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Correspondence - 09/24/2025
kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 September 24, 2025 Matt Simpson City of Fort Collins Stormwater Engineering 281 N. College Ave. Fort Collins, CO 80524 RE: QuikTrip Fort Collins #4301 Drainage Compliance Letter Dear Mr. Simpson: The purpose of this drainage letter is to demonstrate that the proposed drainage design for QuikTrip Fort Collins #4301 (the "Project") conforms to the drainage patterns set forth by the master drainage report on file with the City of Fort Collins (the "City") that was approved with the overall SWC Drake/College Development (the “Master Development”). The SWC Drake/College drainage report, "Final Drainage Report – SWC Drake/College" was prepared by Kimley-Horn and Associates in August of 2025 (“Master Drainage Report”). Excerpts from the Master Drainage Report are attached to this letter as Exhibit E. The Project is located south of W Drake Road and west of S College Avenue, on Lot 1 and 2 of the SWC College/Drake Subdivision (the "Site"). The Project is located in the Northeast ¼ of Section 26, Township 7 North, Range 69 West of the 6th Principal Meridian within the City of Fort Collins, State of Colorado. The Site has an area of 2.33 acres (101,313 square feet) and is currently a car dealership with an existing groundcover consisting of pavement. The proposed project consists of one single-story fuel station convenience store with a to-go kitchen, detached pumps, and associated infrastructure including site grading, utility service installation, parking, sidewalks, and landscaping. Existing Conditions – Master Plan Information The project area is within Basins 1A, 1B, 2A, R1, R2, OS-1, OS-3, and OS-4 of the Master Development as shown in the Master Drainage Map, which is attached to this letter as Exhibit A. Basins 1A and 2A remain on-site while Basins 1B, R1, R2, OS-1, OS-3, and OS-4 discharge offsite. See below for a table summarizing the existing basins with their respective flows by the Master Report: EXISTING BASINS SUMMARY BASIN NAME BASIN AREA (AC) IMPERVIOUSNESS (%) 1A 1.53 80% 1B 0.16 80% R1 0.52 91% R2 0.18 82% OS-1 0.06 95% OS-3 0.08 82% OS-4 0.13 2% TOTAL 2.654 80% Page 2 kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 Per the Master Drainage Report, Basin 1A flows east and discharges to the existing public storm inlets along S. College Avenue. Basin 1B flows north to an existing curb and gutter along Drake Road, then discharges to existing public storm inlets along S. College Avenue. Basin 2A sheet flows to an existing inlet along the eastern property line and eventually discharges to the existing public storm sewer with S. College Avenue. Basins R1 and R2 sheet flow to existing manholes and eventually connect to an underground storm chamber system (“underground system”) that discharges to the existing public storm sewer within S. College Avenue. The underground system is installed by the Master Development and serves as LID treatment and water quality treatment. The Master Development used ADS SC-800 Stormtech chambers. Basin OS-1 is routed north via curb and gutter in Private Drive B, then flows east along the existing curb and gutter in Drake Road, then flows south towards the existing public storm inlets along S. College Avenue. OS-3 is routed east via curb and gutter in Private Drive A, then flows north towards the existing public storm inlets along S. College Avenue. OS-4 sheet flows east towards S. College Avenue until it is routed to existing public storm inlets. Proposed Conditions The Project has been divided into two types of basins: Sub-Basins P1A1, P1A2, and P1A3 are on-site basins that flow into the underground system by the Master Development via roof drains, curb inlets, and underground piping. Sub-Basins P1B, PR1, PR2, POS-1, POS-3, and POS-4 are on-site basins that flow off-site to existing curb and gutter, existing curb inlets, and an existing underground system by others. See Exhibit B for the Proposed Drainage Map. Sub-Basin P1A1 Sub-Basin P1A1 is 0.15 acres and consists of proposed building area. The proposed ground cover creates an imperviousness value of 90%. Flows from Sub-Basin P1A1 are collected via roof drains and captured by proposed storm sewer infrastructure. The proposed storm sewer infrastructure outfalls into an underground system in the middle of the Site, which routes to the existing storm line installed by the Master Development. Sub-Basin P1A2 Sub-Basin A is 0.17 acres and consists of proposed canopy area. The proposed ground cover creates an imperviousness value of 90%. Flows from Sub-Basin P1A2 are collected via roof drains and captured by proposed storm sewer infrastructure. The proposed storm sewer infrastructure outfalls into an underground system in the middle of the Site, which routes to the existing storm line installed by the Master Development. Sub-Basin P1A3 Sub-Basin P1A3 is 1.13 acres and consists of concrete parking, sidewalks, and landscaping. The proposed ground cover creates an imperviousness value of 66%. Flows from Sub-Basin P1A3 sheet flow towards a proposed inlet and are captured by proposed storm sewer infrastructure. The proposed storm sewer infrastructure outfalls into an underground system in the middle of the Site, which routes to the existing storm line installed by the Master Development. Sub-Basin P1B Sub-Basin P1B is 0.10 acres and consists of sidewalks and landscaping. The proposed ground cover creates an imperviousness value of 17%. Flows from Sub-Basin P1B sheet flow towards existing curb and gutter in W. Drake Road. Page 3 kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 Sub-Basin PR1 Sub-Basin PR1 is 0.57 acres and consists of existing paved roadway and landscaping. The proposed ground cover creates an imperviousness value of 85%. Flows from Sub-Basin PR1 sheet flow towards existing curb and gutter in Private Drive B and route into an existing combination inlet on the eastern side of the drive. The eventual outfall is an existing underground system installed by the Master Development. In the existing 100-YR condition, 5.13 cfs is sent from Basin R1 and in the proposed 100-YR condition, 5.68 cfs is sent to the underground system. Sub-Basin PR2 Sub-Basin PR2 is 0.18 acres and consists of existing paved roadway and landscaping. The proposed ground cover creates an imperviousness value of 78%. Flows from Sub-Basin PR2 sheet flow towards existing curb and gutter in Private Drive A and route into an existing combination inlet on the northern side of the drive. eventual outfall is an existing underground system installed by the Master Development. In the existing 100-YR condition, 1.76 cfs is sent from Basin R2 and in the proposed 100-YR condition, 1.73 cfs is sent to the underground system. Sub-Basin POS-1 Sub-Basin POS-1 is 0.06 acres and consists of existing paved roadway, sidewalks, and landscaping. The proposed ground cover creates an imperviousness value of 89%. Flows from Sub-Basin POS-1 sheet flow towards existing curb and gutter in Private Drive B and route north into W. Drake Road. Sub-Basin POS-3 Sub-Basin POS-3 is 0.08 acres and consists of existing paved roadway and landscaping. The proposed ground cover creates an imperviousness value of 78%. Flows from Sub-Basin POS-3 sheet flow towards existing curb and gutter in Private Drive A and route east into S. College Avenue. Sub-Basin POS-4 Sub-Basin POS-4 is 0.21 acres and consists of sidewalks and landscaping. The proposed ground cover creates an imperviousness value of 5%. Flows from Sub-Basin POS-4 sheet flow towards existing curb and gutter in S. College Avenue. Proposed Drainage Facilities Site grading is designed to convey stormwater to proposed inlets and storm drain lines via grass swales, sheet flow, concrete pans and curb and gutter. The proposed storm sewer system will convey runoff to the existing storm sewer pipe running west to east through the middle of the site. On-site minor and major flows will be conveyed to the existing underground system by the Master Development via the proposed storm sewer system. Final design will include additional detail regarding overflow paths in the event that storm drains are clogged. Street conveyance will be minimized wherever possible and will be designed to maintain access for emergency vehicles. Proposed LID and Water Quality Treatment The existing underground system will serve as LID treatment and will provide water quality treatment for the additional imperviousness added by the QuikTrip. LID is required to treat 75% of all newly added or modified impervious area based on FCSCM Section 2.3.7. Basins P1A1, P1A2, and P1A3 have 46,730 SF of modified impervious area, requiring 35,048 SF for LID treatment. The entirety of these Page 4 kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 basins (63,163 SF) is routed to the underground system for LID treatment, which exceeds the required LID treatment amount. The underground system also serves as water quality capture. The Water Quality Capture Volume (WQCV) for the developed site was calculated used Equation 7-1 in the FCSCM. A 12-hour drain time based on Equation 7-1 and Table 5.1-1 was used to determine the minimum WQCV for the basins draining to the underground system. Basins P1A1, P1A2, P1A3, PR1, and PR2 drain to the underground system and have a required water quality capture volume (WQCV) of 2,338 CF. The underground system is designed to capture 2,430 CF with 30 isolator rows. The underground system and isolator rows were sized according to the FCSCM and the associated calculations are included within Exhibit C. Drainage Design Criteria The Project was designed to conform to the requirements outlined in the Fort Collins Stormwater Criteria Manual (FCSCM) and the latest Mile High Flood District (MHFD) Urban Storm Drainage Criteria Manual (USDCM). As previously discussed, the Project maintains the Master Drainage Report drainage patterns with runoff from each basin directed to the existing storm sewer pipe running west to east through the middle of the site. Per the Master Drainage Plan, detention is not required on-site, and LID treatment is provided via underground system. The underground system and isolator rows were sized according to the FCSCM and the associated calculations are included within Exhibit C. With the proposed improvements, the Site is proposing less impervious area than anticipated in the Master Drainage Report. The Rational Method was used for all subbasins since the areas are less than 90 acres. Per the FCSCM, the storm frequencies used to analyze the drainage design were the 2-year and the 100-year storms. Rainfall intensities used for the rational calculations were obtained from Table 3.4-1 in the FCSCM. Rainfall depths for the 2-year, 1-hour and 100-year, 1-hour storm events are 0.82 and 2.86 inches, respectively. Rational method calculations are attached to this letter in Exhibit C. Conclusion The Master Drainage Report shows the project area as Basins 1A, 1B, 2A, R1, R2, OS-1, OS-3, and OS-4 with an assumed weighted imperviousness of 80%. The proposed project will have an impervious value of 68%, which is less than what was assumed. As such, the proposed project conforms with the original assumptions and conclusions of the Master Drainage plan. Please contact us with any questions or concerns. Thank You, KIMLEY-HORN AND ASSOCIATES, INC. James Waller, P.E. Page 5 kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 Exhibits A – Existing Drainage Map (Delineations from Master Report) B – Proposed Drainage Map C – Rational Method Calculations D – FEMA Flood Map and NRCS Soil Report E – Excerpts from Master Drainage Report kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 EXHIBIT A – Existing Drainage Map (Delineations from Master Report) ELEC VAULT F.O. ELEC VAULT F.O. VAULT F.O. TRAFFIC VAULT T S ELECT X T T T T T T T TTTT OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU E E E E E SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS ELEC C VAULT ELEC G G G G G G G G G G G G G G W W W W W W W CT V W W W W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W D D D D D S WWWWWWWW W W W W W W W W W W W W W SSSSSSSSSSSSSSSS SS SS SS SS SS SS SS SS SS SS WIR ELEC VAULT F.O. ELEC VAULT F.O. VAULT F.O. TRAFFIC VAULT T S ELECT X T T T T T T T TTTT OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU E E E E E SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS ELEC C VAULT ELEC G G G G G G G G G G G G G G W W W W W W W CT V W W W W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W D D D D D S WWWWWWWW W W W W W W W W W W W W W SSSSSSSSSSSSSSSS SS SS SS SS SS SS SS SS SS SS WIR W. DRAKE ROAD PR I V A T E D R I V E B PRIVATE DRIVE A S. C O L L E G E A V E N U E COMBINATION INLET BY OTHERS COMBINATION INLET BY OTHERS 43 0 1 SW C W D R A L E R D & S C O L L E G E A V E FO R T C O L L I N S , C O 096888057 P-123 001 Qu i k T r i p N o . A SHEET TITLE: SHEET NUMBER: DIVISION: DESIGNED BY: 1 © COPYRIGHT QUIKTRIP CORPORATION 2011 ANY UNAUTHORIZED USE, REPRODUCTION, PUBLICATION, DISTRIBUTION, OR SALE IN WHOLE OR IN PART, IS STRICTLY FORBIDDEN. OR I G I N A L I S S U E D A T E : PROTOTYPE: VERSION: PROJECT NO.: DRAWN BY: REVIEWED BY: RE V DA T E DE S C R I P T I O N B C D E F G H J K L M N P Q A B C D E F G H J K L M N P Q 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 09 / 2 4 / 2 0 2 5 AIA BSF JPW FOR REVIEW ONLY NOT FOR Kimley-Horn and Associates, Inc. CONSTRUCTION R Know what's below. Call before you dig. PROPERTY LINE LEGEND: PROPOSED CATCH CURB AND GUTTER PROPOSED STORM LINE # = BASIN DESIGNATION AC = AREA IN ACRES I = % IMPERVIOUSNESS # = DESIGN POINT PROPOSED BASIN BOUNDARY PROPOSED FLOW ARROW EXISTING FLOW ARROW NORTH C7.0 EXISTING DRAINAGE EXHIBIT kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 EXHIBIT B – Proposed Drainage Map SU B M E R G E D PU M P AN N U L A R SU B M E R G E D PU M P AN N U L A R SU B M E R G E D PU M P AN N U L A R SU B M E R G E D PU M P AN N U L A R VE N T / VA P O R VE N T / VA P O R VE N T / VA P O R VE N T / VA P O R PR O B E SU B M E R G E D PU M P AN N U L A R VE N T / VA P O R FIL L PR O B E FIL L PR O B E FI L L PR O B E FIL L PR O B E FIL L SU B M E R G E D PU M P AN N U L A R SU B M E R G E D PU M P AN N U L A R SU B M E R G E D PU M P AN N U L A R SU B M E R G E D PU M P AN N U L A R VE N T / VA P O R VE N T / VA P O R VE N T / VA P O R VE N T / VA P O R PR O B E SU B M E R G E D PU M P AN N U L A R VE N T / VA P O R FIL L PR O B E FIL L PR O B E FI L L PR O B E FIL L PR O B E FIL L ELEC VAULT F.O. ELEC VAULT F.O. VAULT F.O. TRAFFIC VAULT T S ELECT X T T T T T T T TTTT OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU E E E E E SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS ELEC C VAULT ELEC G G G G G G G G G G G G G G W W W W W W W CT V W W W W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W D D D D D S WWWWWWWW W W W W W W W W W W W W W SSSSSSSSSSSSSSSS SS SS SS SS SS SS SS SS SS SS WIR ELEC VAULT F.O. ELEC VAULT F.O. VAULT F.O. TRAFFIC VAULT T S ELECT X T T T T T T T TTTT OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU E E E E E SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS ELEC C VAULT ELEC G G G G G G G G G G G G G G W W W W W W W CT V W W W W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W D D D D D S WWWWWWWW W W W W W W W W W W W W W SSSSSSSSSSSSSSSS SS SS SS SS SS SS SS SS SS SS WIR W. DRAKE ROAD PR I V A T E D R I V E B PRIVATE DRIVE A S. C O L L E G E A V E N U E COMBINATION INLET BY OTHERS COMBINATION INLET BY OTHERS 43 0 1 SW C W D R A L E R D & S C O L L E G E A V E FO R T C O L L I N S , C O 096888057 P-123 001 Qu i k T r i p N o . A SHEET TITLE: SHEET NUMBER: DIVISION: DESIGNED BY: 1 © COPYRIGHT QUIKTRIP CORPORATION 2011 ANY UNAUTHORIZED USE, REPRODUCTION, PUBLICATION, DISTRIBUTION, OR SALE IN WHOLE OR IN PART, IS STRICTLY FORBIDDEN. OR I G I N A L I S S U E D A T E : PROTOTYPE: VERSION: PROJECT NO.: DRAWN BY: REVIEWED BY: RE V DA T E DE S C R I P T I O N B C D E F G H J K L M N P Q A B C D E F G H J K L M N P Q 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 09 / 2 4 / 2 0 2 5 AIA BSF JPW FOR REVIEW ONLY NOT FOR Kimley-Horn and Associates, Inc. CONSTRUCTION R Know what's below. Call before you dig. PROPERTY LINE LEGEND: PROPOSED CATCH CURB AND GUTTER PROPOSED STORM LINE # = BASIN DESIGNATION AC = AREA IN ACRES I = % IMPERVIOUSNESS # = DESIGN POINT PROPOSED BASIN BOUNDARY PROPOSED FLOW ARROW EXISTING FLOW ARROW NORTH C7.1 PROPOSED DRAINAGE EXHIBIT kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 EXHIBIT C – Rational Method and Drainage Calculations TIME 2 YR 10 YR 100 YR 5 2.85 4.87 9.95 6 2.67 4.56 9.31 7 2.52 4.31 8.80 8 2.40 4.10 8.38 9 2.30 3.93 8.03 10 2.21 3.78 7.72 11 2.13 3.63 7.42 12 2.05 3.50 7.16 13 1.98 3.39 6.92 14 1.92 3.29 6.71 15 1.87 3.19 6.52 20 1.61 2.74 5.60 25 1.43 2.44 4.98 30 1.30 2.21 4.52 40 1.07 1.83 3.74 50 0.92 1.58 3.23 60 0.82 1.40 2.86 120 0.49 0.86 1.84 Note: Time Intensity Frequency Tabulation Intensity values from the City of Fort Collins Intensity-Duration-Frequency Tables; Chapter 5, Section 3.4- 1 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. RAINFALL INTENSITY K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\EX CIA Calcs_QT4301.xlsx PROJECT NAME:QuikTrip 4301 9/22/2025 PROJECT NUMBER:96888057 CALCULATED BY:OAT CHECKED BY:AIA SOIL: GROUP C Lawns, Clayey Soil Rooftop Asphalt, Concrete Gravel/Pavers Commercial LAND USE:AREA AREA AREA AREA AREA 2-YEAR COEFF.0.20 0.95 0.95 0.50 0.85 100-YEAR COEFF.0.20 0.95 0.95 0.50 0.85 IMPERVIOUS %2%90%100%40%80% Lawns, Clayey Soil Rooftop Asphalt, Concrete Gravel/Pavers Commercial TOTAL DESIGN DESIGN AREA AREA AREA AREA AREA AREA BASIN POINT (AC)(AC)(AC)(AC)(AC)(AC)C(2)C(100)Imp % 1A 1A 0.00 0.00 0.00 0.00 1.53 1.53 0.85 1.00 80% 0.00 0.00 0.00 0.00 1.53 1.53 0.85 1.00 80% 0%0%0%0%100% 1B 1B 0.00 0.00 0.00 0.00 0.16 0.16 0.85 1.00 80% R1 R1 0.03 0.00 0.39 0.00 0.10 0.52 0.89 1.00 91% R2 R2 0.02 0.00 0.10 0.00 0.06 0.18 0.83 1.00 82% OS-1 OS-1 0.00 0.00 0.05 0.00 0.02 0.06 0.92 1.00 95% OS-3 OS-3 0.01 0.00 0.04 0.00 0.03 0.08 0.83 1.00 82% OS-4 OS-4 0.13 0.00 0.00 0.00 0.00 0.13 0.20 0.25 2% 0.19 0.00 0.58 0.00 0.36 1.12 0.79 0.99 77% 17%0%52%0%32% R1 & R2 R1 & R2 0.05 0.00 0.49 0.00 0.16 0.69 0.88 1.00 89% 7%0%71%0%23% Notes: 1. Imperviousness, I, values per UDFCD Criteria Manual Volume 1, Table 6-3 2. Runoff Coefficient values are from the City of Fort Collins Runoff Coefficient Tables 3.2-2 and 3.2-3; Chapter 5, Section 3.2 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. Frequency adjustment factor has been applied to composite C values per Table 3.2-3. BASIN SUBTOTAL On-Site Basins Flowing On-site RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION On-Site Basins Flowing Off-site BASIN SUBTOTAL On-Site Roadway Basins Flowing to Underground Chamber System K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\EX CIA Calcs_QT4301.xlsx QuikTrip 4301 DATE: 9/22/2025 96888057 OAT AIA FINAL Tc DESIGN AREA C2 LENGTH SLOPE Ti LENGTH SLOPE R VEL Tt COMP. TOTAL TOTAL TOTAL Tc BASIN Ac Ft %Min.Ft.%fps Min.tc LENGTH SLOPE IMP.Min.Min. 1A 1.53 0.85 0 0.0%0.0 201 0.1%0.195 1.2 2.7 2.7 201 0.1%80%11.1 5.0 1B 0.16 0.85 0 0.0% 0.0 205 1.2% 0.195 4.2 0.8 0.8 205 1.2% 80% 11.1 5.0 R1 0.52 0.89 17 5.6% 0.9 255 0.7% 0.195 3.2 1.3 2.2 272 1.0% 91% 11.5 5.0 R2 0.18 0.83 7 0.4% 1.8 149 1.3% 0.195 4.4 0.6 2.4 156 1.3% 82% 10.9 5.0 OS-1 0.06 0.92 17 1.7% 1.1 52 3.1% 0.195 6.8 0.1 1.3 69 2.7% 95% 10.4 5.0 OS-3 0.08 0.83 17 0.9% 2.2 77 3.8% 0.195 7.5 0.2 2.3 94 3.2% 82% 10.5 5.0 OS-4 0.13 0.20 28 5.6%5.0 0 0.0%0.195 0.0 0.0 5.0 28 5.6%2%10.2 5.0 R1 & R2 0.69 0.88 7 0.4% 1.5 334 0.5% 0.195 2.7 2.1 3.6 341 0.5% 89% 11.9 5.0 On-Site Roadway Basins Flowing to Underground Chamber System On-Site Basins Flowing Off-Site CHECKED BY: On-Site Basins 2-Year Time of Concentration Tc CHECK (URBANIZED BASINS) PROJECT NAME: PROJECT NUMBER: DATA INITIAL TIME (Ti) TRAVEL TIME (Tt) SUB-BASIN CALCULATED BY: K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\EX CIA Calcs_QT4301.xlsx QuikTrip 4301 DATE:9/22/2025 96888057 OAT AIA FINAL Tc DESIGN AREA C100 LENGTH SLOPE Ti LENGTH SLOPE R VEL Tt COMP. TOTAL TOTAL TOTAL Tc BASIN Ac Ft %Min.Ft.%fps Min.tc LENGTH SLOPE IMP.Min.Min. 1A 1.53 1.00 0 0% 0.0 201 0% 0.195 1.2 2.7 2.7 201 0.1% 80% 11.1 5.0 1B 0.16 1.00 0 0.0%0.0 205 1.2%0.195 4.2 0.8 0.8 205 1.2%80%11.1 5.0 R1 0.52 1.00 17 5.64% 0.4 255 0.69% 0.195 3.2 1.3 1.8 272 1.0% 91% 11.5 5.0 R2 0.18 1.00 7 0.40% 0.7 149 1.30% 0.195 4.4 0.6 1.2 156 1.3% 82% 10.9 5.0 OS-1 0.06 1.00 17 1.7%0.6 52 3.1%0.195 6.8 0.1 0.8 69 2.7%0%10.4 5.0 OS-3 0.08 1.00 17 0.9%0.8 77 3.8%0.195 7.5 0.2 1.0 94 3.2%2%10.5 5.0 OS-4 0.13 0.25 28 5.6%4.8 0 0.0%0.195 0.0 0.0 4.8 28 5.6%0%10.2 5.0 R1 & R2 0.69 1.00 7 0.4% 0.7 334 0.5% 0.195 2.7 2.1 2.8 341 0.5% 79% 11.9 5.0 On-Site Basins Flowing Off-Site On-Site Roadway Basins Flowing to Underground Chamber System On-Site Basins CHECKED BY: SUB-BASIN INITIAL TRAVEL TIME Tc CHECK DATA TIME (Ti) (Tt) (URBANIZED BASINS) 100-Year Time of Concentration PROJECT NAME: PROJECT NUMBER: CALCULATED BY: K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\EX CIA Calcs_QT4301.xlsx DATE: 9/22/2025 QuikTrip 4301 96888057 OAT P1 (1-Hour Rainfall) =0.82 AIA REMARKS DE S I G N PO I N T AR E A (A C ) RU N O F F CO E F F tc (m i n ) C* A ( a c ) I (i n / h r ) Q (c f s ) 1A 1.53 0.85 5.00 1.30 2.85 3.71 Future Lot 1 drainage flows to connect via storm sewer at Design point 1A 1B 0.16 0.85 5.00 0.13 2.85 0.38 Future Lot 1 drainage flows off-site towards W. Drake Road at Design point 1B R1 0.52 0.89 5.00 0.46 2.85 1.31 Flows to proposed inlet within roadway to underground storm system at R1 R2 0.18 0.83 5.00 0.15 2.85 0.42 Flows to proposed inlet within roadway to underground storm system at R2 OS-1 0.06 0.92 5.00 0.06 2.85 0.17 Flows North to W. Drake Street OS-3 0.08 0.83 5.00 0.07 2.85 0.19 Flows East within roadway to S College Avenue OS-4 0.13 0.20 5.03 0.03 2.85 0.07 Flows East along landscaping to S College Avenue R1 & R2 0.69 0.88 5.00 0.61 2.85 1.73 Flows to Underground Chamber System On-Site Basins On-Site Roadway Basins Flowing to Underground Chamber System OS-3 1A R2 R1 1B R1 & R2 On-Site Basins Flowing Off-Site OS-1 OS-4 DE S I G N BA S I N STORM DRAINAGE DESIGN - RATIONAL METHOD 2 YEAR EVENT PROJECT NAME: PROJECT NUMBER: CALCULATED BY: CHECKED BY: K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\EX CIA Calcs_QT4301.xlsx DATE: 9/22/2025 QuikTrip 4301 96888057 OAT P1 (1-Hour Rainfall) =2.86 AIA REMARKS DE S I G N PO I N T AR E A (A C ) RU N O F F CO E F F tc (m i n ) C* A ( a c ) I (i n / h r ) Q (c f s ) 1A 1.53 1.00 5.00 1.53 9.95 15.23 Future Lot 1 drainage flows to connect via storm sewer at Design point 1A 1B 0.16 1.00 5.00 0.16 9.95 1.58 Future Lot 1 drainage flows off-site towards W. Drake Road at Design point 1B R1 0.52 1.00 5.00 0.52 9.95 5.13 Flows to proposed inlet within roadway to underground storm system at R1 R2 0.18 1.00 5.00 0.18 9.95 1.76 Flows to proposed inlet within roadway to underground storm system at R2 OS-1 0.06 1.00 5.00 0.06 9.95 0.64 Flows North to W. Drake Street OS-3 0.08 1.00 5.00 0.08 9.95 0.78 Flows East within roadway to S College Avenue OS-4 0.13 0.25 5.00 0.03 9.95 0.32 Flows East along landscaping to S College Avenue R1 & R2 0.69 1.00 5.00 0.69 9.95 6.88 Flows to Underground Chamber System OS-4 R1 & R2 On-Site Roadway Basins Flowing to Underground Chamber System CHECKED BY: 1B CALCULATED BY: STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT PROJECT NAME: PROJECT NUMBER: OS-3 On-Site Basins Flowing Off-Site OS-1 DE S I G N BA S I N On-Site Basins 1A R1 R2 K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\EX CIA Calcs_QT4301.xlsx PROJECT NAME: QuikTrip 4301 DATE: 9/22/2025 PROJECT NUMBER: 96888057 CALCULATED BY: OAT CHECKED BY: AIA IMPERVIOUSNESS % Q2 Q100 1A 1A 1.53 80%3.71 15.23 1.53 80%3.71 15.23 1B 1B 0.16 80%0.38 1.58 R1 R1 0.52 91% 1.31 5.13 R2 R2 0.18 82% 0.42 1.76 OS-1 OS-1 0.06 95% 0.17 0.64 OS-3 OS-3 0.08 82% 0.19 0.78 OS-4 OS-4 0.13 2%0.07 0.32 1.12 77%2.54 10.21 R1 & R2 R1 & R2 0.69 89% 1.73 6.88 On-Site Roadway Basins Flowing to Underground Chamber System On-Site Basins Flowing On-Site DESIGN POINT On-Site Basins Flowing Off-Site TOTAL TOTAL RATIONAL CALCULATIONS SUMMARY TRIBUTARY BASINS TRIBUTARY AREA (AC) PEAK FLOWS (CFS) K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\EX CIA Calcs_QT4301.xlsx TIME 2 YR 10 YR 100 YR 5 2.85 4.87 9.95 6 2.67 4.56 9.31 7 2.52 4.31 8.80 8 2.40 4.10 8.38 9 2.30 3.93 8.03 10 2.21 3.78 7.72 11 2.13 3.63 7.42 12 2.05 3.50 7.16 13 1.98 3.39 6.92 14 1.92 3.29 6.71 15 1.87 3.19 6.52 20 1.61 2.74 5.60 25 1.43 2.44 4.98 30 1.30 2.21 4.52 40 1.07 1.83 3.74 50 0.92 1.58 3.23 60 0.82 1.40 2.86 120 0.49 0.86 1.84 Note: Time Intensity Frequency Tabulation Intensity values from the City of Fort Collins Intensity-Duration-Frequency Tables; Chapter 5, Section 3.4- 1 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. RAINFALL INTENSITY K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx PROJECT NAME:QuikTrip Fort Collins #4301 9/22/2025 PROJECT NUMBER:96888057 CALCULATED BY:OAT CHECKED BY:AIA SOIL: GROUP C Lawns, Clayey Soil Rooftop Asphalt, Concrete Gravel/Pavers LAND USE:AREA AREA AREA AREA 2-YEAR COEFF.0.20 0.95 0.95 0.50 100-YEAR COEFF.0.20 0.95 0.95 0.50 IMPERVIOUS %2%90%100%40% Lawns, Clayey Soil Rooftop Asphalt, Concrete Gravel/Pavers TOTAL DESIGN DESIGN AREA AREA AREA AREA AREA BASIN POINT (AC)(AC)(AC)(AC)(AC)C(2)C(100)Imp % P1A1 P1A1 0.00 0.15 0.00 0.00 0.15 0.95 1.00 90% P1A2 P1A2 0.00 0.17 0.00 0.00 0.17 0.95 1.00 90% P1A3 P1A3 0.39 0.00 0.75 0.00 1.13 0.69 0.87 66% 0.39 0.32 0.75 0.00 1.45 0.75 0.94 72% 27%22%51%0% P1B P1B 0.09 0.00 0.02 0.00 0.10 0.32 0.40 17% PR1 PR1 0.08 0.00 0.49 0.00 0.57 0.84 1.00 85% PR2 PR2 0.04 0.00 0.14 0.00 0.18 0.78 0.98 78% POS-1 POS-1 0.01 0.00 0.05 0.00 0.06 0.86 1.00 89% POS-3 POS-3 0.02 0.00 0.06 0.00 0.08 0.78 0.98 78% POS-4 POS-4 0.21 0.00 0.01 0.00 0.21 0.22 0.28 5% 0.44 0.00 0.76 0.00 1.20 0.67 0.84 64% 37%0%63%0% P1A UCS 0.39 0.32 0.75 0.00 1.45 0.75 0.94 72% PR1 & PR2 UCS 0.13 0.00 0.62 0.00 0.75 0.82 1.00 84% 0.51 0.32 1.37 0.00 2.20 0.77 0.97 76% 17%0%83%0% Notes: 1. Imperviousness, I, values per UDFCD Criteria Manual Volume 1, Table 6-3 2. Runoff Coefficient values are from the City of Fort Collins Runoff Coefficient Tables 3.2-2 and 3.2-3; Chapter 5, Section 3.2 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. Frequency adjustment factor has been applied to composite C values per Table 3.2-3. BASIN SUBTOTAL On-Site Basins Flowing On-site RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION On-Site Basins Flowing Off-site BASIN SUBTOTAL Basins Flowing to Underground Chamber System (UCS) BASIN SUBTOTAL K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx QuikTrip Fort Collins #4301 DATE:9/22/2025 96888057 OAT AIA FINAL Tc DESIGN AREA C2 LENGTH SLOPE Ti LENGTH SLOPE R VEL Tt COMP. TOTAL TOTAL TOTAL Tc BASIN Ac Ft %Min.Ft.%fps Min.tc LENGTH SLOPE IMP.Min.Min. P1A1 0.15 0.95 30 0.5%1.9 258 0.5%0.195 2.7 1.6 3.5 288 0.5%90%11.6 5.0 P1A2 0.17 0.95 33 0.5%2.0 441 0.5%0.195 2.7 2.7 4.7 474 0.5%90%12.6 5.0 P1A3 1.13 0.69 246 1.0%12.1 237 0.8%0.195 3.5 1.1 13.2 483 0.9%66%12.7 12.7 P1B 0.10 0.32 47 6.3%5.4 216 0.5%0.195 2.7 1.3 6.8 263 1.5%17%11.5 6.8 PR1 0.57 0.84 7 0.4%1.8 149 1.3%0.195 4.4 0.6 2.3 156 1.3%85%10.9 5.0 PR2 0.18 0.78 17 1.7%2.1 52 3.1%0.195 6.8 0.1 2.2 69 2.7%78%10.4 5.0 POS-1 0.06 0.86 17 0.9%1.9 77 3.8%0.195 7.5 0.2 2.1 94 3.2%89%10.5 5.0 POS-3 0.08 0.78 28 5.6%1.8 0 0.0%0.195 0.0 0.0 1.8 28 5.6%78%10.2 5.0 POS-4 0.21 0.22 30 5.3%5.2 0 0.0%0.195 0.0 0.0 5.2 30 5.3%5%10.2 5.2 P1A 1.45 0.75 246 1.0% 10.4 237 0.8% 0.195 3.5 1.1 11.5 483 0.9% 72% 12.7 11.5 PR1 & PR2 0.75 0.82 7 0.4% 1.8 149 1.3% 0.195 4.4 0.6 2.4 156 1.3% 84% 10.9 5.0 Basins Flowing to Underground Chamber System On-Site Basins Flowing Off-Site CHECKED BY: On-Site Basins 2-Year Time of Concentration Tc CHECK (URBANIZED BASINS) PROJECT NAME: PROJECT NUMBER: DATA INITIAL TIME (Ti) TRAVEL TIME (Tt) SUB-BASIN CALCULATED BY: K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx QuikTrip Fort Collins #4301 DATE:9/22/2025 96888057 OAT AIA FINAL Tc DESIGN AREA C100 LENGTH SLOPE Ti LENGTH SLOPE R VEL Tt COMP. TOTAL TOTAL TOTAL Tc BASIN Ac Ft %Min.Ft.%fps Min.tc LENGTH SLOPE IMP.Min.Min. P1A1 0.15 1.00 30 0.5% 1.3 258 0.5% 0.195 2.7 1.6 2.9 288 0.5% 90% 11.6 5.0 P1A2 0.17 1.00 33 0.5% 1.4 441 0.5% 0.195 2.7 2.7 4.0 474 0.5% 90% 12.6 5.0 P1A3 1.13 0.87 246 1.0% 6.9 237 0.8% 0.195 3.5 1.1 8.1 483 0.9% 66% 12.7 8.1 P1B 0.10 0.40 47 6.3%4.9 216 0.5%0.195 2.7 1.3 6.2 263 1.5%85%11.5 6.2 PR1 0.57 1.00 7 0.4%0.7 149 1.3%0.195 4.4 0.6 1.2 156 1.3%78%10.9 5.0 PR2 0.18 0.98 17 1.7%0.8 52 3.1%0.195 6.8 0.1 0.9 69 2.7%89%10.4 5.0 POS-1 0.06 1.00 17 0.9%0.8 77 3.8%0.195 7.5 0.2 1.0 94 3.2%0%10.5 5.0 POS-3 0.08 0.98 28 5.6%0.7 0 0.0%0.195 0.0 0.0 0.7 28 5.6%5%10.2 5.0 POS-4 0.21 0.28 30 5.3%4.8 0 0.0%0.195 0.0 0.0 4.8 30 5.3%0%10.2 5.0 P1A 1.45 0.94 246 1.0% 4.8 237 0.8% 0.195 3.5 1.1 6.0 483 0.9% 0% 12.7 6.0 PR1 & PR2 0.75 1.00 7 0.4% 0.7 149 1.3% 0.195 4.4 0.6 1.2 156 1.3% 68% 10.9 5.0 On-Site Basins Flowing Off-Site Basins Flowing to Underground Chamber System On-Site Basins CHECKED BY: SUB-BASIN INITIAL TRAVEL TIME Tc CHECK DATA TIME (Ti) (Tt) (URBANIZED BASINS) 100-Year Time of Concentration PROJECT NAME: PROJECT NUMBER: CALCULATED BY: K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx DATE: 9/22/2025 QuikTrip Fort Collins #4301 96888057 OAT P1 (1-Hour Rainfall) =0.82 AIA REMARKS DE S I G N PO I N T AR E A (A C ) RU N O F F CO E F F tc (m i n ) C* A ( a c ) I (i n / h r ) Q (c f s ) P1A1 0.15 0.95 5.00 0.15 2.85 0.41 Building roof drains to connect underground via storm sewer at Design point P1A P1A2 0.17 0.95 5.00 0.16 2.85 0.45 Canopy roof drains to connect underground via storm sewer at Design point P1B P1A3 1.13 0.69 12.68 0.79 2.05 1.61 Area sheet flows to proposed inlet at Design point P2A. P1B 0.10 0.32 6.76 0.03 2.67 0.09 Area drainage flows off-site towards W. Drake Road at Design point 1B PR1 0.57 0.84 5.00 0.48 2.85 1.36 Flows to proposed inlet within Private Drive B to underground storm system at R1 PR2 0.18 0.78 5.00 0.14 2.85 0.40 Flows to proposed inlet within Private Drive A to underground storm system at R2 POS-1 0.06 0.86 5.00 0.05 2.85 0.15 Flows North to W. Drake Street POS-3 0.08 0.78 5.00 0.06 2.85 0.18 Flows East within roadway to S College Avenue POS-4 0.21 0.22 5.16 0.05 2.85 0.13 Flows East along landscaping to S College Avenue UCS 1.45 0.75 11.53 1.09 2.13 2.32 Flows to Underground Chamber System by others. UCS 0.75 0.82 5.00 0.62 2.85 1.76 Flows to Underground Chamber System by others. On-Site Basins Basins Flowing to Underground Chamber System POS-3 P1A1 P1A2 P1A3 P1B PR1 & PR2 On-Site Basins Flowing Off-Site POS-1 POS-4 PR1 PR2 P1A DE S I G N BA S I N STORM DRAINAGE DESIGN - RATIONAL METHOD 2 YEAR EVENT PROJECT NAME: PROJECT NUMBER: CALCULATED BY: CHECKED BY: K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx DATE: 9/22/2025 QuikTrip Fort Collins #4301 96888057 OAT P1 (1-Hour Rainfall) =2.86 AIA REMARKS DE S I G N PO I N T AR E A (A C ) RU N O F F CO E F F tc (m i n ) C* A ( a c ) I (i n / h r ) Q (c f s ) P1A1 0.15 1.00 5.00 0.15 9.95 1.52 Building roof drains to connect underground via storm sewer at Design point P1A P1A2 0.17 1.00 5.00 0.17 9.95 1.66 Canopy roof drains to connect underground via storm sewer at Design point P1B P1A3 1.13 0.87 8.06 0.98 8.38 8.23 Area sheet flows to proposed inlet at Design point P2A. P1B 0.10 0.40 6.20 0.04 9.31 0.38 Area drainage flows off-site towards W. Drake Road at Design point 1B PR1 0.57 1.00 5.00 0.57 9.95 5.68 Flows to proposed inlet within Private Drive B to underground storm system at R1 PR2 0.18 0.98 5.00 0.17 9.95 1.73 Flows to proposed inlet within Private Drive A to underground storm system at R2 POS-1 0.06 1.00 5.00 0.06 9.95 0.60 Flows North to W. Drake Street POS-3 0.08 0.98 5.00 0.08 9.95 0.77 Flows East within roadway to S College Avenue POS-4 0.21 0.28 5.00 0.06 9.95 0.58 Flows East along landscaping to S College Avenue UCS 1.45 0.94 8.06 1.36 8.38 11.41 Flows to Underground Chamber System by others. UCS 0.75 1.00 5.00 0.75 9.95 7.45 Flows to Underground Chamber System by others. POS-4 PR1 & PR2 Basins Flowing to Underground Chamber System CHECKED BY: P1A2 P1A3 P1B P1A CALCULATED BY: STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT PROJECT NAME: PROJECT NUMBER: POS-3 On-Site Basins Flowing Off-Site POS-1 DE S I G N BA S I N On-Site Basins P1A1 PR2 PR1 K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx PROJECT NAME: QuikTrip Fort Collins #4301 DATE: 9/22/2025 PROJECT NUMBER: 96888057 CALCULATED BY: OAT CHECKED BY: AIA IMPERVIOUSNESS % Q2 Q100 P1A1 P1A1 0.15 90% 0.41 1.52 P1A2 P1A2 0.17 90% 0.45 1.66 P1A3 P1A3 1.13 66%1.61 8.23 1.45 72%2.48 11.41 P1B P1B 0.10 17% 0.09 0.38 PR1 PR1 0.57 85% 1.36 5.68 PR2 PR2 0.18 78% 0.40 1.73 POS-1 POS-1 0.06 89% 0.15 0.60 POS-3 POS-3 0.08 78% 0.18 0.77 POS-4 POS-4 0.21 5%0.13 0.58 1.20 64%2.30 9.73 P1A P1A 1.45 72% 2.48 11.41 PR1 & PR2 PR1 & PR2 0.75 84%1.76 7.40 2.20 76%4.24 18.82TOTAL RATIONAL CALCULATIONS SUMMARY TRIBUTARY BASINS TRIBUTARY AREA (AC) PEAK FLOWS (CFS) TOTAL Basins Flowing to Underground Chamber System On-Site Basins Flowing On-Site DESIGN POINT On-Site Basins Flowing Off-Site TOTAL K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx PROJECT NAME: QuikTrip Fort Collins #4301 DATE: 9/22/2025 PROJECT NUMBER: 96888057 CALCULATED BY: OAT CHECKED BY: AIA Imperviousness: 66% a: 0.8 WQCV: 0.208 in Drain Time: 12 hours WQCV: 1026.03 ft3 Area: 1.13 acres Total Site Area: 1.45 acres Req'd Imp Area for LID Treatment: 0.80 acres Total Site Impervious Area: 1.07 acres Total Site Area to LID: 1.1 acres Added/Modified Impervious Area: 1.07 acres Provided Impervious Area to LID: 0.7 acres Inputs Results Low Impact Development Area Calculation WQCV Calculation Inputs Results K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx PROJECT NAME:QuikTrip Fort Collins #4301DATE: ### PROJECT NUMBER: 96888057 CALCULATED BY: OAT CHECKED BY: AIA SF SF SF SF SF SF SF SFTotal Treatment Area Percent Total Project Area Treated 1026 49391 49391 48 49391 100% TOTAL TREATMENT VALUES Overall Run-on Ratio for Rain Garden (50:1 Max) Total Rain Garden Treatment Area Run-on area for Rain Garden Rain Garden Area LID TREATMENT MEASURES Rain Garden Target Treatment Percentatge Minimum Area of LID Treatment: 75% 29635 LID TREATMENT SUMMARY TABLE Project Summary Imperviousness: Total Impervious Area: Total Area: 49391 80% 39513 K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx PROJECT NAME: QuikTrip Fort Collins #4301 DATE: 9/22/2025 PROJECT NUMBER: 96888057 CALCULATED BY: OAT CHECKED BY: AIA Design Point: 1 WQCV: 1026 ft3 Design Storm: 100-yr Det. Vol.: 3475 ft3 Developed "C": 0.94 Total Vol. 4501 ft3 Area (A): 1.45 acres 0.10 ac-ft Max. Release (QOUT):5.02 cfs Time Time 100-yr Intensity Q100 Inflow (Runoff) Volume Outflow (Release) Volume Storage Detention Volume (Minutes) (Seconds) (in/hr) (cfs)(ft3)(ft3)(ft3) 5 300 9.95 13.55 4066 1506 2560 10 600 7.72 10.52 6309 3012 3297 15 900 6.52 8.88 7993 4518 3475 20 1200 5.60 7.63 9153 6024 3129 25 1500 4.98 6.78 10175 7530 2645 30 1800 4.52 6.16 11082 9036 2046 35 2100 4.08 5.56 11670 10542 1128 40 2400 3.74 5.09 12226 12048 178 45 2700 3.46 4.71 12724 13554 -830 50 3000 3.23 4.40 13198 15060 -1862 55 3300 3.06 4.17 13754 16566 -2812 60 3600 2.86 3.90 14024 18072 -4048 65 3900 2.71 3.69 14396 19578 -5182 70 4200 2.59 3.53 14816 21084 -6268 75 4500 2.47 3.36 15139 22590 -7451 80 4800 2.38 3.24 15560 24096 -8536 85 5100 2.29 3.12 15907 25602 -9695 90 5400 2.21 3.01 16255 27108 -10853 95 5700 2.13 2.90 16537 28614 -12077 100 6000 2.06 2.81 16835 30120 -13285 105 6300 2.00 2.72 17162 31626 -14464 110 6600 1.94 2.64 17440 33132 -15692 115 6900 1.88 2.56 17669 34638 -16969 120 7200 1.84 2.51 18044 36144 -18100 FAA Detention Pond Volume Calculation Existing ODP Pond Volume Capacity Inputs Results K:\DEN_Civil\096888057_QuikTrip 4301 Fort Collins\_Project Files\Eng\Drainage\CALCS\PR CIA Calcs_QT4301.xlsx PROJECT NAME: QuikTrip Fort Collins #4301 DATE: 9/22/2025 PROJECT NUMBER: 96888057 CALCULATED BY: OAT CHECKED BY: AIA Total Site Area: 2.65 acres P2A 2.20 acres 0.8 Imperviousness 76% 0.244 2337.7 CF 1377 CFTotal WQCV Provided a: (12 hours draintime) PROJECT INFORMATION WQCV Calculations WQCV Total WQCV Req. (CF) Chamber ID Total Required WQ Volume (cf)a WQ Inflowb (cfs) Chamber Type Chamber Unit Release Ratec (cfs) Chamber Unit Volumed (cf) Installed Chamber Unit Volume, inc. Aggregatee (cf) Mimimum No. of Chambers for WQCVf Minimum WQ Release Rateg (cfs) Minimum Required Isolator Row Volume by FAA Methodh (cf) Design Controli No. of Chambers Provided Provided WQ Release Ratej (cfs) Provided Isolator Row Volumek (cf) Total Installed System Volumel (cf) 1 2338 2.12 SC-800 0.024 50.60 81.00 29 0.68 820 WQCV 30 0.71 1518 2430 SC-740 a. Total required WQCV calculated per 12-hr drain time. b. WQ inflow is approximated as one-half the 2-yr peak runoff rate. c. Release rate per chamber, limited by flow through geotextile with accumulated sediment. d. Volume within chamber only, not accounting for void spaces in surrounding aggregate. The Isolator Row(s) are sized per this unit volume. e. Volume includes chamber and void spaces (40%) in surrounding aggregate, per chamber unit. The total system WQCV is sized per this unit volume. f. Number of chambers required to provide full WQCV within total installed system, including aggregate. g. Release rate per chamber times number of chambers. This is used at the 'outlet control' for the FAA calculations. h. Minimum 'chamber-only' volume to ensure dirty water is fully contained within Isolator Row. i. Is design controlled by Isolator Row volume or WQCV. j. Release rate per chamber times number of chambers provided. This is the approximate controlled discharge from the WQ event. k. Volume provided in chambers only (no aggregate storage). This number must meet or exceed the required FAA storage volume. l. System volume includes total number of chambers, plus surrounding aggregate. This number must meet or exceed the required 12-hr WQCV. Chamber Configuration Summary Project Number: Project Location: Calcs By: Design Point:2 Design Storm: WQ Isolator Volume 820 ft3 Developed "C":0.77 Area (A):2.20 acres Max. Release (QOUT):0.68 cfs Time Time WQ Intensity QWQ Inflow (Runoff) Volume Outflow (Release) Volume Storage Detention Volume (Minutes) (Seconds) (in/hr) (cfs)(ft3)(ft3)(ft3) 5 300 1.43 2.41 724 204 520 10 600 1.11 1.87 1123 408 715 15 900 0.94 1.58 1426 612 814 20 1200 0.81 1.36 1636 816 820 25 1500 0.72 1.21 1817 1020 797 30 1800 0.65 1.10 1982 1224 758 35 2100 0.59 0.99 2081 1428 653 40 2400 0.54 0.91 2175 1632 543 45 2700 0.50 0.84 2264 1836 428 50 3000 0.46 0.78 2338 2040 298 55 3300 0.44 0.74 2432 2244 188 60 3600 0.41 0.69 2500 2448 52 65 3900 0.39 0.66 2577 2652 -75 70 4200 0.37 0.62 2597 2856 -259 75 4500 0.35 0.59 2668 3060 -392 80 4800 0.33 0.56 2683 3264 -581 85 5100 0.32 0.54 2765 3468 -703 90 5400 0.31 0.52 2790 3672 -882 95 5700 0.29 0.49 2800 3876 -1076 100 6000 0.28 0.47 2846 4080 -1234 105 6300 0.27 0.46 2881 4284 -1403 110 6600 0.26 0.44 2907 4488 -1581 115 6900 0.26 0.43 2981 4692 -1711 120 7200 0.25 0.42 2988 4896 -1908 Isolator Row Volume Calculation (FAA Method) P1A Inputs Results QuikTrip Fort Collins #4301 96888057 QuikTrip 4301 OAT kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 EXHIBIT D – FEMA Flood Map & NRCS Soil Report United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Larimer County Area, ColoradoNatural Resources Conservation Service November 5, 2024 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Larimer County Area, Colorado......................................................................13 73—Nunn clay loam, 0 to 1 percent slopes.................................................13 References............................................................................................................15 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map 44 8 8 9 1 0 44 8 8 9 4 0 44 8 8 9 7 0 44 8 9 0 0 0 44 8 9 0 3 0 44 8 9 0 6 0 44 8 9 0 9 0 44 8 8 9 1 0 44 8 8 9 4 0 44 8 8 9 7 0 44 8 9 0 0 0 44 8 9 0 3 0 44 8 9 0 6 0 44 8 9 0 9 0 493200 493230 493260 493290 493320 493350 493380 493410 493440 493470 493500 493200 493230 493260 493290 493320 493350 493380 493410 493440 493470 493500 40° 33' 9'' N 10 5 ° 4 ' 4 9 ' ' W 40° 33' 9'' N 10 5 ° 4 ' 3 6 ' ' W 40° 33' 2'' N 10 5 ° 4 ' 4 9 ' ' W 40° 33' 2'' N 10 5 ° 4 ' 3 6 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300 Feet 0 20 40 80 120 Meters Map Scale: 1:1,410 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography 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 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: Larimer County Area, Colorado Survey Area Data: Version 19, Aug 29, 2024 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 2, 2021—Aug 25, 2021 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 73 Nunn clay loam, 0 to 1 percent slopes 6.7 100.0% Totals for Area of Interest 6.7 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. Custom Soil Resource Report 11 An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 12 Larimer County Area, Colorado 73—Nunn clay loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: 2tlng Elevation: 4,100 to 5,700 feet Mean annual precipitation: 14 to 15 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 135 to 152 days Farmland classification: Prime farmland if irrigated Map Unit Composition Nunn and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nunn Setting Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Pleistocene aged alluvium and/or eolian deposits Typical profile Ap - 0 to 6 inches: clay loam Bt1 - 6 to 10 inches: clay loam Bt2 - 10 to 26 inches: clay loam Btk - 26 to 31 inches: clay loam Bk1 - 31 to 47 inches: loam Bk2 - 47 to 80 inches: loam Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:7 percent Maximum salinity:Nonsaline (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum:0.5 Available water supply, 0 to 60 inches: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: R067BY042CO - Clayey Plains Hydric soil rating: No Custom Soil Resource Report 13 Minor Components Heldt Percent of map unit:10 percent Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY042CO - Clayey Plains Hydric soil rating: No Wages Percent of map unit:5 percent Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Ecological site:R067BY002CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 14 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 15 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 16 National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone 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 Levee Zone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood Hazard Zone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped 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 11/5/2024 at 11:44 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. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 105°5'1"W 40°33'21"N 105°4'23"W 40°32'54"N Basemap Imagery Source: USGS National Map 2023 kimley-horn.com 3325 South Timberline Road, Suite 130, Fort Collins, CO 80525 970 822 7911 EXHIBIT E – Excerpts From Master Report OVERALL DEVELOPMENT PLAN AND FINAL DRAINAGE AND EROSION CONTROL REPORT SWC Drake/College Fort Collins, Colorado Prepared for: KRF Drake, LLC 1509 York St, Suite 201 Denver, CO 80206 Prepared by: Kimley-Horn and Associates, Inc. 3325 South Timberline Road - Suite 130 Fort Collins, Colorado 80525 (970) 822-7911 City of Fort Collins Project #: ODP24002 and BDR240018 KH Project #: 096315014 Prepared: May 21, 2025 kimley-horn.com 3325 S Timberline Rd, Suite 130, Fort Collins, CO 80525 970-822-7911 April 9, 2025 City of Fort Collins Stormwater Engineering 281 N. College Ave. Fort Collins, CO 80524 RE: SWC Drake/College Overall Development Plan and Final Drainage and Erosion Control Report Dear Reviewer: Kimley-Horn and Associates, Inc. is pleased to submit this Overall Development Plan and Final Drainage and Erosion Control Report for your review as part of the Overall Development Plan (ODP) and Basic Development Review (BDR) submittal for the above referenced project. This report and attached drainage plans have been prepared in accordance with the Fort Collins Stormwater Criteria Manual (“FCSCM”) and the latest Mile High Flood District Urban Storm Drainage Criteria Manual (“USDCM”). These documents serve to document stormwater impacts associated with the proposed SWC Drake/College Project. We understand the review by the City of Fort Collins is to ensure general compliance with standardized criteria contained in the FCSCM and USDCM. Please contact us with any questions or concerns. Thank You, KIMLEY-HORN AND ASSOCIATES, INC. Bryce Willaby, P.E. Overall Development Plan and Final Drainage Report Drake and College Mixed-Use – Fort Collins, Colorado Appendix B – Hydrologic Calculations and Exhibits TIME 2 YR 10 YR 100 YR 5 2.85 4.87 9.95 6 2.67 4.56 9.31 7 2.52 4.31 8.80 8 2.40 4.10 8.38 9 2.30 3.93 8.03 10 2.21 3.78 7.72 11 2.13 3.63 7.42 12 2.05 3.50 7.16 13 1.98 3.39 6.92 14 1.92 3.29 6.71 15 1.87 3.19 6.52 20 1.61 2.74 5.60 25 1.43 2.44 4.98 30 1.30 2.21 4.52 40 1.07 1.83 3.74 50 0.92 1.58 3.23 60 0.82 1.40 2.86 120 0.49 0.86 1.84 Note: Time Intensity Frequency Tabulation Intensity values from the City of Fort Collins Intensity-Duration-Frequency Tables; Chapter 5, Section 3.4 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. RAINFALL INTENSITY K:\NCO_Civil\096315014_Kentro Drake-College\Project Files\Eng\Drainage\PR CIA Calcs.xlsx PROJECT NAME:Drake and College Mixed Use 4/7/2025 PROJECT NUMBER:96315014 CALCULATED BY:BAW CHECKED BY:AGR SOIL: GROUP C Lawns, Clayey Soil Rooftop Asphalt, Concrete Gravel/Pavers Commercial LAND USE:AREA AREA AREA AREA AREA 2-YEAR COEFF.0.20 0.95 0.95 0.50 0.85 100-YEAR COEFF.0.25 1.00 1.00 0.63 1.00 IMPERVIOUS %2%90%100%40%80% Lawns, Clayey Soil Rooftop Asphalt, Concrete Gravel/Pavers Commercial TOTAL DESIGN DESIGN AREA AREA AREA AREA AREA AREA BASIN POINT (AC)(AC)(AC)(AC)(AC)(AC)C(2)C(100)Imp % 1A 1A 0.00 0.00 0.00 0.00 0.98 0.98 0.85 1.00 80% 2B 2B 0.00 0.00 0.00 0.00 0.55 0.55 0.85 1.00 80% 3A 3A 0.00 0.00 0.00 0.00 1.25 1.25 0.85 1.00 80% 4A 4A 0.00 0.00 0.00 0.00 1.99 1.99 0.85 1.00 80% R1 R1 0.03 0.00 0.39 0.00 0.10 0.52 0.89 0.96 91% R2 R2 0.02 0.00 0.10 0.00 0.06 0.18 0.83 0.92 82% 0.05 0.00 0.49 0.00 4.93 5.47 0.85 0.99 81% 1%0%9%0%90% 1B 1B 0.00 0.00 0.00 0.00 0.16 0.16 0.85 1.00 80% 3B 3B 0.00 0.00 0.00 0.00 0.17 0.17 0.85 1.00 80% 4B 4B 0.00 0.00 0.00 0.00 0.15 0.15 0.85 1.00 80% OS1 OS1 0.00 0.00 0.05 0.00 0.02 0.06 0.69 0.91 95% OS2 OS2 0.01 0.00 0.03 0.00 0.00 0.04 0.73 0.98 72% OS3 OS3 0.01 0.00 0.04 0.00 0.03 0.08 0.55 0.73 82% OS4 OS4 0.13 0.00 0.00 0.00 0.00 0.13 0.20 0.31 2% 0.15 0.00 0.12 0.00 0.53 0.80 0.74 0.86 68% 19%0%15%0%66% R1 & R2 R1 & R2 0.05 0.00 0.49 0.00 0.16 0.69 0.68 0.90 89% 7%0%71%0%23% Notes: 1. Imperviousness, I, values per UDFCD Criteria Manual Volume 1, Table 6-3 2. Runoff Coefficient values are from the City of Fort Collins Runoff Coefficient Tables 3.2-2 and 3.2-3; Chapter 5, Section 3.2 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. Frequency adjustment factor has been applied to composite C values per Table 3.2-3. BASIN SUBTOTAL On-Site Basins Flowing On-site RUNOFF COEFFICIENTS - IMPERVIOUS CALCULATION On-Site Basins Flowing Off-site BASIN SUBTOTAL On-Site Roadway Basins Flowing to Underground Chamber System K:\NCO_Civil\096315014_Kentro Drake-College\Project Files\Eng\Drainage\PR CIA Calcs_Drake & College.xlsx Drake and College Mixed Use DATE:4/7/2025 96315014 BAW AGR FINAL Tc DESIGN AREA C2 LENGTH SLOPE Ti LENGTH SLOPE R VEL Tt COMP. TOTAL TOTAL TOTAL Tc BASIN Ac Ft %Min.Ft.%fps Min.tc LENGTH SLOPE IMP.Min.Min. 1A 0.98 0.85 0.0 0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 2B 0.55 0.85 0.0 0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 3A 1.25 0.85 0.0 0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 4A 1.99 0.85 0.0 0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 R1 0.52 0.89 60 2.0%2.4 200 0.6%0.195 3.0 1.1 3.5 260 0.9%91%11.4 5.0 R2 0.18 0.83 60 2.0%3.1 200 0.6%0.195 3.0 1.1 4.2 260 0.9%82%11.4 5.0 1B 0.16 0.85 0.0 0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 3B 0.17 0.85 0.0 0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 4B 0.15 0.85 0.0 0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 OS1 0.06 0.69 75 2.0%5.2 15 0.6%0.195 3.0 0.1 5.3 90 1.8%95%10.5 5.3 OS2 0.04 0.73 40 2.0%3.4 55 3.5%0.195 7.2 0.1 3.6 95 2.9%72%10.5 5.0 OS3 0.08 0.55 40 2.0%5.2 55 3.5%0.195 7.2 0.1 5.3 95 2.9%82%10.5 5.3 OS4 0.13 0.20 40 2.0%8.4 55 3.5%0.195 7.2 0.1 8.6 95 2.9%2%10.5 8.6 R1 & R2 0.69 0.68 35 2.0% 3.6 100 0.6% 0.195 3.0 0.6 4.2 135 1.0% 89% 10.8 5.0 On-Site Roadway Basins Flowing to Underground Chamber System On-Site Basins Flowing Off-Site CHECKED BY: On-Site Basins 2-Year Time of Concentration Tc CHECK (URBANIZED BASINS) PROJECT NAME: PROJECT NUMBER: DATA INITIAL TIME (Ti) TRAVEL TIME (Tt) SUB-BASIN CALCULATED BY: K:\NCO_Civil\096315014_Kentro Drake-College\Project Files\Eng\Drainage\PR CIA Calcs_Drake & College.xlsx Drake and College Mixed Use DATE:4/7/2025 96315014 BAW AGR FINAL Tc DESIGN AREA C100 LENGTH SLOPE Ti LENGTH SLOPE R VEL Tt COMP. TOTAL TOTAL TOTAL Tc BASIN Ac Ft %Min.Ft.%fps Min.tc LENGTH SLOPE IMP.Min.Min. 1A 0.98 1.00 0 0 0.0 0 0 0.195 0.0 0.0 0.0 0 #DIV/0! 80% 10.0 5.0 2B 0.55 1.00 0 0 0.0 0 0 0.195 0.0 0.0 0.0 0 #DIV/0! 80% 10.0 5.0 3A 1.25 1.00 0 0 0.0 0 0 0.195 0.0 0.0 0.0 0 #DIV/0! 80% 10.0 5.0 4A 1.99 1.00 0 0 0.0 0 0 0.195 0.0 0.0 0.0 0 #DIV/0! 80% 10.0 5.0 R1 0.52 0.96 60 0 1.6 200 0 0.195 3.0 1.1 2.7 260 0.9% 91% 11.4 5.0 R2 0.18 0.92 60 0 2.1 200 0 0.195 3.0 1.1 3.2 260 0.9% 82% 11.4 5.0 1B 0.16 1.00 0 0.0%0.0 0 0.0%0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 3B 0.17 1.00 0 0.0%0.0 0 0.0%0.195 0.0 0.0 0.0 0 #DIV/0!80%10.0 5.0 4B 0.15 1.00 0 0.0%0.0 0 0.0%0.195 0.0 0.0 0.0 0 #DIV/0!95%10.0 5.0 OS1 0.06 0.91 75 2.0%2.4 15 0.6%0.195 3.0 0.1 2.5 90 1.8%0%10.5 5.0 OS2 0.04 0.98 40 2.0%1.1 55 3.5%0.195 7.2 0.1 1.3 95 2.9%82%10.5 5.0 OS3 0.08 0.73 40 2.0%3.5 55 3.5%0.195 7.2 0.1 3.6 95 2.9%2%10.5 5.0 OS4 0.13 0.31 40 2.0%7.4 55 3.5%0.195 7.2 0.1 7.5 95 2.9%0%10.5 7.5 R1 & R2 0.69 0.90 35 2.0% 1.7 100 0.6% 0.195 3.0 0.6 2.3 135 1.0% 79% 10.8 5.0 On-Site Basins Flowing Off-Site On-Site Roadway Basins Flowing to Underground Chamber System On-Site Basins CHECKED BY: SUB-BASIN INITIAL TRAVEL TIME Tc CHECK DATA TIME (Ti) (Tt) (URBANIZED BASINS) 100-Year Time of Concentration PROJECT NAME: PROJECT NUMBER: CALCULATED BY: K:\NCO_Civil\096315014_Kentro Drake-College\Project Files\Eng\Drainage\PR CIA Calcs_Drake & College.xlsx DATE: 4/7/2025 Drake and College Mixed Use 96315014 BAW P1 (1-Hour Rainfall) =0.82 AGR REMARKS DE S I G N PO I N T AR E A (A C ) RU N O F F CO E F F tc (m i n ) C* A ( a c ) I (i n / h r ) Q (c f s ) 1A 0.98 0.85 5.00 0.83 2.85 2.38 Future Lot 1 drainage flows to connect via storm sewer at Design point 1A 2B 0.55 0.85 5.00 0.47 2.85 1.34 Future Lot 2 drainage flows to connect via storm sewer at Design point 2A 3A 1.25 0.85 5.00 1.06 2.85 3.02 Future Lot 3 drainage flows to connect via storm sewer at Design point 3A 4A 1.99 0.85 5.00 1.69 2.85 4.83 Future Lot 4 drainage flows to connect via storm sewer at Design point 4A R1 0.52 0.89 5.00 0.46 2.85 1.31 Flows to proposed inlet within roadway to underground storm system at R1 R2 0.18 0.83 5.00 0.15 2.85 0.42 Flows to proposed inlet within roadway to underground storm system at R2 1B 0.16 0.85 5.00 0.13 2.85 0.38 Future Lot 1 drainage flows off-site towards W. Drake Road at Design point 1B 3B 0.17 0.85 5.00 0.15 2.85 0.42 Future Lot 3 drainage flows off-site towards W. Drake Road at Design point 3B 4B 0.15 0.85 5.00 0.13 2.85 0.37 Future Lot 4 drainage flows off-site towards W. Thunderbird Drive at Design point 4B OS1 0.06 0.69 5.30 0.04 2.85 0.13 Flows North to W. Drake Street OS2 0.04 0.73 5.00 0.03 2.85 0.08 Flows South to W. Thunderbird Rd OS3 0.08 0.55 5.28 0.04 2.85 0.12 Flows East within roadway to S College Avenue OS4 0.13 0.20 8.58 0.03 2.40 0.06 Flows East along landscaping to S College Avenue R1 & R2 0.69 0.68 5.00 0.47 2.85 1.35 Flows to Underground Chamber System OS2 OS4 3B 4B On-Site Basins On-Site Roadway Basins Flowing to Underground Chamber System OS3 1A 2B R2 3A 4A R1 1B R1 & R2 On-Site Basins Flowing Off-Site OS1 DE S G I N BA S I N STORM DRAINAGE DESIGN - RATIONAL METHOD 2 YEAR EVENT PROJECT NAME: PROJECT NUMBER: CALCULATED BY: CHECKED BY: K:\NCO_Civil\096315014_Kentro Drake-College\Project Files\Eng\Drainage\PR CIA Calcs_Drake & College.xlsx DATE: 4/7/2025 Drake and College Mixed Use 96315014 BAW P1 (1-Hour Rainfall) =2.86 AGR REMARKS DE S I G N PO I N T AR E A (A C ) RU N O F F CO E F F tc (m i n ) C* A ( a c ) I (i n / h r ) Q (c f s ) 1A 0.98 1.00 5.00 0.98 9.95 9.76 Future Lot 1 drainage flows to connect via storm sewer at Design point 1A 2B 0.55 1.00 5.00 0.55 9.95 5.51 Future Lot 2 drainage flows to connect via storm sewer at Design point 2A 3A 1.25 1.00 5.00 1.25 9.95 12.41 Future Lot 3 drainage flows to connect via storm sewer at Design point 3A 4A 1.99 1.00 5.00 1.99 9.95 19.82 Future Lot 4 drainage flows to connect via storm sewer at Design point 4A R1 0.52 0.96 5.00 0.49 9.95 4.92 Flows to proposed inlet within roadway to underground storm system at R1 R2 0.18 0.92 5.00 0.16 9.95 1.61 Flows to proposed inlet within roadway to underground storm system at R2 1B 0.16 1.00 5.00 0.16 9.95 1.58 Future Lot 1 drainage flows off-site towards W. Drake Road at Design point 1B 3B 0.17 1.00 5.00 0.17 9.95 1.73 Future Lot 3 drainage flows off-site towards W. Drake Road at Design point 3B 4B 0.15 1.00 5.00 0.15 9.95 1.52 Future Lot 4 drainage flows off-site towards W. Thunderbird Drive at Design point 4B OS1 0.06 0.91 5.30 0.06 9.95 0.58 Flows North to W. Drake Street OS2 0.04 0.98 5.00 0.04 9.95 0.39 Flows South to W. Thunderbird Rd OS3 0.08 0.73 5.28 0.06 9.95 0.57 Flows East within roadway to S College Avenue OS4 0.13 0.31 8.58 0.04 8.38 0.34 Flows East along landscaping to S College Avenue R1 & R2 0.69 0.90 5.00 0.63 9.95 6.23 Flows to Underground Chamber System 4B 3B OS2 OS4 R1 & R2 On-Site Roadway Basins Flowing to Underground Chamber System CHECKED BY: 2B 3A 1B CALCULATED BY: STORM DRAINAGE DESIGN - RATIONAL METHOD 100 YEAR EVENT PROJECT NAME: PROJECT NUMBER: OS3 On-Site Basins Flowing Off-Site OS1 DE S I G N BA S I N On-Site Basins 1A 4A R1 R2 K:\NCO_Civil\096315014_Kentro Drake-College\Project Files\Eng\Drainage\PR CIA Calcs_Drake & College.xlsx PROJECT NAME: Drake and College Mixed Use DATE: 4/7/2025 PROJECT NUMBER: 96315014 CALCULATED BY: BAW CHECKED BY: AGR IMPERVIOUSNESS % Q2 Q100 1A 1A 0.98 80%2.38 9.76 2B 2B 0.55 80%1.34 5.51 3A 3A 1.25 80%3.02 12.41 4A 4A 1.99 80%4.83 19.82 R1 R1 0.52 91%1.31 4.92 R2 R2 0.18 82% 0.42 1.61 5.47 81%13.29 54.03 1B 1B 0.16 80% 0.38 1.58 3B 3B 0.17 80% 0.42 1.73 4B 4B 0.15 80% 0.37 1.52 OS1 OS1 0.06 95% 0.13 0.58 OS2 OS2 0.04 72% 0.08 0.39 OS3 OS3 0.08 82% 0.12 0.57 OS4 OS4 0.13 2% 0.06 0.34 0.80 68%1.57 6.71 R1 & R2 R1 & R2 0.69 89% 1.35 6.23 On-Site Roadway Basins Flowing to Underground Chamber System On-Site Basins Flowing On-Site DESIGN POINT On-Site Basins Flowing Off-Site TOTAL RATIONAL CALCULATIONS SUMMARY TRIBUTARY BASINS TRIBUTARY AREA (AC) PEAK FLOWS (CFS) TOTAL K:\NCO_Civil\096315014_Kentro Drake-College\Project Files\Eng\Drainage\PR CIA Calcs_Drake & College.xlsx PROJECT NAME: Drake & College Mixed-Use DATE: 4/7/2025 PROJECT NUMBER: 96315014 CALCULATED BY: BAW CHECKED BY: AGR Total Site Area: 6.27 acres Road Improvement Area to LID (Sub-basin R1 & R2):0.69 acres 0.8 Imperviousness 89% 0.314 Total Site Impervious Area: 0.49 acres 947.7 CF Added/Modified Impervious Area: 0.49 acres 972 CFTotal WQCV Provided a: (12 hours draintime) PROJECT INFORMATION WQCV Calculations WQCV Total WQCV Req. (CF) Fort Collins Duration (min.) Intensity WQ (in/hr) Intensity 2-year (in/hr) Intensity 10-year (in/hr) Intensity 100-year (in/hr) 5 1.43 2.85 4.87 9.95 6 1.34 2.67 4.56 9.31 7 1.26 2.52 4.31 8.80 8 1.20 2.40 4.10 8.38 9 1.15 2.30 3.93 8.03 10 1.11 2.21 3.78 7.72 11 1.07 2.13 3.63 7.42 12 1.03 2.05 3.50 7.16 13 0.99 1.98 3.39 6.92 14 0.96 1.92 3.29 6.71 15 0.94 1.87 3.19 6.52 16 0.91 1.81 3.08 6.30 17 0.88 1.75 2.99 6.10 18 0.85 1.70 2.90 5.92 19 0.83 1.65 2.82 5.75 20 0.81 1.61 2.74 5.60 21 0.78 1.56 2.67 5.46 22 0.77 1.53 2.61 5.32 23 0.75 1.49 2.55 5.20 24 0.73 1.46 2.49 5.09 25 0.72 1.43 2.44 4.98 26 0.70 1.40 2.39 4.87 27 0.69 1.37 2.34 4.78 28 0.67 1.34 2.29 4.69 29 0.66 1.32 2.25 4.60 30 0.65 1.30 2.21 4.52 31 0.64 1.27 2.16 4.42 32 0.62 1.24 2.12 4.33 33 0.61 1.22 2.08 4.24 34 0.60 1.19 2.04 4.16 35 0.59 1.17 2.00 4.08 36 0.58 1.15 1.96 4.01 37 0.58 1.16 1.93 3.93 38 0.56 1.11 1.89 3.87 39 0.55 1.09 1.86 3.80 40 0.54 1.07 1.83 3.74 41 0.53 1.05 1.80 3.68 42 0.52 1.04 1.77 3.62 43 0.51 1.02 1.74 6.56 44 0.51 1.01 1.72 3.51 45 0.50 0.99 1.69 3.46 46 0.49 0.98 1.67 3.41 47 0.48 0.96 1.64 3.36 48 0.48 0.95 1.62 3.31 49 0.47 0.94 1.60 3.27 50 0.46 0.92 1.58 3.23 51 0.46 0.91 1.56 3.18 52 0.45 0.90 1.54 3.14 53 0.45 0.89 1.52 3.10 54 0.44 0.88 1.50 3.07 55 0.44 0.87 1.48 3.06 56 0.43 0.86 1.47 2.99 57 0.43 0.85 1.45 2.96 58 0.42 0.84 1.43 2.92 59 0.42 0.83 1.42 2.89 60 0.41 0.82 1.40 2.86 65 0.39 0.78 1.32 2.71 70 0.37 0.73 1.25 2.59 75 0.35 0.70 1.19 2.47 80 0.33 0.66 1.14 2.38 85 0.32 0.64 1.09 2.29 90 0.31 0.61 1.05 2.21 95 0.29 0.58 1.01 2.13 100 0.28 0.56 0.97 2.06 105 0.27 0.54 0.94 2.00 110 0.26 0.52 0.91 1.94 115 0.26 0.51 0.88 1.88 120 0.25 0.49 0.86 1.84 IDF Table for Rational Method (FCSCM Table 3.4.1) Chamber ID Total Required WQ Volume (cf)a WQ Inflowb (cfs) Chamber Type Chamber Unit Release Ratec (cfs) Chamber Unit Volumed (cf) Installed Chamber Unit Volume, inc. Aggregatee (cf) Mimimum No. of Chambers for WQCVf Minimum WQ Release Rateg (cfs) Minimum Required Isolator Row Volume by FAA Methodh (cf) Design Controli No. of Chambers Provided Provided WQ Release Ratej (cfs) Provided Isolator Row Volumek (cf) Total Installed System Volumel (cf) 1 948 0.71 SC-800 0.024 50.60 81.00 12 0.28 297 WQCV 12 0.28 607 972 SC-740 a. Total required WQCV calculated per 12-hr drain time. b. WQ inflow is approximated as one-half the 2-yr peak runoff rate. c. Release rate per chamber, limited by flow through geotextile with accumulated sediment. d. Volume within chamber only, not accounting for void spaces in surrounding aggregate. The Isolator Row(s) are sized per this unit volume. e. Volume includes chamber and void spaces (40%) in surrounding aggregate, per chamber unit. The total system WQCV is sized per this unit volume. f. Number of chambers required to provide full WQCV within total installed system, including aggregate. g. Release rate per chamber times number of chambers. This is used at the 'outlet control' for the FAA calculations. h. Minimum 'chamber-only' volume to ensure dirty water is fully contained within Isolator Row. i. Is design controlled by Isolator Row volume or WQCV. j. Release rate per chamber times number of chambers provided. This is the approximate controlled discharge from the WQ event. k. Volume provided in chambers only (no aggregate storage). This number must meet or exceed the required FAA storage volume. l. System volume includes total number of chambers, plus surrounding aggregate. This number must meet or exceed the required 12-hr WQCV. Chamber Configuration Summary Project Number: Project Location: Calcs By: Design Point:1 Design Storm: WQ Isolator Volume 297 ft3 Developed "C":0.99 Area (A):0.69 acres Max. Release (QOUT):0.31 cfs Time Time WQ Intensity QWQ Inflow (Runoff) Volume Outflow (Release) Volume Storage Detention Volume (Minutes) (Seconds) (in/hr) (cfs)(ft3)(ft3)(ft3) 5 300 1.43 0.98 293 93 200 10 600 1.11 0.76 454 186 268 15 900 0.94 0.64 576 279 297 20 1200 0.81 0.55 662 372 290 25 1500 0.72 0.49 734 465 269 30 1800 0.65 0.45 801 558 243 35 2100 0.59 0.40 841 651 190 40 2400 0.54 0.37 879 744 135 45 2700 0.50 0.34 915 837 78 50 3000 0.46 0.32 945 930 15 55 3300 0.44 0.30 983 1023 -40 60 3600 0.41 0.28 1011 1116 -105 65 3900 0.39 0.27 1042 1209 -167 70 4200 0.37 0.25 1050 1302 -252 75 4500 0.35 0.24 1079 1395 -316 80 4800 0.33 0.23 1085 1488 -403 85 5100 0.32 0.22 1118 1581 -463 90 5400 0.31 0.21 1128 1674 -546 95 5700 0.29 0.20 1132 1767 -635 100 6000 0.28 0.19 1151 1860 -709 105 6300 0.27 0.18 1165 1953 -788 110 6600 0.26 0.18 1175 2046 -871 115 6900 0.26 0.17 1205 2139 -934 120 7200 0.25 0.17 1208 2232 -1024 Isolator Row Volume Calculation (FAA Method) Chamber 1 Inputs Results Drake-College 96315014 College and Drake BAW X 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W D D D D D 50 2 5 50 2 5 50 3 0 50 3 0 50 2 3 50 2 3 50 2 4 50 2 4 50 2 6 50 2 6 50 2 6 50 2 6 50 2 6 50 2 6 502 7 50 2 7 5028 50 2 8 5029 50 2 9 50 3 1 50 3 1 50 3 0 5027 5028 50 2 9 50 3 1 50 3 1 5025 50 3 0 50 2 7 50 2 8 50 2 9 5026 5027 5027 5028 5028 50 2 5 50 2 2 50 2 3 50 2 4 502 7 50 2 8 50 2 9 502 9 5028 5028 5028 50 2 5 50 2 4 5026 5025 5026 5027 50 2 9 50 2 9 50 3 0 503 0 502750 2 8 50 2 9 50 2 3 50 2 3 50 2 4 50 2 2 5025 503 0 50 2 3 50 2 4 5026 502 7 502 8 502 9 50 3 1 DRAKE ROAD CO L L E G E A V E N U E THUNDERBIRD DRIVE PROPOSED STORM LINEPROPOSED ADS SC-800 STORM TECH OR APPROVED EQUAL PROPOSED RIGHT-OF-WAY PROPOSED RIGHT-OF-WAY PROPOSED RIGHT-OF-WAY EXISTING RIGHT-OF-WAY EXISTING RIGHT-OF-WAY EXISTING RIGHT-OF-WAY PROPOSED RIGHT-OF-WAY MC C L E L L A N D D R I V E EXISTING STORM INLETS STRM INLET B1 SINGLE COMBO INLET STRM INLET A3-2 SINGLE COMBO INLET STRM INLET A TRIPLE COMBO INLET STORM DRAIN A SEE SHEET C4.8 STORM DRAIN B SEE SHEET C4.9 EX . 1 5 " C M P S T O R M EX . 1 5 " R C P S T O R M EX . 1 5 " R C P S T O R M EX . 1 5 " R C P S T O R M EX . 2 2 " R C P S T O R M 12' FUTURE SIDEWALK TH I S D O C U M E N T , T O G E T H E R W I T H T H E C O N C E P T S A N D D E S I G N S P R E S E N T E D H E R E I N , A S A N I N S T R U M E N T O F S E R V I C E , I S I N T E N D E D O N L Y F O R T H E S P E C I F I C P U R P O S E A N D C L I E N T F O R W H I C H I T W A S P R E P A R E D . R E U S E O F A N D I M P R O P E R R E L I A N C E O N T H I S D O C U M E N T W I T H O U T W R I T T E N A U T H O R I Z A T I O N A N D A D A P T A T I O N B Y K I M L E Y - H O R N A N D A S S O C I A T E S , I N C . S H A L L B E W I T H O U T L I A B I L I T Y T O K I M L E Y - H O R N A N D A S S O C I A T E S , I N C . R Know what's below. Call before you dig. DESIGNED BY: DRAWN BY: CHECKED BY: DATE: NO . RE V I S I O N BY DA T E © 2 0 2 4 K I M L E Y - H O R N A N D A S S O C I A T E S , I N C . 33 2 5 S O U T H T I M B E R L I N E R O A D , S U I T E 1 3 0 FO R T C O L L I N S , C O L O R A D O 8 0 5 2 5 ( 9 7 0 ) 8 2 2 - 7 9 1 1 K: \ N C O _ C i v i l \ 0 9 6 3 1 5 0 1 4 _ K e n t r o D r a k e - C o l l e g e \ C A D D \ P l a n S h e e t s \ 0 9 6 3 1 5 0 1 4 _ C - D R N G . d w g PROJECT NO. SHEET SW C D R A K E / C O L L E G E 2/19/2025 BAW MKL AGR 096315014 FOR REVIEW ONLY NOT FOR Kimley-Horn and Associates, Inc. CONSTRUCTION PROPERTY LINE LEGEND: PROPOSED CATCH CURB AND GUTTER PROPOSED STORM LINE C7.0 DR A I N A G E E X H I B I T 34 OF 34 # = BASIN DESIGNATION AC = AREA IN ACRES I = % IMPERVIOUSNESS # = DESIGN POINT PROPOSED BASIN BOUNDARY PROPOSED FLOW ARROW EXISTING FLOW ARROW NORTH W W W SS S S IR W W W SS S S IR F.O. ELEC C F.O. ELEC T S VAULTCABLE ELEC ELEC VAULTF.O.ELEC VAULT F.O. ELEC VAULT F.O. VAULT F.O. TRAFFICVAULT T S OHU OHU OHU OHU OHU OHU OHU CSCS HYD ELEC H2O S S C S S S S VAULTELEC H2O HYD 12 " W 12 " W 12 " W 12 " W 12 " W CTV CTV CTV CTV CTV D D D D D S 50 2 5 50 2 5 50 3 0 50 3 0 50 2 3 50 2 3 50 2 4 50 2 4 50 2 6 50 2 6 50 2 6 50 2 6 50 2 6 50 2 6 502 7 50 2 7 5028 50 2 8 5029 50 2 9 50 3 1 50 3 1 50 3 0 5027 5028 50 2 9 50 3 1 50 3 1 5025 50 3 0 50 2 7 50 2 8 50 2 9 5026 5027 5027 5028 5028 50 2 5 50 2 2 50 2 3 50 2 4 502 7 50 2 8 50 2 9 502 9 5028 5028 5028 50 2 5 50 2 4 5026 5025 5026 5027 50 2 9 50 2 9 50 3 0 503 0 502750 2 8 50 2 9 50 2 3 50 2 3 50 2 3 50 2 3 50 2 3 50 2 4 50 2 3 50 2 4 50 2 2 5025 503 0 50 2 3 50 2 4 5026 502 7 502 8502 9 5031 50 3 1 50 3 1 WEST DRAKE ROAD Mc C L E L L A N D D R I V E THUNDERBIRD DRIVE CO L L E G E A V E N U E UNDERGROUND SYSTEM 1 TREATMENT AREA: 0.49 AC REQUIRED VOLUME: 948 CF PROVIDED VOLUME: 972 CF 12' FUTURE SIDEWALK © 2024 KIMLEY-HORN AND ASSOCIATES, INC. 3325 S. TIMBERLINE RD, SUITE 130, FORT COLLINS, CO, 80525 PHONE: (970) 822-7911 K:\NCO_CIVIL\096315014_KENTRO DRAKE-COLLEGE\CADD\EXHIBITS\DRAKE & COLLEGE_LID EXHIBIT.DWG PROJECT NUMBER:DATE: LID EXHIBIT SWC COLLEGE/DRAKE 096315014A 7, 2025 NORTH LEGEND PROPERTY LINE RIGHT-OF-WAY LINE EASEMENT LINE EXISTING MAJOR CONTOUR EXISTING MINOR CONTOUR CENTERLINE UNDERGROUND CHAMBER TREATMENT AREA (CURRENT IMPROVEMENTS) UNDERGROUND CHAMBER SYSTEM AREA TO BE TREATED BY INDIVIDUAL LOT UNTREATED AREA PROPOSED MAJOR CONTOUR PROPOSED MINOR CONTOUR UNDERGROUND CHAMBER TREATMENT AREA (FUTURE IMPROVEMENTS) UNTREATED AREA (ASSUMED 80% IMPERVIOUS) PROJECT LID SUMMARY TOTAL IMPERVIOUS AREA FOR IMPROVEMENTS 33,381 SF MINIMUM AREA TO BE TREATED BY LID MEASURES TOTAL REQUIRED TREATED IMPERVIOUS AREAS BY UNDERGROUND SYSTEM 25,036 SF 75.0% TOTAL PROPOSED TREATED IMPERVIOUS AREAS BY UNDERGROUND SYSTEM 26,717 SF 80.0% 50 2 5 50 2 5 50 3 0 50 3 0 50 2 3 50 2 3 50 2 4 50 2 4 50 2 6 50 2 6 50 2 6 50 2 6 50 2 6 50 2 6 502 7 50 2 7 5028 50 2 8 5029 50 2 9 50 3 1 50 3 1 50 3 0 5027 5028 50 2 9 50 3 1 50 3 1 5025 LOT 3 LOT 1 LOT 2 LOT 4 ELEC X OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU OHU CT V 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W 12 " W CT V CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV CTV D D D D D 50 3 0 50 2 7 50 2 8 50 2 9 5026 5027 5027 5028 5028 50 2 5 50 2 2 50 2 3 50 2 4 502 7 50 2 8 50 2 9 502 9 5028 5028 5028 50 2 5 50 2 4 5026 5025 5026 5027 50 2 9 50 2 9 50 3 0 503 0 502750 2 8 50 2 9 50 2 3 50 2 3 50 2 4 50 2 2 5025 503 0 50 2 3 50 2 4 5026 502 7 502 8 502 9 50 3 1 DRAKE ROAD CO L L E G E A V E N U E THUNDERBIRD DRIVE 12' FUTURE SIDEWALK TH I S D O C U M E N T , T O G E T H E R W I T H T H E C O N C E P T S A N D D E S I G N S P R E S E N T E D H E R E I N , A S A N I N S T R U M E N T O F S E R V I C E , I S I N T E N D E D O N L Y F O R T H E S P E C I F I C P U R P O S E A N D C L I E N T F O R W H I C H I T W A S P R E P A R E D . R E U S E O F A N D I M P R O P E R R E L I A N C E O N T H I S D O C U M E N T W I T H O U T W R I T T E N A U T H O R I Z A T I O N A N D A D A P T A T I O N B Y K I M L E Y - H O R N A N D A S S O C I A T E S , I N C . S H A L L B E W I T H O U T L I A B I L I T Y T O K I M L E Y - H O R N A N D A S S O C I A T E S , I N C . R Know what's below. Call before you dig. DESIGNED BY: DRAWN BY: CHECKED BY: DATE: NO . RE V I S I O N BY DA T E © 2 0 2 4 K I M L E Y - H O R N A N D A S S O C I A T E S , I N C . 33 2 5 S O U T H T I M B E R L I N E R O A D , S U I T E 1 3 0 FO R T C O L L I N S , C O L O R A D O 8 0 5 2 5 ( 9 7 0 ) 8 2 2 - 7 9 1 1 K: \ N C O _ C i v i l \ 0 9 6 3 1 5 0 1 4 _ K e n t r o D r a k e - C o l l e g e \ C A D D \ E x h i b i t s \ 2 0 2 4 - 1 1 2 7 D r a i n a g e E x h i b i t s \ 0 9 6 3 1 5 0 1 4 _ P r o p o s e d I m p e r v i o u s . d w g PROJECT NO. SHEET SW C D R A K E / C O L L E G E 2/19/2025 BAW MKL AGR 096315014 FOR REVIEW ONLY NOT FOR Kimley-Horn and Associates, Inc. CONSTRUCTION PROPERTY LINE LEGEND: EX-D PR O P O S E D I M P E R V I O U S E X H I B I T 1 OF 1 NORTH EASEMENT LINE PROPOSED CURB AND GUTTER PERVIOUS AREA IMPERVIOUS AREA PROPOSED IMPERVIOUS AREA (ASSUMES 80% IMPERVIOUSNESS) IMPERVIOUS AREA SUMMARY CALCULATIONS PROJECT AREA 6.27 AC EXISTING IMPERVIOUS AREA 6.18 AC PROPOSED IMPERVIOUS AREA 4.84 AC REDUCTION IN IMPERVIOUS AREA 1.34 AC Overall Development Plan and Final Drainage Report Drake and College Mixed-Use – Fort Collins, Colorado Appendix C – Hydraulic Calculations MHFD-Inlet, Version 5.03 (August 2023) Worksheet Protected INLET NAME Inlet A3-2 (R1)Inlet B1 (R2)User-Defined Site Type (Urban or Rural)URBAN URBAN Inlet Application (Street or Area)STREET STREET Hydraulic Condition In Sump In Sump Inlet Type CDOT/Denver 13 Combination CDOT/Denver 13 Combination USER-DEFINED INPUT User-Defined Design Flows Minor QKnown (cfs)1.3 0.4 Major QKnown (cfs)4.9 1.6 Bypass (Carry-Over) Flow from Upstream Inlets must be organized from upstream (left) to downstream (right) in order for bypass flows to be linked. Receive Bypass Flow from:No Bypass Flow Received No Bypass Flow Received Minor Bypass Flow Received, Qb (cfs)0.0 0.0 Major Bypass Flow Received, Qb (cfs)0.0 0.0 Watershed Characteristics Subcatchment Area (acres) Percent Impervious NRCS Soil Type Watershed Profile Overland Slope (ft/ft) Overland Length (ft) Channel Slope (ft/ft) Channel Length (ft) Minor Storm Rainfall Input Design Storm Return Period, Tr (years) One-Hour Precipitation, P1 (inches) Major Storm Rainfall Input Design Storm Return Period, Tr (years) One-Hour Precipitation, P1 (inches) CALCULATED OUTPUT Minor Total Design Peak Flow, Q (cfs)1.3 0.4 Major Total Design Peak Flow, Q (cfs)4.9 1.6 Minor Flow Bypassed Downstream, Qb (cfs)N/A N/A Major Flow Bypassed Downstream, Qb (cfs)N/A N/A INLET MANAGEMENT Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =2.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =26.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.020 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =13.0 13.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =4.9 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.03 (August 2023) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) SWC Drake-College Inlet A3-2 (R1) MHFD-Inlet_v5.03.xlsm, Inlet A3-2 (R1) 4/7/2025, 12:38 PM Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =2.00 2.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =4.9 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =3.00 3.00 feet Width of a Unit Grate Wo =1.73 1.73 feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =0.43 0.43 Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =0.50 0.50 Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =3.30 3.30 Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =0.60 0.60 Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =3.00 3.00 feet Height of Vertical Curb Opening in Inches Hvert =6.50 6.50 inches Height of Curb Orifice Throat in Inches Hthroat =5.25 5.25 inches Angle of Throat Theta =0.00 0.00 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.70 3.70 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.66 0.66 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =0.43 0.52 ft Depth for Curb Opening Weir Equation dCurb =0.24 0.33 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =0.76 0.94 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =N/A N/A Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =0.76 0.94 MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =2.8 5.1 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =1.3 4.9 cfs CDOT/Denver 13 Combination INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.03 (August 2023) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT/Denver 13 Combination Override Depths MHFD-Inlet_v5.03.xlsm, Inlet A3-2 (R1) 4/7/2025, 12:38 PM Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =2.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK =0.012 Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =24.0 ft Gutter Width W =2.00 ft Street Transverse Slope SX =0.020 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =12.0 12.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =4.6 4.6 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.03 (August 2023) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) SWC Drake-College Inlet B1 (R2) MHFD-Inlet_v5.03.xlsm, Inlet B1 (R2) 4/7/2025, 12:38 PM Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =2.00 2.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =4.6 4.6 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =3.00 3.00 feet Width of a Unit Grate Wo =1.73 1.73 feet Open Area Ratio for a Grate (typical values 0.15-0.90)Aratio =0.43 0.43 Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =0.50 0.50 Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =3.30 3.30 Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =0.60 0.60 Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =3.00 3.00 feet Height of Vertical Curb Opening in Inches Hvert =6.50 6.50 inches Height of Curb Orifice Throat in Inches Hthroat =5.25 5.25 inches Angle of Throat Theta =0.00 0.00 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =2.00 2.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.70 3.70 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.66 0.66 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =0.41 0.41 ft Depth for Curb Opening Weir Equation dCurb =0.22 0.22 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =0.72 0.72 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =N/A N/A Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =0.72 0.72 MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =2.3 2.3 cfs Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak)Q PEAK REQUIRED =0.4 1.6 cfs CDOT/Denver 13 Combination INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.03 (August 2023) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT/Denver 13 Combination Override Depths MHFD-Inlet_v5.03.xlsm, Inlet B1 (R2) 4/7/2025, 12:38 PM