operator site, and also may be used to seek damages from a contractor if monetary penalties are issued to a permittee for permit violations Example Developer Dan sells a lot to Builder Bob Following,the procedures discussed in Section G 1 b or c, above, Builder Bob obtains separate permit coverage for his new lot, ending at the curb line Because the site infrastructure is being utilized by several different builders at the project, Developer Dan maintains permit coverage for the streets, storm drain system, and a large retention pond that is designed and implemented as a BMP to manage pollutants from construction activities at the development (including Builder Bob's lot) In addition to the large pond, inlet protection is also being used to protect storm sewer inlets located on Developer Dan's roads, and street sweeping is occurnng to control sediment tracked onto Developer Dan's roads Builder Bob is relying on the pond, inlet protection, and street sweeping to manage pollutants from his lot, and therefore has included the BMPs in his SWMP, as discussed in Section G 2 b, above The BMPs are also included in Developer Dan's SWMP because they are being used to control pollutants from property he still maintains control over, as discussed in Section G 2 a, above In addition, Developer Dan and Builder Bob enter into a contract that clearly defines Developer Dan as being responsible for implementing and maintaining the infrastructure BMPs (i e , the pond, inlet protection, and street sweeping BMPs), and requires Builder Bob to implement additional BMPs on his lots, such as vehicle tracking control and construction waste management If the infrastructure BMPs are not properly operated and maintained, or discharges of sediment and/or other pollutants from Builder Bob's lot are not properly controlled and overwhelm the infrastructure BMPs, both Developer Dan and Builder Bob may be in violation of their permits Therefore, Builder Bob and Developer Dan must both remain diligent in ensunng that conditions of their contract are being met and BMPs operated by both parties continue to be implemented in accordance with their SWMPs H SALE OF RESIDENCE TO HOMEOWNERS Residential lots that have been conveyed to a homeowner and that meet the specific cntena below do not require coverage under the Stormwater Construction Permit In this case, the conveyed lot may be removed from coverage under the permtttee's certification, and the permittee is no longer responsible for meeting the terms and conditions of this permit for the conveyed lot, including the requirement to transfer or reassign permit coverage The permittee remains responsible for eventual inactivation of the original certification (see Part F, above) The cntena for these lots are as follows 1) The lot has been sold to the homeowner(s) for private residential use, 2) the lot is less than one acre of disturbed area, 3) all construction activity conducted by the permittee on the lot is completed, Page 9 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver, CO 80246 1530 P 303 692 2000 www colorado gov/cdphe ,* Yc u.virc�Y John W Hlckenlooper Governor I Larry Walk, MD MSPH Executive Director and Chief Medical Officer tC.Q„ •� 4) a certificate of occupancy (or equivalent) has been awarded to the homeowner, and 5) the SWMP has been amended to indicate the lot is no longer covered by permit Lots not meeting oil of the above criteria require continued permit coverage However, the permit coverage for the conveyed lot may be transferred or reassigned to a new owner or operator (see Parts F and G 1, above) 1 CONSTRUCTION DEWATERING Construction dewaterng water can NOT be discharged to surface waters or to storm sewer systems V \ without separate permit coverage The discharge of Construction dewatenng water to the ground, under the specific conditions listed below may be allowed by the Stormwater Construction Permit when appropriate BMPs are implemented Two options are available for managing uncontaminated Construction Dewatenng water on a construction site Construction Dewatenng water discharged from the project site, to surface waters or to storm sewer systems, is considered a process water and requires an industrial process water permit Applications for dischargers engaged in the dewatenng of uncontaminated groundwater from a construction site are available from the Division's web site or by contacting the Division (see first page for address information) Alternatively, Construction Dewatenng water may be discharged to the ground if all of the following conditions are met 1) The discharge and the BMPs are included in the SWMP, 2) Adequate BMPs are included to control stormwater pollution, 3) The discharge does not leave the site as surface runoff or to surface waters/stone sewer systems, and 4) The groundwater being pumped is not contaminated so as to exceed State groundwater standards If the above conditions are not met, a separate permit (see above) is needed for discharges to the ground and/or surface waters Further Information concerning Construction Dewatenng, including what constitutes contamination of groundwater, can be found in the Stormwater Construction Permit and Rationale These documents and others can be obtained from the Division's web site or by contacting the Division (see first page for address information) J CONCRETE WASHOUT Concrete Washout water can NOT be discharged to surface waters or to storm sewer systems without V \ separate permit coverage The discharge of Concrete Washout water to the ground, under the specific conditions listed below may be allowed by the Stormwater Construction Permit when appropnate BMPs are implemented Concrete Washout water from washing of tools and concrete mixer chutes may be discharged to the ground if all of the following conditions are met 1) The source is identified in the SWMP, 2) Adequate BMPs are included in the SWMP to prevent pollution of groundwater, and 3) These discharges do not leave the site as surface runoff or to surface waters/storm sewer systems The use of the washout site should be temporary (less than 1 year), and the washout site should be not be located in an area where shallow groundwater may be present, such as near natural drainages, springs, or wetlands Concrete washout water must not be discharged to state surface waters or to storm sewer systems Also, on site permanent disposal of concrete washout waste is not authorized by this permit Further information concerning Concrete Washout can be found in the Stormwater Construction Permit and Rationale These documents can be obtained from the Division's web site at www coloradowaterpennits com Page 10 of 10 Revised 7 2015 4300 Cherry Creek Dove 5 Denver CO 80246 1510 P 303 692 2000 www colorado gov/cdphe John W Hickenlooper Governor I Larry Walk MD MSPH, Executive Director and Chief Medical Officer CO ODP,!(Pr r7 Final Drainage Report ATD Job #2019-112 Richard Miller Lot "B" of Recorded Exemption No 1053 -3 -1 -RE -683 Located Within the Northeast Quartet of the Northeast Quarter of Section 3, Township 4 North, Range 64 West of the 6t° Principal Meridian, County of Weld, State of Colorado Use by Special Review No USR, Richard Miller 27808 County Road 50 Weld County, Colorado June 8, 2020 Prepared by Dan Campbell EIT 74322 14 "1 hereby attest that this report for the Final drainage design for Richard Miller was prepared by me, or under my direct supervision, in accordance with the provisions of the Weld County Storm Drainage Design Criteria for the responsible parties thereof I understand that Weld County does not and shall not assume liability for drainage facilities designed by others " Maik A Taylor Registered Professional Engineer State of Colorado No 46065 1 Table of Contents General Location and Description Location Description of Property Drainage Basins and Sub -Basins Major Basin Description Sub -Basin Description Drainage Design Criteria Development Criteria Reference and Constraints Hydrological Cntena Hydraulic Criteria Drainage Facility Design General Concept Specific Details Conclusions Compliance with the Weld County CODE Drainage Concept References Appendices 2 4 4 4 5 5 6 7 7 8 I1 12 12 13 14 14 14 14 15 Appendix A Page Data Al -6 Property Information A7-10 Aerial Maps AI 1-35 Web Soil Survey Data A36 FIRM A37-44 Drainage Calculations (Historic and Developed) A45-50 IDF Tables/Curves A51-52 Interpolations for Rainfall Intensity Values A53-54 Interpolations for Runoff Coefficient, C A55 Table R0-5 — Runoff Coefficients, C A56-57 Modified FAA Method for Detention Pond Volume A58 Detention Pond Volume Calculations A59 WQCV Calculations A60-61 Detention Pond Release Time A62-76 Riprap Design Data A77 Weir Wall Sizing Calculations A78 Culvert Outlet Protection A79-90 Memorandum, Water Rights in Colorado A91-100 CDPHE - Stormwater Fact Sheet — Construction 3 I General Location and Description A Location 1 The subject property, Parcel No 105303000020, described as Lot "B" of Recorded Exemption No 1053 -3 -1 -RE -683, recorded July 03, 1984 as Reception No 01972686, is located in the Northeast Quarter (NE 1/4) of the Northeast Quarter (NE 1/4) of Section 3, Township 4 North, Range 64 West of the P M , County of Weld, State of Colorado 2 The subject property is zoned Agricultural Currently, the agricultural land area for crop production is 18 13 +/- acres The proposed development of the site will reduce the agricultural land area by 3 98 +/- acres, leaving 14 15 +/- acres for future agricultural production 3 The subject property does not he within the Weld County MS4 Zone per Weld County Property Portal Website 4 The subject property is approximately 2 6 miles southeast of the Town of Kersey limits and is considered non -urbanizing Weld County Code Sec 8-11-20 defines non -urbanizing as an area farther than '/4 mile from municipal boundanes 5 Weld County Road (WCR) 50 borders the property on the north WCR 57 is 0 08 +/- miles east of the property WCR 55 is 0 70 +/- miles west of the property WCR 48 is 0 80 +/- miles south of the property 6 No major open channels, lakes, streams, imgation or other water resource facilities lie within and/or adjacent to the project site The Latham Ditch is located 0 33 +/- miles east of the site The Loloff Reservoir is located 0 27 +/- miles northeast of the site Ownership information for the Latham ditch was researched and could not be determined 7 To the north of the subject property, adjacent to WCR 50, is an Agricultural property owned by James & Sally Eckhardt Adjacent to the east of the site is a Residential property owned by David Ohlendorf Adjacent to the southeast of the site is a Residential property owned by Gary & Valeen Jackson Adjacent to the south of the site is an Agricultural property owned by Roberto & Raquel Lara Adjacent to the west of the site is an Agricultural property owned by David & Dorothy Bates The properties surrounding the subject property are either zoned Agricultural or Residential B Description of Property I The total area of the subject property is 21 84 +/- acres (Gross) and 21 01 +/- acres (Net) The Net area equals the Gross area minus the 30' existing ROW and the 10' reserved R O W on the north The proposed development is 6 71 +/- acres 4 2 The existing ground cover is a mix of native vegetation and prairie grass as well as agricultural crops According to the United States Department of Agriculture's (USDA) WebSoil Survey, the entire site is made up of approximately 92% Olney fine sandy loam (Hydrologic soil group Type B) and 8% Vona sandy loam (Hydrologic soil group Type A) The majority of the site is Olney fine sandy loam (Soil map unit symbol 47), all drainage calculations will use Type B Soils 3 The proposed development includes • a 40' x 40' agriculture storage building c three 50' x 80' equipment maintenance shops (phased, built as needed) o a packed gravel parking/dnving surface for equipment storage and tractor trailer parking o a detention pond with weir wall and release structure o an emergency overflow spillway for the detention pond • a landscaping berm for screening O a modified access entrance with 60' radius curves • an RCP culvert below the access entrance to convey stormwater in the WCR 50 borrow ditch O a cattle guard for permanent tracking control O removal of the existing oil tank batteries located near the entrance • removal of the eastern entrance into the oil tank battery area 4 From the Web Soils Survey, the depth to ground water is 6 5 feet or deeper The onsite OWTS permit records, Permit# SP -9700185, indicates that groundwater was observed at 7 0 +/- feet below grade in the soil profile Alles, Taylor & Duke (ATD) did not perform any observations or testing of on -site soils or groundwater H Drainage Basins and Sub -Basins A Major Basin Description 1 Weld County Public Works was contacted in regards to existing drainage reports and master drainage plans in the area No information was available 2 The subject property is located in the South Platte Drainage basin The South Platte Drainage Basin includes much of the populated region of the Front Range extending outward to the eastern plains of Colorado The South Platte River Corridor has experienced a trend of increased urbanization in recent years 3 Floodplam the site is located in Zone X (area of minimal flood hazard) per Firm Panel 08123C1775E, effective date January 20, 2016 Please see the attached map 4 A topographical survey was conducted by ATD and 1 ft contours on the existing and proposed surfaces are provided on the grading plan 5 B Sub -Basin Description 1 Historic drainage patterns on the site are as follows Stormwater runoff on the subject property sheet flows in a northeast direction at approximately 1% to 3% slopes Stormwater runoff ultimately reaches the borrow ditch along WCR 50 and flows cast Historic Basin -1 (HB-1) is 6 40 +/- Acres with the boundanes shown on sheet C-2 of the drawing set An impervious value of 2% was used for historic drainage analysis The 10-yr runoff coefficient is 0 17 and the 100-yr runoff coefficient is 0 36 The allowable release rate for the detention pond is based on the historic site conditions for a non -urbanized area, for the 10-yr storm event, which is 1 74 cfs (0 272 cfs/acre) Surrounding and adjacent properties in the area have similar histonc drainage patterns as the project site, stormwater runoff flows in a northeast direction at approximately 1% to 3% slopes With the proposed development, there are six drainage Sub -Basins (SB-A through SB-E and B-1) All proposed drainage basin boundaries are shown on sheet C-4 of the drawing set The developed Sub -Basin descriptions are as follows Sub -Basin A (SB-A) is 4 68 +/- acres with a calculated impervious value of 39% SB-A comprises most of the proposed development including the existing structures and residence area, some landscaped areas, the proposed structures, and a large portion of the proposed packed gravel surface The 10-yr runoff coefficient is 0 36 and the 100-yr runoff coefficient is 0 50 Stormwater runoff from SB-A sheet flows to Design Point 1 Sub -Basin B (SB-B) is 0 84 +/- acres with a calculated impervious value of 40% SB-B consists of a large portion of the proposed packed gravel surface The 10-yr runoff coefficient is 0 36 and the 100-yr runoff coefficient is 0 50 Stormwater runoff from SB-B sheet flows to Design Point 2 Sub -Basin C (SB-C) is 0 54 +/- acres with a calculated impervious value of 64% SB-C consists of a small portion of the proposed packed gravel surface, some landscaped areas, and the detention pond The 10-yr runoff coefficient is 0 48 and the 100-yr runoff coefficient is 0 58 Stormwater runoff from SB-C sheet flows into the detention pond The detention pond was analyzed with an impervious value of 100% Sub -Basin D (SB-D) is 0 34 +/- acres with a calculated impervious value of 19% SB-D consists of packed gravel surface near the site entrance and landscaped areas east of the entrance The 10-yr runoff coefficient is 0 27 and the 100-yr runoff coefficient is 0 44 Stormwater runoff from SB-D does not contribute to the detention pond and sheet flows into the WCR 50 borrow ditch 6 Sub -Basra E (SB-E) is 0 47 +/- acres with a calculated impervious value of 2% SB-E consists of a portion of land that will remain as agricultural use The 10-yr runoff coefficient is 0 17 and the 100-yr runoff coefficient is 0 36 Stormwater runoff from SB-E sheet flows to the detention pond and is accounted for at the overflow weir but not for sizing the detention pond Basin -1 (B-1) is 6 06 +/- acres with a calculated impervious value of 42% B-1 consists of SB-A, SB-B, and SB-C and is the basin that contributes stonnwater runoff to the detention pond The 10-yr runofl coefficient is 0 37 and the 100-yr runoff coefficient is 0 50 2 Offsite stormwater flows from the west and south are intercepted by an irrigation ditch that runs along the penmeter and will not enter the site Offsite stormwater flows from the north and east flow away from the site and will not enter the site There are no offsite flows from the neighboring properties affecting this site III Drainage Design Criteria A Development Criteria Reference and Constraints I No foreseeable site constraints such as slopes, streets, adjacent properties, utilities, existing structures, will negatively impact the proposed drainage plan The historic drainage patterns on the site will be maintained in such a manner that it will reasonably preserve the natural character of the area as much as possible while mitigating mcreased runoff to the surrounding properties 2 Methodologies used in preparing this report are as follows o The Rational Method was used to determine stormwater runoff rates for historic and developed flows, equation (RO-1) found in Urban Storm Drainage Criteria Manual, Volume 1, Revised Apn12008 (USDCM Vol 1) o Time of concentration values for historic and developed conditions were determined using equations (RO-2), (RO-3), (RO-4), and (RO-5) found in (USDCM Vol 1) o Rainfall curves/tables were determined using NOAA Atlas 14, Volume 8, Version 2, and the rainfall intensity equation (RA -3) provided in (USDCM Vol 1) o The runoff Coefficients, C were obtained from Table R0-5 found in (USDCM Vol 1) o The Water Quality Capture Volume (WQCV) was calculated using equations 3-1 and 3-3 found in Chapter 3 of the (USDCM Vol 3), Best Management Practices, Updated November 2010 The required detention pond volume was calculated using the Modified FAA Method spreadsheet found in the Urban Drainage & Flood Control Distract (UDFCD) Detention Basin Volume Estimating Workbook Version 2 34, Released November 2013 7 o The designed detention pond volume was calculated using the average area method with 0 1' contours around the detention pond (Average Area Method = ((Al + A2)/2) x Stage Depth = Stage Volume (CF) o The restnctor plate orifice sizing used to control the WQCV release was calculated using Orifice Flow equation 11 4 3 13 found in the City of Greeley Design Criteria and Construction Specifications Manual, Storm Drainage Volume II, Addendum June 2008 (COG Vol 2) o The orifice plate orifice sizing used to control the 100-yr volume release was calculated using Orifice Flow equation 11 4 3 13 found in COG Vol 2 o The nprap emergency overflow spillway and detention pond rundowns were designed using the Rock Chute Design Data Spreadsheet, Version WI -July - 2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998 o The sizing of the emergency overflow weir wall in the detention pond was calculated using Equation 11 4 3 A(1) found in COG Vol 2 o A spreadsheet is included that shows the stormwater release time of the entire pond (WQCV and 100-yr volume) o A spreadsheet is included that shows the designed detention pond volume using the average area method o A spreadsheet is included that shows all drainage calculations using the Rational Method Spreadsheets are included that show interpolated values for Runoff coefficients and Storm Intensity values o Soil information from NRCS Web Soil Survey Website is included in this report Aerial maps from Weld County Property Portal are included this report B Hydrological Criteria 1 The calculated Time of Concentration values for historic and developed stormwater flows are as follows o Historic Basin T. His = 51 minutes o Sub -Basin A To Hey= 16 minutes o Sub -Basin B Dom= 13 minutes o Sub -Basin C Dc= 11 minutes o Sub -Basin D T. De.= 11 minutes o Sub -Basin E Dc.=16 minutes o Basin -1 T. Dr= 16 minutes 2 The Historic Basin rainfall intensity values calculated with a time concentration of 51 minutes are as follows o li0 His i 60 in/hr o Iioo Hs 3 03 in/hr 8 The Sub -Basin A rainfall intensity values calculated with a time of concentration of 16 minutes are as follows O Iio Dev 3 13 in/hr O Iioo ocv 5 95 in/hr The Sub -Basin B rainfall intensity values calculated with a time of concentration of 13 minutes are as follows O lie Dev 3 47 in/hr o Iioo txv 6 58 in/hr The Sub -Basin C rainfall intensity values calculated with a time of concentration of 11 minutes are as follows O Iio ixv 3 72 in/hr O Imo oev 7 05 in/hr The Sub -Basin D rainfall intensity values calculated with a time of concentration of 11 minutes are as follows o Iio Dev 3 72 in/hr O Iioo Dev 7 05 in/hr The Sub -Basin E rainfall intensity values calculated with a time of concentration of 16 minutes are as follows o Lc) rim 3 13 in/hr O Iioo Dcv 5 95 in/hr The Basin -1 rainfall intensity values calculated with a time of comcentration of 16 minutes are as follows O Iis Dev 3 13 in/hr O Iioo Dee 5 95 in/hr 3 The runoff coefficients, C for Histonc Basin Flows (Type B Soils at 2% imperviousness) are as follows o Cm 9s 0 17 O Cioo ii,, 0 36 The runoff coefficients, C for Sub -Basin A Flows (Type B soils at 39% imperviousness) are as follows e CIO Dev 0 36 O Goo Dev 0 50 The runoff coefficients, C for Sub -Basin B Flows (Type B Soils at 40% imperviousness) are as follows o CIO Dcv 0 36 o Goo D,v 0 50 9 The runoff coefficients, C for Sub -Basin C Flows (Type B Soils at 64% imperviousness) are as follows O CIO Dcv 0 48 • CIOs Dev 0 58 The runoff coefficients, C for Sub -Basin D Flows (Type B Soils at 19% imperviousness) are as follows o CIO Dw 0 27 • Ci00 De, 044 The runoff coefficients, C for Sub -Basin E Flows (Type B Soils at 2% imperviousness) are as follows a CIO Dcv 0 17 e Cloo Dcv 0 36 The runoff coefficients, C for Basin -1 Flows (Type B Soils at 42% imperviousness) are as follows o Cio Dev 0 37 • CIO° Dev 0 50 4 The design storm recurrence intervals used in this drainage report are the ten (10) year, and one hundred (100) year storm events The detention pond will hold slightly more than the 100-yr storm volume and will be released at the maximum 10-yr histonc flow rate for the non -urbanized site The maximum discharge rate for releasing the detained stormwater is Q= 1 74 cfs (0 272 cfs/acre) 5 The Rational Method was used to calculate stormwater runoff rates, equation (RO-1) found in USDCM Vol I The Rational Method is based on the Rational Formula Q = CIA, in which • Q = the maximum rate of runoff (cfs) o C = a runoff coefficient that is the ratio between the runoff volume from an area and the average rate of rainfall depth over a given duration for that area • I = average intensity of rainfall in inches per hour for a duration equal to the time of concentration, Tc o A = area (acres) The Histonc Basin peak flow values are as follows o Qio His= 1 74 cfs (0 272 cfs/acre) o Qioo Ha= 6 99 cfs (1 091 cfs/acre) The Sub -Basin A peak flow values (Design Point 1) are as follows o Qio ocv= 5 27 cfs (1 127 cfs/acre) o (boo oov= 13 91 cfs (2 975 cfs/acre) 10 The Sub -Basin B peak flow values (Design Point 2) are as follows O Qio Doi= 1 05 cfs (I 249 cfs/acre) G Qioo Doi= 2 77 cfs (3 290 cfs/acre) The Sub -Basin C peak flow values are as follows o Qio D,O= 0 97 cfs (I 786 cfs/acre) o Qioo oe,,= 2 23 cfs (4 089 cfs/acre) The Sub -Basin D peak flow values are as follows O Qio Dov= 0 34 cfs (I 004 cfs/acre) O Qioo Dr= 1 05 cfs (3 102 cfs/acre) The Sub -Basin E peak flow values are as follows o Qio DM= 0 25 cfs (0 610 cfs/acre) O Qioo Dov= 1 02 cfs (2 452 cfs/acre) The Basin -1 peak flow values are as follows O Qio Dv= 7 02 cfs (1 158 cfs/acre) G Qioo Dov= 18 04 cfs (2 975 cfs/acre) 6 The required 100-yr detention volume was calculated as 30,806 cubic feet (cf) The WQCV was calculated as 4,072 cf The total required storage volume is 30,806 cf+ 4,072 cf = 34,878 cf The designed detention pond volume was calculated as approximately 40,071 cf The detention pond is oversized by approximately 5,193 cf (14 9%) C Hydi aulic Criteria 1 The designed detention outlet is a two -stage release The first stage is for WQCV, which is designed to release m approximately 44 4 hours The second stage is designed to release the rest of the pond at the maximum rate of 1 74 cfs (0 272 cfs/acre) in approximately 7 0 hours The entire pond is designed to be released within approximately 51 5 hours, which is under the 72 hours required per Colorado State Legislation Please see attached spreadsheet for release time calculations 2 The WQCV outlet structure will consist of a concrete box with inner wall dimensions of 3 0' x 3 7' The box will have a centered straight notch opening 1 5" in width from bottom to top A restnctor plate (10 5" x 23 5" x 0 25") will be placed centered over the straight notch opening 0 5" from the bottom of the concrete box (elevation of 4636 04') The orifice sizing to control the WQCV flows will be 1 5" x 0 5", which will be released in approximately 44 4 hours Please see sheet C-5 in the drawing set for further details 3 The release of the 100-yr volume will be controlled with an onfice plate centered over the 12 0" diameter corrugated metal pipe (CMP) opening in the weir wall The I orifice plate will have a 3 0" x 6 7" rectangle orifice centered at the bottom of the plate The 100-yr volume down to the top of the WQCV structure will drain in approximately 7 0 hours Please see sheet C-5 in the drawing set for further details 4 All criteria and calculation methods used in this report are presented in either Weld County Code, or in compliance with Urban Storm Drainage Criteria Manuals Volumes I, II, and ill dated June 2001 (revised in April 2008) IV Drainage Facility Design A General Concept 1 The historic drainage patterns on the site will be maintained in such a manner that it will reasonably preserve the natural character of the area as much as possible while mitigating increased runoff to the surrounding properties Historic drainage pattems on the site are as follows Stormwater runoff on the subject property sheet flows in a northeast direction at approximately 1% to 3% slopes Stormwater runoff ultimately reaches the borrow ditch along WCR 50 and flows east The proposed drainage plan is as follows All stormwater runoff will flow away from structures at minimum 2% slopes and will sheet flow m a northern direction at approximate 1% to 3% slopes until reaching the detention pond The detained stormwater in the detention pond will be released into the WCR 50 borrow ditch through the outlet structure with a 12" CMP 2 The anticipated hydraulic structures for this drainage design includes two detention pond rundowns, a weir wall, an emergency spillway with cutoff wall, a concrete outlet structure with a restnctor plate to control the release of the WQCV, an orifice plate on the weir wall to control the release of the 100-yr volume, a 12" CMP release pipe from the outlet structure to the WCR 50 borrow ditch, an 18" RCP culvert to be placed under the modified entrance Detention Pond Rundowns Two detention pond rundowns will be utilized to convey stormwater into the detention pond Both rundowns will have soil nprap type "VL" for erosion protection Please see Sheet C-6 in the drawing set and the attached Rock Chute sheets for further detail Weir Wall The calculated horizontal length of the weir is 23 0' Using a weir length of 23 0' resulted in a flow rate of 21 1 cfs The stormwater flows contributing to the weir include Basin -1 + Sub -Basin E (18 04 + 1 02) cfs = 19 06 cfs The weir wall is adequately sized The width of the weir wall is 0 67' The weir wall is to extend 3 0' into undisturbed soil #4 rebar will be used for durability purposes (not for structural) 12 1 in the weir wall Please see Sheet C-5 in the drawing set and the attached spreadsheet for further detail Emergency Overflow Spillway The length of the spillway from the weir wall to the stilling basin is approximately 29 9' with a slope of 21 5% The width of the spillway is 27' at the weir wall and 23' at the stilling basin The side slopes of the spillway are 4 i l'ype "VL" soil nprap will be used for the spillway, Dso = 6 0" with a rock chute thickness of 12 0" for erosion protection Please see Sheets C-5 and C-6 in the drawing set and the attached Rock Chute sheets for further detail Cutoff Wall The cutoff wall for the 12" CMP will be located 9' north of the weir wall and 2' south of the future ROW The cutoff will be centered in the spillway and will be 11' in length and 0 67' in width The cutoff wall will extend 3' into undisturbed soil Please see sheets C-5 and C-6 in the drawing set for further detail Detention Pond Release Pipe The outlet pipe extends from the release structure to the emergency spillway stilling basin, which is where the pipe ends The outlet pipe is a 12 0" CMP with a Length of approximately 30 6' and a slope of 1 44% Please see sheets C-5 and C-6 for further details WCR 50 Borrow Ditch Culvert An 18" RCP culvert located under the site entrance will be used to convey stormwater through the WCR 50 borrow ditch The length of the culvert including the flared end sections is approximately 123 3' with a slope of 0 81% A minimum of l' of cover over the culvert is required Type "VL" soil nprap will be used on both the inlet and outlet ends for erosion protection Please see sheet C-6 in the drawing set for further details B Specific Details 1 Maintenance will be manageable and routine for the detention pond The side slopes of the detention pond will not be greater than 3 I, so traditional maintenance equipment will be adequate to ensure the pond is utilized as designed After a storm event that produces stormwater runoff into the detention pond, the detention pond shall be checked for erosion, if erosion is found at this time or any time within the life of the pond, it shall be repaired in a timely manner All vegetation across the site shall be kept at less than one foot tall per Weld County Code, the pond shall be mowed and maintained on a regular basis to ensure its optimal function After any storm event that results in water flowing through the release structure and pipe, the release structure and pipe should be checked for blockage of any kind If a storm event results in storm water going over the overflow weir, the weir and nprap shall be checked for erosion, if there is any erosion it shall be repaired in a timely manner 13 Detention pond cleaning, silt removal, can be performed using small equipment such as a skid -steer loader The detention pond shall be visually inspected one year after closing of the grading permit to check for sediments and general mtegnty of the pond If heavy silting is observed at this time, an as -built with a survey of the pond may be required Sediment build up is likely influenced by the overall imperviousness of the site The lower the I value, the more often the ponds need to be checked for sediment build up For example, I = 80%, most of the site is paved and stormwater runoff is relatively clean (pond should be inspected every 5 years) For example, I = 40%, sediments from gravel surfaces are prone to movement into low laying areas such as the detention pond (pond should be inspected more frequently, every 1 to 3 years) 2 Necessary copies of Draft CDPHE, CAFO, DBMS, or State Engineer's permit applications will be included for this project, the site is larger than 1 0 acre V Conclusions A Compliance with the Weld County CODE 1 The stormwater drainage design is in compliance with the Weld County Code The drainage design will adequately protect public health, safety, and general welfare and have no adverse impacts on public nghts-of-way or offsite properties B Drainage Concept 1 The drainage design will mitigate site stormwater runoff form the higher storm events The detention pond will hold up to the 100-yr storm volume and will be released at the maximum 10-yr historic flow rate (Non -urbanized site) The maximum discharge rate for releasing the detained stormwater is Q = 1 74 cfs (0 272 cfs/acre) 2 There are no foreseeable influences of the proposed development on any Weld County Master Drainage Plan recommendations VI References a Urban Storm Drainage Cntena Manual, Volumes I and II, (Revised Apnl 2008) b Urban Storm Drainage Cntena Manual, Volume III, (Revised November 2010) c City of Greeley Design Cntena and Construction Specifications, Storm Drainage Volume II, (Addendum June 2008) d UDFCD Detention Basin Volume Estimating Workbook Version 2 34, Released November 2013 e USDA Natural Resource Conservation Service, Web Soil Survey, Website f Rock Chute Design Data Spreadsheet, Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Dadavy, ASAE, 1998 g Weld County Engineenng and Construction Cntena, April 2012, Draft Copy 14 h NOAA Atlas 14, Volume 8, Version 2, Website i Weld County Online Mapping Website www weldgov com/departments/assessor VII Appendices Appendix A Page Data Al -6 Property Information A7-10 Aenal Maps A11-35 Web Soil Survey Data A36 FIRM A37-44 Drainage Calculations (Historic and Developed) A45-50 IDF Tables/Curves A51-52 Interpolations for Rainfall Intensity Values A53-54 Interpolations for Runoff Coefficient, C A55 Table R0-5 — Runoff Coefficients, C A56-57 Modified FAA Method for Detention Pond Volume A58 Detention Pond Volume Calculations A59 WQCV Calculations A60-61 Detention Pond Release Time A62-76 Riprap Design Data A77 Weir Wall Sizing Calculations A78 Culvert Outlet Protection A79-90 Memorandum, Water Rights in Colorado A91-100 CDPHE — Stormwater Fact Sheet — Construction 15 4/8/2020 Property Report JARDS Weld County PROPERTY PORTAL Property Information (970) 400-3650 Technical Support (970) 400-4357 Account: R4257186 April 8, 2020 Account Information Account Parcel Space Account Type Tax Year Buildings Actual Value Assessed Value R4257186 105303000020 Agricultural 2020 4 425,763 42,790 Legal PT NE4NE4 3-4-64 LOT B REC EXEMPT RE -683 (.75R) Subdivision Block Lot Land Economic Area KERSEY RURAL Property Address Property Zip Section Township Range 27808 COUNTY ROAD 50 WELD 03 04 64 Owner(s) Account T Owner Name Address R4257186 TEN SLEEP INVESTMENT GROUP LLC 2986 W 29TH ST UNIT B-12 GREELEY, CO 806318547 Document History httpsJ/propertyreport.co.weld.co.usfaccount=R4257186 1/10 4/8/2020 Property Report Reception Rec Date I Type Grantor 1 Grantee Doc Foe sale Date Sale Price 01867074 08-21-1981 WON 0.00 01-01-1900 0 1972686 07-03-1984 RE RE -683 RE -683 0.00 07-03-1984 0 1972686 07-03-1984 RE RECORDED RE -683 0.00 EXEMPTION 0 ‘. 2454890 09-11-1995 WD BRANCH LLOYD & JEAN MC NUTf RONALD J & KAREN F 37.50 09-08-1995 375,000 2900980 11-15-2001 QCN MC NUTT' RONALD J & KAREN F MCNUTT RONALD J TRUST NO 1 & 0.00 11-07-2001 0 3024609 01-16-2003 FQCN MCNUTT RONALD J & MCNUTT RONALD J & 0.00 01-10-2003 0 MCNUTT 3035304 02-24-2003 QCN MCNUTT RONALD J & KAREN F RONALD J & KAREN F TRUSTEES OF 0.00 01-10-2003 0 MCNUTT KAREN F TRUST NO 4517100 08-23-2019 SWD 1; MCNUTT RONALD J & KAREN F TRUSTEES OF; TEN SLEEP INVESTMENT GROUP LLC 91.95 08-16-2019 919,500 MCNUTT et al. Building Information Building 1 AccountNo Building ID Occupancy RR4257186 1 Single Family Residential on Ag httpsJ/propertyreport.co.weld.co.us/?account=R4257186 2/10 4/8/2020 Property Report ID Type NBHD Occupancy Complete Bedrooms Baths Rooms 1 Residential 6201 Single Family Residential on Ag 100 3 3 0 ID Exterior Roof Cover Interior HVAC Perimeter Units Type Make 1 Frame Masonry Veneer Drywall Electric Baseboard 364 0 ID Square Ft Condo SF Total Basement SF Finished Basement SF Garage SF Carport SF Balcony SF Porch SF 1 3,156 0 0 0 880 0 0 490 Built As Details for Bullding 1 ID Built As Square Ft Year Built Stories Length Width 1 00 2 Story 3156 1975 2 0 0 Additional Details for Build' ID Detail Type Description Units 1 Add On Fireplace Wood 1 1 Add On Swimming Pools 1 1 Appliance Allowance 1 1 Fixture Allowance 1 1 Fixture Bath 2 1 1 Fixture Bath 3 2 1 Garage Detached 880 1 Porch Open Slab 360 1 Porch Slab Roof Cell 350 1 Porch Slab Roof Cell 140 h5peJlpropertyreporico weld co usflaccoust 84257186 3110 4/82020 Property Report Building 2 AccountNo Building ID Occupancy R4257186 2 Utility Building ID Type NBHD Occupancy Complete Bedrooms Baths Rooms 2 Out Building Utility Budding 100 0 0 0 ID Exterior Roof Cover interior HVAC Perimeter Units TYPe Make 2 None 170 0 ID Square Ft Condo SF Total Basement SF Finished Basement SF Garage SF Carport SF Balcony SF Porch SF 2 1500 0 0 0 0 0 0 0 Built As Details for Building 2 ID Built As Square Ft Year Built Stones Length Width 2 00 Utility Building 1 500 1976 0 60 25 No Additional Details for Building 2 Building 6 AccountNo Building ID Occupancy R4257166 6 Equipment Building https!/propertyreport co weld co us/7account=R4257186 4/10 4/8/2020 Property Report ID I Type NBHD Occupancy Complete Bedrooms Baths Rooms 6 I Out Building Equipment Building 100 0 0 0 ID Exterior Roof Cover Interior HVAC Perimeter Units Unit ryPe Make 6 None 320 0 ID S uare Ft Condo SF Total Basement SF Finished Basement SF Garage SF Carport SF Balcony SF Porch SF I6 5 376 0 0 0 0 0 0 0 Built As Details for Bu Iding 6 ID Built As Square Ft Year Built Stories Length Width 6 00 Equipment Building 5 376 1886 0 112 48 No Additional Details for Building 6 Building 7 AccountNo Building ID Occupancy R4257186 7 Shed -Equipment ID Type NBHD Occupancy Complete Bedrooms Baths Rooms 7 Out Building Shed - Equipment 100 0 0 0 ID Exterior Roof Cover Interior HVAC Perimeter Units U it Make 7 None 100 0 heps.//properlyreport co weld co us/accounteR4257188 5/10 4/8/2020 Property Report 7 -T Total ID • Square Condo Basement I Ft SF SF 7 1,200 0 0 Finished Basement SF 0 Built As Details for Building T T Built As Square Year Ft Built ID 7.00 Shed Equipment 1,200 Garage SF 0 1886 No Additional Details for Building 7 Carport SF 0 Stories 0 Balcony SF Porch SF 0 0 Length 40 Width Valuation Information Type Code Description Actual Value Assessed Value Acres Land SqFt I Improvement 4277 FARM/RANCH RESIDENCE- IMPS 369,239 26,400 0.000 0 Improvement 4279 FARM RANCH SUPPORT BLDGS 35,921 f 10,420 0.000 0 Land 4117 FLOOD IRRIGATED LAND - AGRICULTURAL 20,603 5,970 21.250 925,650 Totals - - 425,763 42,790 21.250 925,650 Comparable sales for your Residential property may be found using our SALES SEARCH TOOL Tax Authorities https.//propertyreport.co.weld.co.us/?account=R4257186 w10 Ths rrta0.s a .x xrr „IT : sr .t....,,tr. it •ro ,. s- lnt_rr ; - s# and is t.• - rs that - 3r or, :^rs m. , rrr., a Ca actur.ae. Ctrt_. rrtfh.ir.r r 7atH THIS MAP IS NOT TO BE USED FOR NAVIGATION This p es u -r r+brterateci rat( r :Apo frr m an ht- -r,st m;)n vn sn-t refe' - ,'xe e+Y. r 43 .r, that ;.. r !Iv 1r.a .: r . ; a m ; r r _ . . THIS MAP IS NOT TO BE USED FOR NAVIGATION .nt'ra; - : '.,d: :>utjX.: ! _ art : r . r--, , f.•:y vie <t 1 t is ['..r : I _tees th_t ap_ . r nr t is me -)m,• c• r'i • nut to icct►rffi . •t t.i•t,Our t;'rot.y+Vier' tm. 54• •srsit. • that apt •. I c t *!us mer r t rtti . t• : t ! .. :oral? Hydrologic Soil Group Weld County, Colorado, Southern Part 40° ?0' 56- N 40` lU & N 104 31 SS 'h I i I I I t 5388,0 a31b0 53,10 515133 510010 540 Map Sole: 1.2,150 f prnttd on A portred (8.5"x 11') std N 0 33 eo 121 leo Meters 0 top XJ0 a tri tet Map prulectlon: Web Meee ter Confer 0o001sles: W2304 Edge tier WM Zone 13N WGS84 �5(y� Natural Resources Web Soil Survey Conservation Service National Cooperative Sod Survey 3 1f28/2020 page 1 of 4 40" 20. 56' N 4O' ti 41 ti Hydrologic Soil Group Weld County. Colorado, Southern Part MAP LEGEND Area of Interest (AOI) Area of Interest (AU!) Soils Soil Rating Polygons U Li A A, B B/D C C/D D Not rated or not avaiIaole Soil Rating Lines iaa. A sties AID — B ,y B/D C — CC f C • • Not rated or rot available Soli Rating Points • ■ ■ A ND B B/D to a a C V a Not rated or not available Water Features Stearns ard Canals Transportation 1-+4 Rails air Irte:staterlighways US Routes Major Roads Local Roads Background Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1 24,000. 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 tEPSG•3857; Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape out 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 Pan Survey Area Data. Version 18. Sep 13, 2019 Soil map units are labeled (as space allows) for map scales 1-50.000 or larger. Date(s) aerial images were photographed Jul 17, 2015 Oct 2. 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps As a result. some minor shifting of map uric boundaries may be evident USDA Natural Resources Web Soil Survey IF" Conservation Service National Cooperative Soil Survey 1128/2020 Page 2 of 4 Hydrologic Soil Group —Weld County Colorado Southern Part Hydrologic Soil Group Map unit symbol I Map unit name I Rating I Acres In AOl I Percent of AOl 47 76 Olney fine sandy loam B 1 l0 3 percent slopes Vona sandy loam 1 to 3 A percent slopes Totals for Area of Interest Description 20 1 17 21 8 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 B/D and CID) 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 matenal These soils have a very slow rate of water transmission If a soil is assigned to a dual hydrologic group (ND 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 92 0% 80% 1000% USDA Natural Resources Conservation Service Web Soil Survey 112 812 02 0 National Cooperative Sari Survey Page 3 of 4 Hydrologic Soil Group —Weld County Colorado Southern Part Aggregation is the process by which a set of component attnbute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more' components A component is either some type of soil or some nonsoll entity a g rock outcrop For the attribute being aggregated the first step of the aggregation process is to denve one attnbute value for each of a map unit's components From this set of component attributes the next step of the aggregation process derives a single value that represents the map unit as a whole Once a single value for each map unit is denved a thematic map for soil map units can be rendered Aggregation must be done because on any soil map map units are delineated but components are not For each of a map unit's components a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a critical factor in some but not all, aggregation methods The aggregation method Dominant Condition' first groups like attribute values for the components in a map unit For each group percent composition is set to the sum of the percent composition of all components participating in that group These groups now represent 'conditions rather than components The attribute value associated with the group with the highest cumulative percent composition is returned If more then one group shares the highest cumulative percent composition the corresponding 'tie break rule determines which value should be returned The tie break' rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified all components in the database will be considered The data for some contrasting soils of minor extent may not be In the database and therefore are not considered Tie -break Rule Higher The tie -break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie EtiNatural Resources Conservation Service Web Soil Survey 129/2020 National Cooperative Soil Survey Page 4 el 4 Map Und Description Olney fine sandy loam 1 l0 3 percent slopes— Weld County Colorado Southern Pan Weld County, Colorado, Southern Part 47 —Olney fine sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol 362v Elevation 4,600 to 5 200 feet Mean annual precipitation 11 to 15 inches Mean annual air temperature 46 to 54 degrees F Frost -free penod 125 to 175 days Farmland classification Prime farmland if irngated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Map Unit Composition Olney and similar soils 85 percent Minor components 15 percent Estimates are based on observations, descnptions, and transects of the mapunit Description of Olney Setting Landform Plains Down -slope shape Linear Across -slope shape Linear Parent matenal Mixed deposit outwash typical profile H1 - 0 to 10 inches fine sandy loam H2 - 10 to 20 inches sandy clay loam H3 - 20 to 25 inches sandy clay loam H4 - 25 to 60 inches fine sandy loam Properties and qualities Slope 1 to 3 percent Depth to reslnctive feature More than 80 inches Natural drainage class Well drained Runoff class Low Capacity of the most limiting layer to transmit water (Ksat) Moderately high to high (0 57 to 2 00 In/hr) Depth to water table More than 80 inches Frequency of flooding None Frequency of ponding None Calcium carbonate maximum in profile 15 percent Salinity maximum in profile Nonsaline to very slightly saline (0 0 to 2 0 mmhos/cm) Available wafer storage in profile Moderate (about 7 0 inches) Interpretive groups Land capability classification (irrigated) 3e Land capability classification (nonimgated) 4c Hydrologic Soil Group B in Natural Resources Coneervatlon Service Web Soll Survey 128/2020 National Cooperative Solt Survey Page 1 of 2 i Map Unit Descnptton Olney fine sandy loam 1 to 3 percent slopes —Weld County Colorado Southern Part Ecological site Sandy Plains (R067BY024CO) Hydnc soil rating No Minor Components Zigweid Percent of map unit 10 percent Hydnc soil rating No Vona Percent of map unit 5 percent Hydnc soil rating No Data Source Information Soil Survey Area Weld County Colorado, Southern Part Survey Area Data Version 18, Sep 13 2019 vs_0 Natural Resources C Conservation Service Web Soil Survey 1/28f2020 National Cooperative Soil Survey Page 2 012 Map Unit Description Vona sandy learn 1 to 3 percent slopes— Weld County Colorado Southern Part Weld County, Colorado, Southern Part 76 —Vona sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol 363w Elevation 4 600 to 5 200 feet Mean annual precipitation 13 to 15 inches Mean annual air temperature 48 to 55 degrees F Frost free pond 130 to 160 days Farmland classification Farmland of statewide importance Map Unit Composition Vona and similar soils 85 percent Minor components 15 percent Estimates are based on observations descnptions and transects of the mapunit Description of Vona Setting Landform Terraces plains Down slope shape Linear Across slope shape Linear Parent matenal Alluvium and/or eoltan deposits Typical profile H1 - 0 to 6 inches sandy loam H2 - 6 to 28 inches fine sandy loam H3 - 28 to 60 inches sandy loam Properties and qualities Slope 1 to 3 percent Depth to restnctive feature More than 80 inches Natural drainage class Well drained Runoff class Very low Capacity of the most limiting layer to transmit water (Ksat) High (1 98 to 6 00 in/hr) Depth to water table More than 80 Inches Frequency of flooding None Frequency of pending None Calcium carbonate maximum in profile 15 percent Salinity maximum in profile Nonsaline to slightly saline (0 0 to 4 0 mmhos/cm) Available water storage in profile Moderate (about 6 8 inches) Interpretive groups Land capability classification (imgated) 3e Land capability classification (nonimgated) 4e Hydrologic Soil Group A Ecological site Sandy Plains (R067BY024CO) Hydnc soil rating No l.S Natural Resources Conservation Service Web Solt Survey 1/2812020 National Cooperative Solt Survey Page 1 of 2 Map Unit Description Vona sandy loam 1 l0 3 percent slopes —Weld County Colorado Southern Part Minor Components Remmit Percent of map unit 9 percent Hydnc soil rating No Olney Percent of map unit 3 percent Hydnc sulfating No Julesburg Percent of map unit 3 percent Hydnc sal rating No Data Source Information Soil Survey Area Weld County Colorado Southern Part Survey Area Data Version 18 Sep 13 2019 MNatural Resources Conservation Service Web Sal Survey 1/2/2020 National Cooperative Soil Survey Page 2 012 400 20 56" N 4U` a it N 5x810 Map S:ale: 1:2,150 sf printed on A portrat (8.5" x 11")sheet Depth to Water Table —Weld County. Colorado. Southern Part 533010 g nN 0 30 eo 120 Meters 1W ,Feet 0 1W 20 400 t Mep projection: web r+ermoor Cnrnermotyneoes: W0394 Edge bcs: URA Zone ON WG384 uscies Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey County Road 50 3 pM VCCOD 54Crtii 1/218;2020 Page 1 of 4 400 2C S4V 0 NC" N Depth to Water Table —Weld County. Colorado. Southern Part MAP LEGEND MAP INFORMATION Area of Interest (AO0) Area of Interest (ACI) O Not rated or not available The soil surveys that comprise your AOl were mapped at 124.000 Water Features Soils Strearrs and Canals Soil Rating Polygons tI 0 • 25 25 - 50 50-100 100 - 150 150 - 200 > 200 Not rated or not available Soil Rating Lines 0-25 aso 25-50 • e 50-100 n 100 - 150 — 150 - 200 0%0 5 200 ' Not rated or not available Soil Rating Points • 0-25 O 25 - 50 O 50 100 © 100 - 150 150-200 In >200 Transportation tit Rails ti Interstate Highways US Routes Ma)or Roads Local Roads Background Anal P''otagrapt'y 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 I'lease 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 Soli 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 18, Sep 13. 2019 Soil map units are labeled (as space allows) for map scales 1 50.000 or larger Date(s) aerial images were photographed Jul 17. 2015 —Oct 2. 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps As a result, some minor shifting of map umt boundaries may be evident USDA Natural Resources Web Sail Survey Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 of 4 Depth to Water Table —Weld County Colorado Southern Part Depth to Water Table Map unit symbol I Map unit name I Rating (centimeters) I Acres in ACi I Percent of AO1 47 76 Olney fine sandy loam >200 1 l0 3 percent slopes Vona sandy loam 1 to 3 >200 percent slopes Totals for Area of Interest Description 201 17 218 Water table' refers to a saturated zone in the soil It occurs dunng specified months Estimates of the upper limit are based mainly on observations of the water table at selected sites and on evidence of a saturated zone namely grayish colors (redoximorphic features) in the soil A saturated zone that lasts for less than a month Is not considered a water table This attribute is actually recorded as three separate values in the database A low value and a high value indicate the range of this attribute for the soil component A representative' value indicates the expected value of this attnbute for the component For this soil property only the representative value is used Rating Options Units of Measure centimeters Aggregation Method Dominant Component Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more 'components" A component is either some type of soil or some nonsoil entity e g rock outcrop For the attribute being aggregated the first step of the aggregation process is to denve one attnbute value for each of a map unit's components From thls set of component attributes the next step of the aggregation process denves a single value that represents the map unit as a whole Once a single value for each map unit Is derived a thematic map for soil map units can be rendered Aggregation must be done because on any soil map map units are delineated but components are not For each of a map units components a corresponding percent composition Is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a critical factor in some but not all, aggregation methods 92 0% 80% 100 0% tinNatural Resources Conservation Service Web Soil Survey 1/26/2020 Nabonal Cooperative Soli Survey Page 3 of 4 Depth to Water Table —Weld County Colorado Southern Part The aggregation method Dominant Component returns the attnbute value associated with the component with the highest percent composition in the map unit If more than one component shares the highest percent composition the corresponding "tie break rule determines which value should be returned The 'tie -break' rule indicates whether the lower or higher attnbute value should be returned in the case of a percent composition tie The result returned by this aggregation method may or may not represent the dominant condition throughout the map unit Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value Is specified all components in the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered Tie break Rule Lower The tie -break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie Interpret Nulls as Zero No This option indicates if a null value for a component should be converted to zero before aggregation occurs This will be done only if a map unit has at least one component where this value Is not null Beginning Month January Ending Month December n Natural Resources Conservation Service Web Soil Survey 1128O020 National Cooperative Soil Survey Page 4 014 Small Commercial Buildings —Weld County Colorado Southern Part oven 1O245SN 0 2000 4 mac.... ...L ..-� _. �._Yr_ -.4-. �� •; _ jaw,�y, !ci.}�ydI +"0 ;'x i u '11 '{i 'i i.;+�;•: lip. 'YV"L' I ( xJ1; fJ " +r .fj 7-4 swop Mao.:de 12,150rpsmom mApmbeCle5 cll)Over- teem SUM N 90 ® 129 1'S Feet 0 10) ZD W._Y.�.W. �... 4m eC0 Map 1er1 12n. 000Meroter Conle'm0ffioave WG931 Edge So.OT IZoe 13NNGB1 IA% Natural Resources cam" Conservation Service Web Soil Survey National Cooperative Soil Survey bra" saw N 1128/2020 Page 1 of 5 20400 Small Commercial Buildings -Weld County. Colorado. Southern Part MAP LEGEND Area of Interest (AOI) Area of nterest (AO!) Soils Soil Rating Polygons El II Very limited Somewhat limited Not limited Not rated or not ava fable Soil Rating Lines oy,/ Very limited Somewhat limited "NONot limited r Not rated or not ava lable Soil Rating Points Very limited O Somewhat Fri ted ® Not limited Not rated or not available Water Features Streams and Canals Transportation }+.a Rails omit interstate Highways US Routes Major Roads Local Roads Background 4enal Ptiotograp^y MAP INFORMATION The soil surveys that comprise your AOI were mapped a: 1:24.000. 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 -MRCS certified data as of the version date(s) listed below Soil Survey Area: Weld County. Colorado, Southern Part Survey Area Data: Version ' 8. Sep 13. 2019 Soi, map units are labeled (as space allows) for map scales 1:50.000 or larger Date(s) aerial images were photographed: Jul 17. 2015 —Oct 2. 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result. some minor shifting of map unit boundaries may be evident LSDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 of 5 Smell Commercial Buildings —Weld County Colorado Southern Pen Small Commercial Buildings Map unit symbol Map unit name Rating Component name (percent) Rating reasons (numeric values) Acres In AOI Percent of AOI 47 Olney fine sandy Not limited loam 1 l0 3 percent slopes 70 Vona sandy Not limited Vona (85%) loam 1 to 3 percent slopes Totals for Area of Interest Olney (85%) 20 1 82 0% 17 80% 21 8 1000% Rating Acres In AOI Percent of AOI Not limited Totals for Area of Interest 218 21 8 100 0% 1000% yyp Natural Resources Conservation Service Web Soil Survey 1128/2020 National Cooperative Soil Survey Page 3 of 5 Small Commercial Buildings —Weld County Colorado Southern Part Description Small commercial buildings are structures that are less than three stories high and do not have basements The foundation is assumed to consist of spread footings of reinforced concrete built on undisturbed soil at a depth of 2 feet or at the depth of maximum frost penetration whichever is deeper The ratings are based on the soil properties that affect the capacity of the soil to support a load without movement and on the properties that affect excavation and construction costs The properties that affect the load supporting capacity include depth to a water table ponding flooding, subsidence linear extensibility (shrink -swell potential) and compressibility (which is Inferred from the Unified classification of the soil) The properties that affect the ease and amount of excavation include flooding depth to a water table ponding slope depth to bedrock or a cemented pan hardness of bedrock or a cemented pan and the amount and size of rock fragments The ratings are both verbal and numencal Rating class terms indicate the extent to which the soils are limited by all of the soil features that affect the specified use "Not limited" indicates that the soil has features that are very favorable for the specified use Good performance and very low maintenance can be expected Somewhat limited' indicates that the soil has features that are moderately favorable for the specified use The limitations can be overcome or minimized by special planning design or installation Fair performance and moderate maintenance can be expected Very limited" indicates that the soil has one or more features that are unfavorable for the specified use The limitations generally cannot be overcome without major soil reclamation special design or expensive installation procedures Poor performance and high maintenance can be expected Numerical ratings Indicate the severity of individual limitations The ratings are shown as decimal fractions ranging from 0 01 to 1 00 They indicate gradations between the point at which a soil feature has the greatest negative impact on the use (1 00) and the point at which the soil feature is not a limitation (0 00) The map unit components listed for each map unit in the accompanying Summary by Map Unit table in Web Soil Survey or the Aggregation Report in Soil Data Viewer are determined by the aggregation method chosen An aggregated rating class is shown for each map unit The components listed for each map unit are only those that have the same rating class as listed for the map unit The percent composition of each component in a particular map unit is presented to help the user better understand the percentage of each map unit that has the rating presented Other components with different ratings may be present in each map unit The ratings for all components, regardless of the map unit aggregated rating can be viewed by generating the equivalent report from the Soil Reports tab in Web Soil Survey or from the Soil Data Mart site Onsite investigation may be needed to validate these interpretations and to confirm the identity of the soil on a given site flS Natural Resources ��^ Conservation Service Web Sod Survey 112612020 National Cooperative Soil Survey Page 4 of 5 Small Commeraal Buildings —Weld County Colorado Southern Part Rating Options Aggregation Method Dominant Condition Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more components' A component is either some type of soil or some nonsoll entity e g rock outcrop For the attnbute being aggregated, the first step of the aggregation process is to derive one attribute value for each of a map units components From this set of component attributes the next step of the aggregation process denves a single value that represents the map unit as a whole Once a single value for each map unit is derived, a thematic map for soil map units can be rendered Aggregation must be done because on any soil map, map units are delineated but components are not For each of a map unit s components a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a cntical factor in some but not all aggregation methods The aggregation method ' Dominant Condition first groups like attribute values for the components in a map unit For each group percent composition is set to the sum of the percent composition of all components participating in that group These groups now represent "conditions" rather than components The attribute value associated with the group with the highest cumulative percent composition is returned If more than one group shares the highest cumulative percent composition the corresponding 'tie break" rule determines which value should be returned The 'tie break" rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified all components in the database will be considered The date for some contrasting soils of minor extent may not be in the database and therefore are not considered Tie -break Rule Higher The tie -break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie r : Natural Resources Web Soil Survey Conservation Service National Cooperative Sod Survey 1/28f2020 Page 5 of 5 Corrosion of Concrete —Weld County. Colorado. Southern Part 40° 20' 55 N 4(r 2U' 42' N Map Sale: 1:2,1501 pentad on A porba* (85Th W) Meet. A 538810 3 2) rn' l4/ ('(0.�. r5Ca VIA ia <11f: fit r ; 1 @ i"1'Mr Meters 0 30 so 120 180 Feet 0 1W 200 400 me Map on:le:don: Web Mercers( Corner coordinates' WGS84 Edge ors: U111 Zone 13N WGS84 �i u Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/28/2020 Page 1 of 4 40' 20'55 N 400 2U 42'N Corrosion of Concrete —Weld County Colorado. Southern Part MAP LEGEND MAP INFORMATION Area of Interest (AO') Background Area of Interest (AOI) ® Aeria: Photography Soils Soil Rating Polygons II 0 High Moderate Low No: rated or not available Soil Rating Lines High • • Moderate [Ow • Not rated or not ava lable Soil Rating Points ® High O Mocerate Low O Not rated or no: ava Sable Water Features Streams and Canals Transportation Rails A/ Interstate Highways US Routes Ma:or Roads Local Roads The soil surveys that comprise your AOI were mapped at 1:24.000 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 pro)cct'on that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are requirea This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Sol Survey Area Weld County, Colorado. Southern Part Survey Area Data Version 18. Sep 13, 2019 Soil map units are labeled (as space allows) for map scales 1.50,000 or larger Dates) aerial images were photographed. Jul 17. 2015 —Oct 2. 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps As a result, some minor shifting of map unit boundanes may be evident Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 of a Corrosion of Concrete —Weld County Colorado Southern Pad Corrosion of Concrete Map unit symbol I Map unit name I Rating I Acres In AOl I Percent of AOI 47 76 Olney fine sandy loam Low 1 to 3 percent slopes Vona sandy loam 1 to 3 Moderate percent slopes Totals for Area of Interest Description 201 17 21 8 Risk of corrosion' pertains to potential soil induced electrochemical or chemical action that corrodes or weakens concrete The rate of corrosion of concrete is based mainly on the sulfate and sodium content texture moisture content and acidity of the soil Special site examination and design may be needed if the combination of factors results in a severe hazard of corrosion The concrete in installations that intersect soil boundaries or soil layers is more susceptible to corrosion than the concrete in installations that are entirely within one kind of soil or within one soil layer The nsk of corrosion is expressed as low moderate' or high " Rating Options Aggregation Method Dominant Condition Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more "components A component is either some type of soil or some nonsoil entity e g rock outcrop For the attribute being aggregated the first step of the aggregation process is to denve one attnbute value for each of a map units components From this set of component attributes, the next step of the aggregation process derives a single value that represents the map unit as a whole Once a single value for each map unit is denved a thematic map for sod map units can be rendered Aggregation must be done because on any soil map map units are delineated but components are not For each of a map units components, a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a critical factor in some but not all aggregation methods 920% 8 0% 100 0% race Natural Resources Conservation Service Web Soil Survey 1/2812020 National Cooperative Soil Survey Page 3 014 Corrosion of Concrete —Weld County Colorado Southern Part The aggregation method Dominant Condition' first groups like attribute values for the components in a map unit For each group percent composition is set to the sum of the percent composition of all components participating In that group These groups now represent conditions rather than components The attribute value associated with the group with the highest cumulative percent composition is returned If more than one group shares the highest cumulative percent composition the corresponding 'tie -break' rule determines which value should be returned The tie break rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified all components in the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered Tie -break Rule Higher The tie break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition he tip Natural Resources Conservation Service Web Soil Survey 1/28/2020 National Cooperotive Soil Survey Page 4 of 4 Corrosion of Steel —Weld County, Colorado, Southern Part ti 1 690950 IIIt fSLO i�'(� �C 1-R MI l l! �' l`T�,u l��i: :a° JrSs• v/ A hrotr 530810 530 5300'0 53ekitlu Map Scale: 1:2,150 if prvnted on A portrait (85" x 11") sheet. Meters 0 30 aD 1X lee Feet 0 100 ADO 400 OX) Map prgection: Web Mermtor Caner mordnates: WGSS4 Edge tics: UTM an 13'4 WG3S4 530613 530060 LSDA Natural Resources ma Conservation Service Web Soil Survey National Cooperative Soil Survey 5,0010 wasp 4 a WOOD 1/28/2020 Page 1 of 4 40' 20'56-N 4W X14: N Corrosion of Steel —Weld County Colorado. Southern Part MAP LEGEND Area of Interest (AO') Background Area of Interest (AO1) Aena: Photography Soils Soil Rating Polygons I High Moderate Low Not rated or rot avatiabe Soil Rating Lines High • • Moderate oat/ Low • • Not rated or not ava,latle Soli Rating Points ■ High Q Moderate ■ tow • Not rated or not availaole Water Features Streams and Canals Transportation 1 Rails A/ I^te'state Hghways US Routes Major Roads Local Roads MAP INFORMATION The soil surveys that compnse your AOI were mapped at 1:24,000 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 iEPSG.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 he 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) I.stee below Soil Survey Area: Weld County. Colorado, Southern Part Survey Area Data Version 18. Sep 13 2019 Soil map units are labeled (as space allows) for map scales 1 50.000 or larger. Date(s) aerial images were photographed. Jul 17 2015 —Oct 2, 2017 The orthophoto or other base map on which the so.l Ines 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 usuA Natural Resources Web Soil Survey a Conservation Service National Cooperative Soil Survey 1/28/2020 Page 2 of 4 Corrosion of Steel —Weld County Colorado Southern Pan Corrosion of Steel Map unit symbol I Map unit name I Rating I Acres in AO! I Percent o}AOI 47 76 Olney fine sandy loam High 1 to 3 percent slopes Vona sandy loam 1 to 3 High percent slopes Totals for Area of Interest Description 20 1 17 02 0% 60% 21 6 100 0% ' Risk of corrosion' pertains to potential soil induced electrochemical or chemical action that corrodes or weakens uncoated steel The rate of corrosion of uncoated steel is related to such factors as soil moisture particle size distribution acidity and electrical conductivity of the soil Special site examination and design may be needed if the combination of factors results Ina severe hazard of corrosion The steel in installations that intersect soil boundaries or soil layers is more susceptible to corrosion than the steel in installations that are entirely within one kind of soil or within one soil layer The nsk of corrosion Is expressed as 'low' ' moderate ' or 'high " Rating Options Aggregation Method Dominant Condition Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole A map unit is typically composed of one or more 'components" A component is either some type of soil or some nonsoil entity e g rock outcrop For the attnbute being aggregated the first step of the aggregation process is to denve one attnbute value for each of a map unit s components From this set of component attributes the next step of the aggregation process derives a single value that represents the map unit as a whole Once a single value for each map unit is denved a thematic map for soil map units can be rendered Aggregation must be done because, on any soil map, map units are delineated but components are not For each of a map units components a corresponding percent composition is recorded A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit Percent composition is a cntical factor in some but not all, aggregation methods 0 Natural Resources Conservation Sorvlce Web Sod Survey 1/28/2020 National Cooperative Soil Survey Page 3 014 Corrosion of Steel —Weld County Colorado Southern Part The aggregation method 'Dominant Condition' first groups like attribute values for the components in a map unit For each group percent composition is set to the sum of the percent composition of all components participating in that group These groups now represent "conditions' rather than components The attribute value associated with the group with the highest cumulative percent composition is returned If more than one group shares the highest cumulative percent composition the corresponding tie break rule determines which value should be returned The'tle break' rule indicates whether the lower or higher group value should be retumed in the case of a percent composition tie The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred Component Percent Cutoff None Specified Components whose percent composition is below the cutoff value will not be considered If no cutoff value is specified all components in the database will be considered The data for some contrasting soils of minor extent may not be in the database and therefore are not considered Tie break Rule Higher The tie break rule indicates which value should be selected from a set of multiple candidate values or which value should be selected in the event of a percent composition tie rANatural Resources Conservation Service Web San Survey 1/28/2020 National Cooperative Soll Survey Page 4 0t4 National Flood Hazard Layer FIRMette 40°21'0.29"N 40°20'32 87"N 0 250 500 1.000 1,500 Feet 2.000 1:6,000 hi., }. )? FEMA Legend SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A Y, 499 With BFE or Depth Zone AE AO, AN VE. AR Regulatory Floodway OTHER AREAS OF FLOOD HAZARD OTHER AREAS r • INO SCREEN 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Zone X Future Conditions 1% Annual Chance Flood Hazard zone x Area with Reduced Flood Risk due to Levee. See Notes. zone x Area with Flood Risk due to Levee/0re o Area of Minimal Flood Hazard Zone x Effective LOMRs Area of Undetermined Flood Hazard /one u GENERAL - Channel. Culvert, or Storm Sewer STRUCTURES i I 1 1 i 1 I Levee. Dike, or Floodwall 20.2 17.5 Cross Sections with 1% Annual Chance Water Surface Elevation Coastal Transect ... 5,3.,,.._. Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary Coastal Transect Baseline OTHER _ Profile Baseline FEATURES Hydrographic Feature MAP PANELS 9 y71 Digital Data Available No Digital Data Available Unmapped N The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 4/8/2020 at 6:07:28 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear basemap imagery, flood zone labels, legend. scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. DRAINAGE CALCULATIONS Job Name Job No. Dale Richert Miter 2019-112 1/3012020 PERCENT IMPERVIOUS HISTORIC BASIN Site Aran - 27%561 re Existing Sib Conditions roved 0 4' Packet Gravel 0 ft; Runts/Cm roe 0 ff' andscaprglJndtvnprd 278961 tY ' 6 40 AC Percent imperviousness Existing (Calruetedl 0 02 • f C, • nxu'$ coeflicitnl for 5 -year frequency ;from Table RO.5)('Note Sn& Type) C,. ' rugff a,eficGe^t 1cr 10 year frequency (Iron Table RO.5) ('Mete Sod Type) C,Q. • nnoal coefficient kx 100 ear 'rcquency((ma' Title RO 5) (•Note Sal' Type) Constant ur inikrW twin boxes above If out vnli* of note Cocilated hue Value that seldom changes Percent tmptr oousnese from able RO-3 raved Gavel RuufsCCori.-: tee Geeer'bell/. . &sea' nq 009 0 IT 036 TIME OF CONCENTRATION t, HISTORIC E�.'L•L EquatiA1RVi L .,. • tomputeo bale of concentration tm,rt,tes) L = ovesntric (inutai) tow time (m flutes) L = ch nnetized now sme (m001.4) L' (0 396(1 1-CsXt "ma's' Equation RO 3 L • withal or overland Row lime (minutes) C, : turd! coefficient Ion 5 -year freef,ency prom Table HO b) ("4014I Sal Typo) L, • Ionetr, t I ove'1rr tl 'low (!). riot greater Fan 300' (urban) of 500' (rural) S, - awuage sk,l,e Hinny :wmiand lbw pan (We) Hiatonc Ora nago Patn 1 L, • Delta = 500 47 1.00 040 090 002 I Sol Type ft. not greater than 330'(urban) or 500 (rural) n S. = C,= L• 4162 minutes L • L,4(e0'C.1'(s.*')) • Lf63V, Equation RO-4 I, - rhMneuzed nun lino (m.wleal C. • Conveyance CoeMucnl ( labs R0 1; L, • length of charne(iuo (low (II) S. = average slope *arc t3tarlrvkzet 'low pat I Nail L, - 716.9 it Dtyta - 12 3 It Therefore. 0 COW 009 MI Table R0-5 Stec K• 0 01 72 10 912 5074 HISTORIC FLOW VALUE FOR S -YEAR O=C IA Equation FtO1 O=poMrate ofrtnf (CFS) C • Runoff coefficient I • Ng Inlsrwty of rainfall for a dilates equal to grin I. (mini) A • are (Aires/ C. = 000 Imperviousness _ 2% Is a 1 26 Malt LAIN lamas fnterpotneon hone R9lnfad iDF "rabies lc = 51 Mututas A = 6 40 Acres Ooiew'r •I rr Wit ten, rVtl Table RO 2 T'nutcs • Use Tc • 51 Minutes B 0.14 HISTORIC FLOW VALUE FOR 10 -YEAR UtCEA Equation HO CFS= 0115 CFSJAC O • peak rale of rtnol;CFS) C • Rutolf coefficient I - rig 1Mtnityal'aidAl fo' a rbeaton equal to giver t. (mu) A = area (Acre!) Cl. {w• A= 0., 60 6 40 Imperviousness • 2'. tam. using into, tr-ste olaeor from Rasn'Sl IDF Tables. Tc • 51 Minutes Acres 1 74 CFS • 0 272 CF S/AC HISTORIC FLOW VALUE FOR 100•YEAR O=CIA Equation RC -1 O = peak rate of runoff (CFS) C = Runoff coefficient I ' avg intensity of rainfall for a duration equal to given 1, (INhr) A =' area (Acres) CIO„ 0.36 Impervloksi ess - 2-. l,0• = 3.03 in/x using linear interpolation from Rainfall ICE Tables, Tc = 51 Minute* A ■ 6.40 Acres O ilia w • f _ 699 CFS = 1091 ,CFSIAC PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN A Site Area = Proposed Site Conditions Pavel/PtKlt , Gravel Roofs/Goi,crete Landscaping 203107 It' fl' 123114 ft' 31381 ft' 49152 fr • Percent tmpervrousness trom Tabe RO.3 PavedrPonds Gravel Roofs/Corwele I. andscaps g 4.60 1:C I 0.38 Percent Imperviousness Developed (Calculated) C. - ruwff ale nowt for 5 -year frequency (from Table RO-5) ('Note Soil Type) C10 • runoff cooffic-er4 for 1Dyear frequency (from Table RO5) (•Note Soil Type) C,,• runoff coefficient for 100 -year Ireq.oency (from Tablt RO-5) ('Note Sol Type) TIME OF CONCENTRATION 4 DEVELOPED 4 r ' t•i, Equation RO 2 l:s • oo'nguled time 01 concentrabon (minutes) t, a overland (initial) flow tine (minutes) 1, = chenneiized flow time ( mr'dies) % = (0 395(1 1-CsM1,'s)YS.°*' Equation RO-3 I. a overland (initial) flow tine (minutes) C4 a rutU coefficient for 5.year frequency (from Table RO-5` ('Note Soil Type) L, a length of overland Now ((U. not greater than 303' (urban) or 50O ;rural) S. • average slope along overland flow path (Pitt) L, a 500 It, not greater than 300 (unoan) or SOU (rust) Delta • 1 40 h 029 0.36 0.50 'Developed Path 1 1 00 040 090 002 S, a C,= 0009 0 29 tuft Tame RP 5 Sall Type I 8 V 3411 minute, I. • LI((60•ca•(S.0')) a L 00V, Equation RO-4 = channelized flow tune (minus*; C.' Conveyance Coefficient (Toole RO 21 L = length of charnmzcd flow (n) S,.= average slope along dlarsnefrzed flow patt (ft'h) Therefore. t Oa 4c Ddta a 603.5 9.6 ft ft S.■ 00191 10 6.08 40.19 1744E Of CONCENTRAnoN CHECic ti„ 91180)+10 m mutes mirx,os ftifi Tads RO.2 Equation RO.5 Ts. not in exceed equation RO-5 al first design pt 4 0 . = computed tune o' ccncoiUalion (minutes) L, r length of flow path (II) i a imperviousness in decimal S, = average slope along ttlannt,zed now path (fifft) Della = 039 1003.50 14 h It 1558 Si 014 m nutes Use 4.., _ Use Tc = 16 Minutes for Sub Basin A Drainage Calculations DEVELOPED FLOW VALUE FOR 5 -YEAR • DESIGN POINT 1 O=CIA Equation RO-1 Or, r....i... 16 O = peak rate cf runoff (CFS I C = Runoff coef icient I = avg intensity of ra.ntak ler a duration Equal kr given t, A = area i,AC) = 11 29 imperviousness = 39% I, = 2.52 nth( us nq linear interpolation from Rainfall IDF Tables, Tc = 16 Minutes A - 4 6e Acres (Net: l _ 3.42 CFS= 0731 CFS/AC DEVELOPED FLOW VALUE F OR 10 -YEAR - DESIGN POINT 1 0 -CIA Fit $414,5, HO 1 O r peak rate of runoff (CFS) = Ruoff coerfruent = avg ertenstty of ranfail for a duration equal to gr-.n L. A a area (AC) Cm, _ 0.36 ImpennnisneSs = 39!- Iw ` 3.13 LMV using Know micrpolnuun from Rainfall IDE Tables, Tc = 16 Minutes A • 468 Acres (Net) O.ct...,.4• I 527 CFS = DEVELOPED FLOW VALUE FOR 160 -YEAR - DESIGN POINT 1 O=CIA Equation RO-1 127 , CPS/AC O a peak rate of runoff (CFS) C a Runoff coefficient I - avy intensity of Nadal' fur a d.rralon aqua to given L A - area (AC) C,, ° 0 50 mpornoasnns = 3d% I.,•' 5.95 My using linear interpolation from Rainfall OF Tables. Tc ■ 16 Minutes A a 468 Acres (Nat) Ouse. 'rein `I 1191 CFS = 2.975 ICFS/AC PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN B Site Area r 38711 ft' Proposed Site Conditions Paved/Ponds 0 fir Grovel h' Roots/Congete 0 ft' Landscaping 370 n' 0.84 AC Percent Imperviousness Developed (Osculated) 0.40 = i C. • runoff coefficient for 5 -year frequency ( from Take RO.5) ('Note Soil ' ype C,. a $tad% tud(irlerd toe 10 -yens from 1rru:y (from Tame RO-5) ('Note Soil Type) tuna. = runoff ooeff'caent for 100 -yea lreequency (from I eke RO-5) ('Note Soil ' ype 36341 Percent Imperviousness from Table RO-3 TIME OF CONCENTRATION t, DEVELOPED I.. - +V Equalnr. RO-2 PavecVPonds Gravel RootafCorcrele Landscaping ) 0.30 036 ) x00 t,..,, = computed time of Concentration (mans) L • overland Omuta) flow lime (minutes) t." channelled flow time (minutes) t = (0.395(1 1 -Cal. "')yS "" Equation RO-3 a overland Drawl) flow time (minutus) Ca ■ runoff coefficient for 5 -year frequency (from Table RO-5) ('Note Soil Type) length of overland flew (ft). not greater than 301 (titan) or 500' (rural) S. • average slope along overland flow path (tuft) Developed Path 1 L-• Delta = 4735 8.00 1 00 040 090 002 Soil Type B ft. nut greater then 300 (urban) or 500 ((Oral) ft S.= C. • 0017 030 Itift Table RO-5 t v 26.44 minutes U((80'C.Y(S.•6)) • L+180V, Equation RO.4 I, • C ham$tel flow time (m nutes) C. a Conveyance Coeff.cioil (Table RO.2; 4 = length of c hannelrzed flow (ft) S. a average slope along chamehzed flow path ( fttft) L • 0 ft Delis = 0 ft Therefort7, S„= C.• 0 0000 0 000 2844 TIME OF CONCENTRATION CHECK Ita..•(1/100).10 m nuts minutes rutt Tame RO-2 Equation RO-5 T, not lo exceed e:.uation RO.5 at first desgn of 4 a • computed erne of wnceewsaon (minutes) L, length of now Path (ft) i = knpenioioness in decimal S, • average slope aong Chennelissd flow path 01/41) Dena • C 40 47350 6 ft ft 1263 = 0017 fun minutes Use l rA = 13 • Use Ts - 13 Minutes for Sub -Basin B Drainage Calculations DEVELOPED FLOW VALUE FOR 5 -YEAR - DESIGN POINT 2 O -CIA Equation RO 1 O • peek rate of runoff (CFS) C • Runoff coefficient I - anti intensity cf rsntatl for a du anon equal 10 pivon L A= area (AC) C. • 030 mpervio moss ' 43% Ottr 14 A : 084 Acree (Nell 01137 1 2 79 rvty using linear mlerpc$a,un from Rainfall (OF Teofes Tc • 13 Mimeos 071 CFS • DEVELOPED FLOW VALUE FON 19-YEAN - DESIGN POINT 2 O•CtA Equation RO 1 CI to %.,.can CFS.AC O • Dealt retool runoff (CFS) C a R,st:M cnetfiuccil I = av9 intensify of rarrfatl for a %aeon equal to given L A = area:AC) Cis" 0.36 Imperviousness I,,. I. 3 4' Mi: using lines ntamulal•xi from Rainfall IDF Tables Tc ■ 13 Minutes A = 0154 Aues (Net) f _ 1 05 CFS • DEVELOPED FLOW VALUE FOR 100 -YEAR • DESIGN POINT 2 O•CIA :citation RO-1 1249 ,C FS,AC O - peak rate of runoff ICFS) C • Runoff cneffunert I • evg intensity of rainfall for a duration equal eo given t. A • wee (AC) l _ Cr.," • i„ - A• 50 6'8 064 ImpereciuSness • 40% in/Iv mark' tear ,nierpolaborfrom Rainfall IDE Tables. Tc • 13 Mates Acros (Nell 277 CFS - 3 290 'C PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN C 5 o Area = Proposed Sits Conditions Pry d Gr evN Racifs/Conctete Landerepug 23730, 6 1221 h' 7201 11' 0 R' 4313 M 0 54 FS.AC Percent nnpervwuw-em hoar Table RO•:1 Pend Caravel Roofs/Cancrekr Landscaping AC Percent Imperviousness Developed (Calculated) J 0.64 • t Cs = runoff want -tent for `-year frequency (from Table RO 5) ('Note Soil Type C,,, • runt* Coefl,C:et* for 10 year trequeicy (trem I able NU 5) (*Nolo Sal Typo GK., • n%lo`t rznr.ffxan%ni Inc 0O-yeer 'coleus wy (from Telit RO-5)(*Note Soil Type TIME OF CONCENTRATION t, DEVELOPED 4 ... • C•t Equation R0.2 .,, - an npvtad hale of coftantabon (minutes) C a ovcatand lntia) B0* Omit (minutes) lc nenneWed flow time (mingle`) l • CO 396(1 1 CAL" ?YS," Equation R0.3 - ovtwland (i nbal) flow time (minutes) C. - runoff CoeHic'eml for 5 -year frequency (tram Table RO-51('Nixt Sod Type) L. • lengtr of overlaid floe (1) rol greater then 300" Curbs,.) er SOY (ritA' 9, = sweeps slope eking overlain(' fir path (Mir Developed Path :._ Delta 122 0 3.00 1 00 0.40 090 002 SoN Type 8 iL not greater Lain 300 (urban) W 500 (rare ft S. • C, = 0 024 044 WTI 1 elk NO -5 l • 9 03 m miles l a LJltg'A-C.1*(S;" 1) • L/60V, Egwtiuii RO.4 1, - channettzed flow brne (mnutes) F,^, r Conveyance Cuefftaenl (Tame RO. 1) L. • Ierglt of cha neideo Mow (ft; S. • average stops along e14lne ted Mew path (Mg) L, = C ft ['vita - 0 h 'Mnefurt. L C.. S..- C.o 0 0000 000 0 8? minutrn minutes furl 1 able KO•! TIME. OF CONCENTRATION CHECK uw'(U'80)'10 = computed tint of concentrabun (n' flutes) ) I • imperviousness in decimal S • average slope along chonnel,zed flow pain (ff.fft) 1 - Delia 0 64 12280 -3 1068 m int,lc5 S• 0024 • Use lc • 11 Minutes for Sub -Basin C Urainage Calculations DEVELOPED FLOW VALUE FOR S-YLAR 0 -CA FgWon RO-1 a Use l .,' 11 C = peat rife of ttintf (CFS) C = kunof ooeffrcle w I It awl niensity of raroas for a oura,on egtw Ic given A = area (AC) C, - I, _ A • 054 Apes (Net) I 071 044 2.98 DEVELOPED FLOW VALUE FOR idYEAR O•CtA Equebon RO1 CFS ■ Ey.rlrt u r RO-5 1, rut Y) s,scngc sgrzd*nt RO.3 al fest design ut L. = length Of how path (11) Imperviousness = 64•. rifer wing linear interpolaecn from Rainfall IJF tables. lc - 11 Minutes S'AC O = pea rate of runoff (CFS) C = Runoff coefficient I = avg Waggly of rainfall for a duration equal 10 given (, A • area (AC) Cie• Iu = A- 0 48 3.72 0.54 0 9r DEVELOPED FLOW VALUE FOR t00.YEAR 0= CIA Equat.onRO-I 0 u I %....s„.1 CFS • Imperviousness • 64r• Me using Wear nWpo4Mcn Pam Racer/1 13F Tables. Tc a 11 Manes Aues(Nei) _ 1 788 ICFSIAC = pea4 rate of runoff (CFS) C • Runoff coefficient I = any intensity of rainfall for a duration ewe, to given t A= area (AC) Cr.= 059 I,. • 7.05 An 0.54 2.23 CFS- I mpennotaness = 64% Mt using wow interpolation from Rainfall IJF Tatra. Ti: • 11 Minutes Acre%(NO) 4 089 1CFS/AL PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN D `ilia Area Proposed Sue Conditions Pond Gravel RoofWWConuete Landscspng fl' Pacer( l-npervicaness Developed (Ca:cuuned) Ce = runoff coefhoorw for 5-yeer frequency°Torn Cu, ■ runoff n)&tk eni fur '0 -Year frequency (from - runoff affluent for 100 veer frequency I from 141313 G 66Ti 0 ire f t' nr fir 8191 Pecan! mper.qusr1SY from Tabu RO 3 0 34 IAC 0 19 Table RO-b) ('Note Soil Type) Table RO-5) ('Note SotType) Table RO-5) ('NO(e 5or Type) Pond Gravel _ Root$lConcret _ Landscaping _ C19 027 0 44 1 00 040 090 0 02 Soil Type I f3 PERCENT IMPERVIOUS DEVELOPED - SUB -BASIN E Site Area u Proposed Site Conditions Pond 0 t!, Gravel 0 R' Roofs7Concrete 0 tt2 Landscaping 20087 lY C 47 AC Pertain( imperviousness f eve'aped (Ca.wtaled) Cs a runoff ebelfrerert for b -yew frequency(dom Tab e RO.5) (*Note Soil Type) cm, • runoff eoelfscaent b 10 -year frequency (ko , Tatre RO-51 ('Note Sod Type) Om • runoff coelbwnt for 'W- esr frequency (from Tabs RO 5) I'Noto Sod type) 20687 Itr DEVELOPED FLOW VALUE FOR SYEAR Q=CIA Equation RO.t Percent Imperviousness from Table RO.3 Pond Gravel Roofs/Concrete Landscaping 017 036 1 00 040 090 0 02 Soil Type Et (i = peak rate of neon (C F Si C = R,noff codfioert = ave intensity cf ra'rtal tr a dureson equal to given t, A = area (Ac;) C. = 0.09 imperveoue:r.ess = 2•. 1. • 2-N.2 avty using sneer .rtcrpoliCio n from Rainfall IDF Tables. Tc = 16 Minolta A _ 047 Ades (Neal O►a......- - 0 1 t CFS = 022' IC-SrAC DEVELOPED FLOW VALUE FOR 10 -YEAR O•CIA Equation RO-1 a re rw.w• O • peak rate of runoff (C°S) C • Ru'tcf coefficient I • avg intensity of ra &SI la a dreben equal to given t. A=area ;AC) C,e = 017 impennousres5 = 2% I,. • 3.13 vVn• using linear inlerpotati n from Rarntdl ICF Tattle Tr • 16 Minutes A= 047 Aurs(Netl I 025 DEVELOPED FLOW VALUE FOR 100 -YEAR O•CIA EgtiasonRO1 C.FS - (, SnAC O = Goo. rate of ruref (CFSt C • Runlet( coeffrcern I • am entersty of rental for a Clinton equal lo given L A • ern (AC) C 3C imperviousness : 2% Ir.n • •r.-9` 4nsw us ng linear rrterpn'aabnnt from Rants IDF Tetles, Tc = 16 Minutes A = C.47 Apes (Nell _ 2 142 ICE SAC :FS • PERCENT IMPERVIOUS DEVELOPED - BASIN -1 • Basin -1 is Comprised of Sub -Basins A.B.C. Which Contributes Stormv.aer Runoff to the Detention Pond See Area • Proposed Site Conditions Pond Gravel Rooftsif..:ontrate LandscapuY) 26414e1 12216 166716 31381 53835 f t' it, f f' ft' (t' 606 Percent Imperviousness from labia RO.3 Pond Gravel Roofs/Coljeltr I endscariYJ AC Percent Imperviousness Developed (Calculated) 0 42 a C, - runoff a oHrue.M Fa 5 -year frequency (from Table R¢5) ('Now Soil 'Ile) Co, = runoff coefficient for 10 -year frequency (ham Table RO-5) ('None Sod Type) C. - raft r,oell lent tor 10O -year frequency (from Table RO.5) ('Note Sod Type) 0.31 037 0.50 1 00 0 40 090 007 Sol) Type 8 (WWI OPEw FLOW VALUE FOR 5 -YEAR O'CIA Equation Re -1 O - peak rate o' runoff !CFS) C • Run't coefficient I i avg rrbrtsrly of rainfall for a &rate : equal to given t A = area (AC) C$= 031 Impervctsness = 42% II = 2 52 ,nitr mtricorcer of rpolakon fern Rainfall IDF 'ages. Tc a 16 Minute% A = 606 Acres (NQt) O, 31 4 74 CFS 0.791 CFSJAC DEVELOPED FLOW VALUE FOR 10 -YEAR O -CIA Equation RC -1 I _ O • peak rote o' runoff (CFS) C • Run9 coeffa.mta = avg rrtrns,ty at rainfall Ier • duration epual lc given L. A - art 1(AC) Cy - 0.37 Impervwvsn0ee = 42•. ly = 3 13 iM': using Weer rn4ypniaboo 'min Rsr4Sl DF Tablet Tc = 16 Minutes A = 606 Acres (NM) 101 DEVELOPED FLOW VALUE f(Xi 100•YE.AR O•CIA EquetonRO-1 Or,o rarre•re CFS = Ise I CFSJAC O • peak rate of runoff (CFS) C = Runoff coefficient I • Avg Internrty of rakddl for s dustir I Nu* iv give.% t A • am (AC) A• -j lea 050 5 95 606 Imperviousness = 42% in/hr using linear interpolatxxn from Rainfall OF Tables, Tc. it 16 Minulrs Ave. ( Nei) CFS = 2.975 I CFSJAC 1/28/2020 Precipitation Frequency Data Server NOAA Atlas 14, Volume 8, Version 2 Location name: Kersey, Colorado, USA' Latitude: 40.3463', Longitude: -104.5305° Elevation: 4655.77 ft" ' source: ESRI Maps source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanje Perice. Deborah Merlin. Sandra Peviovic, ',Otani Roy. Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yeide, Geoffery Bonnie NOM, National Weather Sella. Suter Spring. Maryland pF tabular ( ELI) Biwa Maps &perials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour) Average recurrence Interval (years) Duration 1 2 5 10 [ 25 j[ 50 100 (_ 200�L 500 ll 1000 _1 5 -min 2.94 (2.39-3.86) 3.56 (2.88-4.43) 4.72 II (3.80-5.89) 5.83 (4.88.7.32) 7.57 (5.93-10.1) 9.08 (6.88-12.2) 10.8 (7.81-14.9) 12.6 (8.70-17.9) 15.3 1110.1-22.3LJ 17.4 (11.1-25.6) 10 -min 2.15 (1.75-2.68) 2.60 (2.11-3.24) 3.46 , (2.79-4.31) 4.27 (3.42-5.36) 5.54 (4.34-7.41) 6.65 (5.04-8.96) 7.87 (5.72-10.9) 9.22 (6.37-13.1) 11.2 (7.37-18.3) 12.8 (8.14-18.7) 15 -min 1.75 (1.42-2.18) 2.12 (1.72-2.64) 2.81 (2.27-3.51) 3.47 (2.78-4.35) 4.51 4 (3.53-6.02) 5.41 (4.10-7.29) 6.40 (4.65-8.84) 7.50 j (6.18-10.8) 9.08 (6.00-13.3) 10.4 (6.61-15.2) 30 -min 1.18 (0.954-1.48) 1.42 (1.15-1.77) 1.88 , (1.52-2.35) 2.33 (1.88-2.92) 3.03 (2.37-4.05) 3.63 (2.75.4.901 4.30 (3.13-5.95) 5.05. (3.49-7.17) 6.12 (4.04-8.94) 7.01 L(4.46.10.3) 60 -min 0.731 10.593-0.909) 0.870 (0.705-1.08) 1.14 (0.924-1.43) 1.42 (1.14-1.78) 1.86 (1.46-2.50) 2.25 (1.71-3.04) 2.69 (1.96-3.73) 3.18 (2.20-4.53) 3.89 (2.58-5.70) 4.49 (2.86-8.59) 2-h 0.437 (0.357-0.538) 0.515 (0.420-0.838) 0.674 (0.548-0.834) 0.835 (0.674-1.04) 1.10 (0.878-1.47) 1.34 (1.03-1.80) 1.61 (1.18-2 22) 1.91 (1.34-2.71) 2.36 (1.58-3.43) 2.74 (1.78-3.98) 3 -hr 0.319 (0.282-0.391) 0.372 (0.305-0.456) 0.482 (0.394-0.594) 0.597 (0.485-0.739) 0.790 (0.633-1.08) 0.965 (0.745-1.30) 1.17 (0.862-1.80) 1.39 (0.980.1.96) 1.73 (1.16-2.50) 2.01 (1.30-2.90) 6-hr0.183 (0.152-0.223) 0.216 (0.178-0.262) 0.280 (0.231-0.342) 0.345 (0.282-0.423) I 0.,52 (0.384-0.595)) 0.547 (0.425-0.724)1 0.654 (0.487-0.887) 0.775 (0.550.1.08) 0.952 0.648-1.36) I 1.10 (0.719-1.57) 12 -hr 0.106 (0.088-0.128) 0.126 (0.105-0.152) 0.163 (0.138-0.198) 0.199 (0.164-0.242) 0.254 (0.205-0.328) 0.302 (0.235-0.393) 0.354 (0.266-0.472) 0.412 (0294-0.564) 0.495 (0.339-0.697) 0.564 (0.372-0.798) 0.063 0.074 0.094 0.113 0.142 0.166 0.193 0.222 0.264 0.298 24 -hr (0.053-0.075) (0.062-0.089) (0.079-0.113) (0.094-0.138) (0.115-0.180) (0.131-0.214) (0.146-0.254) (0.160-0.301) (0.182-0.367) (0.199-0.417) 2 -day 0.036 (0.031-0.043) 0.043 (0.036-0.051) 0.054 (0.046-0.064) 0.084 (0.054-0.077)) 0.079 0._ 0.119 [R086-0.159)1(0.097-0.191) 0.139 0.155 (0.104-0.215) 3 -day 0.027 (0.023-0.031) 0.031 (0.026-0.036) 0.038 (0.033-0.045) 0.045 (0.038-0.054) 0.055 (0.045-0.069) 0.064 (0.051-0.080) 0.073 (0.056-0.094) 0.082 (0.060-0.109) 0.096 (0.067-0.130) 0.106 (0.072-0.147) 4 -day 0.021 (0.018-0.025) 0.025 (0.021-0.029) 0.030 (0.028-0.036), 0.035 (0.030-0.042) 0.043 (0.035-0.053) 0.049 (0.039-0.082) 0.056 (0.043-0.072) 0.063 (0.048-0.083) 0.073 (0.051-0.100) 0.081 (0.055-0.112) 7 -day 0.014 (0.012-0.016) 0.016 (0.014-0.019) 0.020 (0.017-0.023) 0.023 (0.020-0.027) 0.027 0.023-0.033 0.031 (0.025-0.038) 0.035 (0.027-0.044) 0.039 (0.029-0.051) 0.044 (0.031-0.059) 0.048 (0.033-0.066) 10 -day 0.011 (0.009-0.012) 0.012 (0.011.0.014) 0.015 (0.013-0.018) 0.018 0.021 (0.017-0.025) 0.024 (0.019-0.029)4(0.020-0.033) 0.026 0.029 (0.021-0.037) 0.032 (0.023-0.043) 0.035 (0.024-0.048) 20 -day 0.007 (0.006-0.008�1�0.007-0.009 0.008 0.010 (0.008-0.011) 0.011 (0.009-0.013) 0.013 (0.011-0.015) 0.014 (0.011-0.017) 0.015 (0.012-0.019) 0.017 (0.013-0.021)4(0.013-0.024) 0.019 ((0.014-0.027)1 0.020 30 -day 0.005 (0.005-0.006) 0.006 (0.005-0.007) 0.007 (0.006-0.008) 0.008 (0.007-0.010) 0.010 (0.008-0.011) 0.011 (0.009-0.013) 0.012 (0.009-0.014) 0.013 (0.009-0.016) 0.014 (0.010-0.018)) 0.015 (0.010-0.020 45 -day 0.004 (0.004-0.005) 0.005 (0.004-0.008) 0.006 (0.005-0.007)1 0.007 (0.008-0.008) 0.008 [(0.006-0.009) 0.008 (0.007-0.010) ((0.007-0.011) 0.009 0.010 (0.007-0.012) 0.011 (0.008-0.014) 0.011 1(0.008-0.015)! 60 -day 0.004 A0.0034.004) 0.004 (0.004-0.005) 0.005 (0.004-0.008) 0.006 (0.005-0.008) 0.006 (0.005-0.008) 0.007 (0.008-0.008) 0.008 (0.008-0.009) 0.008 0.006-0.010) 0.009 (0.006-0.011) 0.009 (0.007-0.012) j 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). 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 average recurrence interval) 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.--- — —�� ^ ._ — — ,— - sack to Top PF graphical httpsi/hdsc.nws.noaa.gov/hdsclpfds/pfds_printpage.html?tat=40.3463&Ion=-104.5305&data=intensity&units=english&series=pds 1/4 1/28/2020 Precipitation intensity (in/hr) Precipitation intensity (in/hr) Precipitation Frequency Data Server PDS-based intensity -duration -frequency (IDF) curves Latitude: 40.3463°. Longitude: -104.5305° 100 000 10.000 L000 0.100 0.010 0.001 c cc E E E *A O LA r-/ r-4 0 rn c E O I- N C 0t 'LS) L .-1 Duration L. r N cm a � CO €13 CM -c q -c V -c ? n O N O '42 5 10 25 50 100 200 Average recurrence interval (years) NOAA Atlas 14, Volume 8. Version 2 500 1000 Created (GMT) 1Ue Jan 28 23:00:43 2020 Back to Top Maps & aerials Small scale terrain Average recurrence interval (years) — 1 2 — 5 — 10 25 50 100 200 - 500 1000 Duration 5- mmn — 2 -day 10 -min — 3 -day 15-mtn — 4. -day 30-mn — 7 -day 60 -min — 10 -day 2 -hr — 20 -day 3-r1r -- 30 -day 6fir -- 46 -day 12 -hr — 60 -day 24 -hr httpai hdsc.nws.noaa.govlhdsdpfds/pfdsfirintpage.html?Iat--40.3463&ion=-104.5305x,data=intensity&units=english&series=pds 2/4 I _ 1/28/2020 Precipitation Frequency Data Server Large scale terrain - �Z tr C Fel tCollins • 7Q Longs Feuh, 4345 in . f oulder • - Cheyenne - e Glceley .m. • Lonynicit 100km r� ti6 Fort Cot Di Denver Large scale map 1 Cheyenne G�a Stile Longman' cBotdder Denver 100km t 60mi Large scale aerial https.//hdsc.nws.noaa.gov/hdsc/pfds/pfds _printpage.html?lat=40.3463&Ion=-104.5305&data==intensity&units=engiish&series=pds 3/4 1/28/2020 Precipitation Frequency Data Server Back to Top US Department of Commerce National Oceanic grid Atmogphenc Administration National Weather Service Nationa! Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?' HDSC Questions a@noea gov Disclaimer https://hdsc.nws noaa.gov/hdsclpfds/pfds_printpage htmiellat=40 3463&lon--104.5305&data=intensity&units=english&series=pds 4/4 V _ Intensity -Duration Curves for Rational Method 1 From NOAA Atlas 14 1 -HOUR POINT RAINFALL DEPTHS 2 -YEAR 0.870 S -YEAR 1.140 '0 -YEAR 1.420 25 -YEAR 1.860 50 -YEAR 2.250 100 -YEAR 2.690 - Input Fields Equation 5-1 28.5 P 1 _1 (10 + T4)°'S6 I = rainfall intensity (inches per hour) P, = 1 -hour point rainfall depth (inches) Td= storm duration (minutes) Time (minutes) Intensity -Duration (inches per hour) 2 -year 5 -year 10 -year 25 -year 50 -year 100 -year 5 2.95 3 87 4.82 6.31 7.63 9 12 10 2.35 3.08 3.84 5.03 6.09 7.28 15 1.98 2 59 3 22 4.22 5.11 6 11 20 1.71 2.24 2.79 3.66 4.43 529 25 1.52 199 2 47 3 24 3.92 4 69 30 1.37 179 2.23 2.92 3.53 4.22 35 1.24 1 63 2 03 2.66 3.22 3_85 40 1.15 150 187 2.45 2.95 3.54 45 1.06 1.39 1.73 2.27 2.75 3 29 50 0.99 1.30 1.62 2.12 2.57 3.07 55 0.93 1.22 1.52 1.99 2.41 288 60 088 1 15 1 44 1.88 2.27 2.72 65 0 83 1 09 1 36 1.78 2.15 258 70 0.79 1.04 1 29 1 69 2.05 245 75 0 75 0.99 1 23 1 61 1.95 2 33 80 0 72 0.95 1.18 154 1.87 2/3 85 0 69 0.91 1 13 1 48 1.79 2.14 90 0.66 0.87 1.08 1.42 1.72 2.05 95 0.64 0.84 1.04 1.37 1.65 1.98 100 0 62 0.81 1 01 1.32 1.59 1.91 105 0 60 0.78 0.97 1.27 1.54 1.84 110 0 58 0.75 0 94 1.23 1.49 1.78 115 0.56 0.73 0.9' 1.19 4 1.44 1.72 120 3.54 C.71 0.88 1.16 1 4C 1.67 125 3.52 0.69 086 fr 1 12 1.36 1.62 130 0.5' 0.67 0.83 109 1.32 1.58 135 0.50 0.65 0 81 1.06 1.28 1.53 140 0.48 0.63 0.79 1.03 1.25 1.49 145 0.47 0.62 1.01 1.22 146 0.77 150 0.46 0.6C 0.75 098 1.19 1.42 155 0.45 0.59 0.13 096 1.16 1 39 160 0.44 0.57 0.71 0.94 1.13 1.35 165 043 0 56 0.70 0 9' 1.11 1 32 170 0.42 0.55 0.68 089 1.08 1.29 '75 C41 0.54 C67 088 1.C6 1.27 80 0.40 _ 0.53 0.65 0.86 1.04 1.24 Intensity -Duration Curves for Rational Method —0-7-yea• —♦-5- • ar •a' • 25•-n• tSC-yea- -.4P-- :Cc- *ea• inches per hoar (in/hr) 9.00 ago %:3 6.30 5.99 3.30 !99 1.99 :-Y±L±T:1 . . • • - - • - • -t-- • .,- ..•-- ._,_.�.�_ �— . 4 • • •. _ _t -. _._. _ -. ; • • , ,. _ _ . • _. • __y,--.. • - , __- 4. - f - -I --t- �---1---•1 - 1 • ..• • .-- ..- - ,_ - -• ••-e.•..s....w. • — _''_ , f--. ; J_ L_c _� ♦ r r } -�— ar�� _•_ 1 I 1 I • • Y- . _. - • : .1 r t _ • -•- - . - •- --`•- --- - . .. - . - . - • . - . . ...... • , _+ _ - _l_.. T�� - i ' ? - •-... -- -. • `-r -. I_ I r I - 1. .-.- _ _..... ._ ... ___ r...1 -�._/ _.-... 1 - • - • -1_ _ ... - , : a . ' -- . -• - • ♦ .. • -♦ .♦--•_-4+_-_a- .- -♦ -.r 4- - -• . -7 1 . _ t «-- . _ .._..._. '-~_- ..._._ ..��..._-. -----4- -4- 4 �. ^♦- _ • •• . . - - ....---•--4..............---•--4.........---•--4..........---•• 4.• •_ ♦ M ...-- • ,�- • -r ,� - _ -'-•ice- - le- - - _- lir •• - - rrri 1,!..i. 3 2C 40 60 80 apc 17.9 St0-"1 Dura:•on {^t -Jtes) 4C ?CC Interpolated I Values from Intensity Duration Curves (5-yr, 10-yr, 100-yr) Historic (Tc = 51 Minutes) Sub -Basin A Developed (Tc = 16 Minutes) 5 -Year 50 1 30 51 16 55 1 22 15 = 1 28 10 -Year 50 1 62 51 110 55 1 52 110= 160 100 -Year 50 3 07 51 1100 55 2 88 Iwo = 3 03 5 -Year 15 16 20 Is = 2 59 15 2 24 2 52 10 -Year 15 3 22 16 110 20 2 79 Ito = 3 13 100 -Year 15 611 16 1100 20 5 29 1100 = 5 95 Sub -Basin B (Tc =13 Minutes) Sub -Basin C (Tc = 11 Minutes) 5 -Year 10 13 15 15 = 3 08 I6 2 59 2 79 10 -Year 10 3 84 13 110 15 3 22 110 = 3 47 100 -Year 10 7 28 13 1100 15 611 Iwo = 6 58 5 -Year 10 3 08 11 15 15 2 59 15= 298 10 -Year 10 3 84 11 110 15 3 22 110= 372 100 -Year 10 7 28 11 1100 15 611 1100 = 7 05 Sub -Basin D (Tc = 11 Minutes) Sub -Basin E (Tc = 16 Minutes) 5 -Year 10 3 08 11 15 15 2 59 Is= 298 10 -Year 10 3 84 11 110 15 3 22 110= 372 100 -Year 10 7 28 11 1100 15 6 11 1100 = 7 05 Basin -1 (Tc = 16 Minutes) 5 -Year 15 2 59 16 15 20 2 24 15= 252 10 -Year 15 3 22 16 110 20 2 79 110= 313 100 -Year 15 611 16 1100 20 5 29 Iwo = 5 95 5 -Year 15 2 59 16 15 20 2 24 15= 252 10 -Year 15 3 22 16 110 20 2 79 110= 313 100 -Year 15 611 16 1100 20 5 29 1100 = 5 95 Interpolations of Runoff Coefficients C for Historic and Developed Flows (5-yr, 10 yr, 100 yr) Historic (Type B Soils Table R0 5, I = 2%) Developed (Type B Soils Table R0 5, I= 39%) Historic Basin 5 -Year 0 0 08 2 C5 5 01 C5= 0 09 10 -Year 0 015 2 C10 5 019 C10= 017 100 Year 0 0 35 2 C100 5 0 38 C10o= 036 Sub Basin A 5 Year 35 0 27 39 C5 40 0 30 C5= 029 10 Year 35 034 39 Ci0 40 0 36 C1o= 036 100 Year 35 0 48 39 Cum 40 0 50 C1.= 0 50 Developed (Type B Soils - Table R0-5, I= 40%) Developed (Type B Soils Table R0 5, I = 64%) (Interpolations not needed) Sub Basin B 5 Year C5= 0 30 10 Year C55= 036 100 Year C555= 0 50 Sub Basin C 5 -Year 60 0 41 64 C5 65 0 45 C5= 044 10 -Year 60 0 46 84 C10 65 0 49 C15= 048 100 Year 60 0 56 64 C100 65 0 59 C100 = 0 58 Developed (Type B Sods - Table R0 5, I = 19%1 Developed (Type B Sods Table R0 5.1= 2%1 Sub Basin D 5 Year 15 017 19 C5 20 0 20 C5= 019 10 Year 15 0 25 19 Cie 20 0 27 Cto = 0 27 100 Year 15 0 42 19 C1e5 20 0 44 Ciao= 044 Developed (Type B Sods - Table R0 5, I= 42%1 Basin 1 5 -Year 40 0 30 42 C5 45 0 32 C5= 031 10 Year 40 0 36 42 Cso 45 0 38 Cto= 037 100 Year 40 0 50 42 C1ee 45 0 51 Cm= 0 50 Sub -Basin E 5 Year 0 0 08 2 C5 5 01 C,.-- 0 09 10 Year 0 015 2 Cm 5 0 19 Coo= 017 100 Year 0 0 35 2 CM 5 0 38 Ctoo = 0 36 DRAINAGE CRITERIA MANUAL (V. 1) ' t1! 1 1.11 C. " Table RO-5-- Runoff Coefficients, C RUNOFF Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0:39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 15% 014 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 , 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 _ 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0 68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 _ TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0 53 0.58 0.60 0.62 75% 0.51 ' 0.54 0 58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 _ 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% - 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 RO-11 Urban Drainage and Flood Control District r Project: Richard Miller 2019-112 basin 10 DETENTION VOLUME BY THE MODIFIED FAA METHOD (For catchments less than 10 acres only. For larger catchments. use hydrograph routing method) (NOTE'- for catchments larger tnon BO acres, CUMP hydregroph and routing are recommended; Daterrninallon of M.NOR Detention Volume Using Modified FAA Method Determination of MAJOR Detention Volume Using Modified FAA Method • Design information flnoutt paelan fnformatlon flnautt Itak.toM•t DraLnice InnerttdJW4t I. • 42 00 )r•,C.'A Csichnuni LMee.age imper.qu.n.a. 1. • 4200 'Atari (;atfrenere CMay.9. Area A • O 06 cc,.s Cat, n.ent Drawer Arne A - 116 nunPrude -•.k• rwDap• MRCS Star Op Type • 8 A. 6 C of D 19•Orracinwnl MRCS Soo Gel* 7 nil • p ADC 470 Reton prod lot Oss.rutn Cones 1 • 10 leers (2 4 t0 76 50 or 1001 Ashen fano Ior 0e'anton 0 olio I •J 100 1$04 01 (2 6 10 25 60 or ' c'y: ua Tints of Conoer•Usn dM ' • ner/9 Tc • 16 It wrists ls Time Cow.ertralv>n CO Walsflwd TC • I6 runs's' AIDwso, Unt Release Irate 0 • 0 277 do acre At • it* UM Release Rota it • 0 772 desire One-rvvi Proc4•aeWr. P. • 1 44 arm. Una-AoaL Prec.peatron P. • 2 72 irelW• Design Re n(.M ID! Formula , • C,' P.4CI•TJ•C, Design Rrnlalt OF Fomaul r : C, P,i(C,.TJ'C, ,Cc.'t on n-. C. a 7s AO - - Croaercwn, One C 'I 28 50 CN11c.ent Iwo C ' 10 Coenrcaen Iwo C, - +o (?•eerierg Intee C • 0739 Coe Hors IrM, C • 0102 Determination of A tense Outfaw from the Bash, (talcu(stedti: atarmInat[on of 1Zveraae Outflow from the Basin !al0vTitet . Fiume U411,4 w .. - 0 17 4•rne9 Cretin s _ 0 60 III$JS Peak Rtalon ,; pc • I7 07 cli inik,w Peek Aunufl Oyn •._ 7+.0 cis Alawabls Pen l .Alba& Has Op etA a III C14 Alb.• ode Peal Oo:e- 1 Rabe u✓oW • 1.00 Ms Mot FAA Mira Storage Volume • 7,$J4 eutttc last Moo. FAA Major litovye Vatam, • )0.1•00 ... cubts lest MoJ. IAA Minn Dlmega V* tons • 0.102 tonal Mal. FAA Major Biotag. Volvne is 0.707 aortas iO •.Cara Ra•de, Dug•x.'nn.nenW 'moos Alias Horn is 9 5 b 6.M•nu *51 Ra,Mnl UwNwn nntmcee imperil_ Qenla4 !Men- 41 riches / RI /..ttpull loll.. ' Arms acle'I•et trn4pu1) AJesltronl Factor (ouptl) • stage O.Nb , es (output) Outflow olun+o sue I•rr1 (o.Apat) ' lots („a VWurra sin teal (outp.A+ 1544440 Doran mallet 0Mp'af1 Par tale InW.s4y incites r M (ouloir° ,din* vo.u+e sue-Isei (ouputr former( racial 'm' (Ou1pu11 A -ray. Cnnlbw cis 10040011 Wee. :flume atavism t00100l) Sari ••e APT* etrs-f.• (uute4<I 0 000 0 000 000 000 0 00C 0 023 0041 7057 0 of 4 0 O76 0 000 0 000 0139 0 I 0112 0143 0164 0 16 0171 0165 0 207 0 211 0 273 0 234 0 245 '12S7 0 265 01/9 0 791 0 303 0 311 0 326 0 338 0 341 0 359 0370 0 351 9x3 0 4 14 0 418 0 427 0430 0 4►0 04•i 0 472 0 464 009' • 0 506 0 616 0429 n 5477 05'2 0 563 0 614 0t•11 0.07 0 600 0 070 C031 0 643 0 054 0665 0677 05118 • 0 004 0 000 0 00 7 O 13: 01•• 0 10' 0 17t 0 16' a 18. 014: ti let 0170 n17C 017; 0161 0/57 r 615• ' 0 153 1 ? 0 147 0 141 0 144 0 120 0 121 0 114 0 10/ 0 0W 000: 0 064 0077 0 059 0 001 0.053 0045 0 036 0028 0 ORJ 0 011 0 003 -0000 .0 Ot 6 -n 02. .. .CO21 .n 041 -0 Or%C -C 354 -C 066 •0077 -0 306 -0066 4 104 4 113 43 tin '0137 4 141 -0 151 4) 1110 4 lee -0 179 .014e -Ot98 -0101 •0 71/ 0 10 :0 30 40 50 50 7C ae •c '00 110 120 II1 140 ISO tea +70 100 104 100 710 220 30 140 250 260 ?70 :40 200 300 310 320 330 :140 110 360 170 AO JW 4m 410 420 4. 1 440 470 410 470 480 400 sae $10 520 630 640 650 sac 570 540 690 1100 000 7 20 636 442 364 307 2 71 . 44 223 403 190 i n 167 167 145 141 135 129 1.23 1.19 114 1.10 100 1 03 090 090 094 0.01 046 0 +41 084 087 060 076 Ore C 75 0 73 071 0 73 9779 0 67 n 68 0 6.5 0 64 0 83 061 060 059 068 068 051 060 011 064 053 O 51 0 17 C4I 0S0 040 044 j 0 0F1O 0 304 0 442 0624 0 541 0 640 0 0110 0 714 0743 0709 0712- 0'14 01'4 06'7 0564 0 W 0 'IOC 0 014 0 027 i 0 940 0 .152 0.964 0 975 0 956 n 096 1 006 1 M S 1 024 1 033 1 042 1 0677 1050 • 1 007 1074 i 087 + 060 t 090 1103 1 110 t 117 1 123 1 110 1 130 1.142 1 144 1164 1 /I0 1104 1 171 1177 113? III? 1 193 1104 1.203 1 200 1.213 1217 1222 1227 1 232 ' 0.00 100 0 41 077 0 70 000 013 0 al 00" 000 0S. 0'7 0Y 0Se 056 055 015 0r 0 54 O U 064 014 054 0 53 0 63 U 63 0 13 0 63 013 063 0 53 053 0 53 052 063 067 0 4' 052 0 62 052 052 0 67 0 57 0'2 0 12 012 0 52 062 062 0 62 083 047 017 0 022 051 0 81 041 051 081 051 0 61 000 1 0' 1 4e '2e 116 109 1 04 1 01 910 007 090 004 093 003 002 001 0 GI 090 0 9C 7709 0 84 044 066 056 098 066 0 07 0 57 0 57 0 87 0 57 087 067 040 • CO 058 050 450 C eO 2 I C 0 0 OS 0 •A 1 005 065 065 0 •5 0115 0 45 a 45 004 085 086 065 006 0 65 0 06 066 085 065 . 46 0 000 0 023 i C of t 0Or2 0 0 I4 0 07• 0 0e• 0 000 0106 0120 012. 0141 01St 01M' 0177 0105 0 200 0 211 0 243 0 714 0 245 1.124/ 0 760 0 219 0 291 0 702 O JD n 126 0 336 0 347 0 160 U3/0 0 381 0363 0 404 0 415 Dan 7 0418 0 450 0401 0 472 0464 0 495 0 500 0 6+8 0629 05.43 0657 0483 0 314 0656 0'..? peon 0 620 0611 0 043 0 654 0Cr5 0677 tree 0 601 • 0 000 0 287 040' 0470 0 52? 0 666 0.91 0 610 0634 0W' 0It' 067' 0tec 0667 01.7 0 607 0 700 0 703 0 705 0 Ire 0 7073 0 7072 0 Meg 0 706 0 704 0 704 0 7410 0 700 0 007 000! 0 002 C 68 0 605 0►01 0678 0 074 6960 Cyr C 06i 0059 0651 0.846 0641 0 616 0 633 0625 0 MD 0614 0005 0402 0596 000'1 0 504 01711 0571 0 566 0 If 0561 0646 0'39 0 537 I. 10 • 40 60 60 70 W 90 100 Ito +20 +30 140 160 te0 , 70 +50 100 200 210 120 730 240 ?50 760 7R1 ?80 200 300 31'3 •4., 340 350 060 i i/o 140 300 400 410 420 430 440 450 406 470 450 400 500 eta 1 Flo 530 540 560 M0 570 560 590 000 300 2 W' 273 1 67 1 82 1 M 124 118 10' 101 094 GSe 00.3 079 076 0 71 0 68 0 05 0 63 060 0 68 060 064 0 53 0 51 060 048 3 47 340 • 3 44 343 0 42 041 0 40 • 0 39 0 '9 011 r 0 37 0" 030 0 31 034 034 0 33 033 032 031 U 31 030 030 030 0 20 0 24 078 0 28 0 27 037 027 026 020 { 0 119 0 1 II 0707 0 231 0 251 0 260 0 260 074, 0301 0311 0319 0377 0334 0341 0347 0153 0 " ' 1 0 Ss 0 10 1 0 371 0 378 0 352 0 308 0 990 0 A14 0105 0 401 0 406 0 406 0 412 0415 0.414 042+ 0424 0 427 0429 0431 C 43! C43$ 0 440 C 443 044' 0 447 0 4150 0462 0 454 04!1 e 450 0 441 0403 0465 0 467 0 459 7747+ 0 473 0 475 0417 047, 0451 • 0 462 100 090 071 0 70 DSc 0 61 0 61 060 059 068 03? 067 056 055 055 065 055 054 054 064 054 064 0 53 063 053 0 577 n r' 0' 053 0: 0.11 0 0' 052 0 52 052 0.52 064 0 42 047 0 52 062 062 052 0 52 052 052 062 062 057 052 052 0 62 0 42 D5i 0.61 0' 1 oil 051 r ≥t J 51 1 61 1 44 120 1 14 1 09 1 M 1 01 009 001 090 • 004 • 0.73 U1-, 002 D91 ' 91 090 040 0 19 0 71 0119 045 010 0 M 088 0 47 0 87 0 87 087 0 87 087 0 47 o' C Be 046 060 004 P .•. C, 481 006 006 046 085 0 r• 065 n 66 Dee 0 40 0 M 0a5 085 0 85 0 e6 urn 0 6C 056 066 086 086 0.85 Y .:'9' I, 1A-41140 •, .0 into •• WWtine4.=AA od. Minor 9.aage von o (00410 h ) 7.9377 Mod FAA Miner Storage Vo urns (sar.Jt ) • 0.1822 Mat. FAA Major• SVdum4 (cubic tt I e Sod. FAA Storage Vdbrmn (ac re al I , UOFCD DETEN1ION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34. Released November 2013 30,004 0 1012 11' i76 I? 47 DU �4 DETENTION VOLUME BY THE MODIFIED FAA METHOD Project Richard Miller 2019-112 Basin IL). Inflow and Outflow Volumes vs. Rainfall Duration 1.4 12 1 08 02 0 • 4 • • • • - • • • • - • -+ 000c00000 O O • o OOOO,.O OOOOOOOO OOO 0 100 200 300 400 Duration (Minutes) 500 600 a- ....- w► +.•• 700 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2 34, Released Novernot 201:, 2U1(...117 IAy1.lw FAA . F mai) an Made FM POND VOLUME CALCULATIONS Average Area Method = ((Al + A2)/2) Stage Depth = Stage Volume (CF) Elevation (NAVD 29) Contour Area (ftz) Volume of Stage (ft') Accumulative Volume (83) 4642 0 13992 56 1383 9 40071 4 4641 9 13685 55 1354 5 38687 5 4641 8 13403 75 1326 4 373331 4841 7 13123 31 1298 4 36009 7 4641 6 12644 22 1270 5 34706 3 4841 5 12566 48 1242 8 33437 8 4641 4 12290 11 1215 3 32195 0 4641 3 12015 08 1187 8 30979 7 4641 2 11741 41 1160 5 29791 9 4641 1 11469 10 1133 4 26631 4 4641 0 1119614 1106 3 27498 0 4640 9 10928 11 1079 5 26391 7 4640 8 10661 27 1052 9 25312 2 4640 7 10307 61 1026 7 24259 3 4640 6 10137 13 1000 8 23232 5 4640 5 9875 83 975 3 22231 7 4640 4 9825 72 950 0 21256 4 4640 3 9374 79 9251 20306 4 4640 2 9127 05 900 5 19381 3 4640 1 8882 49 876 2 18480 6 4640 0 8641 11 852 2 17604 6 4639 9 8402 64 828 5 16752 4 4639 8 8167 79 805 2 15923 9 4639 7 7935 96 782 2 15118 7 4638 6 7707 35 759 5 14336 5 4639 5 7481 95 737 1 13577 1 4639 4 7259 78 715 0 12840 0 4639 3 704082 693 3 12125 0 4639 2 6825 08 671 9 11431 7 4639 1 6612 56 650 9 10759 8 4839 0 6403 25 630 0 10109 0 4838 9 6196 94 609 5 9479 0 4638 8 5993 73 589 4 8869 5 4638 7 5793 60 569 5 8280 1 4638 6 5596 66 550 0 7710 8 4638 5 5402 61 530 7 7160 6 4638 4 5211 76 511 8 6629 9 4638 3 5023 99 493 2 6118 1 4638 2 4839 31 474 9 5624 9 4638 1 4657 73 456 8 51501 4638 0 4479 23 437 4 4693 2 46379 426943 4184 42558 4637 8 4097 81 401 3 3837 5 4637 7 3929 19 384 7 34381 4837 6 376417 368 3 3051 5 4637 6 3602 53 352 3 26831 4637 4 3444 30 336 7 2330 8 4837 3 3289 46 321 4 1994 1 46372 313801 3064 16727 46371 2989 95 291 8 1386 3 4837 0 2845 30 2581 1074 6 4638 9 2315 89 209 8 818 5 4636 8 1880 83 170 3 606 7 4636 7 1524 40 138 3 438 4 4636 6 1241 55 109 8 2981 4636 5 954 18 81 4 188 3 4636 4 67415 54 8 106 8 4638 3 422 26 32 2 52 0 4636 2 222 14 15 5 19 8 46381 8702 44 44 46380 000 00 00 Top of Pond/Weir Elevation = 4642 0 100-yr+ WQCV Water Surface Elevation = 4641 6 (Calculated 100 yr Volume + WQCV 34 878 CF) 100-yr Water Surface Elevation = 4641 3 (Calculated 100-yr Volume 30 806 CF) Required Detention Pond Volume = 34 878 CF (WQCV (4 072 CF) + 106. Vol (30 806 CF) = 34 878 CF) Designed Detention Pond Volume = 40 071 CF Detention Pond Is oversized by 5 193 CF (14 9%) Designed WQCV Water Surface Elevation = 4638 0 (Calculated WQCV 4 072 CF) Lowest Pond Elevation = 4636 0 2019-112 Water Quality Capture Volume (WQCV) Calculations WQCV Calculations WQCV = a(0.91 i3-1.1912+0.781) For 40 hr Release a = 1 Required Storage = (WQCV/12)'Area Page SQ-24 Page SQ-24 0.42 Area (AC) = 6.06 Required WQCV Storage = 0.093 AC -ft = 4072 ft' FAA Method 100 YR = WQCV = Total Detention Pond Volume = 30826 4072 34898 ft' ft' ft' Detention Pond Release Time WS Elevation( Si Invert Elea Ifs) C Qinitial (CTS) Qfinal (US) QAvg (6S) Volume of Stage (CF) Time to Empty Stage (hr) AccumalkHe Time (hr) 4642 0 4636 0 0.65 174 173 173 13839 0 22 5145 46419 46360 065 173 171 177 13545 022 5122 4641.8 4636 0 0 65 1 71 170 170 1326 4 0 22 5101 46417 4636 0 0 65 170 168 1 69 1298.4 0 21 50 79 46416 46360 065 168 166 167 12705 021 5058 46415 46360 065 166 165 166 12429 021 S036 46414 46360 065 165 163 164 1215.3 021 5016 4641.3 46360 0.65 163 162 162 11879 020 4995 46412 4636 0 0 65 162 160 161 1160 5 020 49 75 4641.1 46360 065 160 158 159 11334 020 49.55 46410 46360 065 158 157 157 11063 020 49.35 4640 9 4636 0 0 65 157 155 156 1079 5 019 49 15 46408 46360 0.65 155 193 154 10529 019 4896 46407 46360 065 153 151 152 10267 019 4877 46406 46360 065 151 150 1SO 10009 018 4858 46405 46360 065 150 148 149 9753 018 4840 46404 46360 065 148 146 147 9500 018 4822 46403 46360 065 146 140 1.45 9251 018 4804 46402 46360 065 144 1.42 143 9005 017 4786 46401 46360 065 142 1.40 141 8762 017 47 68 46400 46360 065 140 139 139 8522 017 4751 46399 46360 0.65 139 137 138 828 5 017 47 34 46398 46360 065 137 135 136 8052 016 4718 4639 7 46360 0 65 135 133 1 34 782 2 016 47 01 46396 46360 065 133 131 132 7595 016 4685 46395 46360 065 131 129 130 7371 016 4669 46394 46360 065 129 127 128 7150 016 4653 46393 46360 065 127 124 125 6933 015 4637 46392 46360 065 124 122 123 6719 015 4622 46391 46360 065 122 120 121 6508 015 4607 4639.0 46360 065 120 118 119 6300 015 4592 46389 46360 065 118 116 117 6095 015 4577 46388 46360 065 116 113 114 5894 014 4563 46387 46360 065 113 111 112 5695 014 4548 46386 46360 065 111 109 110 5500 014 4534 46385 46360 065 109 106 107 5307 014 4520 46384 46360 065 106 104 105 5118 014 4507 46383 46360 065 104 101 102 4932 013 4493 4638.2 46360 065 101 098 100 474.9 013 4480 46381 46360 065 098 004 051 4568 025 4466 46380 46360 065 004 004 004 4374 322 4442 46379 46360 065 004 004 004 4184 316 4120 46379 46360 065 004 004 004 4013 312 3803 46377 06360 065 004 003 003 3847 308 3491 46376 46360 065 003 003 003 3683 305 3183 46375 46360 065 003 003 003 3523 301 1879 46374 46360 065 003 003 003 3367 299 2577 46373 46360 065 003 003 003 3214 296 2279 46372 46360 065 003 003 003 3064 295 1982 46371 46360 065 003 003 003 2918 294 1687 46370 46360 065 003 003 003 2561 274 1393 46369 46360 065 0.03 002 002 2098 236 1119 46368 46360 065 002 002 002 1703 204 984 46367 46360 065 002 002 002 1383 178 6B0 46366 46360 065 002 002 002 1099 154 501 4636.5 46360 065 002 002 002 814 127 347 46364 46360 065 002 001 002 548 098 219 4636.3 46360 065 001 001 001 322 069 121 46362 46360 065 001 001 001 155 045 052 46361 46360 065 001 003 002 2.6 004 007 4636.04 06360 340 003 000 001 1.8 003 003 46360 46360 x 000 000 000 0.0 000 000 • 100yr4 WQCV Water Surface Elea 46416 •• 100yr Water Surface Elev 4641 3 •• Designed WQCV Water Surface Elea 46380 ••• flow Switches from Orifice to Weir Top of Pond to Water Quality (hr) _ Water Quality to Bottom of Pond (Or) _ Total @r) 7 03 44 42 5145 Orifice Flow Calculations (From water surface elev. 4642.0' to water surface elev. 4638.0') C = CA(2gh)' ` City of Greeley Ec. 11 4.3.8 Rectangle Orifice _ Base 0.250 ft Height 0.558 ft C., , Onfice Coefficient = A= area (f?)= g = gravrtatior►al consta-'t (ft'sec')= h = head on orifice measured from centerf.ne (ft) = Q- 0 65 014 32.2 5 72 1.74 CF5 Water Depth 6 It Orifice Flow Calculations (From water surface elev. 4638.0' to water surface elev. 4636 04') Q = CA(29n)"' City of Greeley Eq. 11.4.3.8 C . Orifice Coefficient = A=area (ft2)= g = gravitational constant (`t'sec')= h = head on orifice measured from centerline (ft) _ U= 065 0.005 32.2 1 98 0.04 C=S Rectangle Orifice Base 0.125 ft Height 0.012 ft Wale' Dept 2 Weir Flow Calculations (from water surface elev. 4636.04' to Invert elov. 4636.0') Q = CLH'' City of Greeley Eq. 11.4.3.A(1 C= L- Length (ft)_ H = Depth of Flow (h) _ ) 3.400 0.125 0.042 0.03 CFS It From table 11.1 City of Greeley manual Rock Chute.xls Page 1 of 3 Rock Chute Design Data (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Emergency Spillway Designer: Dan Campbell Date: March 4. 2020 Input Geometry: ► Upstream Channel Bw = 23.0 ft. Side slopes = 1.0 (m:1) Velocity n -value = 0.013 Bed slope = 0.0010 ft./ft. County: Weld Checked by: Mark Taylor Date: 03104/2C Chia Bw = 23.0 ft. Factor of safety = 1.50 (Fe) 1.2 Min Side slopes = 4.0 (m:1) --' 2.0:1 max. Bed slope (4.7:1) = 0.214 ft./ft --' 3.0:1 max. Note n value = a) velocity n from waterway program Freeboard = 0.5 ft. —' or bLcomputed manning n for channel Outlet apron depth, d = 1.0 ft Downstream Channel Bw = 23.0 ft, Side slopes = 3.0 (m:1) Velocity n -value = 0.022 Bed slope = 0.0010 ft./ft. Base flow = 19.2 cfs Design Storm Data (Table 2, FOTG, WI-NRCS Grade Stabilization Structure No. 410): Apron elev. --- Inlet =42.0 ft. Uutlet 35.6 ft.— (Hdrop = 5.4 ft.) O r,44,, = Runoff from design storm capacity from Table 2, FO TG Standard 410 O, - Runoff from a 5-year,24-hour storm Qi„cr,= 19.2 O5= 0.1 cfs High flow storm through chute cfs Low flow storm through chute Note : The total required capacity is routed through the chute (principal spillway) or in combination with an auxiliary spillway. Input tailwater (Tw) Tw (ft.) = Program Tw (ft. ) = Program Profile and Cross Section (Output): Starting Station = 0+00 0 1 hR, = 0.08 ft. (0 ft.) Hpe= 0.44 ft, Fnergy Grade Line 1 Inlet Channel S Doe = 0.001 ft /ft yn = 0.42 ft. (0.02 ff.) -- A s Hp= 0.36 ft. (0.01 ft.) ye = 0.2 7 ft. (0.01 ft.) hey = 0.14 ft (0 ft.) H„= 0.41 ft. 40(D5o) = 10 ft. VelocitY,,,let = 1.97 fps radius at normal depth Critical Slope check upstream is OK 1 Note: When the normal depth (y„) in the inlet channel is less than the weir head (Hp), ie., the weir capacity is less than the channel capacity, restncted flow or ponding will occur. This reduces velocity and prevents erosion upstream of the inlet apron. 0.715y� = 0.2 ft. "• • N(0.01 ft) 1! Typical Cross Section Freeboard = (- 5 ft. Use Hp along chute but not less than z2. /i Geotextilei Notes: 1) Output given as High Flow (Low Flow) values. 2) Tailwater depth plus d must be at or above the hydraulic jump height for the chute to function 3) Critical depth occurs lye - 4y, upstream of crest. 4) Use WI Const. Spec, 13, Class I non -woven geotextile under rock. = 0.17 tt. Hydraulic Jump (0.01 ft) Height, z2= 0.41 ft. (0 01 ft.) 54ft t 4' / - 0 ft �-I. ----W I. Rock Chute 15(O50)(F,) Bedding I a _Cif A y 1 Profile Along Centerline of Chute Geotextile Rock Chute Bedding Rock ih.ekness = 9.3 in. Fs = zt = n -value = Dso(Fs) 2(DsoXFs) Tw+d= Z2 = The outlet 0.81 cfs/ft. Tw+d = 1.84 ft - Tw o. k. (1.56 ft.) - Tw o. k. 0.84 ft. (0.56 ft.) 2.5 1' Velocityouuei Outlet Channel Slope = 0.001 ft /ft = 1 ft. (1 ft. minimum suggested) 178 fps at normal depth Equivalent unit discharge 1 50 Factor of safety (multiplier) 0.17 ft. 0.044 4.6 in. 9.3 in. 1.84 ft. 0 41 ft. Normal depth in chute Manning's roughness coefficient Minimum Design D50* Rock chute thickness Tailwater above outlet apron Hydraulic jump height will function adequately Hi,9h Flow Storm Information Rock_Chute xis Page 2 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Emergency Spillway Designer: Dan Campbell Date: 3/4/2020 I. Calculate the normal depth in the inlet channel County: Weld Checked by: Date: High Flow Low Flow y„ = 0.42 ft. y„ = 0.02 ft. (Normal depth) Area - 9.7 ft2 Area = 0.5 ft2 (Flow area in channel) ()twin = 19.2 cfs QJaw = 0.1 cfs (Capacity in channel) Scupstreamchannel = 0.003 ft/ft II. Calculate the critical depth in the chute High Flow Low Flow Yc_ Area Qhtgn = H«, = hCv = 10yc = 0.715yc = 0.27 ft. 6.6 ft2 19.2 cfs 0.41 ft 0.14 ft. 2.74 ft. 0.20 ft. Yc _ Area = ()low = Hcs _ hn, _ 0.01 ft. 0.2 ft2 0.1 cfs 0.01 ft. 0.00 ft. 0.715y, = 0.01 ft. III. Calculate the tailwater depth in the outlet channel High Flow Low Flow Tw = Area = QI.KJ., = H; _ 0.84 ft. 21 5 ft2 38.4 cfs 0.00 ft. Tw = Area = ()bw= 112 _ (Critical depth in chute) (Flow area in channel) (Capacity in channel) (Total minimum specific enemy head) (Velocity head corresponding to yr) (Required inlet apron length) (Depth of flow over the weir crest or brink) 0.56 ft. (Tailwater depth) 13 9 ft2 (Flow area in channel) 19.3 cfs (Capacity in channel) 0.00 ft. (Downstream head above weir crest, H2 = 0, if H2 < 0.715*yr) IV. Calculate the head for a trapezoidal shaped broadcrested weir Cd - 1.00 (Coefficient of discharge for broadcrested weirs) High Flow Hp = 0 42 ft. 0.36 ft. (Weir head) Area = 9.8 ft2 8 4 ft? (Flow area in channel) Va = 0.00 fps 2.28 fps (Approach velocity) = 0.00 ft. 0.08 ft. (Velocity head corresponding to Hp) Q,.,�.. = 19.2 cfs 19.2 cfs (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Low Flow Hp = 0.01 ft. Area - 0.3 ft2 V° = 0.00 fps hp„ = 0.00 ft. Q,ow = 0 1 cfs 0.01 ft. (Weir head) 0.3 ft2 (Flow area in channel) 0.44 fps (Approach velocity) 0 00 ft. (Velocity head corresponding to Hp) 0.1 cfs (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Rock Chute.xls Page 3 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy. ASAE, 1998) Project: Miller 19-112 Emergency Spillway Designer: Dan Campbell Date: 3/4/2020 County: Weld Checked by: Date: V. Calculate the rock chute parameters (w/o a factor of safety applied) High Flow qt -- 0.08 CMS/M D50 (mm) = 78.74 > (3.1 /n.) n = 0.044 z, = 0.17 ft. Al = 4.0 ft2 Velocity = 4.76 fps 0.17 ft. 2.06 3.87 ft Zrnean = F, _ Lori( apron Low Flow qt - D50 = n= z1 = A, _ Velocity = Zmean F1 = 0.00 cms/m 5.68 mm 0.030 0.01 ft 0.2 ft2 0.82 fps 0.01 ft. 1.75 VI. Calculate the height of hydraulic jump height (conjugate depth) High Flow z2 = 0.41 ()rug," = 19.2 A2 = ft. cfs 10.2 ft2 Low Flow 0.01 01 0.3 ft. cfs ft2 (Equivalent unit discharge) (Median angular rock size) (Manning's roughness coefficient) (Normal depth in the chute) (Area associated with normal depth) (Velocity in chute slope) (Mean depth) (Froude number) (Length of rock outlet apron = 15`D50) (Hydraulic jump height) (Capacity in channel) (Flow area in channel) VII. Calculate the energy lost through the jump (absorbed by the rock' High Flow E1 = E2 RE= 0.52 ft. 0.47 ft. 10.31 Calculate Quantities for Rock Chute Rock Riprap Volume Area Calculations Length (a Rock CL h = 0.41 Inlet = 9.95 = 4.12 Outlet = 6.15 L = 1.69 Slope = 30.77 Ag = 1.69 2.5:1 Lip = 2.59 x2= 4.00 Total = 49.46 ft. Ab = 27.25 Rock Volume Ab+2"A1 = 30.63 ft2 56.10 yd3 Geotextile Quantity Width Length n, Bot. Rock 2'Slope = 11.63 Totat = 49.45 ft. Bottom = 23.25 Geotextile Area Total = 34.87 ft. 191.62 yd2 E, E2 RE - Low Flow 0.02 ft 0.02 ft. 5.23 (Total energy before the jump) (Total energy after the jump) (Relative loss of energy) Bedding Volume Area Calculations h = 1.41 x, = 0.00 L = 5.81 AS = 0.00 x2 = 0.00 Ab=0.00 Ab+2'A.b = 0.00 ft2 Bedding Thickness t.,t2 = 0 00 in Length (et Bed CL Total = 49.45 ft. Bedding Volume 0.00 yd3 Note, 1) The radius is not considered when calculating quantities of riprap, bedding, or geotextile. 2) The geotextile quantity does not include over - overlapping (18 -in. min.) or anchoring material (18 -in. minalong sides. 24 -in. min. on ends). Rock Chute Design - Plan Sheet (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice. Kadavy, ASAE, 1998) Minimum Project: Miller 19-112 Emergency Spillway Designer: Dan Campbell Date: 3/4/2020 Enter County: \iVe'd Checked by: Date: Design Values 4 6 in. 9.3 in. 3 ft. 6 ft. 10 ft Plan Values D50 dia. = 6 00 in. Ruck,,„, thickness a 12 00 in. Intel apron ienglt - 10 00ft. Outlet apron ength = 6 00 ft. Redius - 17 ft. Rock Gradation Envelope °i Passinjj 050 Dig, Die Diameter, in (weight, lbs.) 9 - 12 (52 - 122) 8-11(34-89) 6-9(15-52) 5-8(8-34) Will bedding be used? H Notes: ° Rock. bedding, and geotextile quantities are determines from the x -section below (neglect radius) Geotextile Class I (non -woven) shall be overlapped and anchored (18-inmin. along sides and 24 -in min, on the ends). Upstream Channel Slope 0 001 ft Rock ChutQ. Stakeout Notes ta. Elev. (Pnt) 0+00.0 42 (t (1) 0+08.2 42 ft (2) 0+10.0 41.9 ft (3) 0+11.7 41.6 ff. (4) 0+40.1 35 56 f (5) 0+46.1 35 56 ft (6) 0+48.6 36.56ft (7) Class I non -woven c O C, r 10.`! --- Radius = 17 h Geotextile Rock gradation envelope can be met with DOT light rtprap Gradation .�- Inlet apron elev. = 42 ft Rock thickness = 1 30 ft 4.67 Quantities Rock = �7 Geotextile (WCS-13)° = 192 Bedding = 0 Excavation = 0 Earthfill = 0 yd3 yd' yd3 yd3 yd3 Seeding = 0.0 acres Degree of angularity = 1 50% angular, 50% rounded 2 100 % rounded Outlet apron elev. = 35 5611.7 5 Downstream / v Channel A Slope 0 00' - - - 6 ft. --- 51 L— d = 1 ft. Profile Along Centerline of Rock Chute Freeboard =0.5 lt. Rock Chute Cost Estimate Unit Unit Cost Cost Rock Geotextile Bedding Excavation Earthfill Seeding $10.00 /yd3 512.001 yd2 $12.00 /yd3 $12.00/yd3 $1.00 /yd3 $2.00 lac. Total $570.00 $2,304.00 $0.00 $0.00 $0.00 $0.00 $2,874.00 1 ..Top width = ik **Note: The outlet wilt function adequately 041 ft. 2..3 ft Geotextile Rock Chute Bedding Rock thicime„ = 12 in • Use Hp throughout chute B' = 23 ft but not less than z2 Rock Chute Cross Section Profile, Cross Sections, and Quantities 4NRCS '.Y .r. .. r.. -vim, V / ...... ... .�. “n • r . I Miller 19-112 Emergency Spillway Weld County 70. Uw Catfl# Page 1 of 1 Rock Chute.xls for construction plan Rock Chute Design - Cut/Paste Plan (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rte, Kadavy, ASAE, 1998) Project: Miller 19-112 Emergency Spillway County: Weld Designer: Dan Campbell Date: 314/2020 Checked by: Date: Design Values D5,, dia. = 6.0 in. Rock,„,, thickness = 12.0 in. Inlet apron length = 10 ft. Outlet apron length = 6 ft. Radius 17 ft. Will bedding be used? No Rock Gradation Envelope % Passing D103 Day D50 O10 Diameter, in. (weight, lbs.) 9-12(52-122) 8-11 (34 - 89) 6-9(15-52) 5-8(8-34) Quantities ° Rock = 57 yd3 Geotextile (WCS-13)b = 192 yd2 Bedding = 0 Excavation = 0 Earthfill = 0 yd3 yd3 yd3 Coefficient of Uniformity, (D 60)/(D 10) < 1.7 Seeding = 0.0 acres .114219A: Rock, bedding, and geotextile quantities are determined from x -section below (neglect radius). " Geotextile Class I (Non -woven) shall be overlapped and anchored (18 -in. minimum along sides and 24-inminimum on the ends) --- quantity not included. Upstream Channei Slope = 0.001 ft./ft, Stakeout Notes Ste Eiev. (Pin) 0+00.0 42 f (1) 0+08.2 42 ft. (2) 0+10.0 41.9 ft. (3) 0+11.7 41 6 ft. (4) 0+40.1 35.56 ft. (5) 0+46.1 35.56 ft. (6) 0+48.6 36.56 ft. (7) Notes: c Inlet apron elev. = 42 ft. 2 Inlet apron 1U ft.--- j, r Radius = 16.68ft-' Geotextile 4 • owf • Rock thickness • • • 12 in Point No. 2 3 4 Outlet apron elev.= 35.56 ft m 1� 4.6/N Description Point of curvature (PC) Point of intersection (PI) Point of tangency (PT) • • Outlet a ron 30 ft. 6 ft. - Profile Along Centerline of Rock Chute r Freeboard = 0 5 ft. Rock gradation envelope can be met with DOT Light riprap Gradation A J � 1 4 Downstream Channel Slope = 0.001 ft /ft d-1ft. \• Rock Chute Bedding Top width - 26 ft. • 0.41 ft LE_23 ft. Berm N Rock thcknoss = B'=23.3ft - Rock Chute Cross Section Geotextile Rock Chute Bedding 12 in • Use Hr, throughout chute but not less than z2. Profile, Cross Sections, and Quantities QINRCS WU) W► re s Cortina) Serra uro•e anti ( parws •I agnw•• Miller 19 112 Emergency Spillway \/Veld County I el s,xca w, Rock _Chute .xls Page 1 of 3 Rock Chute Design Data (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rico, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE Designer: Dan Campbell Date: March 28, 2020 County: Weld Checked by: Mark Taylor Date: 03/28/20 Input Geometry: ► Upstream Channel Bw = 15.0 ft. Side slopes = 35.0(m:1) Velocity n -value = 0.022 Bed slope = 0.0320 ft./ft. Bw = 4.0 ft. Factor of safety - 1.50 (F5) 1.2 Min Side slopes = 5.0 (m:1) -s- 2.0:1 max. Bed slope (16.31) = 0.061 ft./ft -' 3.0:1 max. Note: n value = a) velocity n from waterway program Freeboard = 0.5 ft. or b) computed mannings n for channel Outlet apron depth, d = 0.5 ft. Downstream Channel Bw Side slopes velocity n -value Bed slope = 8.0 ft, = 50.0(m:1) = 0.025 = 0.0100 ft /ft Base flow = 13.9 cf Design Storm Data (Table 2, FOTG, WI-NRCS Grade Stabilization Structure No. 410): Apron elev --- Inlet 0 ft. Outlet !h 5 ft. - (Hd „p - 5 tt: Qnpn = Runoff from design storm capacity from Table 2, FOTG Standard 410 Q, = Runoff from a 5 -yea i,24 -hour storm. °1„ gh= 13.9 cfs High flow storm through chute O5 = 0 I cfs Low flow storm through chute Note The total required capacity is routed through the chute (principal spillway) or in combination with an auxiliary spillway. Input tailwater (Tw) l w (ft.) = Program > Tw (ft.) = Program Profile and Cross Section (Output): Starting Station = 0+00.0 hp„ = t? ft ('O ft) Hp.- 107 ft. Energy Grade Line Hp Inlet Channel Slope - 0.0 = 019 ft. (001 R.) a _ Alt = 1.07 ft. (005ft.) yy= 0 (003ft) ft !ft. 57 R h,= 0.2 ft (0 02 ft) HG,= 0.77 ft. '-v' vis --10y,= ti ft ";1 40(D50) = 10 ft, Velocity,N.t = 3,36 fps radius at normal depth Cr;tical Slope check upstream is unstable 1 Note: When the normal depth (ye) in the inlet channel is less than the weir head (Hg), ie., the weir capacity is less than the channel capacity, restricted flow or ponding will occur. This reduces velocity and prevents erosion upstream of the inlet apron. • • 0.715yc = 0.41 ft. N.,,(0.02 ft.) • • • Typical Cross Section F'uebuard = T * Use HI, along chute but not less than z2. � - 4 ft ---"-' Rock thKknegs = 3 8 1(1 B, • . Geotextile-1 Notes: 1) Output given as High Flow (Low Flow) values 2) Tailwater depth plus d must be at or above the hydraulic jump height for the chute to function. 3) Cntical depth occurs 2ye - 4y, upstream of crest. 4) Use WI Const. Spec. 13, Class I non -woven geotextile under rock. �.�zI=043 t► Hydraulic Jump f _ (0.03 ft ) �- Height, z2 = 0.73 ft. (0.04 it ) tic't • • • 1 • Hd cp = t • • • I . •• `_� "-r--- 6 0 Rock Chute 15(Dso)(F)) Bedding Profile Along Centerline of Chute Berm Geotextile \ Rock Chute Bedding 41.1 Fs = z1= n -value = D5u(Fs) _ 2(D5o)(Fs) = Tw+d= Z2 = The outlet 2.42 cfs/ft. r' Tw+d = 0.92 ft. - Tw o k, (0.81 ft,) - 7w o.k. J A 0.42 ft (0.31 ft.) 2.5 '1 Velocitypon = Outlet Channel Slope = 0,01 ft./ft. 0 5 ft (1 ft minimun, suggosled) 231 fps at normal depth Equivalent unit discharge 1 50 Factor of safety (multiplier) 0.43 ft Normal depth in chute 0 037 Manning's roughness coefficient 4 4 in. Minimum Design D50` 8.8 in. Rock chute thickness 0 92 ft. Tailwater above outlet apron 0 73 ft. Hydraulic jump height will function adequately High Flow Storm Information Rock_Chute.xls Page 2 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE County: Weld Designer: Dan Campbell Date: 3/28/2020 I. Calculate the normal depth in the inlet channel High Flow Y„ = 0.19 ft. Area = 4 1 ft2 Ohio = 13.9 cfs Scupstreamchannel = 0 013 ft/ft II. Calculate the critical depth in the chute High Flow Yc = 0.57 ft. Area = 3.9 ft2 Qn,gr, = 13.9 cfs Fite = 0.77 ft hc,= 020 ft. 10yc = 5.67 ft. 0.715y, = 0.41 ft. Checked by: Date: Low Flow Y„ = 0.01 ft. (Normal depth) Area = 0.2 ft2 (Flow area in channel) U,,,. = 0.1 cfs (Capacity in channel) Low Flow Yo = 0.03 ft. (Critical depth in chute) Area = 0.1 ft`' (Flow area in channel) = 0.1 cfs (Capacity in channel) H� = 0.05 ft, (Total minimum specific energy head) hc, = 0.02 it. (Velocity head corresponding to yc.) - (Required inlet apron length) 0.715yc = 0.02 ft. (Depth of flow over the weir crest or brink) III. Calculate the tailwater depth in the outlet channel High Flow Tw = 0.42 ft. Area = 12.0 ft2 Q,,gh = 27.8 cfs H2 = 0.00 ft. Low Flow Tw = Area QOW = HL 0.31 ft. (Tailwater depth) 7.2 ft2 (Flow area in channel) 14.0 cfs (Capacity in channel) 0.00 ft. (Downstream head above weir crest, H2 = 0, ifH2<0.715'yc) IV. Calculate the head for a trapezoidal shaped broadcrested weir Cd = (Coefficient of discharge for broadcrested weirs) High Flow Hp = 1.07 ft. 1.07 ft. (Weir head) Area = 55.8 ft2 55.8 ft2 (Flow area in channel) V. = 0.00 fps 0.25 fps (Approach velocity) hp„ = 0.00 ft. 0 00 ft. (Velocity head corresponding to Hp) 0,4, = 13.9 cfs 13 9 cfs (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Low Flow Hp = 0.05 ft. Area = 0.8 ft2 Vo = 0 00 fps h,;v = 0.00 ft Olen = 0.1 cfs 0.05 ft. 0.8 ft2 0.16 fps 0.00 ft. 0.1 cfs (Weir head) (Flow area in channel) (Approach velocity) (Velocity head corresponding to Hp) (Capacity in channel) 7rial and error procedure solving simultaneously for velocity and head Rock Chute xis Page 3 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE Designer: Dan Campbell Date: 3(28/2020 County: Checked by: Date: V. Calculate the rock chute parameters (w/o a factor of safety applied) R, D50 (mm) n z, Al Velocity Zmean F1 Lock apron High Flow 0.22 cros/m = 74.85 > (2.95 in) 0.037 0.43 2.6 5.34 0.32 1.67 3.68 ft ft. ft2 fps ft. Low How qt D50 _ n= z1_ A, _ Velocity Zmean F1_ 0.00 cms/m 7.60 mm 0.026 0.03 ft. 0.1 ft2 1.21 fps 0.03 ft 1.35 VI. Calculate the height of hydraulic jump height (conjugate depth) High Flow 12 = A2= 0.73 ft. 13.9 cfs 5.6 ft2 Z2 = Qh,Sg, = A2= Low Flow 0.04 ft. (Hydraulic jump height) 0.1 cfs (Capacity in channel) 0.2 ft2 (Flow area in channel) p (Equivalent unit discharge) (Median angular rock size) (Manning's roughness coefficient) (Normal depth in the chute) (Area associated with normal depth) (Velocity in chute slope) (Mean depth) (Froude number) (Length of rock outlet apron = 15'D50) VII. Calculate the energy lost through the lump (absorbed by the rock) High Flow E, _ E2 = RE _ 0.87 ft. 0.83 ft. 4.65 Calculate Quantities for Rock Chute Area Calculations h - 1.07 = 5.10 L = 5A6 As = 5.46 x2 = 5.00 Ab = 9.20 Au+2'A, = 20.11 ft2 Rock Riprap Volume Length (a. Rock CL Inlet = 9.98 Outlet = 6 11 Slope = 90.07 2.5:1 Lip = 1.24 Total = 107.41 ft. Rock Volume 80.00 Yd3 Geotextile Quantity Width Length (a_ Bet. Rock 2'Slope = 21.11 Total = 107.40 ft. Bottom = 4.20 Geotextile Area Total = 25.31 ft. 302 01 yd2 Low Flow E, _ E2 _ RE _ 0.05 ft 0.05 ft. 0.99 % (Total energy before the jump) ( I otal energy after the jump) (Relative loss of energy) Bedding Volume Area Calculations h=2.07 x, = 0.00 L = 10.55 A, = 0.00 x2 = 0.00 Ab = 0.00 Ab+2'A, = 0.00 ft2 Bedding Thickness t,, t2 = 0.0U in. Length A Bed CL Total = 107.40 ft. Bedding Volume 0 C yd3 Note: 1) The radius is not considered when calculating quantities of riprap, bedding, or geotextile. 2) The geotextile quantity does not include over - overlapping (18 -in. min.) or anchoring material (18 -in. min. along sides, 24 -in. min. on ends). Rock Chute Design - Plan Sheet (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE County: `Nell Minimum Designer: Dan Campbell Date: 3/28/2020 Enter Design Values Plan Values 4.4 in 8,8 in 6 ft. 6 ft. 10 ft. Dx, oia. _ Rock ,,y Irndknets Intel apron eV,' - Cutlet apron length = Raclin r 6 00 in. 12.00in 10OOf 600 ft ,17 ft. Rock Gradation Envelope % Passing Diameter, in (weight. lbs ) 9-12(52-122) 8 - 11 (34 - 89) 6-9(15-52) 5-8(8-34) D100 Dy5 Dso Diu Will bedding be used? No Notes: a Rock, bedding. and geotextile quantities are determined from the x -section below (neglect radius) ° Geotextile Class I (non -woven) shall be overlapped and anchored (18 -in. mmalong sides and 24 -in. min. on the ends). Upstream Channel Rock Chute Radius = 17 f1 -� Stakeout Notes S_ Elev. (PM) 0+00.0 42 ft (1) 0+09.5 42 ft. (2) 0+10.0 42 ft (3) 0+10.5 42 ft (4) 0+99.9 36 5 fl (5) 1+05 9 36 5 ft (6) 1+07.2 37 ft (7) Class I non -woven Rock gradation envelope can be met with DOT light now Gradation Rock Geotextile Inlet apron elev. = 421: Rock thickness= 1 • • • • 1', 12 %r, Checked by: Date: Quantities' Rock = 80 yda Geotextile (WCS-13)° = 303 yd2 Bedding = (; yd3 Excavation = a yd'- Earthfill = 0 Yd' Seeding = 0 0 acres Degree of angularity = 1 1 50% angular, 50% rounded 2 100 % rounded Outlet apron elev. = 36 5 ft ) M Downstream Channel S iz>t, o _ ,? G ; i' o ft----�=-) \---d= 05tt -÷ 2.5 Profile Along Centerline of Rock Chute "Note: The outlet will function adequately Freeboard =0.5 ft. Chute Cost Estimate Unit Unit Cost Cost Rock Geotextile Bedding Excavation Earthfill Seeding $10.00 /yd3 $12.00/yd2 $12.00/yd3 $12.00103 $1.00 /yd3 $2.00 /ac. Total $800.00 $3,636.00 $0.00 $0.00 $0.00 $0.00 $4,436.00 1 5 Jop width = + F ft A K _ 4 4 ft it Geotextile Rock Chute Bedding Rock thickness = Rock Chute Cross Section Profile, Cross Sections, and Quantities 12 in. • Use Hp throughout chute 8' = 4.2 ft but not less than z1 4 MRCS iM.. r "nor.•'. Curry s. Ur... Ur -r WUe. al My d Art ,0• I Miller 19-112 Pond Rundown SE Weld County Page 1 of 1 Rock_Chute.xls for construction plan Rock Chute Design - Cut/Paste Plan (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown SE County: Weld Designer: Dan Campbell Date: 3/28/2020 Checked by: Date: Design Values D50 dia. = 6.0 in. Rocku,ute thickness = 12.0 in. Inlet apron length = 10 ft. Outlet apron length = 6 ft. Radius = 17 ft. Will bedding be used? No Rock Gradation Envelope % Passing Diameter, in. (weight. lbs.) D50 D10 9-12(52-122) 8-11 (34 - 89) 6-9(15-52) 5-8(8-34) Coefficient of Uniformity, (D ,)/(D ,o) < 1.7 Quantities a Rock = 80 Yd3 Geotextile (WCS-13)" = 303 Yd` Bedding = 0 Yd3 Excavation = 0 yd3 Earthfill = 0 yd3 Seeding = 0.0 acres Notes : J Rock, bedding, and geotextile quantities are determined from x -section below (neglect radius). Geotextile Class I (Non -woven) shall be overlapped and anchored (18 -in. minimum along sides and 24 -in. minimum on the ends) --- quantity not included. Upstream o Channel ,o Slope = 0.032 R.lmt. Stakeout Notes Sta. Elev. (Pnt) 0+00.0 42 ft. (1) 0+09.5 42 ft. (2) 0+10.0 42 ft. (3) 0410.5 42 ft. (4) 0+99.9 36.5 ft. (5) 1405.9 36.5 ft. (6) 1+07.2 37 f. (7) Notes: ----- 10 ft.---- Radius = 16.68 Rr Geotextile Inlet apron elev. = 42 ft 2 _3 Rock ji rc•.��eb� • • 90 ft • 12 in. Point No. 2 3 4 Outlet apron elev. = 36.5 ft. 16.35`•;' �• Outlet apron Profile Along Centerline of Rock Chute A Freeboard = 0.5 ft. 1 Rock gradation envelope can be met with DOT Light ricrac Gradation 5 Description Point of curvature (PC) Point of intersection (PI) Point of tangency (PT) Downstream Channel .' .I 6ft ---- ;11 d- 0.5 ft ,Top width = 15 ft. 1.07 ft. 4 It. g'- 42ft Rock Chute Cross Section Rock Chute Bedding rm Slope = 0.01 ft./ft Geotextile Rock Chute \ Bedding Rock thick ins = 12 1n. • Use Hp throughout chute but not less than z2. Profile, Cross Sections, and Quantities N RCS *WI Rt.a.es Caneres i Ursa Vitro sat D...hM+ a<kraal, I Miller 19-112 Pond Rundown SE Weld County ...;t. Rock_Chute.xls Page 1 of 3 Rock Chute Design Data (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West Designer: Dan Campbell Date: March 28, 2020 Input Geometry: County: Weld Checked by: Mark Taylor Date: 03/28/20 ► Upstream Channel > Chute Bw= 10.0 ft. Bw= 40 ft. Side slopes = 20.0(m:1) Factor of safety = 1.50 (F,) 1.2 Min Velocity n -value = 0.022 Side slopes = 8.0 (m:1) ' 2.0:1 max. Bed slope = 0.0200 ft./ft. Bed slope (13 9.1) = 0.072 ft./ft -' 3.0:1 max. Note- n value = a) velocity n from waterway program Freeboard = a5 ft. or b) computed rnannings n for channel Outlet apron depth, d = 0 5 ft. Downstream Channel Bw= 5.0 ft. Side slopes = 50.0(m:1) Velocity n -value = 0.025 Bed slope = 0.0100 ft./ft. Base flow = 2.8 cfs Desipn Storm Data (Table 2, FOTG, WI-NRCS Grade Stabilization Structure No. 410): Apron elev. -- Inlet =42.0 ft. - Outlet 36.5 ft. --- (Hd,3 5 ft.) = Runoff from design storm capacity from Table 2, FOTG Standard 410 Q5 = Runoff! from a 5-year,24-hour storm. Qhtgh= 2.8 cfs High flow storm through chute Qs _ 0 f cfs t ow flow storm through chute Note : The total required capacity is routed through the chute (principal spillway) or in combination with an auxiliary spillway. Input tallwater (Tw) : • T w (ft.) = Program • Tw (ft.) = Program Profile and Cross Section (Output): starling Station =10+00 0 hp„= Oft (0 ft) Hp.= 0.37 ft. Energy Grade Line_ Hp= 0 37k Inlet Channel Slope = 0.02 ft ft. =0.11ft (0.02 ft.) 1.4 (0.05 ft) yc = 0.21 ft. (0.03 ft) h, = 0.09 ft. (0.02 ft.) Hce = 0.3 ft. �-V r 4.715yc = 0.15 ft '•.(0.02 ft.) • • . . • • • • 40(D.,o) = 5 ft Velocity,n,et = 2 01 fps radius at normal depth Critical Slope check upstream is unstable 1 Note When the normal depth (yn) in the inlet channel is less than the weir head (Hp), to , the weir capacity is less than the channel capacity, restricted flow or pending will occur. This reduces velocity and prevents erosion upstream of the inlet apron. Typical Cross Section { Freeboard - (i.5 1 Hr, • ��--• 4ft. " Use Hp along chute Ire - but not less than z2. j,. r • . . Geotextile—} • • .` 1 Notes: 1) Output given as High Flow (Low Flow) values. 2) Tailwater depth plus j must be at or above the hydraulic jump height for the chute to function 3) Critical depth occurs 2y,_ - 4y,; upstream of crest. 4) Use WI Const. Spec. 13, Class I non -woven gootextile under rock =016ft (0.03 ft.) �. HCtop = 5 ft. Rock Chute Bedding rfais 3 ft. --- 15(D50)(F,) Profile Along Centerline of Chute Berm Geotextile Rock Chute Bedding Rock thickness = `1 f% trl. *A * FS= z1 _ n -value = D50(Fs) = 2(D50)(F6) Tw+d= z2 The outlet 0.56 cls/f. Hydraulic Jump Height, z2 = 0.27 ft. (0.04 ft.) Tw+d = 0.72 ft - T vr' o. k. (0.67 ft.) - Tw o.k. 0.22 ft. (0.17 ft.) 2.5 1r -r Veocitye,,,k, = Outlet Channel Ulope = 3.31 ft Mt. d = 0.5 ft. (1 ft. minimum suggestru 1 55 fps at normal depth Equivalent unit discharge 1.50 Factor of safety (multiplier) 0. 16 ft Normal depth in chute 0.034 Manning's roughness coefficient 2.3 in. Minimum Design D50" 4.6 in. Rock chute thickness 0.72 ft Tailwater above outlet apron 0.27 ft. Hydraulic jump height will function adequately High Flow Storm Information Rock_Chute.xls Page 2 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West Designer: Dan Campbell Date: 3/28/2020 I. Calculate the normal depth in the inlet channel High Flow Low Flow = 0.11 ft. Area = 1.4 ft2 2.8 cfs Scupstreamchannel = 0.015 ft/ft II. Calculate the critical depth in the chute Yn _ Area = County: Weld Checked by: Date: 0.02 ft. (Normal depth) 0.2 ft2 (Flow area in channel) 0.1 cfs (Capacity in channel) High Flow Low Flow Y� _ Area = Qom= He. _ h„= 10y� 0.715yc _ 0.21 ft. 1.2 ft2 2.8 cfs 0.30 ft. 0.09 ft. 2.13 ft. 0.15 ft. YC _ Area = ()low H�Q = h„ 0.715yc = III. Calculate the tailwater depth in the outlet channel High Flow Tw = 0.22 ft. Area = 3.6 ft2 ()high = 5.6 cfs H2 = 0.00 ft. 0.03 ft. (Critical depth in chute) 0.1 ft2 (Flow area in channel) 0.1 cfs (Capacity in channel) 0.05 ft, (Total minimum specific energy head) 0.02 ft, (Velocity head corresponding to sic) (Required inlet apron length) 0.02 ft. (Depth of flow over the weir crest or brink) Low Flow Tw = 0.17 ft. (Tailwater depth) Area = 2.2 ft2 (Flow area in channel) = 2.9 cfs (Capacity in channel) H2 = 0.00 ft (Downstream head above weir crest, H2 = 0, if H2 < 0.715'yc) IV. Calculate the head for a trapezoidal shaped broadcrested weir Cd = High Flow HP = Area = V. = hp,, = Qh,yh = 0.37 ft. 6.5 ft2 0.00 fps 0.00 ft. 2.8 cfs 1 00 (Coefficient of discharge for broadcrested weirs) 0.37 ft. 6.4 ft2 0.44 fps 0.00 ft. 2.8 cfs (Weir head) (Flow area in channel) (Approach velocity) (Velocity head corresponding to Hp) (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Low Flow HP = 0.05 ft. 0.05 ft. (Weir head) Area = 0.5 ft2 0.5 ft2 (Flow area in channel) V. = 0.00 fps 0.25 fps (Approach velocity) hp„ = 0.00 ft. 0.00 ft. (Velocity head corresponding to Hp) Qiow = 0 1 cfs 0.1 cfs (Capacity in channel) Trial and error procedure solving simultaneously for velocity and head Rock _Chute .xls Page 3 of 3 Rock Chute Design Calculations (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West Designer: Dan Campbell Date: 3/28/2020 V. Calculate the rock chute parameters County: Weld Checked by: Date: w/o a factor of safety applied) High Flow Low Flow qr = Dso (mm) = n= _ A, _ Velocity = Zmear. = F1 - Lrock anon 0.05 39.24 0.034 0.16 09 3.29 0.13 1.61 1.93 ft. cms/rn (1.54 in.) ft. ft2 fps ft. Dso n z, A, Velocity ;lean FF1 0.00 cms/m 8.58 mm = 0.027 0 03 ft. 0.1 ft2 1.23 fps 0.02 ft. 1.40 VI. Calculate the height of hydraulic jump height (conjugate depth) High Flow 0.27 ft. 2 8 cfs 17 ft2 Al Low Flow (Equivalent unit discharge) (Median angular rock size) (Manning's roughness coefficient) (Normal depth in the chute) (Area associated with normal depth) (Velocity in chute slope) (Mean depth) (Froude number) (Length of rock outlet apron - 15"DS0) 0.04 ft. (Hydraulic jump height) 0.1 cfs (Capacity in channel) 0 2 ft2 (Flow area in channel) VII. Calculate the energy lost through the jump (absorbed by the rock) Hiuh Flow E, _ E2 = RE= 0.33 ft. 0.32 ft 3.74 Calculate Quantities for Rock Chute Rock Riprap Volume Area Calculations Length (d_ Rock CL h = 0.3/ Inlet = 9.98 xi = 8.06 L=2.98 A, = 2.98 x2 = 8.00 Ab= 1212 Ab+2'A, = 18.09 ft2 Outlet = 4.11 Slope = 76.59 2.5:1 Lip = 1.24 Total = 91.93 ft. Rock Volume 61.59 yd3 Geotextile Quantity Width Length Q Bot. Rock 2'Slope - 22.09 Total = 91.92 ft. Bottom = 4.12 Geotextile Area Total = 26.22 ft_ 267.74 yd2 Low Flow E1 _ E2 = RE _ 0.05 ft. 0.05 ft. 0.84 (Total energy before the jump) (Total energy after the jump) (Relative loss of energy) Bedding Volume Area Calculations h = 1.37 x, = 0.00 L= 11.05 A5 = 0.00 x2 = 0.00 Ab = 0.00 At,+2'A, = 0.00 ft2 Bedding Thickness t., 1) pin �n Length (d Bed CL Total = 91.92 ft. Bedding Volume 0.00 yd3 Note 1) The radius is not considered when calculating quantities of riprap, bedding, or geotextile. 2) The geotextile quantity does not include over - overlapping (18 -in. min.) or anchoring material (18 -in. min. along sides. 24 -in. min. on ends) Minimum Rock Chute Design - Plan Sheet (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19.112 Pond Rundown West County: Welc Checked by: Date: Designer: Dan Campbell Date: 312812020 Design Values 2.3 in. 4.6 in. 2 ft. 3 f1 5 ft D50 dia. = Rocky thickness v Inlet apron length = O. uet apron length - Raz: is _ Enter Plan Values 8.00 in. 12.00 in. 10 00ft. 4.00 ft. 17 ft. Rock Gradation Envelope °fo Passing Dieu Des Dy) Di.) Diameter, in. (weight, lbs.) 9.12(52-122) 8 - 11 (34 - 89) 6-9(15-52) 5-8(8-34) Will bedding be used? No Notes: ° Rock, bedding, and geotextile quantities are determined from the x -section below (neglect radius). ° Geotextile Class I (non -woven) shall be overlapped and anchored (18 -in. min. along sides and 24 -in min. on the ends). Upstream Channel Slope 0.02 fol. Rock Chute Stakeout Notes Ste. Elev. (Pnt) 0+00.0 42 ft (1) 0+09.4 42 ft (2) 0+10.0 42 ft (3) 0+10.6 42 f► (4) 0+86.4 36.5 ft (5) 0+90 4 36 5 1t (6) 0;91.6 37 ft (7) Glass I non -woven c Ir. 1 Radius = 17 ft. Geotextile Rock gradation envelope can be met with DOT Light nprap Gradation Inlet apron elev. = 42 ft Rock thickness = 12 in. i • -f— • • 1 • Quantities Rock = 62 Yel3 Geotextile (WCS-13)° = 268 Yd2 Bedding = 0 Yd' Excavation = 0 yd' Earthfill = 0 yd; Seeding = 0 C acres Degree of angularity - 1 50% angular, 50% rounded 2 100 % rounded Outlet apron elev. = 36.5 rt 7a it Profile Along Centerline of Rock Chute Freeboard =0.5 ft. - Rock Chute Cost Estimate Unit Unit Cost Cost Rock Geotextile Bedding Excavation Earthfill Seeding $10.00 /yd3 $12.00/yd2 $12.00 /yd3 $12.001yd3 51 00 /yd3 $2 00 lac. Total $620.00 $3,216.00 $0.00 $0.00 $0.00 $0.00 $3.836.00 S .- • - 4 ft Downstream Channel j Slope = 0 01 tt /ft CI tl}ll U W t,' ----r' 1 d = 0.5 ft. ,I 2.5 **Note: The outlet will function adequately ...LOP width = 10 ft • Y = Rock Chute Cross Section /- Geotextile i Rock Chute Bedding Rock Ihitknrss = 12 in. • Use Hp throughout chute but not less than z2. Profile, Cross Sections, and Quantities 0 N RCS 1YYw Maas YID I.tins /.�tl� `,mu ulw.r Mee 7.M.a.• r b^• per. Miller 19-112 Pond Rundown West Weld County Page 1 of ti. .. %man Rock_Chute.xls for construction plan Rock Chute Design - Cut/Paste Plan (Version WI -July -2010, Based on Design of Rock Chutes by Robinson, Rice, Kadavy, ASAE, 1998) Project: Miller 19-112 Pond Rundown West County: Weld Designer: Dan Campbell Date: 3/28/2020 Checked by: Date: Design Values Rock Gradation Envelope D50 dia. = 6.0 in. % Passing Diameter. in. (weight. lbs.) Rockd„ne thickness = 12.0 in. D,00 9 - 12 (52 - 122) Inlet apron length = 10 ft. D85 8 - 11 (34 - 89) Outlet apron length = 4 ft. Db0 6 - 9 (15 - 52) Radius= 17 ft. D10 ---- 5-8(8-34) Will bedding be used? No Coefficient of Uniformity, (D 60)/(D ,o) < 1.7 Quantities' Rock = 62 Yd3 Geotextile (WCS-13)* = 268 yd2 Bedding = 0 Yd3 Excavation = 0 Yd3 Earthfill = 0 Yd3 Seeding = 0.0 acres Notes: ° Rock, bedding, and geotextile quantities are determined from x -section below (neglect radius). Geotextile Class I (Non -woven) shall be overlapped and anchored (18 -in. minimum along sides and 24 -in. minimum on the ends) -- quantity not included Upstream Channel Slope = 0.02 ftfit Stakeout Notes F/ev. (Fin t1 0+00.0 42 ft. (1) 0+09.4 42 ft. (2) 0+10.0 42 ft. (3) 0+10.6 42 ft. (4) 0+86.4 36.5 ft. (5) 0+90.4 36.5 ft. (6) 0+91.6 37 ft. (7) Notes: c 0 Ct 1. _ 10 ft Radius = 16.68 Geotextile _ Inlet apron elev. = 42 ft. I. • • • Rock t, kness = 12 in. • • • • • 76ft • • • point No, Description 2 Point of curvature (PC) 3 Point of intersection (PI) 4 Point of tangency (PT) Outlet apron elev. = 36.5 ft. p 13.89" C Profile Along Centerline of Rock Chute reeuourd 0 5 ft Rock gradation envelope can be met with DOT Light riprap Gradation r Outlet apror 4 ft. - - Rock Chute Bedding Downstream Channel l ,Top width = 10 ft. Slope r 0.01 ft /ft d- 0.5 ft. Geotextile 1 • "y = 0.37 ft ��=' �� Rock Chute 8 ♦ !��•�.�... ��' , \ Bedding a j Rock,,,on.= 12 in. ♦ B' = 4.1 ft • Use Hp throughout chute but not less than z2. Rock Chute Cross Section Profile, Cross Sections, and Quantities MRCS !.•Lai P•a0v:q C.. .non fen UWC guilts Oprwrni a A,Tnwr• 1 Miller 19-112 Pond Rundown West Weld County to 2019-112 Weir Wall Sizing Emergency Overflow Weir Calculations Q = CLH3/2 City of Greeley Eq 11 4 3 A(1 C= L = Length (ft) = H = Depth of Flow (ft) _ Q= 26 23 05 21 14 CFS > From table 11-1 City of Greeley manual 1906 Basin -1 Quo = 18 04 CFS Sub Basin E Qsw = 102 CFS Q1o0Total = Basin 1 + Sub -Basin E Q ,in Total = 18 04 + 102 (CFS) Q im Total= 19 06 CFS CFS *Note Basin -1 and Sub Basin E flows are accounted for at the Overflow Weir Sub -Basin D flows are not accounted for at the Overflow Weir Determination of Culvert Headwater and Outlet Protection Protect: Miller 19-112 Basin ID: Culvert Check „ I azT 4 -a' - Es. Zir 7 Y Soil Type. rChoose Dix �Sa,� II o,sandy pesian information &(nputl Design Discharge Circular Culvert Barrel Diameter in Inches Inlet Edge Type (Choose from pull -down 'St) Box Culvert' Barrel Height (Rase) in Feel Barrel Width (Span) in Fee: inkei f dyr T ypr (Chootai from pull -down asl) Number of Barrels whet Elevation: Out'ot Elevation Q8 Stove Culvert Lenge, Manning s Roughness Bend Loss Coefficient Exit Loss Coefficient 1 eilwater Surface Elevation Max Allowable Chemist Velocity D g D=J 18 Salon End ProNAwn Height (Rise) _ Width (Span) _ OR No = E1evIN= Elev OUT - L = ke = - Elev Y, _ V 1 4838 4637 123 0.013 0 1 5.7 ds inches ft h ft ft ft ft ft's e ujlred Protection (Output). 1 adwater Surface Height Flow Area at Max Channel Ve ocity Culvert Cross Sectional Area Available Entrance Loss Coeffc ent Fnction Loss Coefficient Sum of Al Losses Coefficients Culvert Normal Depth Culvert Critical Depth Tailwater Depth for Design Adusted Diameter QR Adjusted Rise Expansion Factor Flow/Diameter:5 QR Flowl;Span ' Riser') Fsoude Number Taitwoter/Adjusted Diameter Q$ Taitwater/Adjusted Rise ntet Control Headwater Outs Control Headwater Design Headwater Elevation Headwater/Diarnoter Q$ Headwater/Rise Ratio Minimum Theoretical Riprap Size Nominal Riprap Size UDFCD Riprap Type Length of Protection Width of Protection d= L), = 1/(2'tan(0)) Q!D"2 5 = Fr VIM= KW, HWo� HW = HW/D = dac = da. - Type = Lvs T 0.60 1.58 1,77 0.50 2.23 3 73 1 16 1.16 133 4.18 327 0.99 0.40 2.08 1.83 4,840.08 1.37 4 b VL 5 3 ft ft' ft. ft ft ft ft ft ftAis ft ft in in ft ft URBAN DRAINAGE AND FLOOD CONTROL DISTRICT Paul A Hindman, Executive Director 2480 W 26th Avenue Suite 1568 Denver CO 80211 5304 MEMORANDUM FROM Ken MacKenne, P E Master Planning Program Manager Telephone 303 455 6277 Fax 303 455 7880 www udlcd org SUBJECT New Colorado Revised Statute §37-92-602 (8) "Concerning a Determination that Water Detention Facilities Designed to Mitigate the Advei se Effects of Storm Water Runoff Do Not Mate: tally Injure Water Rights DATE March 9, 2016 (Original July 7, 2015) Senate Bill 15-212 was signed into law by Governor Hickenlooper in May 2015 and became effective on August 5, 2015 as Colorado Revised Statute (CRS) §37-92 602 (8) This statute provides legal protection for any regional or individual site stormwater detention and infiltration facility in Colorado, provided the facility meets the following criteria 1 It is owned or operated by a governmental entity or is subject to oversight by a governmental entity (e g required under an MS4 permit) 2 It continuousl) releases or infiltrates at least 97% of all of the runoff from a rainfall event that is less than or equal to a 5 -year storm within 72 hours after the end of the event 3 It continuously releases or infiltrates as quickly as practicable, but in all cases releases or infiltrates at least 99% of the runoff within 120 hours after the end of events greater than a 5 -year storm 4 It operates passively and does not subject the stormwater runoff to any active treatment process (e g , coagulation, flocculation, disinfection, etc ) 5 If it is in the Fountain Creek (tributary to the Arkansas River) watershed it must be required by or operated in compliance with an MS4 permit The statute specifies that runoff treated in stormwater detention and infiltration facilities shall not be used for any other purpose by the owner/operator/overseer (or that entity's assignees), shall not be released for subsequent diversion or storage by the owner/operator/overseer (or that entity's assignees), and shall not be the basis for a water right or credit plenUren\CRS 37 92 602(81 memo update 20151015 There are specific notification requirements that apply to all new stormwater detention and infiltration facilities, including individual site facilities built by private parties as a development requirement For any stormwater detention and infiltration facility constructed after August 5, 2015 and seeking protection under the new statute, the "entity that owns, operates or has oversight for" shall, prior to operation of the facility, provide notice to all parties on the substitute water supply plan notification email list maintained by the State Engineer This notice must include the following I The location 2 The approximate surface area at design volume 3 Data that demonstrate that the facility has been designed to comply with the release rates described in Items 2 and 3 above The Colorado Division of Water Resources (DWR) maintains seven email lists, one for each of the seven major watersheds in Colorado (these coincide with the seven DWR Divisions) UDFCD worked with DWR and the Colorado Stormwater Council to develop a simple data sheet and an online map -based compliance portal website that will allow all municipalities and counties in Colorado to easily upload this required notification information The website application will then automatically send email notifications to the proper recipients, relieving public works staff of the emailing burden while also minimizing the volume of email going out to the email list recipients Please note that the notification requirement applies only to new stormwater facilities (constructed after August 5, 2015), which the statute provides a "rebuttable presumption ' of non - injury to water rights This rebuttable presumption is contestable but only by comparison to the runoff that would have been generated from the undeveloped land condition prior to the development necessitating the stormwater facility Stormwater facilities in existence before August 5, 2015 are defined in the statute as materially non -injurious to water rights and do not require notification Additionally, the State issued a memorandum on February 11, 2016 indicating that construction BMPs and non -retention BMPs do not require notice pursuant to SB-212 and are allowed at the discretion of the Division Engineer, and that green roofs are allowable as long as they intercept only precipitation that falls within the perimeter of the vegetated area and do not intercept or consume concentrated flow nor store water below the root zone The DWR Statement can be found here, http //water state co us/DWRIPub/Documents/DWR%20Storm%20Water%20Statement pdf The compliance portal can be found here https //manerture diaitaldataservices com/avh/9viewer=cswdif A tutorial YouTube video can also be accessed from that website or found here UDFCD YouTube Video plamlken\CRS 37 92-602(8) memo update 20151015 We also have a list of frequently asked questions with answers which is attached to this memorandum Please email me at kmackenzie(ailudfcd orq with any questions pLm\ken\CRS 37 92-602(8) memo update 20151015 Frequently Asked Questions related to Colorado Revised Statute 37-92-602(8) Statute Related Questions Where can I find out more information on the statute? A memorandum can be found at http //udfcd ore/guidance-documents Does this statute apply only to facilities within MS4s or government owned facilities? Would a private facility located in a rural area need to be uploaded? The statute protects only those stormwater detention and Infiltration facilities that are operated solely for stormwater management and are owned or operated by a governmental entity or are subject to oversight by a governmental entity (e g , required under other statutes for flood protection or water quality) Additionally, to be covered, these facilities must meet the drain time limitations and other criteria specified In the statute and UDFCD memorandum if a hypothetical private facility located in a rural area was voluntarily built (not as an imposed development requirement), it is not protected under the statute and no notification is required, but it may be considered a water diversion out of priority by the State How do these new regulations apply to micropool designs since they typically will exceed the 120 hour release time period? The volume of the micropool is typically 0 0006 times the 5 year Inflow volume (0 06%) and 0 0002 times the 100 year Inflow volume (0 02%), which is well within the allowable criteria The statute says "no other beneficial use' is allowed Define "beneficial " As a municipal corporation, detention Is beneficial to reduce pipe sizes Beneficial use refers to uses for which you would otherwise need a water right, like replacement water or irrigation water Why is Fountain Creek excluded from legislation and what are the requirements to build a detention basin In the Fountain Creek watershed? Facilities In Fountain Creek that meet the other criteria specified in the statute are protected only if they are required by or operated in compliance with a Colorado Issued MS4 permit Those facilities In the Fountain Creek watershed that do not meet this criterion are more susceptible to a claim of water right injury, but they do not otherwise require a water right The exclusion of the Fountain Creek watershed was a necessary concession In order to get the backing of the Colorado Farm Bureau Will existing facilities need to be retrofitted to meet the 72/120 hour drain time requirement? If your existing facility meets the drain time criteria specified in the statute, then the facility meets the compliance criteria if your existing facility Is a retention pond and you don't have a water right, then yes, you should retrofit (or get a water right) CSH 37 92 602181 FAQ UDFCD 2015-08 26 How should retention facilities be handled? Neither retention facilities nor constructed wetlands are protected under 37-92-602(8) CRS These facilities expressly require a water right Does the bill require that operation and maintenance demonstrate on going compliance? What happens if a facility does not function as designed (e g, lack of maintenance, poor infiltration)? The statute protects only those facilities that meet the drain time criteria If a facility does not operate as designed, or if the design proves to be flawed, not only is it not protected under 37-92 602(8) CRS, it also likely violates a CDPS-issued permit and corrective measures are responsibly warranted What about regional facilities that are designed for a future condition but operate in an interim mode that does not comply with the statute? Those constructed after August 5, 2015 should be designed to comply with the statute in their interim condition as well as in the final configuration If they do not comply, they will not be protected under the statute, and no notification is required Those already in operation on August 5, 2015 do not require notification, but are not protected unless they comply with the drain time criteria Are facilities designed to protect areas less than one acre subject to this legislation? Yes There is no size threshold for the notification requirement All stormwater detention and infiltration facilities that meet the definition in the statute and are made operable after August 5, 2015 are subject to the statute Could a water rights holder contest a facility even without any real basis just to tie up a development or make it more difficult to develop a property? What ability do irrigation companies, farmers, etc have to impact a project when these notices go out? The water rights holder must show that the facility has caused injury (not will cause injury) The injury must be further with respect to the water the complainant would have received in the watershed condition that existed as of the water right's priority date, absent the urbanization necessitating the facility In the case of redevelopment' is the calculation from the existing developed condition to the proposed developed condition or from the assumed "predeveloped condition" Any challenge must be with respect to the water the plaintiff would have received in the watershed condition that existed as of the water right's priority date, absent the urbanization necessitating the facility CSR 37 92-602(8( FAQ UDFCD 2015 08 26 What liability and/or responsibility does a contractor have while working on a stormwater detention facility that the responsible party (government entity, operator, design engineer, etc ) faded to comply with the notification requirements? If the facility is designed to drain in the time specified in the statute and proper notification is made, a claim of injury is not likely, since the claim must be in comparison to the water available before any of the land development that necessitated the detention in the first place Statute does not apply to the following Flow through devices (e g , media filter drains, hydrodynamic separators baffle vaults without storage) o Process water holding ponds for the oil and gas Industry o Stock ponds and Irrigation ponds • Construction BMPs (e g sediment traps, etc ) o Any facility not meeting the following criteria o is owned or operated by a governmental entity or is subject to oversight by a governmental entity, o continuously releases or infiltrates at least 97% of the 5 year storm within 72 hours, o continuously releases or infiltrates at least 99% of the 100 year storm within 120 hours, o operates passively and does not subject the stormwater runoff to any active treatment process Cue 37 92 603(8( FAQ UDFCD 2015 08 26 Procedure and Compliance Workbook Related Questions Is the SDI workbook required or can a different PDF documenting drain times be uploaded? (e g, UD Detention) The user can upload any PDF that provides data that demonstrates compliance (i e , drain times) UD Detention would be adequate as it also calculates drain times for various events In the design data spreadsheet do we use the 60 minute 1 year storm value (at basin location) for the WQCV design storm? Is the water quality capture volume drainage time a maximum or minimum of 40 hours? The Urban Storm Drainage Criteria Manual Vol 3, Chap 3 (http //www udfcd org/index html) gives detailed information on sizing the water quality capture volume anywhere in Colorado and guidance on recommended drain times (e g , 40 hours for extended detention, 12 hours for rain gardens) Can we route our own inflow hydrographs through the spreadsheet to show compliance? Yes, there is a table to the right of the printable area that allows you to input your own storm hydrographs in fact, this will be necessary for unusually large watersheds as the largest embedded Inflow storm hydrograph in the workbook is 675 56 acre feet in volume (the smallest is 0 001 acre feet) The workbook has been tested successfully for watersheds as small as 01 acres in area Define an operational' detention facility A detention facility is operational when stormwater is flowing into it and flowing out of it (either on the surface or infiltrating Into the soil below it), while experiencing a change in the detained volume over time (first increasing in volume and then decreasing) Does the design engineer upload the notification or does the government entity with jurisdiction (MS4) upload it? Would It be the City or the property owner? Anyone can upload a site Local jurisdictions have administrative privileges to create, modify, accept, or delete any record within their jurisdiction This Is to allow those jurisdictions to monitor for errant activity Those with administrative privileges will also receive an email immediately whenever a record is created or modified within their jurisdiction What Is the recourse or plan of action against the detention facility owner if they do not comply with the notification compliance? If the facility is designed to drain in the time specified In the statute and proper notification Is made, a claim of injury is not likely, since the claim must be in comparison to the water available before any of the land development that necessitated the detention in the first place After notification, if a downstream water right user objects, what then? The downstream user can't object to a facility before it is operable but they can rebut the presumption of non -injury if they can prove they have been (not will be) injured after the facility is in place (and only then in respect to water they would have received at their priority date) Cue 37 92 602(6) FAQ UDFCO 2015 0&26 What type of feedback do you expect to get from the people receiving a notification? Each record created will have two email addresses, one for the record creator and one for the community having jurisdiction over the site You may anticipate inquiries as to the need for the facility and details about how it operates Would it be acceptable to notify at the time of plan approval and prior to construction? Yes, as long as notification occurs before the facility becomes operable, you are in compliance with the statute We often use future detention basins as temporary sedimentation basins during construction When do we provide notification? Construction sedimentation basins should not be uploaded the portal If you are using the facility in a modified and temporary form during construction, wait until the final detention configuration is complete before entering the record CSR 37 92 602i8) FAQ UDFCo 2016-08 26 Portal & Notification (Noted The compliance portal is located at https //maperture digitaidataservices com/gvh/?viewer=cswdif The compliance portal was developed to streamline the notification requirement of the new statute Anyone can place a pin on the map to create a new stormwater detention/Infiltration facility The portal recognizes counties, cities, and towns as "Jurisdictions" and has assigned to each Jurisdiction administrative privileges Jurisdictions can create, modify, or delete any record within their own Jurisdiction, and must accept into the database a record created by anyone else within their jurisdiction When a Jurisdiction creates a new record it is automatically accepted into the database and its information is put into the queue for the email notification The icon on the map interface will be blue When anyone who is not a Jurisdiction creates a new record in the portal database the icon will remain green and no notification will go out until the Jurisdiction accepts the record into the database which will turn the icon blue and place it in the queue for notification The entity creating a record will be able to later edit that record using the edit password emailed to them by the portal The password is specific to the record Note that the Jurisdiction accepting the record does not indicate approval of the facility it is simply a necessary database quality assurance measure to prevent vandalism and errant records If the Jurisdiction believes the record to be in this class, they may delete the record or contact the creator of the record to verify it If a record Is not accepted or deleted by the Jurisdiction with 30 days of its creation, it will automatically be accepted by the system, turn blue, and notifications will go out within a week of that event Records are perpetually viewable by those with administrative privileges but are removed from the map 30 days after being accepted into the database Portal & Notification Related Questions If you have multiple facilities in series, is it appropriate to upload each separately? For example, four water quality rain gardens In a parking lot drain to a downstream flood control facility How If the facilities are intended for water quality only, they do not require notification (with the exception of extended detention basins) An extended detention basin designed to treat only the water quality capture volume followed by a flood control facility can be entered as two separate facilities or one facility accommodating for the effective stage/storage and drain times of the two facilities In the stated example, only the downstream flood control facility need be uploaded If there are multiple flood control facilities in series, appropriate drain CSR 37 92 602(81 FAQ UDFCD 2015-08 26 many facilities should be uploaded to the site? times should be demonstrated UDFCD recommends documentation outside of the compliance portal workbook for this purpose, (e g , attach SWMM output) Does notification need to take place for modifications to existing detention facilities already in the portal? If the facility is already operable on August 5, 2015, it is defined in the statute as non injurious to water rights provided it meets the other drain time criteria specified In the statute if your modifications are going to make the downstream water rights holders condition better (e g, smaller stored volume or faster drain time), then no notification is required if the opposite is true handle it as a new facility and provide notification of the new configuration Are State agencies and RTD to be given usernames and passwords? Those agencies will be treated in the same manner as jurisdictions and will have editorial privileges necessary to create, modify, and delete only their own records The cities, towns, and counties of Colorado will have administrative privileges to create, modify or delete any record within their jurisdiction Who will be auditing the statewide notification compliance portal for correct data? There is no statutory enforcement mechanism Those communities having administrative privileges will receive an email notice every time a record is created edited, or deleted within their jurisdiction and should review these records for accuracy The DWR does react to complaints If the community uploads the data for the developers, does it appear that the community is the owner? Each record will have two contact email addresses as part of the public record, one for the engineer of record and one for the community having jurisdiction over the facility Why do I have to print a pdf to upload, and not just upload my spreadsheet? Can't this feature be built into the portal? For reasons of consistency and storage limitations the design data sheet can only be in pdf format This also minimizes the risk of document altering by others Where is the compliance portal? https //maperture digitaldataservlces com/gvh/?viewer=cswdif What resources are available to help navigate the compliance portal? A webinar recording is available at UDFCD YouTube Video Do existing facilities need to be entered? No, if the facility was operable on August 5, 2015, notification is not required These facilities are defined in the statute as non injurious to water rights, provided they meet the other criteria specified in the statute How will Interested parties be notified of newly uploaded facilities? CSR 37 92 602(8) FAQ UDFCD 2015-08 26 A weekly digest email will be sent out to the recipients In each of the DWR's seven divisions Each division will receive an email on a different day of the week to minimize traffic loading on the compliance portal Only those posted since the previous email will be Included Additionally, those facilities In existence for more than 90 days will no longer be visible to the general audience, only to those with editorial or administrative privileges This is to reduce clutter on the portal and ease navigation for the end user Is there a backup of the site's data somewhere? The site has robust security features and automatic backups are produced and stored offsite at regular frequent time intervals If a detention facility is below grade, is that apparent to users of the portal? Is water surface area needed? The statute applies to facilities above and below grade, and there is no requirement to distinguish which type the facility is The water surface at design volume is one of three pieces of information mandated under the statute's notification requirement Do not enter zero for this value, Instead enter the area of the vault Do we need to input an address, a latitude and longitude, what are the criteria to place a facility in the portal correctly? The map feature offers a number of ways to zoom to the correct location, including "zoom to address" and "zoom to map " Any of these methods should enable you to place a marker within 100 feet of the exact location This meets the intent of the notification requirement Once you place the pin, the latitude, longitude, DWR division, and local jurisdiction will all be automatically populated In the database Flow do you prevent duplicate entries? What if two separate entities report compliance for the same facility The map interface feature should eliminate this problem When placing a marker icon, if there is already a marker icon at your location, click on that icon to retrieve the specific data for comparison The local government will receive an email notice Immediately when a new record is created within their jurisdiction What types of facilities require notification per SB-2127 Water Quality Only Flood Control Included BMPs Grass Buffers Not Required Not Required Grass Swales Not Required Not Required Bioretention (with or without an underdrain) Not Required Required Green Roof Not Required N/A Extended Detention Basin Required Required Sand Filter Not Required Required Permeable Pavement Systems Not Required Required Media Filter Drain Not Required Not Required Underground Detention Vaults Required Required Constructed Wetland Pond N/A SUBJECT TO WATER RIGHTS Constructed Wetland Channel N/A, SUBJECT TO WATER RIGHTS C58 37 92 502(8) FAQ UDFCD 2015 OS 26 COLORADO Department of Public \ .t. Health &Environment Dedicated to protecting and improving the health and ern ironmenl of the people of Colorado STORMWATER FACT SHEET — CONSTRUCTION Contents A Introduction 1 B Obtaining Regulatory Coverage 2 1 Do you need a Permit' 2 a Applying for a Permit 3 b Options Small Construction Sites 3 i Qualifying Local Programs 3 ti R Factor Waiver 3 2 Who May Apply/ 4 C Permit Requirements 4 D Local Stormwater Requirements 5 E Amending Your Permit Certification 5 F Ending Your Permit Coverage 6 G Multiple Owner/Developer Sites 7 1 Permit Coverage 7 2 Permit Compliance 8 H Sale of Residence to Homeowners 10 I Construction Dewatenng 10 J Concrete Washout 10 A INTRODUCTION Look for this symbol throughout this guide for brief summaries of the most important information you need to know about stormwater permitting for construction activities Then read further if you want more details In 1992, the State of Colorado stormwater regulation went into effect to control municipal and industnal stormwater discharges, based on EPA regulations The regulation is meant to reduce the amount of pollutants entering streams, rivers, lakes, and wetlands as a result of runoff from residential, commercial and industrial areas The State regulation (5 CCR 1002 61) covers discharges from specific types of industries including construction sites, and storm sewer systems for certain municipalities In Colorado, the program is under the Colorado Department of Public Health & Environment, Water Quality Control Division (the Division) The Colorado program is referred to as the Colorado Discharge Permit System (CDPS), and regulated stormwater discharges from construction activities are covered under the CDPS General Permit for Stormwater Discharges Associated with Construction Activities (the Stormwater Construction Permit) Construction activities produce many different kinds of pollutants which may cause storrnwater contamination problems The main pollutant of concern at construction sites is sediment Grading activities remove grass, rocks, pavement and other protective ground covers, resulting in the exposure of underlying soil to the elements The soil is then easily picked up by wind and/or washed away by rain or snowmelt Sediment runoff rates from construction sites are typically 10 to 20 times greater than those from agncultural lands, and 1,000 to 2,000 times greater than those from forest lands During a short period of time, construction activity can contribute more sediment to streams than would normally be deposited over several decades, causing physical, chemical, and biological harm to our State's waters The added sediment chokes the river channel and covers the areas where fish spawn and plants grow Excess sediment can cause a number of other problems for water bodies, such as increased difficulty in filtenng drinking water, and clouding the waters, which can kill plants growing in the river and suffocate fish A number of pollutants, such as nutrients, are absorbed onto sediment particles and also are a source of pollution associated with sediment discharged from construction sites Page 1 of 10 Revised 7 2015 4300 Cherry Creek Drives Denver CO 80246 1530 P 303 692 2000 vnvw colorado gov/cdphe John W Hickenlooper Governor I Larry Wolk MD MSPH Executive Director and Chief Medical Officer In addition, construction activities often require the use of toxic or hazardous materials such as fuel, fertilizers, pesticides and herbicides, and building materials such as asphalt, sealants and concrete, which may also pollute stormwater These matenals can be harmful to humans, plants and aquatic life This Fact Sheet provides general guidance for compliance with the COPS permitting requirements for stormwater discharges from construction activities The Division reserves the nght to interpret the permitting requirements on a case by case basis, as necessary B OBTAINING REGULATORY COVERAGE FOR CONSTRUCTION SITES A You must obtain permit coverage (or an R -Factor waiver) to discharge stormwater from any construction activity that disturbs at least 1 acre of land (or is part of a larger common plan of development or sale that will disturb at least 1 acre) The owner or operator must apply for coverage under the Stormwater Construction Permit at least 10 days prior to the start of construction activities The application is available from the Division's web page 1) Do you need to obtain coverage under the Stormwater Construction Permit? Construction Sites that disturb one acre or greater, or are part of a larger common plan of development disturbing one acre or greater, are covered under Colorado s stormwater permitting requirements Generally, permit coverage is required, as discussed in Part B 1 a, below However, additional options may exist if your project or plan of development will disturb less than 5 acres (Small Construction Site), as discussed in Part B 1 b, below If permit coverage is required, or a waiver applied for, it must be maintained until the site is finally stabilized Is it part of a larger common plan of development or sale, "A common plan of development or sale' is a site where multiple separate and distinct construction activities may be taking place at different times on different schedules Examples include 1) phased projects and projects with multiple filings or lots, even if the separate phases or filings/lots will be constructed under separate contracts or by separate owners (e g , a project where developed lots are sold to separate builders), 2) a development plan that may be phased over multiple years, but is still under a consistent plan for long term development, and 3) projects in a contiguous area that may be unrelated but still under the same contract, such as construction of a building extension and a new parking lot at the same facility If the project is part of a common plan of development or sale, the disturbed area of the entire plan must be used in determining permit requirements Disturbance associated with utilities, pipelines, or roads that are constructed for the purpose of serving a facility, are considered together with that facility to be part of a common plan of development However, adjacent construction of trunk lines or roads that are part of a regional network and not directly associated with the facility construction, are not usually considered to be part of the common plan for that facility Note that permit coverage or an R Factor waiver is still required for each individual project (facility or adjacent construction activity) that disturbs one or more acres What is the total estimated area of disturbance? The area of disturbance is the total area at the site where any construction activity is expected to result in disturbance of the ground surface This includes any activity that could increase the rate of erosion, including, but not limited to, cleanng, grading, excavation, and demolition activities, installation of new or improved haul roads and access roads, staging areas, heavy vehicle traffic areas, stockpiling of fill materials, and borrow areas Construction does not include routine maintenance to maintain original line and grade, hydraulic capacity, or onginal purpose of the facility 'Finally Stabilized" means that all ground surface disturbing activities at the site have been completed, and all disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed Re seeding alone does not qualify Page 2 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 mwor colorado gov/cdphe John W Hickenfooper Governor I Larry Wolk, MD MSPH Executive Director and Chief Medical Officer O). What are the requirements for recommencing construction activities at a later date at a site that has been completely stabilized and the permit terminated? If a common plan of development is completely stabilized such that the entire common plan of development meets the definition of finally stabilized and permit coverage for that common plan of development has been terminated (the permittee has submitted a notice of termination to the division and the division has confirmed that the certification has been inactivated), then a new determination of "common plan of development" shall be made for any future construction activities conducted by a different owner(s)/developer(s) that occur within the previously permitted area to determine if permit coverage is needed However, if the original owner/developer of a common plan of development, that achieved final stabilization and terminated permit coverage, is the one who is restarting construction activities within that development, then any construction activity they are engaged in would be considered part of the original larger common plan of development and therefore require permit coverage if one acre or greater Note that if the site has never been finally stabilized, then this does not apply as the original development is considered ongoing a) Applying for a permit Application for coverage under the Stormwater Construction Permit must be made at least 10 days pnor to the start of construction activities, unless the site is a Small Construction Site that qualifies for an alternative option discussed in B 1 b, below An application, which includes guidance on developing a Stormwater Management Plan (SWMP), is available from the Division The SWMP must be completed prior to application See Section C, "Permit Requirements," for further information If your application is complete, it will be processed and your permit certification mailed to you The Stormwater Construction Permit certification must be inactivated once the site has been finally stabilized, in order to end permit coverage and billing An inactivation form is supplied with the permit certification b) Additional Options for Small Construction Sites (at least 1 acre, but less than 5 acres of disturbance) The following options may apply to Small Construction Sites that disturb less than 5 acres, and are not part of a larger common plan of development exceeding 5 acres (Regardless of which option applies at the State level, all local requirements must still be met as discussed in Section D, below ) The options discussed under Parts b i and b ii below are not available for Large Construction Sites i) Obtain coverage under a State designated Qualifying Local Program (For Small Construction Sites Only) The Division may designate a local municipality's stormwater quality control program as a Qualifying Local Program This means that the local program's requirements are at least as stringent as the State permit in this case, it is not required for the owner or operator to apply for permit coverage under the Stormwater Construction Permit The local municipality will be responsible for notifying you that you do not need to apply for State coverage, if this is an option You can also view a list of the few municipalities with Qualifying Local Programs at the Division's web page (see first page for web address) The local program must have been formally designated by the Division to qualify Most municipalities have some type of local program and may require permits and fees However simply having a local program in place does not necessarily mean that it is a qualifying program and that the Division's Stormwater Construction Permit application is not required The current designated Qualifying Local Programs in Colorado are the Cities of Durango, Golden, and Lakewood ii) Apply for coverage under the R Factor Waiver (Available for Small Construction Sites only) The R Factor waiver allows a site owner or operator to apply for a waiver from coverage under the Division's Stormwater Construction Permit, if the R Factor, calculated using the State approved method, is less than 5 during the period of construction The R Factor is a way to measure erosion potential based on the length of the project and time of year An application with instructions for using the State approved method is available from the Division's web page (see first page for web address) In general, the only projects that will qualify for the waiver are projects that are completely stabilized within a month or two after the start of construction That means that projects relying on seeding for revegetation will usually not qualify for the waiver, because the vegetation must be established before the Page 3 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 www colorado gov/cdphe Caol«,� John W Hlckenlooper, Governor I Larry Wolk, MD MSPH Executive Director and Chief Medical Officer I e o site is considered stabilized During the spring and summer months, when Colorado experiences the bulk of its rainfall, many projects will not qualify at all for the waiver in addition, the Division will not grant waivers for construction sites located in areas where snow cover exists at, or up gradient of, the site for extended periods of time, if the construction site will potentially remain active and unstabilized during spring runoff This waiver does not relieve the operator or owner from complying with the requirements of local agencies, such as meeting local stormwater quality requirements, including those required by a Qualifying Local Program as discussed in Section B 1 b 1, above 2) Who may apply for permit coverage? The Permit applicant must be a legal entity that meets the definition of the owner and/or operator of the construction site, in order for this application to legally cover the activities occurring at the site The applicant must have day to day supervision and control over activities at the site and implementation of the SWMP Although it is acceptable for the applicant to meet this requirement through the actions of a contractor, as discussed in the examples below, the applicant remains liable for violations resulting from the actions of their contractor and/or subcontractors Examples of acceptable applicants include • Owner or Developer An owner or developer who is operating as the site manager or otherwise has supervision and control over the site, either directly or through a contract with an entity such as those listed below o General Contractor or Subcontractor A contractor with contractual responsibility and operational control (including 5WMP implementation) to address the impacts construction activities may have on stormwater quality o Other Designated Agents/Contractors Other agents, such as a consultant acting as construction manager under contract with the owner or developer, with contractual responsibility and operational control (including SWMP implementation) to address the impacts construction activities may have on stormwater quality An entity conducting construction activities at a site may be held liable for operating without the necessary permit coverage if the site does not have a permit certification in place that is issued to an owner and/or operator For example, if a site (or portion of a site) is sold or the contractor conducting construction activities changes, the site's permit certification may end up being held by a permittee (e g , the previous owner or contractor) who is no longer the current owner and/or operator In this case, the existing permit certification will no longer cover the new operator's activities, and a new certification must be issued, or the current certification transferred See Section F, below, for additional guidance on scenarios with multiple owners and/or operators Utilities, Other Subcontractors, etc A separate permit certification is not needed for subcontractors, such as utility service line installers, where the permittee or their contractor is identified as having the operational control to address any impacts the subcontractor's activities may have on stormwater quality Although separate permit coverage may not be needed in some cases, these entities are not exempt from the stormwater regulations for all of their projects and may still be held liable if their activities result in the discharge of pollutants Leases When dealing with leased land or facilities, the lessee shall be considered the "owner" for the purposes of stormwater permitting if they are responsible for the activities occurring at the site C PERMIT REQUIREMENTS The primary requirement of the Stormwater Construction Permit is the development and implementation 21 of a Stormwater Management Plan (SWMP) The permit application includes guidance that must be followed for development and implementation of the SWMP Permit requirements are the same for both Small and Large Construction Sites The Stormwater Construction Permit requires dischargers to control and eliminate the sources of pollutants In stormwater through the development and implementation of a Stormwater Management Plan (SWMP) The purpose of a SWMP is to identify possible pollutant sources that may contribute pollutants to stormwater, and identify Best Management Practices (BMPs) that, when implemented, will reduce or eliminate any possible water quality impacts For construction activities, the most common pollutant source is sediment Other pollutant sources include fuels, fueling practices and chemicals/matenals stored on site, concrete washout, etc BMPs encompass a wide range of practices, both structural and non structural in nature, and may include silt fence, sediment ponds, vehicle tracking Page 4 of 10 Revised 7 2015 4300 Cherry Creek Drive 5 Denver CO 80246 1530 P 303 692 2000 www coloredo gov/cdphe I * r John W Hickenlooper Governor I Larry Wolk MD M5PH, Executive Director and Chief Medical Officer derma r7 C Q� controls, good housekeeping, inspection and maintenance schedules, training, etc The SWMP is not submitted with the permit application unless requested An up to date copy of the SWMP must be kept on site, for use by the operator, and so that Division, EPA, or local inspectors can review it during an inspection If an office location is not available at the site, the SWMP must be managed so that it is available at the site when construction activities are occurnng (e g , by keeping the SWMP in a supenntendent's vehicle ) Further information concerning the contents of the SWMP can be found in Appendix A of the application, "Preparing a Stormwater Management Plan " This document and others can be obtained from the Division's web site or by contacting the Division (see first page for address information) D LOCAL STORMWATER REQUIREMENTS FOR CONSTRUCTION _3\Where local requirements exist for stormwater management, an owner/operator must comply with both the Division's and the local agency's requirements In addition to the requirement to obtain and comply with the Division's Stormwater Construction Permit, it is possible that additional government agencies (I e , cities, counties, and special districts) may impose local requirements to control the discharge of pollutants from construction activities An owner or operator of a construction activity must comply with the Stormwater Construction Permit requirements discussed in this Fact Sheet, even if they are also covered by a local program's requirements (However, in the case of a Qualifying Local Program, as discussed in Section B 1 b ii, some administrative requirements for the Stormwater Construction Permit may be simplified ) Likewise, the Stormwater Construction Permit does not pre empt or supersede the authonty of local agencies to prohibit, restnct, or control discharges of stormwater Where a local program places additional restnctions on stormwater management at a construction site within its jurisdiction, the owner/operator must comply with those stncter requirements in addition to the Division's permitting requirements For example, although the Division allows several options for permitting at multiple owner/operator sites, a local authonty may restrict these options and require specific procedures to be followed for who maintains permit coverage and authonty for stormwater discharges MS4 Permits Many cities, counties, and special distncts are covered by a Municipal Separate Storm Sewer System (MS4) permit These permits require the governmental entity to implement various programs to improve stormwater quality in their jurisdiction Included in these permits is the requirement to implement a program to manage the discharge of pollutants from construction sites within their junsdiction Therefore, if a construction site located within the jurisdiction of one of these government entities does not properly manage stormwater at that site, the government entity may be in violation of their permit in addition to the construction site owner and operator E AMENDING YOUR PERMIT CERTIFICATION Thls section is only applicable if the limited information on the construction project submitted In the two Y page application form changes In such case, it may be necessary to provide the Division with revised Information If the information provided by the penmittee in their two page application form is no longer accurate, the permittee must provide the revised information to the Division This includes such items as the planned total disturbed acreage, and the project legal descnption or map originally submitted with the application (Note it is not necessary to revise the anticipated final stabilization date, since the information provided was only an estimate) To revise this information, provide a letter to the Division's Stormwater Program (see the contact information on page 1) that includes the revised information The Division will not respond to this letter, so you are advised to obtain delivery confirmation from your postal service to confirm receipt When the Stormwater Management Plan is revised, as required by the Stormwater Construction Permit, it is not necessary to notify the Water Quality Control Division When BMPs or other site details discussed in the SWMP are modified, the SWMP must be updated to accurately reflect the actual field conditions Examples include, but are not Page 5 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver, CO 80246 1530 P 303 692 2000 www colorado govicdphe John W Hickenlooper Governor I Larry Wolk MD MSPH Executive Director and Chief Medical Officer limited to, removal of BMPs, addition of BMPs, modification of BMP design specifications, and changes in items included in the site map and/or descnption However, this information is not submitted to the Division, unless requested F ENDING YOUR PERMIT COVERAGE A Stormwater Construction Permit certification remains active until inactivatedor transferred or reassigned to a new responsible party Forms for inactivation, transfer or reassignment of a permit certification can be obtained from the Division's web site or by contacting the Division (see first page for address Information) 1) Inactivation notice Permit coverage for a site that has been finally stabilized in accordance with the SWMP (see definition in Section 8 1, above), may be inactivated by submitting a completed Inactivation Notice form This form contains a certification statement that must be signed in accordance with the General Requirements of the permit Also, the permittee may inactivate permit coverage at sites where all areas have been removed from their permit coverage, by one or more of the methods below • reassignment of permit coverage (see Section F 3), sale to homeowner(s) (see Section H), and/or amendment by the permittee, as discussed in Section E, above for areas where permit coverage has been obtained by a new operator (see Part G 1, below) or the area is returned to agricultural use (see the Division's Oil and Gas Construction Fact Sheet) In these cases the permittee would no longer have any land covered under their permit certification, and therefore there would be no areas remaining to finally stabilize Submittal of an Inactivation Notice is still required and must discuss how the above conditions have been met 2) Transfer of permit Permit coverage for a construction site may be transferred to a new entity when responsibility for stormwater discharges at the site changes from the permittee to the new entity To transfer permit coverage, the permittee must submit a completed Notice of Transfer and Acceptance of Terms form that is signed in accordance with the General Requirements of the permit If the new entity wilt not complete their portion of the transfer form, the permit certification may be inactivated if the permittee has no legal responsibility for the construction activities at the site, requests inactivation in written correspondence to the Division, and submits a completed Inactivation Notice form 3) Reassignment of permit Permit coverage for a specific portion of a permitted site may be reassigned to a new entity when a permittee no longer has control of that portion of the site, and wishes to transfer coverage of that portion to a second party To reassign permit coverage for a specific portion of a permitted site, the permittee must submit a completed Notice of Reassignment of Permit Coverage form that is signed in accordance with the General Requirements of the permit If the new entity will not complete their portion of the reassignment form, the specific portion of the site may be removed from permit coverage if the permittee has no legal responsibility for the construction activities at the portion of the site, and a wntten request (including contact Information for the new entity) is submitted to the Division G PERMITTING FOR DEVELOPMENTS WITH MULTIPLE OWNERS AND/OR OPERATORS For situations where multiple entities meet the definition of owners and/or operators for different portions of a development (e g , a single development with multiple lots being owned and operated by separate entities), extra care must be taken to ensure that proper permit coverage is maintained and that stormwater management practices are correctly documented and implemented Local stormwater quality programs may have diffenng requirements for who must maintain permit coverage, and what actions must occur when permitted areas and/or activities change Construction site owners and operators must ensure Page 6 of 10 Revised 7 2015 4300 Cherry Creek Dove 5 Denver CO 80246 1530 P 303 692 2000 ewe Colorado gov/cdphe John W Hlckenloaper, Governor I Larry Wolk MD, MSPH, Executive Director and Chief Medical Officer kit me that their actions do not result in violations of local program requirements Refer to Section D for additional information 1) Permit Coverage for Multiple Owner/Operator Development When a portion of a permitted site is sold to a new owner, a permit certification must be in place that is held by an entity meeting the definition of owner and/or operator of the sold area (see the discussion in Section B 2, above) This may be accomplished in one of the following ways a) Coverage Under the Existing Certification Activities at the sold area may continue to be covered under an existing permit certification for the project ff the current permittee meets the definition of operator for the sold area To meet the definition of operator, the current permittee must have contractual responsibility and operational control to address the impacts that construction activities at the sold area may have on stormwater runoff (including implementation of the SWMP for the sold area) Therefore, a legally binding agreement must exist assigning this responsibility to the current permit holder on behalf of the new owner and/or operator for the sold area It is not necessary to notify the Division in such case However, documentation of the agreement must be available upon request, and the SWMP must be maintained to include all activities covered by the Stormwater Construction Permit Example Developer Dan sells a lot to Builder Bob Developer Dan is currently covered by a permit certification that covers a larger area, which includes the sold lot Developer Dan and Builder Bob may enter into a contract that assigns the responsibility for permit coverage and stormwater management to Developer Dan for Builder Bob's lot Developer Dan is also responsible for making sure his SWMP includes the activities on the sold lot Developer Dan's permit certification will continue to cover construction activities on Builder Bob's lot b) New Certification Issued - Reassignment A new permit certification may be issued to the new owner and/or operator of the sold area The existing permittee and the new owner and/or operator must complete the Reassignment Form (available from the Division's web page, see page 1) to remove the sold area from the existing permit certification and cover it under a certification issued to the owner and/or operator of the sold area Both entities must have SWMPs in place that accurately reflect their current covered areas and activities Example Developer Dan sells a lot to Builder Bob Developer Dan is currently covered by a permit certification that covers a larger area, which includes the sold lot For this example, Developer Dan and Builder Bob must jointly submit the Reassignment Form Builder Bob will be issued a new permit certification for his lot and the lot will be removed from Developer Dan's permit coverage Pnor to submittal of the Reassignment Form, Developer Dan must revise his SWMP to reflect the changes in his covered area and activities, and Builder Bob must develop his own SWMP to cover the area and activities he will obtain coverage for c) Amend Existing Permit Certifications - In some cases, both parties (the onginal owner/operator and the new owner/operator of an area undergoing transfer of ownership or operation) will already both be permit holders for their portions of the overall project (i e , at least two permit certifications are issued for the project and cover both the party wishing to reassign coverage and the party wishing to accept coverage) When an additional area is transferred between the two parties, the permittees may simply amend their permit certifications instead of completing the Reassignment Form Both parties must separately complete the procedures discussed in Section E to amend their permit coverage, removing the applicable area(s) from the original owner/operator's permit coverage, and adding the area(s) to the new owner/operator's permit coverage The requests must cite both permit certification numbers (Note this request may be submitted jointly if it is signed by both entities) This option will likely be used in cases where a developer and an owner have already submitted a Reassignment Form, as discussed in Part b, above, where an initial transfer of lots has occurred, and then additional lots are transferred at a later date Both entities must have SWMPs in place that accurately reflect their current covered areas and activities Example Developer Dan sells a lot to Builder Bob Developer Dan is currently covered by a permit certification that covers a larger area, which includes the sold lot In addition, Builder Bob also holds a permit certification for other portions of the development which he already owns, and Builder Bob wishes to cover his new lot under this certification Developer Dan submits a request to remove the lot from his permit certification and provides Builder Bob's permit certification number that the lot will now be covered under Builder Bob also submits a request to modify his permit certification to add the lot, and provides Developer Dan's permit Page 7 of 10 Revised 7 2015 4300 Cherry Creek Drive S , Denver, CO 80246 1530 P 303 692 2000 vnvw colored° gov/cdphe John W Hickenlooper, Oovemor I Larry Wolk, MD MSPH Executive Director and Chief Medical Officer '1 Di fl Stcl>, e',. certification number under which the lot was previously covered Developer Dan and Builder Bob must revise their SWMPs to reflect the changes in their covered area and activities 2) Permit Compliance for Multiple Owner/Operator Development V\ As a permittee, the most important concept for projects where multiple entities are involved is if activities within your permitted area result in pollution of stormwater, ymi are the entity responsible for ensuring that those pollutants are properly managed , Permittees are responsible for complying with the Stormwater Construction Permit requirements for the V\ areas and activities for which they have permit coverage, and for all BMPs they are relying on to comply with the permit Properly addressing and documenting the responsibility of various parties at a construction site will help protect an entity from liability in the case where another party's actions result in failure of BMPs a) Pollutants from Outside the Permitted Area V\ A permittee may be held liable for pollutants that pass into and are then discharged from their permitted area or that result from another entity's activities Specifically, a permittee may have responsibility to ensure proper implementation of BMPs to control stormwater discharges from their permitted area, even if another entity is contributing pollutants The Stormwater Construction Permit requires the permittee to ensure the implementation of BMPs which will be used to control the pollutants in stormwater discharges associated with construction activity from their permitted area Therefore, a permittee may be responsible for adequately implementing and maintaining BMPs that are providing treatment for pollutants onginating outside of their permitted area or from another entity's activities An example is when a permittee's property is being used by a separate entity for construction activities (e g , loading and unloading, site access, matenals storage, etc ), or BMPs located on the permittee's property are being relied on to treat stormwater runoff from another site This scenano is common when a developer sells off lots to a builder As a practical matter, what most often occurs is that the developer must allow the builder to use the developer's infrastructure (e g , roads, storm drains, ponds, etc ) for activities and BMPs that cannot realistically be limited to the builder's property In this case, the developer remains a liable party (in addition to the builder) to ensure that proper stormwater management is implemented for the project Permit coverage may instead be assigned to the builder for this infrastructure, if the builder has been designated as the operator of the area for stormwater quality purposes (See Section B 2) However, this may not always be practical when multiple builders are operating in an area or when the developer is still performing their own construction activities Refer to the Liability and Example sections, below, for further guidance b) BMPs Located Outside the Permitted Area Aif a permittee will be relying on BMPs that are outside of the area they own and/or operate, the specific actions listed below must be taken to ensure compliance with the Stormwater Construction Permit The permittee is responsible for ensunng the proper managment all pollutants from their permitted area Even if the BMP are implemented by another party, the permittee may still be liable if their pollutants are eventually discharged The permittee is responsible for ensunng the operation and maintenance of all BMPs that are used to control pollutants that onginate from their activities, even if the BMPs are located outside of the area owned and/or operated by the permittee For example, a builder may only have ownership of a single lot, but may have to rely on BMPs that are located off of their lot and on a developer's property to adequately manage stormwater runoff, such as inlet protection that is on the developer's streets If a permittee will rely on BMPs that are outside the area that they own and/or operate, the following measures must be taken 1) Any off site BMPs must be documented in the permittee's SWMP This includes structural BMPs (e g , inlet protection and sediment ponds) and non structural BMPs (e g , concrete wash out areas and street sweeping) By including the BMPs In the SWMP, the permittee can effectively include the practices under Page 8 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 www Colorado gov/cdphe I John W Hlckenlooper Govemor I Larry Wolk MD MSPH Executive Director and Chief Medical Officer �,covu er /op their permit coverage In such cases, the same off site BMPs may actually be included in two or more parties' SWMPs it) The permittee must have adequate permission from the land and/or BMP owner(s) to utilize the off site conveyances and BMPs and to ensure proper maintenance and operation The permittee must be able to provide evidence of this agreement upon request iii) The off site BMPs must be operated and maintained in accordance with the SWMP(s) and must control the discharge of pollutants It may be necessary to enter into agreements with other parties to ensure operation and maintenance of these BMPs Regardless of who actually comes out the operation and maintenance of a BMP, all permittees who make use of the BMP to control pollutants from their construction activities remain liable if the BMP is not adequately operated and maintained iv) All BMPs must be located prior to discharge to surface waters or municipally owned storm sewer systems Liability In the above examples, to reduce liability, the developer and builder should communicate on stormwater management issues and document who will be responsible for specific BMPs (e g , who will maintain inlet protection and implement street sweeping) If BMPs are not being adequately implemented by the party defined as responsible, the other party should take the necessary action to ensure pollutants originating from, or passing through, their permitted area are properly controlled It is recommended that stormwater management responsibilities be addressed in contracts or other legal agreements between applicable owners and operators for construction sites where one party's actions may impact another party's permit compliance These legal agreements will both help define roles and responsibilities at a multi owner/operator site, and also may be used to seek damages from a contractor if monetary penalties are issued to a permittee for permit violations Example Developer Dan sells a lot to Builder Bob Following the procedures discussed in Section G 1 b or c, above, Builder Bob obtains separate permit coverage for his new lot, ending at the curb line Because the site infrastructure is being utilized by several different builders at the project, Developer Dan maintains permit coverage for the streets, storm drain system, and a large retention pond that is designed and implemented as a BMP to manage pollutants from construction activities at the development (including Builder Bob's lot) In addition to the large pond, inlet protection is also being used to protect storm sewer inlets located on Developer Dan's roads, and street sweeping is occurnng to control sediment tracked onto Developer Dan's roads Builder Bob is relying on the pond, inlet protection, and street sweeping to manage pollutants from his lot, and therefore has included the BMPs in his SWMP, as discussed in Section G 2 b, above The BMPs are also included in Developer Dan's 5WMP because they are being used to control pollutants from property he still maintains control over, as discussed in Section G 2 a, above In addition, Developer Dan and Builder Bob enter into a contract that clearly defines Developer Dan as being responsible for implementing and maintaining the infrastructure BMPs (i e , the pond, inlet protection, and street sweeping BMPs), and requires Builder Bob to implement additional BMPs on his lots such as vehicle tracking control and construction waste management If the infrastructure BMPs are not properly operated and maintained, or discharges of sediment and/or other pollutants from Builder Bob's lot are not properly controlled and overwhelm the infrastructure BMPs, both Developer Dan and Builder Bob may be in violation of their permits Therefore, Builder Bob and Developer Dan must both remain diligent in ensuring that conditions of their contract are being met and BMPs operated by both parties continue to be implemented in accordance with their SWMPs H SALE OF RESIDENCE TO HOMEOWNERS Residential lots that have been conveyed to a homeowner and that meet the specific cntena below do not require coverage under the Stormwater Construction Permit in this case, the conveyed lot may be removed from coverage under the permittee's certification, and the permittee is no longer responsible for meeting the terms and conditions of this permit for the conveyed lot, including the requirement to transfer or reassign permit coverage The permittee remains responsible for eventual inactivation of the onginal certification (see Part F, above) The criteria for these lots are as follows 1) The lot has been sold to the homeowner(s) for private residential use, 2) the lot is less than one acre of disturbed area, 3) all construction activity conducted by the permittee on the lot is completed, Page 9 of 10 Revised 7 2015 4300 Cherry Creek Drive S Denver CO 80246 1530 P 303 692 2000 www colorado Bov/cdphe John W Hickenlooper Governor I Larry Wolk, MD MSPH Executive Director and Chief Medical Officer I r 4) a certificate of occupancy (or equivalent) has been awarded to the homeowner, and 5) the SWMP has been amended to indicate the lot Is no longer covered by permit Lots not meeting all of the above criteria require continued permit coverage However, the permit coverage for the conveyed lot may be transferred or reassigned to a new owner or operator (see Parts F and G 1, above) I CONSTRUCTION DEWATERING Construction dewatenng water can NOT be discharged to surface waters or to storm sewer systems V \ without separate permit coverage The discharge of Construction dewatenng water to the ground, under • the specific conditions listed below, may be allowed by the Stormwater Construction Permit when appropriate BMPs are implemented Two options are available for managing uncontaminated Construction Dewatenng water on a construction site Construction Dewatenng water discharged from the project site, to surface waters or to storm sewer systems, is considered a process water and requires an industrial process water permit Applications for dischargers engaged in the dewatenng of uncontaminated groundwater from a construction site are available from the Division's web site or by contacting the Division (see first page for address information) Alternatively. Construction Dewatenng water may be discharged to the ground if all of the following conditions are met 1) The discharge and the BMPs are included in the SWMP 2) Adequate BMPs are included to control stormwater pollution, 3) The discharge does not leave the site as surface runoff or to surface waters/storm sewer systems, and 4) The groundwater being pumped Is not contaminated so as to exceed State groundwater standards If the above conditions are not met, a separate permit (see above) is needed for discharges to the ground and/or surface waters Further information concerning Construction Dewatenng, including what constitutes contamination of groundwater, can be found in the Stormwater Construction Permit and Rationale These documents and others can be obtained from the Division s web site or by contacting the Division (see first page for address information) J CONCRETE WASHOUT j\Concrete Washout water can NOT be discharged to surface waters or to storm sewer systems without . separate permit coverage The discharge of Concrete Washout water to the ground, under the specific conditions listed below, may be allowed by the Stormwater Construction Permit when appropriate BMPs are implemented Concrete Washout water from washing of tools and concrete mixer chutes may be discharged to the ground if all of the following conditions are met 1) The source is Identified in the SWMP, 2) Adequate BMPs are included in the SWMP to prevent pollution of groundwater, and 3) These discharges do not leave the site as surface runoff or to surface waters/storm sewer systems The use of the washout site should be temporary (less than 1 year), and the washout site should be not be located in an area where shallow groundwater may be present, such as near natural drainages, spnngs, or wetlands Concrete washout water must not be discharged to state surface waters or to storm sewer systems Also, on site permanent disposal of concrete washout waste is not authonzed by this permit Further information concerning Concrete Washout can be found in the Stormwater Construction Permit and Rationale These documents can be obtained from the Division's web site at www coloradowaterpermits corn Page 1O of 10 Revised 7 2O15 4300 Cherry Creek Dove S Denver CO 80246 1530 P 303 692 2000 WNW colorado gov/cdphe John W Hickentooper Governor I tarry Wolk MD MSPH, Executive Director and Chief Medical Officer [corner 0.1k,fi r�7 Hello