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HomeMy WebLinkAboutKUM & GO #0951 - PDP210013 - DOCUMENT MARKUPS - ROUND 2 - DRAINAGE REPORT PRELIMINARY DRAINAGE REPORT KUM & GO #0 951 FORT COLLINS , CO 949 E PROSPECT RD Prepared for: Kum & Go, L.C. 1459 Grand Avenue Des Moines, IA 50309 Contact: Ryan Halder (515) 457-6232 Prepared by: Olsson 1880 Fall River Drive, Suite 200 Loveland, CO 80538 Contact: Josh Erramouspe, PE (970) 461-7733 June 30, 2021 Olsson Project No. 020-2883 December 2018 Kum & Go #951 Project No. 020-2883 S-1 ENGINEER’S STATEMENT This report and plan for the drainage design for Kum & Go #0951 was prepared by me (or under my direct supervision) and is correct to the best of my knowledge and belief. Said report has been prepare d in accordance with the City of Fort Collins Storm Drainage Criteria. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others. I accept responsibility for any liability caused by any negligent acts, errors, or omissions on my part in preparing this report. Josh Erramouspe Colorado Licensed Professional Engineer No. 42141 Kum & Go #951 Project No. 020-2883 S-2 TABLE OF CONTENTS 1.0 GENERAL LOCATION AND DESCRIPTION ....................................................................... 1 2.0 DRAINAGE BASIN AND SUB-BASINS ................................................................................ 2 3.0 DRAINAGE BASIN CRITERIA ............................................................................................. 4 4.0 DRAINAGE FACILITY DESGIN ........................................................................................... 5 5.0 CONCLUSION ..................................................................................................................... 6 6.0 REFERENCES ..................................................................................................................... 7 APPENDICES APPENDIX A HYDROLOGIC CALCULATIONS APPENDIX B HYDRAULIC CALCULATIONS APPENDIX C REFENECED INFORMATION Kum & Go #951 Project No. 020-2883 1 1.0 GENERAL LOCATION AND DESCRIPTION This document is the Final Drainage Report for Kum & Go #0951 (the “SITE”). The purpose of this report is to identify onsite and offsite drainage patterns, storm sewer, inlet locations, and areas tributary to the site with the goal of safely routing developed storm water runoff to adequate outfall facilities. The proposed project is located within at 949 E Prospect Road, being a portion of the northwest quarter of Section 24, Township 7 North, Range 69 west of the 6th P.M., City of Fort Collins, County of Larimer, State of Colorado. The proposed site is bordered on the north by Prospect Road, on the east by Lemay Avenue, and on the west and south by residential houses. Currently the site consists of a convenience store with two fuel pumps, three single story houses, two garages, a storage shed, and a concrete retaining wall. Development of the site will require demolition of the existing structures, as well as the convenience’s store fuel pumps and concrete retaining wall. The proposed area of improvements is 1.46 acres while the proposed Kum & Go property is to be 1.20 acres. The remainder 0.26 acres is to be for improvements to the adjacent right-of-way along Lemay Avenue and Prospect Road. Based on the NRCS soil survey, the entirety of the soil present on the site is classified as Hydrologic Group C. The site generally slopes away from each of the existing structures. There are curb inlets located adjacent to the property along Prospect Street and Lemay Avenue. Changes to the site grading are proposed to ensure proper drainage around the proposed building and parking lot. These changes will include installation of curb, gutter, concrete paving, storm sewer infrastructure, and an underground detention facility. Per FEMA Map Panel 08069C0983H, dated May 2nd, 2012, the majority of the site is within Zone X, Area of Minimal Flood Hazard. The southern property line and western curb and gutter of Lemay Avenue are within Zone AE, with small portions crossing into the subject property. The proposed building and canopy will both be within Zone X. Kum & Go #951 Project No. 020-2883 2 2.0 DRAINAGE BASIN AND SUB -BASINS Existing Basin Description: In the existing condition, the site drains towards the adjacent streets and is collected by curb inlets and underground storm sewer pipes that convey stormwater to the south towards Spring Creek. Using the rational method, runoff generated within the site’s proposed property line was calculated to be 0.70 cfs and 5.66 cfs for the 2-year and 100-year storm events, respectively. The existing drainage patterns for the land surrounding the property will not be impacted and there will be no drainage routed through the site from the surrounding properties. Proposed Major Basin Description: The proposed area of improvements has been divided into 3 Major Drainage Basins. The first of these Major Basins is the area within the proposed Kum & Go property that will be conveyed to the proposed storm sewer system and underground detention facility. This Major Basin include sub-basins A through K. The second of the Major Basins is the remainder of the area within the proposed Kum & Go property that will not be conveyed to the proposed storm sewer system and undergro und detention facility. This Major Basin is comprised of sub-basin L. The final Major Basin is the remainder of the proposed area of improvements that is not within the proposed Kum & Go property line. This Major Basin is comprised of sub-basin M. A description of each of the sub-basins can be found in the following section. Proposed Sub-Basin Description: Due to proposed changes to the site grading, the overall area of improvements was divided up into 13 drainage sub-basins. These sub-basins can also be found on the Drainage Basin Map in Appendix C. Basin A consists of proposed building roof area. Runoff generated in this basin will be captured by roof drains and conveyed to the proposed storm sewer system and underground detention facility. Basin B consists of proposed canopy area. Runoff generated in this basin will be captured by roof drains and conveyed to the proposed storm sewer system and underground detention facility. Basin C consists of the western portion of the pavement area that will drain south to a proposed curb inlet in the southwest corner of the site. Stormwater collected in this inlet drains to the proposed underground detention facility. Kum & Go #951 Project No. 020-2883 3 Basin D consists of the central portion of the pavement area that will drain south to a proposed curb inlet in the southern curb line. Stormwater collected in this inlet drains to the proposed underground detention facility. Basin E consists of an eastern portion of the pavement area that will drain south to a proposed curb inlet in the eastern curb line. Stormwater collected in this inlet drains to the proposed underground detention facility. Basin F consists of an eastern portion of the pavement area that will drain southeast to a proposed trench in the access drive along the property line. Stormwater collected in this inlet drains to the proposed underground detention facility. Basin G consists of proposed landscape area in the southwestern corner. Runoff generated in the basin will flow overland in a grass swale before being captured by an area inlet and conveyed to the proposed storm sewer system and underground detention facility. Basin H consists of proposed landscape area in the western portion of the property. Runoff generated in the basin will flow overland in a grass swale before being captured by an area inlet and conveyed to the proposed storm sewer system and underground detention facility. Basin I consists of proposed landscape area in the northwestern corner of the site, north of the trash enclosure. Runoff generated in the basin will flow overland in a grass swale before being captured by an area inlet and conveyed to the proposed storm sewer system and underground detention facility. Basin J consists of proposed sidewalk and landscape area along the eastern side of the building. Runoff generated in the basin will be captured by an area inlet and conveyed to the proposed storm sewer system and underground detention facility. Basin K consists of the proposed sidewalk and landscape area adjacent to the western side of the building. Runoff generated in the basin will be captured by a landscape drain and conveyed to the proposed storm sewer system and underground detention facility. Basin L consists of the remainder of the proposed property that will not be detained within the onsite underground storage tanks. This basin consists of landscape area, sidewalks with the property line, and some building sidewalk. Runoff generated in this basin is designed to flow via overland flow and curb and gutter to curb inlets along Prospect Street and Lemay Avenue. Basin M consists of the remainder of the proposed area of improvements that is not within the property line. Runoff generated in this basin is designed to flow via overland flow and curb and gutter to curb inlets along Prospect Street and Lemay Avenue. Kum & Go #951 Project No. 020-2883 4 The calculated runoff generated from each of these basins is as shown below and can also be seen in Appendix A. Basin Q2 (cfs) Q100 (cfs) A 0.20 0.78 B 0.13 0.50 C 0.65 2.42 D 0.25 0.92 E 0.06 0.24 F 0.25 0.95 G 0.00 0.33 H 0.00 0.08 I 0.00 0.09 J 0.00 0.09 K 0.01 0.08 L 0.05 0.67 M 0.52 2.18 Table 1. Proposed Sub-basins 3.0 DRAINAGE BASIN CRITERIA Development Criteria Reference and Constraints: The design of the proposed drainage system was completed in accordance with the criteria set forth Mile High Flood District Criteria Manual and the amendments that pertain to Fort Collins. Hydrological Criteria: Hydrologic calculations have been prepared in accordance with criteria set forth in Mile High Flood District Criteria Manual and the amendments that pertain to the City of Fort Collins. Hydraulic Criteria: Hydraulic calculations have been prepared in accordance with the criteria set forth Mile High Flood District Criteria Manual and the amendments that pertain to the City of Fort Collins. The Mile High Flood District Detention Basin and the ADS StormTech Stage Areas for Colorado MHFD Detention spreadsheet was used to size the underground detention system that will provide water quality treatment and full spectrum detention for the proposed Kum & Go property. Floodplain Regulations Compliance: Portions of the property are located within the FEMA- regulatory, Spring Creek floodplain and must conform to the safety regulations of Chapter 10 of City Municipal Code. Any development in the floodplain must be preceded by an approved floodplain use permit. Modifications of Criteria: There are no proposed modifications to the criteria for this project. Kum & Go #951 Project No. 020-2883 5 4.0 DRAI NAGE FACILITY DESGIN General Concept: In the developed condition, the majority of runoff generated on-site is designed to collected within the underground storage tanks. Runoff will be conveyed via sheet flow and curb and gutter to the storm sewer system. Runoff from the building roof and canopy will be collected and conveyed in roof drains, and runoff from the parking and landscape areas will be conveyed to their respective inlets. 100-year flows entering the storm sewer system will be conveyed to the underground storage system before being discharged at a rate no greater than the historic 2-year runoff rate. Specific Details: Low Impact Design The City of Fort Collins requires Low Impact Design (LID) for new projects. For this project, every effort was made to limit directly connected impervious areas and to route stormwater through landscape areas before in enters the proposed storm sewer system. Flexstorm inserts are also to be placed within inlets to provide additional water quality. The proposed storm sewer system will convey stormwater to an underground detention facility that will be used to treat the majority of the impervious area, excluding the undetained flow outside of the site’s property line. The underground storage system was sized using the Mile High Flood District Detention Basin spreadsheet, in conjunction with the ADS StormTech Stage Areas for Colorado UD Detention spreadsheet. See Appendix B for the MHFD and the ADS StormTech spreadsheets and Table 2 below for more details on the underground storage system. Minimum Required Storage Volume Water quality and runoff attenuation for the site will be provided in the underground detention facility. Calculations for the required storage volume was completed using the City of Collins FAA Method spreadsheet. This method resulted in a required detention of 10,329 cubic feet (0.237 acre-feet). Using the Mile High Flood District Detention Basin and Outlet spreadsheet, it was found that the facility would only reach a maximum storage volume of 7,335 cubic feet (0.168 acre-feet) within the 100-year storm. The outlet structure’s weir will provide emergency overflow for any flows greater than the 100-year storm. The underground detention facility has been sized to this maximum storage volume, as the City of Collins FAA Method required the facility to be oversized by roughly 3,000 cubic feet of volume that would never be utilized in any scenario. The calculations from these spreadsheets can be seen in Appendix B. Table 2 below highlights the maximum and provided volumes and release rates of the underground detention facility. Kum & Go #951 Project No. 020-2883 6 100-Year Maximum Storage Volume (AC-FT) 0.168 Provided Storage Volume (AC-FT) 0.178 Allowable Release Rate (CFS) 0.03 Provided Release Rate (CFS) 0.03 Table 2. Underground Detention Parameters Outlet Structure and Spillway The outlet structure is designed to release the 100-year volume at, or below, the site’s historic 2- year runoff rate of 0.7 cfs minus the rate of undetained flow leaving the site, as represented by sub-basin L. This undetained flow has a 100-year flowrate of 0.67 cfs, therefore allowing the outlet structure to discharge at a rate of 0.03 cfs. The outlet structure will be comprised of a 4-foot diameter concrete manhole with a weir and orifice plate covering a cutout at the bottom portion of the weir. The orifice plate contains a single orifice to control the WQCV release rate with its invert at the base of stone elevation of the underground detention facility. A second orifice is location nine inches above the WQCV orifice invert and controls the minor and major storm event release rates. Emergency overflow for the detention is provided by the weir within the outlet structure, as the top of the weir is set above the 100-year water surface elevation. See appendix B for more details on the design and calculations of the outlet structure. 5.0 CONCLUSION This report has been prepared in accordance with common engineering practices, the criteria set forth Mile High Flood District Criteria Manual and the amendments that pertain to City of Fort Collins. Developed runoff generated on the proposed site will be directed to the underground detention system located underneath the proposed pavement area. The outlet structure is designed to release the 100-year volume at rate of 0.03 cfs in order to meet the site’s 2-year historic runoff rate of 0.70 cfs. These outfall calculations can be found in Appendix B. Kum & Go #951 Project No. 020-2883 7 6.0 REFERENCES Mile High Flood District Criteria Manual, Volume 1 August 2018, Volume 2 September 2017, and Volume 3 November 2010. Fort Collins Amendments to Mile High Flood District Criteria Manual dated December 2011 APPENDIX A HYDROLOGIC CALCULATIONS Kum & Go #951Hydrologic Calculations1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733 APPENDIX B HYDRAULIC CALCULATIONS 100 Year This is to convert % imp. to a C value 100-year (must insert % imp. and C pervious). ft3 acre-ft. 'C' value 0.82 10329.4 0.237 'C' * 1.25 1.00 Area 0.796 acres Modified Modified Release Rate 0.03 M. FATER D. JUDISH C. LI May-95 Nov-97 Nov-98 DETENTION POND SIZING TIME TIME INTENSITY Q 100 Runoff Release Required Required cum 100 year Volume Cum total Detention Detention (mins) (secs) (in/hr) (cfs) (ft^3) (ft^3) (ft^3) (ac-ft) 0 0 0 0.00 0 0.0 0.0 0.0000 5 300 9.950 7.92 2376.06 9.0 2367.1 0.0543 10 600 7.720 6.15 3687.072 18.0 3669.1 0.0842 15 900 6.520 5.19 4670.928 27.0 4643.9 0.1066 20 1200 5.600 4.46 5349.12 36.0 5313.1 0.1220 25 1500 4.980 3.96 5946.12 45.0 5901.1 0.1355 30 1800 4.520 3.60 6476.256 54.0 6422.3 0.1474 35 2100 4.080 3.25 6820.128 63.0 6757.1 0.1551 40 2400 3.740 2.98 7144.896 72.0 7072.9 0.1624 45 2700 3.460 2.75 7436.232 81.0 7355.2 0.1689 50 3000 3.230 2.57 7713.24 90.0 7623.2 0.1750 55 3300 3.030 2.41 7959.204 99.0 7860.2 0.1804 60 3600 2.860 2.28 8195.616 108.0 8087.6 0.1857 65 3900 2.720 2.17 8443.968 117.0 8327.0 0.1912 70 4200 2.590 2.06 8658.888 126.0 8532.9 0.1959 75 4500 2.480 1.97 8883.36 135.0 8748.4 0.2008 80 4800 2.380 1.89 9093.504 144.0 8949.5 0.2055 85 5100 2.290 1.82 9296.484 153.0 9143.5 0.2099 90 5400 2.210 1.76 9499.464 162.0 9337.5 0.2144 95 5700 2.130 1.70 9664.236 171.0 9493.2 0.2179 100 6000 2.060 1.64 9838.56 180.0 9658.6 0.2217 105 6300 2.000 1.59 10029.6 189.0 9840.6 0.2259 110 6600 1.940 1.54 10191.98 198.0 9994.0 0.2294 115 6900 1.890 1.50 10380.64 207.0 10173.6 0.2336 120 7200 1.840 1.46 10545.41 216.0 10329.4 0.2371 125 7500 1.790 1.42 10686.3 225.0 10461.3 0.2402 130 7800 1.750 1.39 10865.4 234.0 10631.4 0.2441 135 8100 1.710 1.36 11025.4 243.0 10782.4 0.2475 140 8400 1.670 1.33 11166.29 252.0 10914.3 0.2506 145 8700 1.630 1.30 11288.08 261.0 11027.1 0.2531 150 9000 1.600 1.27 11462.4 270.0 11192.4 0.2569 155 9300 1.570 1.25 11622.4 279.0 11343.4 0.2604 160 9600 1.540 1.23 11768.06 288.0 11480.1 0.2635 165 9900 1.510 1.20 11899.4 297.0 11602.4 0.2664 170 10200 1.480 1.18 12016.42 306.0 11710.4 0.2688 175 10500 1.450 1.15 12119.1 315.0 11804.1 0.2710 180 10800 1.420 1.13 12207.46 324.0 11883.5 0.2728 185 11100 1.400 1.11 12369.84 333.0 12036.8 0.2763 190 11400 1.380 1.10 12522.67 342.0 12180.7 0.2796 195 11700 1.360 1.08 12665.95 351.0 12315.0 0.2827 200 12000 1.340 1.07 12799.68 360.0 12439.7 0.2856 205 12300 1.320 1.05 12923.86 369.0 12554.9 0.2882 210 12600 1.300 1.03 13038.48 378.0 12660.5 0.2906 215 12900 1.280 1.02 13143.55 387.0 12756.6 0.2929 220 13200 1.260 1.00 13239.07 396.0 12843.1 0.2948 225 13500 1.240 0.99 13325.04 405.0 12920.0 0.2966 230 13800 1.220 0.97 13401.46 414.0 12987.5 0.2982 235 14100 1.210 0.96 13580.56 423.0 13157.6 0.3021 240 14400 1.200 0.96 13754.88 432.0 13322.9 0.3059 Required detention Page 1 Project: Basin ID: Depth Increment = ft Watershed Information Top of Micropool -- 0.00 -- -- -- 1,284 0.029 Selected BMP Type =EDB -- 0.08 -- -- -- 1,284 0.029 103 0.002 Watershed Area = 0.79 acres -- 0.17 -- -- -- 1,284 0.029 218 0.005 Watershed Length = 250 ft -- 0.25 -- -- -- 1,284 0.029 321 0.007 Watershed Length to Centroid = 100 ft -- 0.33 -- -- -- 1,284 0.029 424 0.010 Watershed Slope = 0.010 ft/ft -- 0.42 -- -- -- 1,284 0.029 539 0.012 Watershed Imperviousness = 82.40% percent -- 0.50 -- -- -- 1,284 0.029 642 0.015 Percentage Hydrologic Soil Group A = 0.0% percent -- 0.58 -- -- -- 2,794 0.064 805 0.018 Percentage Hydrologic Soil Group B = 0.0% percent -- 0.67 -- -- -- 2,788 0.064 1,056 0.024 Percentage Hydrologic Soil Groups C/D = 100.0% percent -- 0.75 -- -- -- 2,774 0.064 1,279 0.029 Target WQCV Drain Time = 40.0 hours -- 0.83 -- -- -- 2,758 0.063 1,500 0.034 Location for 1-hr Rainfall Depths = User Input -- 0.92 -- -- -- 2,743 0.063 1,748 0.040 -- 1.00 -- -- -- 2,724 0.063 1,966 0.045 -- 1.08 -- -- -- 2,704 0.062 2,183 0.050 Optional User Overrides -- 1.17 -- -- -- 2,683 0.062 2,426 0.056 Water Quality Capture Volume (WQCV) = 0.023 acre-feet acre-feet -- 1.25 -- -- -- 2,659 0.061 2,640 0.061 Excess Urban Runoff Volume (EURV) = 0.064 acre-feet acre-feet -- 1.33 -- -- -- 2,635 0.060 2,851 0.065 2-yr Runoff Volume (P1 = 0.82 in.) = 0.039 acre-feet 0.82 inches -- 1.42 -- -- -- 2,607 0.060 3,087 0.071 5-yr Runoff Volume (P1 = 1.09 in.) = 0.055 acre-feet inches -- 1.50 -- -- -- 2,579 0.059 3,295 0.076 10-yr Runoff Volume (P1 = 1.33 in.) = 0.070 acre-feet inches -- 1.58 -- -- -- 2,553 0.059 3,500 0.080 25-yr Runoff Volume (P1 = 1.69 in.) = 0.095 acre-feet inches -- 1.67 -- -- -- 2,518 0.058 3,728 0.086 50-yr Runoff Volume (P1 = 1.99 in.) = 0.114 acre-feet inches -- 1.75 -- -- -- 2,483 0.057 3,928 0.090 100-yr Runoff Volume (P1 = 2.86 in.) = 0.172 acre-feet 2.86 inches -- 1.83 -- -- -- 2,447 0.056 4,125 0.095 500-yr Runoff Volume (P1 = 3.14 in.) = 0.191 acre-feet inches -- 1.92 -- -- -- 2,408 0.055 4,344 0.100 Approximate 2-yr Detention Volume = 0.040 acre-feet -- 2.00 -- -- -- 2,367 0.054 4,535 0.104 Approximate 5-yr Detention Volume = 0.057 acre-feet -- 2.08 -- -- -- 2,327 0.053 4,723 0.108 Approximate 10-yr Detention Volume = 0.069 acre-feet -- 2.17 -- -- -- 2,279 0.052 4,930 0.113 Approximate 25-yr Detention Volume = 0.081 acre-feet -- 2.25 -- -- -- 2,211 0.051 5,110 0.117 Approximate 50-yr Detention Volume = 0.087 acre-feet -- 2.33 -- -- -- 2,150 0.049 5,284 0.121 Approximate 100-yr Detention Volume = 0.118 acre-feet -- 2.42 -- -- -- 2,092 0.048 5,475 0.126 -- 2.50 -- -- -- 2,019 0.046 5,639 0.129 Define Zones and Basin Geometry -- 2.58 -- -- -- 1,935 0.044 5,798 0.133 Zone 1 Volume (WQCV) = 0.023 acre-feet -- 2.67 -- -- -- 1,833 0.042 5,967 0.137 Zone 2 Volume (2-year - Zone 1) = 0.017 acre-feet -- 2.75 -- -- -- 1,698 0.039 6,108 0.140 Zone 3 Volume (100-year - Zones 1 & 2) = 0.078 acre-feet -- 2.83 -- -- -- 1,477 0.034 6,235 0.143 Total Detention Basin Volume = 0.118 acre-feet -- 2.92 -- -- -- 1,396 0.032 6,365 0.146 Initial Surcharge Volume (ISV) = user ft 3 -- 3.00 -- -- -- 1,322 0.030 6,473 0.149 Initial Surcharge Depth (ISD) = user ft -- 3.08 -- -- -- 1,284 0.029 6,578 0.151 Total Available Detention Depth (Htotal) = user ft -- 3.17 -- -- -- 1,284 0.029 6,693 0.154 Depth of Trickle Channel (HTC) =user ft -- 3.25 -- -- -- 1,284 0.029 6,796 0.156 Slope of Trickle Channel (STC) = user ft/ft -- 3.33 -- -- -- 1,284 0.029 6,899 0.158 Slopes of Main Basin Sides (Smain) = user H:V -- 3.42 -- -- -- 1,284 0.029 7,014 0.161 Basin Length-to-Width Ratio (RL/W) = user -- 3.50 -- -- -- 1,284 0.029 7,117 0.163 -- 3.58 -- -- -- 1,284 0.029 7,220 0.166 Initial Surcharge Area (AISV) =user ft 2 -- 3.67 -- -- -- 1,284 0.029 7,335 0.168 Surcharge Volume Length (LISV) =user ft -- 3.75 -- -- -- 1,284 0.029 7,438 0.171 Surcharge Volume Width (WISV) =user ft -- 3.83 -- -- -- 1,284 0.029 7,541 0.173 Depth of Basin Floor (HFLOOR) =user ft -- 3.92 -- -- -- 1,284 0.029 7,656 0.176 Length of Basin Floor (LFLOOR) =user ft -- 4.00 -- -- -- 1,284 0.029 7,759 0.178 Width of Basin Floor (WFLOOR) =user ft -- -- -- -- Area of Basin Floor (AFLOOR) =user ft 2 -- -- -- -- Volume of Basin Floor (VFLOOR) =user ft 3 -- -- -- -- Depth of Main Basin (HMAIN) =user ft -- -- -- -- Length of Main Basin (LMAIN) =user ft -- -- -- -- Width of Main Basin (WMAIN) =user ft -- -- -- -- Area of Main Basin (AMAIN) =user ft 2 -- -- -- -- Volume of Main Basin (VMAIN) =user ft 3 -- -- -- -- Calculated Total Basin Volume (Vtotal) =user acre-feet -- -- -- -- DETENTION BASIN STAGE-STORAGE TABLE BUILDER Optional Override Area (ft 2) Length (ft) Optional Override Stage (ft) Stage (ft) Stage - Storage Description Area (ft 2) Width (ft) MHFD-Detention, Version 4.04 (February 2021) Volume (ft 3) Volume (ac-ft) Area (acre) After providing required inputs above including 1-hour rainfall depths, click 'Run CUHP' to generate runoff hydrographs using the embedded Colorado Urban Hydrograph Procedure. Example Zone Configuration (Retention Pond) MHFD-Detention_v4 04.xlsm, Basin 6/30/2021, 10:36 AM Project: Basin ID: Estimated Estimated Stage (ft) Volume (ac-ft) Outlet Type Zone 1 (WQCV) 0.65 0.023 Orifice Plate Zone 2 (2-year) 0.93 0.017 Circular Orifice Zone 3 (100-year) 2.26 0.078 Weir (No Pipe) Total (all zones) 0.118 User Input: Orifice at Underdrain Outlet (typically used to drain WQCV in a Filtration BMP)Calculated Parameters for Underdrain Underdrain Orifice Invert Depth = N/A ft (distance below the filtration media surface) Underdrain Orifice Area = N/A ft2 Underdrain Orifice Diameter = N/A inches Underdrain Orifice Centroid = N/A feet User Input: Orifice Plate with one or more orifices or Elliptical Slot Weir (typically used to drain WQCV and/or EURV in a sedimentation BMP)Calculated Parameters for Plate Invert of Lowest Orifice = 0.00 ft (relative to basin bottom at Stage = 0 ft) WQ Orifice Area per Row = 3.068E-03 ft2 Depth at top of Zone using Orifice Plate = 0.66 ft (relative to basin bottom at Stage = 0 ft) Elliptical Half-Width = N/A feet Orifice Plate: Orifice Vertical Spacing = N/A inches Elliptical Slot Centroid = N/A feet Orifice Plate: Orifice Area per Row = 0.44 sq. inches (diameter = 3/4 inch)Elliptical Slot Area = N/A ft2 User Input: Stage and Total Area of Each Orifice Row (numbered from lowest to highest) Row 1 (required) Row 2 (optional) Row 3 (optional) Row 4 (optional) Row 5 (optional) Row 6 (optional) Row 7 (optional) Row 8 (optional) Stage of Orifice Centroid (ft) 0.00 Orifice Area (sq. inches) 0.44 Row 9 (optional) Row 10 (optional) Row 11 (optional) Row 12 (optional) Row 13 (optional) Row 14 (optional) Row 15 (optional) Row 16 (optional) Stage of Orifice Centroid (ft) Orifice Area (sq. inches) User Input: Vertical Orifice (Circular or Rectangular)Calculated Parameters for Vertical Orifice Zone 2 Circular Not Selected Zone 2 Circular Not Selected Invert of Vertical Orifice = 0.75 N/A ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Area = 0.00 N/A ft2 Depth at top of Zone using Vertical Orifice = 0.72 N/A ft (relative to basin bottom at Stage = 0 ft) Vertical Orifice Centroid = 0.02 N/A feet Vertical Orifice Diameter = 0.38 N/A inches User Input: Overflow Weir (Dropbox with Flat or Sloped Grate and Outlet Pipe OR Rectangular/Trapezoidal Weir (and No Outlet Pipe) Calculated Parameters for Overflow Weir weir Zone 3 Weir Not Selected Zone 3 Weir Not Selected Overflow Weir Front Edge Height, Ho = 3.75 N/A ft (relative to basin bottom at Stage = 0 ft)Height of Grate Upper Edge, Ht =N/A N/A feet Overflow Weir Bottom Length = 3.83 N/A feet Overflow Weir Slope Length = N/A N/A feet Overflow Weir Side Slopes = 0.00 N/A H:V Grate Open Area / 100-yr Orifice Area = N/A N/A Horiz. Length of Weir Sides = N/A N/A feet Overflow Grate Open Area w/o Debris = N/A N/A ft2 Overflow Grate Type = N/A N/A Overflow Grate Open Area w/ Debris = N/A N/A ft2 Debris Clogging % = N/A N/A % User Input: Outlet Pipe w/ Flow Restriction Plate (Circular Orifice, Restrictor Plate, or Rectangular Orifice)Calculated Parameters for Outlet Pipe w/ Flow Restriction Plate Not Selected Not Selected Not Selected Not Selected Depth to Invert of Outlet Pipe = N/A N/A ft (distance below basin bottom at Stage = 0 ft)Outlet Orifice Area = N/A N/A ft2 Circular Orifice Diameter = N/A N/A inches Outlet Orifice Centroid = N/A N/A feet Half-Central Angle of Restrictor Plate on Pipe = N/A N/A radians User Input: Emergency Spillway (Rectangular or Trapezoidal)Calculated Parameters for Spillway Spillway Invert Stage= ft (relative to basin bottom at Stage = 0 ft) Spillway Design Flow Depth= feet Spillway Crest Length = feet Stage at Top of Freeboard = feet Spillway End Slopes = H:V Basin Area at Top of Freeboard = acres Freeboard above Max Water Surface = feet Basin Volume at Top of Freeboard = acre-ft Spillway position relative to Overflow Weir = Max Ponding Depth of Target Storage Volume =3.64 feet Discharge at Top of Freeboard = cfs Routed Hydrograph Results Design Storm Return Period =WQCV EURV 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year 500 Year One-Hour Rainfall Depth (in) =N/A N/A 0.82 1.09 1.33 1.69 1.99 2.86 3.14 CUHP Runoff Volume (acre-ft) =0.023 0.064 0.039 0.055 0.070 0.095 0.114 0.172 0.191 Inflow Hydrograph Volume (acre-ft) =N/A N/A 0.039 0.055 0.070 0.095 0.114 0.172 0.191 CUHP Predevelopment Peak Q (cfs) =N/A N/A 0.0 0.1 0.2 0.5 0.7 1.4 1.6 OPTIONAL Override Predevelopment Peak Q (cfs) =N/A N/A Predevelopment Unit Peak Flow, q (cfs/acre) =N/A N/A 0.01 0.10 0.27 0.69 0.95 1.75 1.99 Peak Inflow Q (cfs) =N/A N/A 0.7 1.0 1.3 1.8 2.1 3.2 3.6 Peak Outflow Q (cfs) =0.01 0.02 0.01 0.02 0.02 0.02 0.03 0.03 0.30 Ratio Peak Outflow to Predevelopment Q =N/A N/A N/A 0.2 0.1 0.0 0.0 0.0 0.2 Structure Controlling Flow =Plate Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Vertical Orifice 1 Overflow Weir 1 Max Velocity through Grate 1 (fps) =N/A N/A N/A N/A N/A N/A N/A N/A N/A Max Velocity through Grate 2 (fps) =N/A N/A N/A N/A N/A N/A N/A N/A N/A Time to Drain 97% of Inflow Volume (hours) =36 62 49 58 66 77 86 105 105 Time to Drain 99% of Inflow Volume (hours) =39 68 53 63 72 84 92 114 114 Maximum Ponding Depth (ft) =0.66 1.31 0.87 1.12 1.36 1.77 2.12 3.64 3.83 Area at Maximum Ponding Depth (acres) =0.06 0.06 0.06 0.06 0.06 0.06 0.05 0.03 0.03 Maximum Volume Stored (acre-ft) =0.024 0.064 0.037 0.052 0.067 0.091 0.110 0.167 0.173 The user can override the default CUHP hydrographs and runoff volumes by entering new values in the Inflow Hydrographs table (Columns W through AF). DETENTION BASIN OUTLET STRUCTURE DESIGN MHFD-Detention, Version 4.04 (February 2021) Example Zone Configuration (Retention Pond) MHFD-Detention_v4 04.xlsm, Outlet Structure 6/30/2021, 10:54 AM COUNTA for Basin Tab = 1 Ao Dia WQ Plate Type Vert Orifice 1Vert Orifice 2 Count_Underdrain = 0 0.11(diameter = 3/8 inch)2 2 1 Count_WQPlate = 1 0.14(diameter = 7/16 inch) Count_VertOrifice1 = 1 0.18(diameter = 1/2 inch)Outlet Plate 1 Outlet Plate 2 Drain Time Message Boolean Count_VertOrifice2 = 0 0.24(diameter = 9/16 inch)1 1 5yr, <72hr 0 Count_Weir1 = 1 0.29(diameter = 5/8 inch)>5yr, <120hr 0 Count_Weir2 = 0 0.36(diameter = 11/16 inch)Max Depth Row Count_OutletPipe1 = 0 0.42(diameter = 3/4 inch)WQCV 67 Watershed Constraint Check Count_OutletPipe2 = 0 0.50(diameter = 13/16 inch)2 Year 88 Slope 0.010 COUNTA_2 (Standard FSD Setup)= 0 0.58(diameter = 7/8 inch)EURV 132 Shape 1.81 Hidden Parameters & Calculations 0.67(diameter = 15/16 inch)5 Year 113 MaxPondDepth_Error? FALSE 0.76 (diameter = 1 inch)10 Year 137 Spillway Depth Cd_Broad-Crested Weir 3.00 0.86(diameter = 1-1/16 inches)25 Year 178 WQ Plate Flow at 100yr depth = 0.03 0.97(diameter = 1-1/8 inches)50 Year 213 CLOG #1= N/A 1.08(diameter = 1-3/16 inches)100 Year 365 1 Z1_Boolean n*Cdw #1 = #VALUE! 1.20(diameter = 1-1/4 inches)500 Year 384 1 Z2_Boolean n*Cdo #1 = #VALUE! 1.32(diameter = 1-5/16 inches)Zone3_Pulldown Message 1 Z3_Boolean Overflow Weir #1 Angle = 0.000 1.45(diameter = 1-3/8 inches)1 Opening Message CLOG #2= N/A 1.59(diameter = 1-7/16 inches)Draintime Running n*Cdw #2 = N/A 1.73(diameter = 1-1/2 inches)Outlet Boolean Outlet Rank Total (1 to 4) n*Cdo #2 = N/A 1.88(diameter = 1-9/16 inches)Vertical Orifice 1 1 1 2 Overflow Weir #2 Angle = N/A 2.03(diameter = 1-5/8 inches)Vertical Orifice 2 0 0 Boolean Underdrain Q at 100yr depth = 0.00 2.20(diameter = 1-11/16 inches)Overflow Weir 1 1 2 0 Max Depth VertOrifice1 Q at 100yr depth = 0.01 2.36(diameter = 1-3/4 inches)Overflow Weir 2 0 0 0 500yr Depth VertOrifice2 Q at 100yr depth = 0.00 2.54(diameter = 1-13/16 inches)Outlet Pipe 1 0 0 0 Freeboard 2.72(diameter = 1-7/8 inches)Outlet Pipe 2 0 0 0 Spillway Count_User_Hydrographs 0 2.90(diameter = 1-15/16 inches)0 Spillway Length CountA_3 (EURV & 100yr) = 0 3.09(diameter = 2 inches)FALSE Time Interval CountA_4 (100yr Only) = 0 3.29(use rectangular openings)Button Visibility Boolean COUNTA_5 (FSD Weir Only)= 1 0 WQCV Underdrain COUNTA_6 (EURV Weir Only)= 1 1 WQCV Plate 0 EURV-WQCV Plate Outlet1_Pulldown_Boolean 0 EURV-WQCV VertOriice Outlet2_Pulldown_Boolean 0 Outlet 90% Qpeak Outlet3_Pulldown_Boolean 0 Outlet Undetained 0 Weir Only 90% Qpeak 0 Five Year Ratio Plate 0 Five Year Ratio VertOrifice EURV_draintime_user Spillway Options Offset Overlapping Overflow Weir 1 S-A-V-D Chart Axis Default X-axis Left Y-Axis Right Y-Axis minimum bound 0.00 0 0 maximum bound 4.00 10,000 10 S-A-V-D Chart Axis Override X-axis Left Y-Axis Right Y-Axis minimum bound maximum bound MHFD-Detention, Version 4.04 (February 2021) DETENTION BASIN OUTLET STRUCTURE DESIGN 0 0.5 1 1.5 2 2.5 3 3.5 4 0.1 1 10FLOW [cfs]TIME [hr] 500YR IN 500YR OUT 100YR IN 100YR OUT 50YR IN 50YR OUT 25YR IN 25YR OUT 10YR IN 10YR OUT 5YR IN 5YR OUT 2YR IN 2YR OUT EURV IN EURV OUT WQCV IN WQCV OUT 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0.1 1 10 100PONDING DEPTH [ft]DRAIN TIME [hr] 500YR 100YR 50YR 25YR 10YR 5YR 2YR EURV WQCV 0 1 2 3 4 5 6 7 8 9 10 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 OUTFLOW [cfs]AREA [ft^2], VOLUME [ft^3]PONDING DEPTH [ft] User Area [ft^2] Interpolated Area [ft^2] Summary Area [ft^2] Volume [ft^3] Summary Volume [ft^3] Outflow [cfs] Summary Outflow [cfs] MHFD-Detention_v4 04.xlsm, Outlet Structure 6/30/2021, 10:54 AM Outflow Hydrograph Workbook Filename: Inflow Hydrographs The user can override the calculated inflow hydrographs from this workbook with inflow hydrographs developed in a separate program. SOURCE CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP CUHP Time Interval TIME WQCV [cfs] EURV [cfs] 2 Year [cfs] 5 Year [cfs] 10 Year [cfs] 25 Year [cfs] 50 Year [cfs] 100 Year [cfs] 500 Year [cfs] 5.00 min 0:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.06 0:15:00 0.00 0.00 0.04 0.13 0.19 0.15 0.21 0.31 0.36 0:20:00 0.00 0.00 0.32 0.46 0.57 0.40 0.50 0.74 0.83 0:25:00 0.00 0.00 0.69 0.97 1.24 0.87 1.07 1.57 1.76 0:30:00 0.00 0.00 0.75 1.02 1.27 1.75 2.12 3.10 3.43 0:35:00 0.00 0.00 0.63 0.85 1.05 1.74 2.10 3.23 3.56 0:40:00 0.00 0.00 0.52 0.69 0.85 1.55 1.86 2.83 3.12 0:45:00 0.00 0.00 0.40 0.55 0.69 1.27 1.52 2.40 2.64 0:50:00 0.00 0.00 0.33 0.47 0.57 1.07 1.28 1.99 2.19 0:55:00 0.00 0.00 0.27 0.38 0.47 0.85 1.02 1.64 1.81 1:00:00 0.00 0.00 0.22 0.31 0.39 0.69 0.83 1.38 1.53 1:05:00 0.00 0.00 0.18 0.26 0.33 0.56 0.67 1.17 1.29 1:10:00 0.00 0.00 0.15 0.23 0.31 0.43 0.51 0.85 0.94 1:15:00 0.00 0.00 0.13 0.21 0.30 0.36 0.44 0.67 0.74 1:20:00 0.00 0.00 0.12 0.19 0.27 0.30 0.36 0.50 0.56 1:25:00 0.00 0.00 0.12 0.18 0.24 0.26 0.31 0.40 0.44 1:30:00 0.00 0.00 0.11 0.17 0.21 0.22 0.26 0.33 0.37 1:35:00 0.00 0.00 0.11 0.16 0.19 0.19 0.23 0.29 0.32 1:40:00 0.00 0.00 0.11 0.14 0.18 0.18 0.21 0.26 0.29 1:45:00 0.00 0.00 0.11 0.13 0.18 0.17 0.20 0.24 0.27 1:50:00 0.00 0.00 0.11 0.12 0.17 0.16 0.19 0.24 0.26 1:55:00 0.00 0.00 0.09 0.12 0.16 0.16 0.19 0.23 0.26 2:00:00 0.00 0.00 0.08 0.11 0.14 0.16 0.19 0.23 0.26 2:05:00 0.00 0.00 0.05 0.07 0.09 0.10 0.12 0.15 0.17 2:10:00 0.00 0.00 0.03 0.04 0.06 0.07 0.08 0.10 0.11 2:15:00 0.00 0.00 0.02 0.03 0.04 0.04 0.05 0.06 0.07 2:20:00 0.00 0.00 0.01 0.02 0.02 0.03 0.03 0.04 0.04 2:25:00 0.00 0.00 0.01 0.01 0.01 0.02 0.02 0.02 0.03 2:30:00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 2:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:05:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:10:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:15:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:20:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:25:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:30:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:35:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:40:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:45:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:50:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5:55:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6:00:00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 DETENTION BASIN OUTLET STRUCTURE DESIGN MHFD-Detention_v4 04.xlsm, Outlet Structure 6/30/2021, 10:54 AM Weir Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Wednesday, Jun 30 2021 <Name> Rectangular Weir Crest = Sharp Bottom Length (ft) = 3.83 Total Depth (ft) = 1.00 Calculations Weir Coeff. Cw = 3.33 Compute by: Known Q Known Q (cfs) = 6.49 Highlighted Depth (ft) = 0.64 Q (cfs) = 6.490 Area (sqft) = 2.44 Velocity (ft/s) = 2.66 Top Width (ft) = 3.83 0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5 Depth (ft)Depth (ft)<Name> -0.50 -0.50 0.00 0.00 0.50 0.50 1.00 1.00 1.50 1.50 2.00 2.00 Length (ft)Weir W.S. Project: Chamber Model - SC-740 Units -Imperial 160 Number of chambers - 95 Voids in the stone (porosity) - 40 % Base of Stone Elevation - 44.75 ft Amount of Stone Above Chambers - 12 in Amount of Stone Below Chambers - 6 in Area of system -3211 sf Min. Area - Height of System Incremental Single Chamber Incremental Total Chamber Incremental Stone Incremental Ch & St Cumulative Chamber Elevation (inches)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(cubic feet)(feet) 48 0.00 0.00 107.03 107.03 7756.80 48.75 47 0.00 0.00 107.03 107.03 7649.76 48.67 46 0.00 0.00 107.03 107.03 7542.73 48.58 45 0.00 0.00 107.03 107.03 7435.70 48.50 44 0.00 0.00 107.03 107.03 7328.66 48.42 43 0.00 0.00 107.03 107.03 7221.63 48.33 42 0.00 0.00 107.03 107.03 7114.60 48.25 41 0.00 0.00 107.03 107.03 7007.56 48.17 40 0.00 0.00 107.03 107.03 6900.53 48.08 39 0.00 0.00 107.03 107.03 6793.50 48.00 38 0.00 0.00 107.03 107.03 6686.46 47.92 37 0.00 0.00 107.03 107.03 6579.43 47.83 36 0.05 5.22 104.94 110.17 6472.40 47.75 35 0.16 15.48 100.84 116.32 6362.23 47.67 34 0.28 26.78 96.32 123.10 6245.91 47.58 33 0.60 57.38 84.08 141.46 6122.81 47.50 32 0.80 76.16 76.57 152.73 5981.35 47.42 31 0.95 90.31 70.91 161.22 5828.62 47.33 30 1.07 102.08 66.20 168.28 5667.39 47.25 29 1.18 112.15 62.17 174.32 5499.11 47.17 28 1.27 120.24 58.94 179.18 5324.79 47.08 27 1.36 128.73 55.54 184.27 5145.62 47.00 26 1.45 138.14 51.78 189.92 4961.35 46.92 25 1.52 144.85 49.09 193.94 4771.43 46.83 24 1.58 150.32 46.90 197.23 4577.49 46.75 23 1.64 156.02 44.63 200.64 4380.26 46.67 22 1.70 161.45 42.45 203.91 4179.62 46.58 21 1.75 166.53 40.42 206.95 3975.71 46.50 20 1.80 171.27 38.53 209.79 3768.76 46.42 19 1.85 176.22 36.54 212.77 3558.97 46.33 18 1.89 179.84 35.10 214.94 3346.20 46.25 17 1.93 183.73 33.54 217.27 3131.26 46.17 16 1.97 187.62 31.98 219.61 2913.99 46.08 15 2.01 190.94 30.66 221.60 2694.38 46.00 14 2.04 194.27 29.32 223.60 2472.78 45.92 13 2.07 197.12 28.18 225.31 2249.18 45.83 12 2.10 199.97 27.05 227.01 2023.88 45.75 11 2.13 202.52 26.03 228.55 1796.87 45.67 10 2.15 204.62 25.19 229.80 1568.32 45.58 9 2.18 206.82 24.31 231.13 1338.52 45.50 8 2.20 208.84 23.50 232.34 1107.39 45.42 7 2.21 209.70 23.15 232.85 875.05 45.33 6 0.00 0.00 107.03 107.03 642.20 45.25 5 0.00 0.00 107.03 107.03 535.17 45.17 4 0.00 0.00 107.03 107.03 428.13 45.08 3 0.00 0.00 107.03 107.03 321.10 45.00 2 0.00 0.00 107.03 107.03 214.07 44.92 1 0.00 0.00 107.03 107.03 107.03 44.83 StormTech SC-740 Cumulative Storage Volumes 3211 sf min. area Include Perimeter Stone in Calculations Click Here for Metric 3130 Verona Avenue • Buford, GA 30518 (866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490 © Nyloplast Inlet Capacity Charts June 2012 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10Capacity (cfs)Head (ft) Nyloplast 8" Dome Grate Inlet Capacity Chart 0.09 0.08 0.33 0.050 0.052 0.102 Inlets P1, O4 Inlet I3 Inlets K1, M2 3130 Verona Avenue • Buford, GA 30518 (866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490 © Nyloplast Inlet Capacity Charts June 2012 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10Capacity (cfs)Head (ft) Nyloplast 2' x 3' Curb Inlet High Flow Grate Inlet Capacity Chart High Hood Setting (8.47" Curb Setting) Mid Hood Setting (6.47" Curb Setting) Low Hood Setting (4.47" Curb Setting) 2.42 Inlet I2 0.92 0.24 0.050 0.050 0.050 Inlet O1 Inlet A Dura Trench Components Selection: Reference: Dura Trench Website, Selecting Channel Drain Components, https://www.duratrench.com/trench-drain-system-components Grate Selection: Channel Selection: Per Rational Calculations, the flow entering the trench drain (Sub-basin F) will be around 0.95 cfs for the hundred year storm: Per Dura Trench, Grate Open Area is defined as: A = Q / (Cd * (2*g*h)^0.5) A = 0.95cfs / (0.6 * (2* 32.2ft/sec/sec * 0.01ft)^0.5) A = 1.97 sqft = 284 sq in Where: A is opening area of drain system in sqft Q is the flow rate to b captured in cfs Cd is a discharge coefficient of 0.6 g is the gravitational constant (32.2 ft/s/s) h is the head in ft The proposed trench drain has a total of length of 42.31 ft OA = A / L = 284sq in / 42.31 ft = 6.72sq in/ft The proposed 12C24DG (12" Heel Guard Ductile Iron Grate) grate provides an OA=56.1sq in/ft The proposed 10" Precast Trench Drain, sloping 0.5%, can withstand 1.27 cfs at the minimum available depth of 7 inches Conclusions: The components of the trench drain proposed within the plans for Kum & Go 951 will be adequate to handle the flow it will be require to capture. The proposed components are as described: The Grate shall be a 12" Heel Guard Ductile Iron Grate (Dura Trench part number 12C24DG) The Channel shall be a 10" Precast Trench Drain with a 7" depth and sloped at 0.5%. (Dura Trench part number DTPF10-HDGS15ZPA) APPENDIX C REFERENCED INFORMATION VICINITY MAPE PROSPECT RD & S LEMAY AVE1880 Fall River Drive, Suite 200Loveland, CO 80538Tel. 970-461-7733SITE RAINFALL INTENSITY-DURATION-FREQUENCY CURVE 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 0.00 10.00 20.00 30.00 40.00 50.00 60.00 STORM DURATION (minutes)RAINFALL INTENSITY (inches/hour)2-Year Storm 10-Year Storm 100-Year Storm Figure RA-16 City of Fort Collins Rainfall Intensity-Duration-Frequency Curves Runoff Chapter 6 6-8 Urban Drainage and Flood Control District January 2016 Urban Storm Drainage Criteria Manual Volume 1 Table 6-3. Recommended percentage imperviousness values Land Use or Percentage Imperviousness (%) Surface Characteristics Business: Downtown Areas 95 Suburban Areas 75 Residential: Single-family 2.5 acres or larger 12 0.75 – 2.5 acres 20 0.25 – 0.75 acres 30 0.25 acres or less 45 Apartments 75 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 10 Playgrounds 25 Schools 55 Railroad yard areas 50 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off-site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 2 Lawns, clayey soil 2 E PROSPECT RD S LEMAY AVESQUARE FOOTAGE: 3,946 BISTRO-RP-2021V1 TTA 0.09 0.74 0.85 B 0.06 0.74 0.85 D.1 0.04 0.83 0.89 M 0.27 0.69 0.82 F 0.11 0.83 0.89 E 0.03 0.83 0.89 D.2 0.06 0.83 0.89 C 0.27 0.83 0.89 I 0.02 0.01 0.49 L.4 0.04 0.14 0.56 G 0.07 0.01 0.49 H 0.02 0.01 0.49 L.3 0.03 0.14 0.56 L.1 0.04 0.14 0.56 J 0.02 0.01 0.49 L.2 0.01 0.14 0.56 K 0.01 0.35 0.66 LEGEND A B C D SHEET NUMBER: CPM: SDM: RDM: 06/30/2021#0951 - FORT COLLINS, COKG PROJECT TEAM:949 E PROSPECT1459 Grand Avenue Des Moines, Iowa 50309 P: 515-226-0128 F: 515-223-9873 DATE: TOM CARRICO RYAN HALDER PERRY DEPHILLIPS CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES.DOCUMENT REVISION DATE: JULY 2013Know what's below. before you dig.CallR www.olsson.comTEL 303.237.20721525 Raleigh St. Suite 400Denver, CO 80204DATEREVISION DESCRIPTION OF 32 DRAINAGE BASIN MAP SHEET 1 KUM & GO #951 FORT COLLINS, CO 949 E PROSPECT RD Fort Collins, Colorado June 2021 Olsson Project No. 020-2883