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HomeMy WebLinkAboutDrainage Report9339 Priority Way West Drive, Suite 100 Indianapolis, Indiana 46240 Telephone 317 844 6777 Facsimile 317 706 6451 www.cripe.biz PIC: 180235-20000 Drainage Design Report for Golf Training/Tennis Pavilion Woodland Country Club 100 Woodland Lane Carmel, Indiana Prepared for: Woodland Country Club 100 Woodland Lane Carmel, IN 46032 December 21, 2022 Revised April 17, 2023 Certified By: _________________________ Thomas J. Green, P.E., P.L.S., CFM PE 11500256 DRAINAGE DESIGN REPORT FOR Woodland Country Club Golf Training/Tennis Pavilion Carmel, Indiana TABLE OF CONTENTS 1.0 Introduction ......................................................................................................... 2 1.1 Project Description ................................................................................................ 2 1.2 Scope of Report .................................................................................................... 2 1.3 Existing Conditions ............................................................................................... 2 1.4 Proposed Conditions ............................................................................................. 4 2.0 Existing Parking Lot Detention Drainage Analysis ......................................... 5 2.1 Pre-Developed Parking Lot Site Conditions .......................................................... 5 2.2 Post-Developed Parking Lot Site Conditions ......................................................... 6 3.0 Post-Developed Project Drainage Analysis ..................................................... 6 3.1 Allowable Release Rate Calculation ..................................................................... 6 3.2 Post-Developed Conditions ................................................................................... 7 4.0 Water Quality Analysis ....................................................................................... 7 4.1 Post-Construction Stormwater Quality Measures .................................................. 7 5.0 Conclusion ............................................................................................................... 8 APPENDICIES Appendix A – Existing Detention Tributary Area Exhibit and Calculations Appendix B – Proposed Detention Exhibit and Calculations Appendix C – Proposed Water Quality Post-Developed Conditions Calculations Appendix D – Proposed Storm Post-Developed Conditions Calculations Appendix E – Memo of Recognitions and Concessions 04/17/2023 1 2 1.0 Introduction This drainage report outlines the stormwater management system to serve the golf training and tennis court improvements at the Woodland Country Club. The proposed development is located across the street from the clubhouse located at 100 Woodland Lane in Carmel, IN. The purpose of this report is to identify the impacts of the stormwater runoff from the proposed tennis courts on the existing stormwater management for the site. The existing detention for the site consists of surface storage in the parking lot and storage in the 18-inch storm sewer pipe prior to the outlet located in a headwall to the ditch located on the east side of the site. The City of Carmel Stormwater Technical Standards Manual was used for the storm sewer hydraulic calculations and the water quality design. 1.1 Project Description The Golf Training and Tennis Pavilion project consists of the construction of a 3,026 sq.ft. golf training building and a 1,378 sq.ft. tennis observation pavilion with restrooms. The proposed improvements will only disturb 1.67 acres of the larger 60+ acre parcel The project involves, but is not limited to, the following: • Constructing the golf training building at the existing driving range • Removing/rerouting the golf cart path to the new golf training building • Removing existing sluice gate • Constructing the tennis observation pavilion over the southeast corner over the existing parking lot • Installation of new water and sanitary services to the new buildings • Construction of 1 new tennis court and 4 new pickleball courts As part of this project’s stormwater management, a hydrodynamic separator and underground detention is proposed for stormwater treatment prior to discharging to the existing 18-inch outlet to the ditch on the east side of the site. This Ditch is the primary stormwater outlet point for the site. 1.2 Scope of Report This report summarizes the stormwater management system for the proposed development of the Golf Training and Tennis Pavilion project. 1.3 Existing Conditions The existing tennis court location consists of open green space north of the existing tennis courts. The location of the proposed tennis pavilion consists mainly of asphalt of the existing parking lot. The proposed golf cart path and golf training building location is mainly grass area of the existing driving range or the area adjacent. 04/17/2023 2 3 The site currently drains to the west/northwest, east/northeast, and south. The driving range area is on top of the hill and drains to the south. The eastern portion of the grass area north of the existing tennis courts drains to the east/northeast. The area around the south and east side of the existing parking lot drains into the parking lot. Figure 1 - Existing Site The disturbed area drains to the existing parking lot inlets or to the ditch located to along the east side of the side. The existing stormwater detention for the parking lot tributary area was designed in the 1980s as surface storage in the 04/17/2023 3 4 parking lot. The storm sewer outlets to a headwall via an 18 -inch pipe with a sluice gate. The adjoining properties zoning consist of the following: North: Golf Course South: Golf course East: Single Family home R-1 West: Single Family home R-1 The soils maps from the US Department of Agriculture, Soil Conservation Service identifies the proposed disturbed area as predominantly Miami Silt loam (Ms) and Brookston Silt loam (Bv). The Firm map panel number 18057C0228G dated November 19, 2014, indicates that the site lies in Flood Zone “X”. The location of the project area is depicted outside of the 100 or 500-year floodplain areas. Adjacent to the site 1.4 Proposed Conditions The proposed work consists of the construction of a new golf training building, tennis courts, tennis pavilion, golf cart path to the driving range, a sidewalk ramp from the existing parking lot up to the driving range, underground stormwater detention and associated site utilities to the new buildings. Refer to Figure 2 below. 04/17/2023 4 5 Figure 2 - Proposed Conditions 2.0 Existing Parking Lot Detention Drainage Analysis 2.1 Pre-Developed Parking Lot Site Conditions The “Existing Detention Tributary Area Pre-Developed Conditions Exhibit” in Appendix A depicts the area that drains to the parking lot where there is existing stormwater detention provided as surface storage along with storage in the 18” pipe that ultimately outlets into the ditch located along the east of the site. There is a 12” sluice gate installed over the end of the 18 -inch pipe at a headwall that is kept in the fully open position. This is modeled as a 12” orifice. The pre-developed detention model for the existing parking lot storage uses assumed pipe lengths and assumed from GIS contour data from image files. The model also uses current rainfall data. The existing tributary area is approximated as 4.96 acres. The overflow weir elevation is the spillover point for the existing parking lot detention. The existing spillover point functions as an existing weir. The weir elevation of 814.70 is on the north side of the proposed tennis courts where it sheet flows east through the grass to the ditch located on the east side of the site. 04/17/2023 5 6 2.2 Post-Developed Parking Lot Site Conditions It is understood by the City of Carmel and the owner that the 1980s parking lot detention system is an existing nonconforming condition. Therefore, it is agreed that the proposed project will maintain or improve this existing condition and remove the existing sluice gate. A grass area of 0.19 acres overlaps the existing parking lot detention area and the proposed project area. This area is removed from the parking lot detention in the post-developed condition and is part of the project detention area. Figure 3 – Parking Lot Detention Summary Pre-Developed Flow (cfs) Max Stage Elevation Post-Developed Flow (cfs) Max Stage Elevation 2-year 8.57 814.09 8.54 814.06 10-year 8.98 814.60 8.94 814.54 100-year 32.44 Flood route 31.05 Flood route See Appendix A for existing parking lot detention system exhibit and calculations. 3.0 Post-Developed Project Drainage Analysis The post developed stormwater management system for the proposed tennis court area consists of 86 feet of 54-inch CMP with an outlet control structure with a 5.5- inch orifice in a concrete weir wall. The restricted release outlets to the existing 18-inch storm sewer pipe that discharges at the headwall located adjacent to the ditch that runs along the east side of the site. 3.1 Allowable Release Rate Calculation The “Proposed Detention Tributary Area Pre-Developed Conditions Exhibit” contained in Appendix B was prepared utilizing HydroCAD hydrologic modeling software which uses procedures developed by the NRCS to produce a fully- integrated interactive stormwater modeling system. The time of concentration was assumed to be the minimum 5 minutes. The typical rainfall values were used for the 10-yr and 100-yr storm events as required by the City of Carmel, 3.83 and 6.46 inches, respectively. The calculated 100 -year release rate from the Pre-Developed model are as follows: • 100-year 1.59 cfs The following values were used as the Allowable Release Rates for the Proposed Conditions: • 10-year 1.11 cfs = 0.7 * 100-year • 100-year 1.59 cfs 04/17/2023 6 7 3.2 Post-Developed Conditions As noted previously, the proposed work consists of the construction of a new golf training building, tennis courts, tennis pavilion, golf cart path to the driving range, a sidewalk ramp from the existing parking lot up to the driving range, underground stormwater detention and associated site utilities to the new buildings. Appendix B contains the Proposed Detention Exhibit and Calculations including the “Proposed Detention Tributary Area Post-Developed Conditions Exhibit” which depicts the following parameters: • Tributary Area 0.34 acres o Impervious 0.34 acres The minimum 5-minute value was used for the time of concentration and the curve number (CN) was 98 for 100% impervious surface. The calculated 10- and 100- year release rates from the Post-Developed model contained in Appendix B are as follows: • 10-year 1.06 cfs • 100-year 1.57 cfs The allowable release rates are met using a 5.5-inch diameter orifice. Figure 4 – Proposed Detention Summary Pre-Developed Flow (cfs) Allowable Flow (cfs) Post-Developed Flow (cfs) Max Stage Elevation 2-year 0.15 N/A 0.83 810.05 10-year 0.50 1.11 1.06 810.80 100-year 1.59 1.59 1.57 813.09 4.0 Water Quality Analysis 4.1 Post-Construction Stormwater Quality Measures As part of the overall Stormwater Management for the site, water quality treatment is provided for the non-direct discharge stormwater runoff. A treatment train is provided via stormwater runoff being treated via a structural BMP hydrodynamic separator prior to discharging to 54-inch CMP underground detention. An Aqua Swirl XC-3 water quality unit is proposed to meet the requirements of the City of Carmel. The runoff from the 10-year rain event is 1.87 cfs and the maximum 10-year flow rate capacity of the XC-3 unit is 2.30 cfs. The 1.87 cfs value is taken from the Subcatchment 1S 10-year calculation of the Post-Developed Conditions Model in Appendix B. 04/17/2023 7 8 Due to the size of the NJDEP particles tested, Indianapolis accepts all systems certified by NJDEP for 50% TSS reduction as having achieved 80% TSS reduction in about the 50-125 micron range. Therefore, one Indianapolis list BMP structure meets Carmel’s requirement for 80% TSS removal of the 50 -125 micron range. XC-3 capacity and third-party testing information is included in Appendix C. This system complies with the design criteria presented in the City of Carmel Stormwater Technical Standards Manual and the Hamilton County Drainage Ordinance. 5.0 Storm Sewer Analysis 4.1 Post-Construction Stormwater Quality Measures Hydraflow Storm Sewers Extension for AutoCAD Civil 3D, v.8 was used to document the capacity of the existing storm sewer network on site as well as verify the capacity of all the proposed storm drainage pipes for the 10-year storm event peak flows. Hydraflow utilizes a graphical pipe network containing pipe data, inlet characteristics, watershed areas, and rainfall information. These flow calculations are valid for both pressure and varied flow situations including hydraulic jumps, backwater elevations, and draw down curves. These calculations are based on the rational method. Factors involved include runoff coefficient (C), time of concentration (Tc) and Area (A). The existing storm sewer was run with the known flow for the 10-year storm from the existing parking lot detention calculations in Appendix A. Factors for the rational method were used for the proposed areas. A C-value of 0.85 was utilized for pavement areas. Tc minimum value is 5 minutes. The are as for the trench drain sections were taken from the proposed detention area divided by three sections of trench drain. The area for the trench drain inlet calculation was the total proposed area divided into one 2-foot section of casting. See calculations and the inlet basin exhibit in Appendix D. 6.0 Conclusion The proposed improvements reduce the amount of tributary area to the existing surface detention in the parking lot and reduces the release for the proposed detention tributary area of the proposed tennis courts. The following is a summary of the allowable release rates: • 10-year 1.11 cfs • 100-year 1.59 cfs The following is a summary of the Post -Developed release rates for the 5.5-inch diameter orifice: • 10-year 1.06 cfs • 100-year 1.57 cfs 04/17/2023 8 9 The proposed storm drainage system complies with the criteria stated in the Memo of Recognitions and Concessions in Appendix E or the City of Carmel Stormwater Technical Standards Manual and the Hamilton County Drainage Ordinance for detention and water quality. No adverse impacts are anticipated as a result of this design. 04/17/2023 9 Appendix A Existing Detention Tributary Area Pre & Post-Developed Conditions Exhibits and Calculations 04/17/2023 10 04/17/2023 11 1S Existing Tributary Area 2P Existing Parking Lot Detention Routing Diagram for Pre Parking Lot Conditions Prepared by Cripe, Printed 4/13/2023 HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Subcat Reach Pond Link 04/17/2023 12 Pre Developed Parking Lot Detention Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 2HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 2 Year - 24 HR Type II 24-hr Default 24.00 1 2.66 2 2 10 - Year, 24 HR. Type II 24-hr Default 24.00 1 3.83 2 3 100 - Year, 24 HR Type II 24-hr Default 24.00 1 6.46 2 04/17/2023 13 Pre Developed Parking Lot Detention Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 3HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 4.960 94 Urban commercial, 85% imp, HSG C (1S) 4.960 94 TOTAL AREA 04/17/2023 14 Pre Developed Parking Lot Detention Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 4HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 4.960 0.000 0.000 4.960 Urban commercial, 85% imp 1S 0.000 0.000 4.960 0.000 0.000 4.960 TOTAL AREA 04/17/2023 15 Pre Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 5HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=4.960 ac 85.00% Impervious Runoff Depth=2.02"Subcatchment 1S: Existing Tributary Area Flow Length=337' Tc=12.4 min CN=94 Runoff=13.47 cfs 0.836 af Peak Elev=814.09' Storage=2,693 cf Inflow=13.47 cfs 0.836 afPond 2P: Existing Parking Lot Detention Outflow=8.57 cfs 0.836 af Total Runoff Area = 4.960 ac Runoff Volume = 0.836 af Average Runoff Depth = 2.02" 15.00% Pervious = 0.744 ac 85.00% Impervious = 4.216 ac 04/17/2023 16 Pre Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 6HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 13.47 cfs @ 12.04 hrs, Volume= 0.836 af, Depth= 2.02" Routed to Pond 2P : Existing Parking Lot Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Area (ac) CN Description 4.960 94 Urban commercial, 85% imp, HSG C 0.744 15.00% Pervious Area 4.216 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.7 193 0.0600 0.27 Sheet Flow, Sheet flow grass area Grass: Short n= 0.150 P2= 2.66" 0.7 144 0.0300 3.52 Shallow Concentrated Flow, Parking Lot Paved Kv= 20.3 fps 12.4 337 Total Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Runoff Area=4.960 ac Runoff Volume=0.836 af Runoff Depth=2.02" Flow Length=337' Tc=12.4 min CN=94 13.47 cfs 04/17/2023 17 Pre Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 7HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing Parking Lot Detention Inflow Area = 4.960 ac, 85.00% Impervious, Inflow Depth = 2.02" for 2 Year - 24 HR event Inflow = 13.47 cfs @ 12.04 hrs, Volume= 0.836 af Outflow = 8.57 cfs @ 12.15 hrs, Volume= 0.836 af, Atten= 36%, Lag= 6.6 min Primary = 8.57 cfs @ 12.15 hrs, Volume= 0.836 af Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 814.09' @ 12.15 hrs Surf.Area= 7,509 sf Storage= 2,693 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 1.5 min ( 797.6 - 796.1 ) Volume Invert Avail.Storage Storage Description #1 813.50' 92,670 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2 808.45' 454 cf 18.0" Round Pipe Storage L= 257.0' S= 0.4000 '/' #3 809.30' 476 cf 15.0" Round Pipe Storage L= 388.0' S= 0.0040 '/' 93,600 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 813.50 0 0 0 814.00 6,279 1,570 1,570 814.70 15,735 7,705 9,275 816.00 15,735 20,455 29,730 820.00 15,735 62,940 92,670 Device Routing Invert Outlet Devices #1 Primary 808.45'12.0" Vert. Orifice - 12" Sluice Gate - Open C= 0.600 Limited to weir flow at low heads #2 Primary 814.70'40.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=8.57 cfs @ 12.15 hrs HW=814.09' (Free Discharge) 1=Orifice - 12" Sluice Gate - Open (Orifice Controls 8.57 cfs @ 10.92 fps) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 04/17/2023 18 Pre Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 8HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: Existing Parking Lot Detention Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=4.960 ac Peak Elev=814.09' Storage=2,693 cf 13.47 cfs 8.57 cfs 04/17/2023 19 Pre Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 9HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=4.960 ac 85.00% Impervious Runoff Depth=3.16"Subcatchment 1S: Existing Tributary Area Flow Length=337' Tc=12.4 min CN=94 Runoff=20.50 cfs 1.305 af Peak Elev=814.60' Storage=8,217 cf Inflow=20.50 cfs 1.305 afPond 2P: Existing Parking Lot Detention Outflow=8.98 cfs 1.305 af Total Runoff Area = 4.960 ac Runoff Volume = 1.305 af Average Runoff Depth = 3.16" 15.00% Pervious = 0.744 ac 85.00% Impervious = 4.216 ac 04/17/2023 20 Pre Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 10HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 20.50 cfs @ 12.04 hrs, Volume= 1.305 af, Depth= 3.16" Routed to Pond 2P : Existing Parking Lot Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83" Area (ac) CN Description 4.960 94 Urban commercial, 85% imp, HSG C 0.744 15.00% Pervious Area 4.216 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.7 193 0.0600 0.27 Sheet Flow, Sheet flow grass area Grass: Short n= 0.150 P2= 2.66" 0.7 144 0.0300 3.52 Shallow Concentrated Flow, Parking Lot Paved Kv= 20.3 fps 12.4 337 Total Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 10 - Year 24 HR. Rainfall=3.83" Runoff Area=4.960 ac Runoff Volume=1.305 af Runoff Depth=3.16" Flow Length=337' Tc=12.4 min CN=94 20.50 cfs 04/17/2023 21 Pre Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 11HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing Parking Lot Detention Inflow Area = 4.960 ac, 85.00% Impervious, Inflow Depth = 3.16" for 10 - Year, 24 HR. event Inflow = 20.50 cfs @ 12.04 hrs, Volume= 1.305 af Outflow = 8.98 cfs @ 12.20 hrs, Volume= 1.305 af, Atten= 56%, Lag= 9.8 min Primary = 8.98 cfs @ 12.20 hrs, Volume= 1.305 af Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 814.60' @ 12.20 hrs Surf.Area= 14,340 sf Storage= 8,217 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 4.2 min ( 788.2 - 783.9 ) Volume Invert Avail.Storage Storage Description #1 813.50' 92,670 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2 808.45' 454 cf 18.0" Round Pipe Storage L= 257.0' S= 0.4000 '/' #3 809.30' 476 cf 15.0" Round Pipe Storage L= 388.0' S= 0.0040 '/' 93,600 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 813.50 0 0 0 814.00 6,279 1,570 1,570 814.70 15,735 7,705 9,275 816.00 15,735 20,455 29,730 820.00 15,735 62,940 92,670 Device Routing Invert Outlet Devices #1 Primary 808.45'12.0" Vert. Orifice - 12" Sluice Gate - Open C= 0.600 Limited to weir flow at low heads #2 Primary 814.70'40.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=8.99 cfs @ 12.20 hrs HW=814.60' (Free Discharge) 1=Orifice - 12" Sluice Gate - Open (Orifice Controls 8.99 cfs @ 11.44 fps) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 04/17/2023 22 Pre Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 12HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: Existing Parking Lot Detention Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=4.960 ac Peak Elev=814.60' Storage=8,217 cf 20.50 cfs 8.98 cfs 04/17/2023 23 Pre Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 13HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=4.960 ac 85.00% Impervious Runoff Depth=5.75"Subcatchment 1S: Existing Tributary Area Flow Length=337' Tc=12.4 min CN=94 Runoff=36.06 cfs 2.378 af Peak Elev=814.92' Storage=13,188 cf Inflow=36.06 cfs 2.378 afPond 2P: Existing Parking Lot Detention Outflow=32.44 cfs 2.378 af Total Runoff Area = 4.960 ac Runoff Volume = 2.378 af Average Runoff Depth = 5.75" 15.00% Pervious = 0.744 ac 85.00% Impervious = 4.216 ac 04/17/2023 24 Pre Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 14HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 36.06 cfs @ 12.03 hrs, Volume= 2.378 af, Depth= 5.75" Routed to Pond 2P : Existing Parking Lot Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100 - Year, 24 HR Rainfall=6.46" Area (ac) CN Description 4.960 94 Urban commercial, 85% imp, HSG C 0.744 15.00% Pervious Area 4.216 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.7 193 0.0600 0.27 Sheet Flow, Sheet flow grass area Grass: Short n= 0.150 P2= 2.66" 0.7 144 0.0300 3.52 Shallow Concentrated Flow, Parking Lot Paved Kv= 20.3 fps 12.4 337 Total Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type II 24-hr 100 - Year 24 HR Rainfall=6.46" Runoff Area=4.960 ac Runoff Volume=2.378 af Runoff Depth=5.75" Flow Length=337' Tc=12.4 min CN=94 36.06 cfs 04/17/2023 25 Pre Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 15HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing Parking Lot Detention Inflow Area = 4.960 ac, 85.00% Impervious, Inflow Depth = 5.75" for 100 - Year, 24 HR event Inflow = 36.06 cfs @ 12.03 hrs, Volume= 2.378 af Outflow = 32.44 cfs @ 12.09 hrs, Volume= 2.378 af, Atten= 10%, Lag= 3.4 min Primary = 32.44 cfs @ 12.09 hrs, Volume= 2.378 af Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 814.92' @ 12.09 hrs Surf.Area= 15,739 sf Storage= 13,188 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 4.6 min ( 773.5 - 768.9 ) Volume Invert Avail.Storage Storage Description #1 813.50' 92,670 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2 808.45' 454 cf 18.0" Round Pipe Storage L= 257.0' S= 0.4000 '/' #3 809.30' 476 cf 15.0" Round Pipe Storage L= 388.0' S= 0.0040 '/' 93,600 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 813.50 0 0 0 814.00 6,279 1,570 1,570 814.70 15,735 7,705 9,275 816.00 15,735 20,455 29,730 820.00 15,735 62,940 92,670 Device Routing Invert Outlet Devices #1 Primary 808.45'12.0" Vert. Orifice - 12" Sluice Gate - Open C= 0.600 Limited to weir flow at low heads #2 Primary 814.70'40.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=18.98 cfs @ 12.09 hrs HW=814.91' (Free Discharge) 1=Orifice - 12" Sluice Gate - Open (Orifice Controls 9.23 cfs @ 11.76 fps) 2=Broad-Crested Rectangular Weir (Weir Controls 9.74 cfs @ 1.15 fps) 04/17/2023 26 Pre Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Pre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 16HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: Existing Parking Lot Detention Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=4.960 ac Peak Elev=814.92' Storage=13,188 cf 36.06 cfs 32.44 cfs 04/17/2023 27 Pre Developed Parking Lot Detention Multi-Event TablesPre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 17HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Events for Subcatchment 1S: Existing Tributary Area Event Rainfall (inches) Runoff (cfs) Volume (acre-feet) Depth (inches) 2 Year - 24 HR 2.66 13.47 0.836 2.02 10 - Year, 24 HR. 3.83 20.50 1.305 3.16 100 - Year, 24 HR 6.46 36.06 2.378 5.75 04/17/2023 28 Pre Developed Parking Lot Detention Multi-Event TablesPre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 18HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Events for Pond 2P: Existing Parking Lot Detention Event Inflow (cfs) Primary (cfs) Elevation (feet) Storage (cubic-feet) 2 Year - 24 HR 13.47 8.57 814.09 2,693 10 - Year, 24 HR. 20.50 8.98 814.60 8,217 100 - Year, 24 HR 36.06 32.44 814.92 13,188 04/17/2023 29 Pre Developed Parking Lot Detention Table of ContentsPre Parking Lot Conditions Printed 4/13/2023Prepared by Cripe HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC TABLE OF CONTENTS Project Reports 1 Routing Diagram 2 Rainfall Events Listing 3 Area Listing (all nodes) 4 Ground Covers (all nodes) 2 Year - 24 HR Event 5 Node Listing 6 Subcat 1S: Existing Tributary Area 7 Pond 2P: Existing Parking Lot Detention 10 - Year, 24 HR. Event 9 Node Listing 10 Subcat 1S: Existing Tributary Area 11 Pond 2P: Existing Parking Lot Detention 100 - Year, 24 HR Event 13 Node Listing 14 Subcat 1S: Existing Tributary Area 15 Pond 2P: Existing Parking Lot Detention Multi-Event Tables 17 Subcat 1S: Existing Tributary Area 18 Pond 2P: Existing Parking Lot Detention 04/17/2023 30 1S Existing Tributary Area 2P Existing Parking Lot Detention Routing Diagram for Post Parking Lot Conditions Prepared by Cripe, Printed 4/13/2023 HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Subcat Reach Pond Link 04/17/2023 31 Post Developed Parking Lot Detention Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 2HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 2 Year - 24 HR Type II 24-hr Default 24.00 1 2.66 2 2 10 - Year, 24 HR. Type II 24-hr Default 24.00 1 3.83 2 3 100 - Year, 24 HR Type II 24-hr Default 24.00 1 6.46 2 04/17/2023 32 Post Developed Parking Lot Detention Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 3HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 4.770 94 Urban commercial, 85% imp, HSG C (1S) 4.770 94 TOTAL AREA 04/17/2023 33 Post Developed Parking Lot Detention Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 4HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 4.770 0.000 0.000 4.770 Urban commercial, 85% imp 1S 0.000 0.000 4.770 0.000 0.000 4.770 TOTAL AREA 04/17/2023 34 Post Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 5HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=4.770 ac 85.00% Impervious Runoff Depth=2.02"Subcatchment 1S: Existing Tributary Area Flow Length=337' Tc=12.4 min CN=94 Runoff=12.96 cfs 0.804 af Peak Elev=814.06' Storage=2,446 cf Inflow=12.96 cfs 0.804 afPond 2P: Existing Parking Lot Detention Outflow=8.54 cfs 0.804 af Total Runoff Area = 4.770 ac Runoff Volume = 0.804 af Average Runoff Depth = 2.02" 15.00% Pervious = 0.715 ac 85.00% Impervious = 4.055 ac 04/17/2023 35 Post Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 6HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 12.96 cfs @ 12.04 hrs, Volume= 0.804 af, Depth= 2.02" Routed to Pond 2P : Existing Parking Lot Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Area (ac) CN Description 4.770 94 Urban commercial, 85% imp, HSG C 0.715 15.00% Pervious Area 4.055 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.7 193 0.0600 0.27 Sheet Flow, Sheet flow grass area Grass: Short n= 0.150 P2= 2.66" 0.7 144 0.0300 3.52 Shallow Concentrated Flow, Parking Lot Paved Kv= 20.3 fps 12.4 337 Total Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Runoff Area=4.770 ac Runoff Volume=0.804 af Runoff Depth=2.02" Flow Length=337' Tc=12.4 min CN=94 12.96 cfs 04/17/2023 36 Post Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 7HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing Parking Lot Detention Inflow Area = 4.770 ac, 85.00% Impervious, Inflow Depth = 2.02" for 2 Year - 24 HR event Inflow = 12.96 cfs @ 12.04 hrs, Volume= 0.804 af Outflow = 8.54 cfs @ 12.14 hrs, Volume= 0.804 af, Atten= 34%, Lag= 6.2 min Primary = 8.54 cfs @ 12.14 hrs, Volume= 0.804 af Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 814.06' @ 12.14 hrs Surf.Area= 7,052 sf Storage= 2,446 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 1.3 min ( 797.4 - 796.1 ) Volume Invert Avail.Storage Storage Description #1 813.50' 92,670 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2 808.45' 454 cf 18.0" Round Pipe Storage L= 257.0' S= 0.4000 '/' #3 809.30' 476 cf 15.0" Round Pipe Storage L= 388.0' S= 0.0040 '/' 93,600 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 813.50 0 0 0 814.00 6,279 1,570 1,570 814.70 15,735 7,705 9,275 816.00 15,735 20,455 29,730 820.00 15,735 62,940 92,670 Device Routing Invert Outlet Devices #1 Primary 808.45'12.0" Vert. Orifice - 12" Sluice Gate - Open C= 0.600 Limited to weir flow at low heads #2 Primary 814.70'40.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=8.54 cfs @ 12.14 hrs HW=814.05' (Free Discharge) 1=Orifice - 12" Sluice Gate - Open (Orifice Controls 8.54 cfs @ 10.88 fps) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 04/17/2023 37 Post Developed Parking Lot Detention Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 8HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: Existing Parking Lot Detention Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=4.770 ac Peak Elev=814.06' Storage=2,446 cf 12.96 cfs 8.54 cfs 04/17/2023 38 Post Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 9HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=4.770 ac 85.00% Impervious Runoff Depth=3.16"Subcatchment 1S: Existing Tributary Area Flow Length=337' Tc=12.4 min CN=94 Runoff=19.72 cfs 1.255 af Peak Elev=814.54' Storage=7,414 cf Inflow=19.72 cfs 1.255 afPond 2P: Existing Parking Lot Detention Outflow=8.94 cfs 1.256 af Total Runoff Area = 4.770 ac Runoff Volume = 1.255 af Average Runoff Depth = 3.16" 15.00% Pervious = 0.715 ac 85.00% Impervious = 4.055 ac 04/17/2023 39 Post Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 10HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 19.72 cfs @ 12.04 hrs, Volume= 1.255 af, Depth= 3.16" Routed to Pond 2P : Existing Parking Lot Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83" Area (ac) CN Description 4.770 94 Urban commercial, 85% imp, HSG C 0.715 15.00% Pervious Area 4.055 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.7 193 0.0600 0.27 Sheet Flow, Sheet flow grass area Grass: Short n= 0.150 P2= 2.66" 0.7 144 0.0300 3.52 Shallow Concentrated Flow, Parking Lot Paved Kv= 20.3 fps 12.4 337 Total Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 10 - Year 24 HR. Rainfall=3.83" Runoff Area=4.770 ac Runoff Volume=1.255 af Runoff Depth=3.16" Flow Length=337' Tc=12.4 min CN=94 19.72 cfs 04/17/2023 40 Post Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 11HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing Parking Lot Detention Inflow Area = 4.770 ac, 85.00% Impervious, Inflow Depth = 3.16" for 10 - Year, 24 HR. event Inflow = 19.72 cfs @ 12.04 hrs, Volume= 1.255 af Outflow = 8.94 cfs @ 12.19 hrs, Volume= 1.256 af, Atten= 55%, Lag= 9.5 min Primary = 8.94 cfs @ 12.19 hrs, Volume= 1.256 af Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 814.54' @ 12.19 hrs Surf.Area= 13,563 sf Storage= 7,414 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 4.0 min ( 787.9 - 783.9 ) Volume Invert Avail.Storage Storage Description #1 813.50' 92,670 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2 808.45' 454 cf 18.0" Round Pipe Storage L= 257.0' S= 0.4000 '/' #3 809.30' 476 cf 15.0" Round Pipe Storage L= 388.0' S= 0.0040 '/' 93,600 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 813.50 0 0 0 814.00 6,279 1,570 1,570 814.70 15,735 7,705 9,275 816.00 15,735 20,455 29,730 820.00 15,735 62,940 92,670 Device Routing Invert Outlet Devices #1 Primary 808.45'12.0" Vert. Orifice - 12" Sluice Gate - Open C= 0.600 Limited to weir flow at low heads #2 Primary 814.70'40.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=8.94 cfs @ 12.19 hrs HW=814.54' (Free Discharge) 1=Orifice - 12" Sluice Gate - Open (Orifice Controls 8.94 cfs @ 11.38 fps) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 04/17/2023 41 Post Developed Parking Lot Detention Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 12HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: Existing Parking Lot Detention Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=4.770 ac Peak Elev=814.54' Storage=7,414 cf 19.72 cfs 8.94 cfs 04/17/2023 42 Post Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 13HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=4.770 ac 85.00% Impervious Runoff Depth=5.75"Subcatchment 1S: Existing Tributary Area Flow Length=337' Tc=12.4 min CN=94 Runoff=34.68 cfs 2.287 af Peak Elev=814.90' Storage=12,992 cf Inflow=34.68 cfs 2.287 afPond 2P: Existing Parking Lot Detention Outflow=31.05 cfs 2.287 af Total Runoff Area = 4.770 ac Runoff Volume = 2.287 af Average Runoff Depth = 5.75" 15.00% Pervious = 0.715 ac 85.00% Impervious = 4.055 ac 04/17/2023 43 Post Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 14HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 34.68 cfs @ 12.03 hrs, Volume= 2.287 af, Depth= 5.75" Routed to Pond 2P : Existing Parking Lot Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100 - Year, 24 HR Rainfall=6.46" Area (ac) CN Description 4.770 94 Urban commercial, 85% imp, HSG C 0.715 15.00% Pervious Area 4.055 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.7 193 0.0600 0.27 Sheet Flow, Sheet flow grass area Grass: Short n= 0.150 P2= 2.66" 0.7 144 0.0300 3.52 Shallow Concentrated Flow, Parking Lot Paved Kv= 20.3 fps 12.4 337 Total Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type II 24-hr 100 - Year 24 HR Rainfall=6.46" Runoff Area=4.770 ac Runoff Volume=2.287 af Runoff Depth=5.75" Flow Length=337' Tc=12.4 min CN=94 34.68 cfs 04/17/2023 44 Post Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 15HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: Existing Parking Lot Detention Inflow Area = 4.770 ac, 85.00% Impervious, Inflow Depth = 5.75" for 100 - Year, 24 HR event Inflow = 34.68 cfs @ 12.03 hrs, Volume= 2.287 af Outflow = 31.05 cfs @ 12.09 hrs, Volume= 2.287 af, Atten= 10%, Lag= 3.5 min Primary = 31.05 cfs @ 12.09 hrs, Volume= 2.287 af Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 814.90' @ 12.09 hrs Surf.Area= 15,739 sf Storage= 12,992 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 4.7 min ( 773.5 - 768.9 ) Volume Invert Avail.Storage Storage Description #1 813.50' 92,670 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2 808.45' 454 cf 18.0" Round Pipe Storage L= 257.0' S= 0.4000 '/' #3 809.30' 476 cf 15.0" Round Pipe Storage L= 388.0' S= 0.0040 '/' 93,600 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 813.50 0 0 0 814.00 6,279 1,570 1,570 814.70 15,735 7,705 9,275 816.00 15,735 20,455 29,730 820.00 15,735 62,940 92,670 Device Routing Invert Outlet Devices #1 Primary 808.45'12.0" Vert. Orifice - 12" Sluice Gate - Open C= 0.600 Limited to weir flow at low heads #2 Primary 814.70'40.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=18.16 cfs @ 12.09 hrs HW=814.90' (Free Discharge) 1=Orifice - 12" Sluice Gate - Open (Orifice Controls 9.22 cfs @ 11.75 fps) 2=Broad-Crested Rectangular Weir (Weir Controls 8.94 cfs @ 1.11 fps) 04/17/2023 45 Post Developed Parking Lot Detention Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Post Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 16HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: Existing Parking Lot Detention Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=4.770 ac Peak Elev=814.90' Storage=12,992 cf 34.68 cfs 31.05 cfs 04/17/2023 46 Post Developed Parking Lot Detention Multi-Event TablesPost Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 17HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Events for Subcatchment 1S: Existing Tributary Area Event Rainfall (inches) Runoff (cfs) Volume (acre-feet) Depth (inches) 2 Year - 24 HR 2.66 12.96 0.804 2.02 10 - Year, 24 HR. 3.83 19.72 1.255 3.16 100 - Year, 24 HR 6.46 34.68 2.287 5.75 04/17/2023 47 Post Developed Parking Lot Detention Multi-Event TablesPost Parking Lot Conditions Printed 4/13/2023Prepared by Cripe Page 18HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Events for Pond 2P: Existing Parking Lot Detention Event Inflow (cfs) Primary (cfs) Elevation (feet) Storage (cubic-feet) 2 Year - 24 HR 12.96 8.54 814.06 2,446 10 - Year, 24 HR. 19.72 8.94 814.54 7,414 100 - Year, 24 HR 34.68 31.05 814.90 12,992 04/17/2023 48 Post Developed Parking Lot Detention Table of ContentsPost Parking Lot Conditions Printed 4/13/2023Prepared by Cripe HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC TABLE OF CONTENTS Project Reports 1 Routing Diagram 2 Rainfall Events Listing 3 Area Listing (all nodes) 4 Ground Covers (all nodes) 2 Year - 24 HR Event 5 Node Listing 6 Subcat 1S: Existing Tributary Area 7 Pond 2P: Existing Parking Lot Detention 10 - Year, 24 HR. Event 9 Node Listing 10 Subcat 1S: Existing Tributary Area 11 Pond 2P: Existing Parking Lot Detention 100 - Year, 24 HR Event 13 Node Listing 14 Subcat 1S: Existing Tributary Area 15 Pond 2P: Existing Parking Lot Detention Multi-Event Tables 17 Subcat 1S: Existing Tributary Area 18 Pond 2P: Existing Parking Lot Detention 04/17/2023 49 Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Apr 17 2023 Flood Route Out of Parking Lot Triangular Side Slopes (z:1) = 50.00, 3.00 Total Depth (ft) = 0.76 Invert Elev (ft) = 814.74 Slope (%) = 0.80 N-Value = 0.013 Calculations Compute by: Known Q Known Q (cfs) = 43.35 Highlighted Depth (ft) = 0.60 Q (cfs) = 43.35 Area (sqft) = 9.54 Velocity (ft/s) = 4.54 Wetted Perim (ft) = 31.90 Crit Depth, Yc (ft) = 0.70 Top Width (ft) = 31.80 EGL (ft) = 0.92 0 5 10 15 20 25 30 35 40 45 50 55 Elev (ft) Depth (ft)Section 814.00 -0.74 814.50 -0.24 815.00 0.26 815.50 0.76 816.00 1.26 Reach (ft)04/17/2023 50 Appendix B Proposed Detention Pre & Post-Developed Conditions Exhibit and Calculations 04/17/2023 51 04/17/2023 52 1S Existing Tributary Area Routing Diagram for Existing Conditions Prepared by Cripe, Printed 12/21/2022 HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Subcat Reach Pond Link 04/17/2023 53 Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Existing Conditions Printed 12/21/2022Prepared by Cripe Page 2HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 0.15 cfs @ 11.99 hrs, Volume= 0.009 af, Depth= 0.33" Routed to nonexistent node 2P Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Area (ac) CN Description 0.310 61 >75% Grass cover, Good, HSG B * 0.030 98 Paved Path 0.340 64 Weighted Average 0.310 91.18% Pervious Area 0.030 8.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Assumed Minimum Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Runoff Area=0.340 ac Runoff Volume=0.009 af Runoff Depth=0.33" Tc=5.0 min CN=64 0.15 cfs 04/17/2023 54 Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Existing Conditions Printed 12/21/2022Prepared by Cripe Page 3HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 0.50 cfs @ 11.97 hrs, Volume= 0.025 af, Depth= 0.88" Routed to nonexistent node 2P Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83" Area (ac) CN Description 0.310 61 >75% Grass cover, Good, HSG B * 0.030 98 Paved Path 0.340 64 Weighted Average 0.310 91.18% Pervious Area 0.030 8.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Assumed Minimum Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 - Year 24 HR. Rainfall=3.83" Runoff Area=0.340 ac Runoff Volume=0.025 af Runoff Depth=0.88" Tc=5.0 min CN=64 0.50 cfs 04/17/2023 55 Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Existing Conditions Printed 12/21/2022Prepared by Cripe Page 4HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Tributary Area Runoff = 1.59 cfs @ 11.96 hrs, Volume= 0.074 af, Depth= 2.60" Routed to nonexistent node 2P Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100 - Year, 24 HR Rainfall=6.46" Area (ac) CN Description 0.310 61 >75% Grass cover, Good, HSG B * 0.030 98 Paved Path 0.340 64 Weighted Average 0.310 91.18% Pervious Area 0.030 8.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Assumed Minimum Subcatchment 1S: Existing Tributary Area Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 100 - Year 24 HR Rainfall=6.46" Runoff Area=0.340 ac Runoff Volume=0.074 af Runoff Depth=2.60" Tc=5.0 min CN=64 1.59 cfs 04/17/2023 56 04/17/2023 57 1S Proposed Tennis Courts 2P 54" Pipe Storage Routing Diagram for Proposed Conditions Prepared by Cripe, Printed 4/13/2023 HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Subcat Reach Pond Link 04/17/2023 58 Proposed Conditions Table of ContentsProposed Conditions Printed 4/13/2023Prepared by Cripe HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC TABLE OF CONTENTS Project Reports 1 Routing Diagram 2 Rainfall Events Listing 3 Area Listing (all nodes) 4 Ground Covers (all nodes) 2 Year - 24 HR Event 5 Node Listing 6 Subcat 1S: Proposed Tennis Courts 7 Pond 2P: 54" Pipe Storage 10 - Year, 24 HR. Event 9 Node Listing 10 Subcat 1S: Proposed Tennis Courts 11 Pond 2P: 54" Pipe Storage 100 - Year, 24 HR Event 13 Node Listing 14 Subcat 1S: Proposed Tennis Courts 15 Pond 2P: 54" Pipe Storage Multi-Event Tables 17 Subcat 1S: Proposed Tennis Courts 18 Pond 2P: 54" Pipe Storage 04/17/2023 59 Proposed Conditions Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 2HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 2 Year - 24 HR Type II 24-hr Default 24.00 1 2.66 2 2 10 - Year, 24 HR. Type II 24-hr Default 24.00 1 3.83 2 3 100 - Year, 24 HR Type II 24-hr Default 24.00 1 6.46 2 04/17/2023 60 Proposed Conditions Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 3HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.340 98 Impervious (1S) 0.340 98 TOTAL AREA 04/17/2023 61 Proposed Conditions Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 4HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 0.000 0.000 0.340 0.340 Impervious 1S 0.000 0.000 0.000 0.000 0.340 0.340 TOTAL AREA 04/17/2023 62 Proposed Conditions Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 5HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=0.340 ac 100.00% Impervious Runoff Depth=2.43"Subcatchment 1S: Proposed Tennis Tc=5.0 min CN=98 Runoff=1.29 cfs 0.069 af Peak Elev=810.05' Storage=352 cf Inflow=1.29 cfs 0.069 afPond 2P: 54" Pipe Storage Outflow=0.83 cfs 0.069 af Total Runoff Area = 0.340 ac Runoff Volume = 0.069 af Average Runoff Depth = 2.43" 0.00% Pervious = 0.000 ac 100.00% Impervious = 0.340 ac 04/17/2023 63 Proposed Conditions Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 6HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Proposed Tennis Courts Runoff = 1.29 cfs @ 11.95 hrs, Volume= 0.069 af, Depth= 2.43" Routed to Pond 2P : 54" Pipe Storage Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Area (ac) CN Description * 0.340 98 Impervious 0.340 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Assumed Minimum Subcatchment 1S: Proposed Tennis Courts Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 2 Year - 24 HR Rainfall=2.66" Runoff Area=0.340 ac Runoff Volume=0.069 af Runoff Depth=2.43" Tc=5.0 min CN=98 1.29 cfs 04/17/2023 64 Proposed Conditions Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 7HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: 54" Pipe Storage Inflow Area = 0.340 ac,100.00% Impervious, Inflow Depth = 2.43" for 2 Year - 24 HR event Inflow = 1.29 cfs @ 11.95 hrs, Volume= 0.069 af Outflow = 0.83 cfs @ 12.02 hrs, Volume= 0.069 af, Atten= 35%, Lag= 4.5 min Primary = 0.83 cfs @ 12.02 hrs, Volume= 0.069 af Routed to nonexistent node 4P Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 810.05' @ 12.02 hrs Surf.Area= 356 sf Storage= 352 cf Plug-Flow detention time= 3.3 min calculated for 0.069 af (100% of inflow) Center-of-Mass det. time= 3.3 min ( 759.1 - 755.7 ) Volume Invert Avail.Storage Storage Description #1 808.64' 1,368 cf 54.0" Round Pipe Storage L= 86.0' S= 0.0010 '/' Device Routing Invert Outlet Devices #1 Primary 813.20'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #2 Primary 808.64'5.4" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.83 cfs @ 12.02 hrs HW=810.03' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Orifice/Grate (Orifice Controls 0.83 cfs @ 5.19 fps) 04/17/2023 65 Proposed Conditions Type II 24-hr 2 Year - 24 HR Rainfall=2.66"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 8HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: 54" Pipe Storage Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=0.340 ac Peak Elev=810.05' Storage=352 cf 1.29 cfs 0.83 cfs 04/17/2023 66 Proposed Conditions Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 9HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=0.340 ac 100.00% Impervious Runoff Depth=3.60"Subcatchment 1S: Proposed Tennis Tc=5.0 min CN=98 Runoff=1.87 cfs 0.102 af Peak Elev=810.80' Storage=632 cf Inflow=1.87 cfs 0.102 afPond 2P: 54" Pipe Storage Outflow=1.06 cfs 0.102 af Total Runoff Area = 0.340 ac Runoff Volume = 0.102 af Average Runoff Depth = 3.60" 0.00% Pervious = 0.000 ac 100.00% Impervious = 0.340 ac 04/17/2023 67 Proposed Conditions Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 10HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Proposed Tennis Courts Runoff = 1.87 cfs @ 11.95 hrs, Volume= 0.102 af, Depth= 3.60" Routed to Pond 2P : 54" Pipe Storage Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83" Area (ac) CN Description * 0.340 98 Impervious 0.340 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Assumed Minimum Subcatchment 1S: Proposed Tennis Courts Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)2 1 0 Type II 24-hr 10 - Year 24 HR. Rainfall=3.83" Runoff Area=0.340 ac Runoff Volume=0.102 af Runoff Depth=3.60" Tc=5.0 min CN=98 1.87 cfs 04/17/2023 68 Proposed Conditions Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 11HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: 54" Pipe Storage Inflow Area = 0.340 ac,100.00% Impervious, Inflow Depth = 3.60" for 10 - Year, 24 HR. event Inflow = 1.87 cfs @ 11.95 hrs, Volume= 0.102 af Outflow = 1.06 cfs @ 12.04 hrs, Volume= 0.102 af, Atten= 43%, Lag= 5.2 min Primary = 1.06 cfs @ 12.04 hrs, Volume= 0.102 af Routed to nonexistent node 4P Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 810.80' @ 12.04 hrs Surf.Area= 386 sf Storage= 632 cf Plug-Flow detention time= 4.2 min calculated for 0.102 af (100% of inflow) Center-of-Mass det. time= 4.2 min ( 752.1 - 747.9 ) Volume Invert Avail.Storage Storage Description #1 808.64' 1,368 cf 54.0" Round Pipe Storage L= 86.0' S= 0.0010 '/' Device Routing Invert Outlet Devices #1 Primary 813.20'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #2 Primary 808.64'5.4" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=1.06 cfs @ 12.04 hrs HW=810.77' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Orifice/Grate (Orifice Controls 1.06 cfs @ 6.65 fps) 04/17/2023 69 Proposed Conditions Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 12HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: 54" Pipe Storage Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)2 1 0 Inflow Area=0.340 ac Peak Elev=810.80' Storage=632 cf 1.87 cfs 1.06 cfs 04/17/2023 70 Proposed Conditions Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 13HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=0.340 ac 100.00% Impervious Runoff Depth=6.22"Subcatchment 1S: Proposed Tennis Tc=5.0 min CN=98 Runoff=3.17 cfs 0.176 af Peak Elev=813.09' Storage=1,361 cf Inflow=3.17 cfs 0.176 afPond 2P: 54" Pipe Storage Outflow=1.57 cfs 0.176 af Total Runoff Area = 0.340 ac Runoff Volume = 0.176 af Average Runoff Depth = 6.22" 0.00% Pervious = 0.000 ac 100.00% Impervious = 0.340 ac 04/17/2023 71 Proposed Conditions Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 14HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Proposed Tennis Courts Runoff = 3.17 cfs @ 11.95 hrs, Volume= 0.176 af, Depth= 6.22" Routed to Pond 2P : 54" Pipe Storage Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100 - Year, 24 HR Rainfall=6.46" Area (ac) CN Description * 0.340 98 Impervious 0.340 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Assumed Minimum Subcatchment 1S: Proposed Tennis Courts Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)3 2 1 0 Type II 24-hr 100 - Year 24 HR Rainfall=6.46" Runoff Area=0.340 ac Runoff Volume=0.176 af Runoff Depth=6.22" Tc=5.0 min CN=98 3.17 cfs 04/17/2023 72 Proposed Conditions Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 15HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Pond 2P: 54" Pipe Storage Inflow Area = 0.340 ac,100.00% Impervious, Inflow Depth = 6.22" for 100 - Year, 24 HR event Inflow = 3.17 cfs @ 11.95 hrs, Volume= 0.176 af Outflow = 1.57 cfs @ 12.05 hrs, Volume= 0.176 af, Atten= 50%, Lag= 6.0 min Primary = 1.57 cfs @ 12.05 hrs, Volume= 0.176 af Routed to nonexistent node 4P Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 813.09' @ 12.05 hrs Surf.Area= 107 sf Storage= 1,361 cf Plug-Flow detention time= 6.0 min calculated for 0.176 af (100% of inflow) Center-of-Mass det. time= 6.0 min ( 744.9 - 739.0 ) Volume Invert Avail.Storage Storage Description #1 808.64' 1,368 cf 54.0" Round Pipe Storage L= 86.0' S= 0.0010 '/' Device Routing Invert Outlet Devices #1 Primary 813.20'5.0' long x 0.5' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32 #2 Primary 808.64'5.4" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=1.57 cfs @ 12.05 hrs HW=813.09' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Orifice/Grate (Orifice Controls 1.57 cfs @ 9.90 fps) 04/17/2023 73 Proposed Conditions Type II 24-hr 100 - Year, 24 HR Rainfall=6.46"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 16HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Pond 2P: 54" Pipe Storage Inflow Primary Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)3 2 1 0 Inflow Area=0.340 ac Peak Elev=813.09' Storage=1,361 cf 3.17 cfs 1.57 cfs 04/17/2023 74 Proposed Conditions Multi-Event TablesProposed Conditions Printed 4/13/2023Prepared by Cripe Page 17HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Events for Subcatchment 1S: Proposed Tennis Courts Event Rainfall (inches) Runoff (cfs) Volume (acre-feet) Depth (inches) 2 Year - 24 HR 2.66 1.29 0.069 2.43 10 - Year, 24 HR. 3.83 1.87 0.102 3.60 100 - Year, 24 HR 6.46 3.17 0.176 6.22 04/17/2023 75 Proposed Conditions Multi-Event TablesProposed Conditions Printed 4/13/2023Prepared by Cripe Page 18HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Events for Pond 2P: 54" Pipe Storage Event Inflow (cfs) Primary (cfs) Elevation (feet) Storage (cubic-feet) 2 Year - 24 HR 1.29 0.83 810.05 352 10 - Year, 24 HR. 1.87 1.06 810.80 632 100 - Year, 24 HR 3.17 1.57 813.09 1,361 04/17/2023 76 Channel Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Monday, Apr 17 2023 Overflow from Proposed UGD Rectangular Bottom Width (ft) = 4.00 Total Depth (ft) = 2.00 Invert Elev (ft) = 813.10 Slope (%) = 0.40 N-Value = 0.013 Calculations Compute by: Known Q Known Q (cfs) = 3.96 Highlighted Depth (ft) = 0.33 Q (cfs) = 3.960 Area (sqft) = 1.32 Velocity (ft/s) = 3.00 Wetted Perim (ft) = 4.66 Crit Depth, Yc (ft) = 0.32 Top Width (ft) = 4.00 EGL (ft) = 0.47 0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5 Elev (ft) Depth (ft)Section 812.50 -0.60 813.00 -0.10 813.50 0.40 814.00 0.90 814.50 1.40 815.00 1.90 815.50 2.40 816.00 2.90 Reach (ft)04/17/2023 77 Appendix C Proposed Water Quality Post-Developed Conditions Calculations 04/17/2023 78 1S Proposed Tennis Courts 2P 54" Pipe Storage Routing Diagram for Proposed Conditions Prepared by Cripe, Printed 4/7/2023 HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Subcat Reach Pond Link 04/17/2023 79 Proposed Conditions Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83"Proposed Conditions Printed 4/13/2023Prepared by Cripe Page 10HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Proposed Tennis Courts Runoff = 1.87 cfs @ 11.95 hrs, Volume= 0.102 af, Depth= 3.60" Routed to Pond 2P : 54" Pipe Storage Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10 - Year, 24 HR. Rainfall=3.83" Area (ac) CN Description * 0.340 98 Impervious 0.340 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Assumed Minimum Subcatchment 1S: Proposed Tennis Courts Runoff Hydrograph Time (hours) 10095908580757065605550454035302520151050Flow (cfs)2 1 0 Type II 24-hr 10 - Year 24 HR. Rainfall=3.83" Runoff Area=0.340 ac Runoff Volume=0.102 af Runoff Depth=3.60" Tc=5.0 min CN=98 1.87 cfs 04/17/2023 80 Proposed Conditions Multi-Event TablesProposed Conditions Printed 4/13/2023Prepared by Cripe Page 18HydroCAD® 10.20-2d s/n 11639 © 2021 HydroCAD Software Solutions LLC Events for Pond 2P: 54" Pipe Storage Event Inflow (cfs) Primary (cfs) Elevation (feet) Storage (cubic-feet) 2 Year - 24 HR 1.29 0.83 810.05 352 10 - Year, 24 HR. 1.87 1.06 810.80 632 100 - Year, 24 HR 3.17 1.57 813.09 1,361 04/17/2023 81 City of Indianapolis Stormwater Quality Unit (SQU) Selection Guide Pg. 2 05/10/2022 Version 22 Manufactured SQU SQU System Model Max Treatment Flow (cfs) Max 10-yr On-Line Flow Rate (cfs) Cleanout Depth (Inches) 3-ft 0.85 1.84 9 4-ft 1.5 3.24 9 5-ft 2.35 5.08 9 6-ft 3.38 7.30 9 7-ft 4.60 9.94 9 Hydro International First Defense High Capacity 8-ft 6.00 12.96 9 HS-3 0.50 1.00 6 HS-4 0.88 1.76 6 HS-5 1.37 2.74 6 HS-6 1.98 3.96 6 HS-7 2.69 5.38 6 HS-8 3.52 7.04 6 HS-9 4.45 8.9 6 HS-10 5.49 10.98 6 HS-11 6.65 13.3 6 HydroStorm by Hydroworks, LLC HS-12 7.91 15.82 6 XC-2 0.57 1.16 6 XC-3 1.13 2.30 6 XC-4 1.86 3.79 6 XC-5 2.78 5.66 6 XC-6 3.88 7.90 6 XC-7 5.17 10.52 6 XC-8 6.64 13.51 6 XC-9 8.29 16.87 6 XC-10 10.13 20.62 6 XC-11 12.15 24.73 6 XC-12 14.35 29.20 6 AquaShield Aqua-Swirl Xcelerator1 XC-13 15.53 31.60 6 CS-3 1.02 2.27 9 CS-4 1.80 4.03 9 CS-5 2.81 6.29 9 CS-6 4.05 9.07 9 CS-8 7.20 16.1 9 CS-10 11.3 25.3 9 Contech Cascade Separator CS-12 16.2 36.3 9 04/17/2023 82 06/28/07 Exhibit 701-1: Curve Number Calculation for Water Quality Storm Event Water Quality Curve Number7072747678808284868890929496981000 102030405060708090100Percent ImperviousnessWater Quality Curve Number (CNwq)04/17/2023 83 1 July 23, 2019 Mark B. Miller, Research Scientist AquaShield™, Inc. 2733 Kanasita Drive, Suite 111 Chattanooga, TN 37343 Re: MTD Lab Certification Aqua-Swirl® XCelerator Stormwater Treatment System On-line Installation TSS Removal Rate 50% Dear Mr. Miller: The Stormwater Management rules under N.J.A.C. 7:8-5.5(b) and 5.7(c) allow the use of manufactured treatment devices (MTDs) for compliance with the design and performance standards at N.J.A.C. 7:8-5 if the pollutant removal rates have been verified by the New Jersey Corporation for Advanced Technology (NJCAT) and have been certified by the New Jersey Department of Environmental Protection (NJDEP). AquaShield™, Inc. has requested an MTD Laboratory Certification for the Aqua-Swirl® XCelerator Stormwater Treatment System (Aqua- Swirl® XCelerator). The project falls under the “Procedure for Obtaining Verification of a Stormwater Manufactured Treatment Device from New Jersey Corporation for Advance Technology” dated January 25, 2013. The applicable protocol is the “New Jersey Laboratory Testing Protocol to Assess Total Suspended Solids Removal by a Hydrodynamic Sedimentation Manufactured Treatment Device” dated January 25, 2013. NJCAT verification documents submitted to the NJDEP indicate that the requirements of the aforementioned protocol have been met or exceeded. The NJCAT letter also included a recommended certification TSS removal rate and the required maintenance plan. The NJCAT Verification Report with the Verification Appendix (dated June 2019) for this device is published online at http://www.njcat.org/verification-process/technology-verification- database.html. DEPARTMENT OF ENVIRONMENTAL PROTECTION PHILIP D. MURPHY CATHERINE R. MCCABE Governor Commissioner SHEILA Y. OLIVER Lt. Governor New Jersey is an Equal Opportunity Employer Printed on Recycled Paper and Recyclable Bureau of Nonpoint Pollution Control Division of Water Quality 401-02B Post Office Box 420 Trenton, New Jersey 08625-0420 609-633-7021 Fax: 609-777-0432 http://www.state.nj.us/dep/dwq/bnpc_home.htm 04/17/2023 84 2 The NJDEP certifies the use of the Aqua-Swirl® XCelerator Stormwater Treatment System at a TSS removal rate of 50% when designed, operated, and maintained in accordance with the information provided in the Verification Appendix and the following conditions: 1. The maximum treatment flow rate (MTFR) for the manufactured treatment device (MTD) is calculated using the New Jersey Water Quality Design Storm (1.25 inches in 2 hrs) in N.J.A.C. 7:8-5.5. 2. The Aqua-Swirl® XCelerator shall be installed using the same configuration reviewed by NJCAT and shall be sized in accordance with the criteria specified in item 6 below. 3. This Aqua-Swirl® XCelerator cannot be used in series with another MTD or a media filter (such as a sand filter) to achieve an enhanced removal rate for total suspended solids (TSS) removal under N.J.A.C. 7:8-5.5. 4. Additional design criteria for MTDs can be found in Chapter 9.6 of the New Jersey Stormwater Best Management Practices (NJ Stormwater BMP) Manual, which can be found online at www.njstormwater.org. 5. The maintenance plan for a site using this device shall incorporate, at a minimum, the maintenance requirements for the Aqua-Swirl® XCelerator. A copy of the maintenance plan is attached to this certification. However, it is recommended to review the maintenance website at https://cdn.websites.hibu.com/a97c027d62d54a948588ae7d58f831d0/files/uploaded/XC%20IM%20Manua l_04-19_karG16DlTgiSiif2vPL4.pdf for any changes to the maintenance requirements. 6. Sizing Requirement: The example below demonstrates the sizing procedure for the Aqua-Swirl® XCelerator: Example: A 0.25-acre impervious site is to be treated to 50% TSS removal using an Aqua-Swirl® XCelerator. The impervious site runoff (Q) based on the New Jersey Water Quality Design Storm was determined to be 0.79 cfs. Maximum Treatment Flow Rate (MTFR) Evaluation: The site runoff (Q) was based on the following: time of concentration = 10 minutes i = 3.2 in/hr (page 5-8, Fig. 5-3 of the NJ Stormwater BMP Manual) c = 0.99 (runoff coefficient for impervious) Q = ciA = 0.99 x 3.2 x 0.25 = 0.79 cfs Given the site runoff is 0.79 cfs and based on Table A-1 below, the Aqua-Swirl® XCelerator Model XC-3 with an MTFR of 1.13 cfs would be the smallest model approved that could be used for this site to remove 50% of the TSS from the impervious area without exceeding the MTFR. 04/17/2023 85 3 The sizing table corresponding to the available system models is noted below. Additional specifications regarding each model can be found in the Verification Appendix under Tables A-1 and A-2. Table A-1 Aqua-Swirl® XCelerator Models and Associated MTFRs Model Manhole Diameter (ft) NJDEP 50% TSS Maximum Treatment Flow Rate, MTFR (cfs) 50% Maximum Sediment Storage Area Volume (ft3) XC-2 2.5 0.57 2.46 XC-3 3.5 1.13 4.81 XC-4 4.5 1.86 7.95 XC-5 5 2.30 9.82 XC-6 6 3.31 14.14 XC-7 7 4.50 19.24 XC-8 8 5.88 25.14 XC-9 9 7.44 31.81 XC-10 10 9.19 39.27 XC-11 11 11.12 47.52 XC-12 12 13.23 56.55 XC-13 13 15.53 66.37 A detailed maintenance plan is mandatory for any project with a stormwater BMP subject to the Stormwater Management rules under N.J.A.C. 7:8. The plan must include all of the items identified in the Maintenance requirements section of the Stormwater Management rules under N.J.A.C. 7:8-5.8. Such items include, but are not limited to, the list of inspection and maintenance equipment and tools, specific corrective and preventative maintenance tasks, indication of problems in the system, and training of maintenance personnel. Additional information can be found in Chapter 8: Maintenance and Retrofit of Stormwater Management Measures. 04/17/2023 86 4 If you have any questions regarding the above information, please contact Brian Salvo of my office at (609) 633-7021. Sincerely, Gabriel Mahon, Chief Bureau of Nonpoint Pollution Control Attachment: Maintenance Plan cc: Chron File Richard Magee, NJCAT Jim Murphy, NJDEP-BNPC Vince Mazzei, NJDEP - DLUR Brian Salvo, NJDEP - BNPC 04/17/2023 87 City of Indianapolis Storm Water Specifications Manual Page 7-1 May 2022 Effective – FINAL Chapter 700. Stormwater Quality Section 701. Introduction 701.01 Chapter Description This chapter provides design criteria for stormwater quality best management practices, or BMPs that are required in order for newly developed or redeveloped properties to comply with the City’s policies for managing the post - construction quality of stormwater runoff found in Section 104.02 of this Manual. 701.02 Purpose and Background BMPs discussed in this chapter refer to post-construction BMPs, intended to control the quality of stormwater runoff after construction has been completed and the site has been stabilized. Installing certain BMPs, such as bioretention areas and sand filters, prior to stabilization can cause failure of the measure due to clogging from construction site run-off sediment. However, with a strict construction sequence and appropriate construction site erosion and sediment controls, detention ponds can be installed initially, during construction, and used as sediment control measures. In those instances, the construction sequence must require that the pond(s) are cleaned out with pertinent elevations and storage and treatment capacities reestabl ished as designed and permitted. 701.03 Stormwater Quality Control Requirements The City of Indianapolis has adopted a stormwater runoff quality policy (Section 104.02 of this Manual) based on the control of total suspended solids and floatables in stormwater runoff. In addition, designers may be required to include the control of other pollutants as required by the City’s MS4 NPDES permit. The water quality design requirements are as follows: 1.Total Suspended Solids (TSS). BMPs must be capable of removing eighty percent (80%) of the TSS load from post-construction runoff. Constructed BMPs listed in this section are approved to meet this requirement and manufactured BMPs approved in accordance with the City’s Stormwater Quality Unit (SQU) Evaluation Criteria are also acceptable to meet this requirement. For the purposes of this requirement, TSS is defined as particles smaller than one hundred twenty-five (125) microns in diameter. Larger material is considered to be part of the total solids load of the stormwater runoff. 2.Floatables. BMPs shall incorporate floatables control. The goal of this requirement is to capture floating debris and remove it as part of the routine maintenance of the BMPs. St andalone BMPs must include floatables control. For BMP systems, or treatment trains, at least one of the components of the BMP system, located after the last inflow point to the system, must provide control of floatables. Development and redevelopment projects shall be required to comply with this chapter if the construction activity disturbs one half (½) acre or more land, as noted in Section 104.02 of this Manual. 701.04 Stormwater Quality Design Methods There are two categories of design methods currently in use in the City of Indianapolis: performance-based design for pre-approved BMPs, and proprietary design for innovative BMPs. 04/17/2023 88 04/17/202389 04/17/202390 Appendix D Proposed Storm Post-Developed Conditions Calculations 04/17/2023 91 04/17/2023 92 04/17/2023 93 04/17/2023 94 04/17/2023 95 04/17/2023 96 04/17/2023 97 04/17/2023 98 04/17/2023 99 04/17/2023 100 04/17/2023 101 04/17/2023 102 04/17/2023 103 Project Name: Project No: Calculations By: Date: Description: PER 2 FT TRENCH DRAIN Depth Over Grate (FT) Weir (CFS) Orifice (CFS) Casting Type NEENAH R-4994-CAB 0.00 0.00 0.00 0.4 0.05 0.05 0.22 2 0.10 0.13 0.31 1 0.15 0.24 0.38 YES 0.20 0.38 0.44 0.2 0.25 0.53 0.49 1.4 0.30 0.69 0.54 (Weir)0.35 0.87 0.58 (Orifice)0.40 1.06 0.62 0.45 1.27 0.66 0.50 1.48 0.69 (10 YR, TC=5 MIN) i = 6.12 IN/HR 0.55 1.71 0.73 C=0.85 A=0.006 AC 14596 SQ FT Total Flow to Inlet 0.03 CFS 120 FT 243.27 SQFT AREA/2FT PER 2 FT TRENCH DRAIN Depth Over Grate (FT) Weir (CFS) Orifice (CFS) Casting Type NEENAH R-4994-CAB 0.00 0.00 0.00 0.4 0.05 0.05 0.22 2 0.10 0.13 0.31 1 0.15 0.24 0.38 YES 0.20 0.38 0.44 0.2 0.25 0.53 0.49 1.4 0.30 0.69 0.54 (Weir)0.35 0.87 0.58 (Orifice)0.40 1.06 0.62 0.45 1.27 0.66 0.50 1.48 0.69 (100 YR, TC=5 MIN) i = 9.12 IN/HR 0.55 1.71 0.73 C= 0.85 A= 0.006 AC 14596 SQ FT Total Flow to Inlet 0.04 CFS 120 FT OF TRENCH D. 243.27 SQFT AREA/2FT 10 YR Depth Over Grate = 0.05 FT OR 0.6 IN100 YR Total Open Area with Clogged Factor (A) Total Weir Perimeter with Clogged Factor (P) Q=3.0*P*D^1.5 Q=4.89*A*D^0.5 Q=CiA STRUCTURE NUMBER Open Area (SQ FT.) Weir Perimeter (LF.) Number of Castings 50% Clogged??? (YES/N0) Depth Over Grate = 0.04 FT STRUCTURE NUMBER Open Area (SQ FT.) Weir Perimeter (LF.) 50% Clogged??? (YES/N0) Number of Castings Total Open Area with Clogged Factor (A) Total Weir Perimeter with Clogged Factor (P) Q=3.0*P*D^1.5 Q=4.89*A*D^0.5 Q=CiA 0.4 IN OR Woodland 220139-20000 EBI, PE 4/14/2023 Inlet Capacity - Ponding Depth 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 0.00 0.20 0.40 0.60Flow through Casting, cfsDepth Over Grate, ft Grate Discharge Weir Orifice 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 0.00 0.20 0.40 0.60Flow through Casting, cfsDepth Over Grate, ft Grate Discharge Weir Orifice O:\2022\220139\20000\Calcs\Engr\Storm\Prelim\2nd Submittal\Excel\Cripe_STM_Ponding Inlet_Calculations_TD_2023-04-14.xlsx - 4/17/2023 04/17/2023 104 Appendix E Memo of Recognitions and Concessions 04/17/2023 105 9339 Priority Way West Drive, Suite 100 Indianapolis, IN 46240 Ph: 317.844.6777 Fax: 317.706.6451 www.cripe.biz Page 1 of 3 MEMORANDUM TO: CrossRoad Engineers FROM: Cripe DATE: 04-12-2023 RE: Woodland Country Club Golf Training / Tennis Pavilion Memo of Recognitions and Concessions Summary The Golf Training and Tennis Pavilion project consists of the construction of a 3,026 sq.ft. golf training building and a 1,378 sq.ft. tennis observation pavilion with restrooms. The proposed improvements will only disturb 1.67 acres of the larger 60+ acre parcel. The existing detention for the parking lot tributary area was designed in the 1980s as surface storage in the parking lot. There were different detention and rainfall requirements at that time. There were no water quality requirements at that time. There is no available copy of the existing detention system drainage report from the 1980s. This detention is an existing nonconforming stormwater storage area. The existing drainage system for this site is not reported to have any negative downstream inpacts in the existing condition. Therefore, the existing condition release rates can be maintained without any negative downstream inpacts in the proposed condition. This memo is comprised of Cripe’s understanding of conversations and emails regarding drainage or water quality agreed to between the City of Carmel and Woodland Country Club. Recognitions and Concessions Emergency Access  There is no existing right-of-way on the existing site.  Dedication of right-of-way shall not be required at this time, but may be required in the future.  The existing access road is not centered in the existing access easement. 04/17/2023 106 9339 Priority Way West Drive, Suite 100 Indianapolis, IN 46240 Ph: 317.844.6777 Fax: 317.706.6451 www.cripe.biz Page 2 of 3  The existing access easement may be rewritten near the proposed tennis courts to shift the easement closser to the existing access road such that the proposed tennis courts, trench drain and water quality BMP will not be located within the access easement. Detention  The existing stormwater detention for the parking lot tributary area was designed in the 1980s as surface storage in the parking lot. This detention is an existing nonconforming stormwater storage area and the volume will remain as in the existing condition with this project.  This project will not be required to update the existing detention area to current detention and water quality standards.  This project will not be required to update the existing detention area to current detention and water quality standards. This shall include easement requirements. A waiver of any easements for the existing system shall be granted.  The storm sewer outlets to a headwall via an 18-inch pipe with a sluice gate kept in the fully open position. The sluice gate will be removed in the proposed condition.  Carmel’s expectation is that the project will provide post-construction detention for the added tennis/pickleball court area. This is a concession by the City from the full project area, and the minimum area that is acceptable to be detained.  Post-construction 100-year detention for the added tennis/pickleball court area will have a release rate that is equal to or less than the 100-year existing conditions for this area. This is a concession by the City from the full project area, and the minimum area that is acceptable to be detained.  Post-construction 100-year detention for the added tennis/pickleball court area will be provided underground. Proper maintenance program for the provided water quality unit and the underground detention structure 2’ sump shall not require additional ten (10) percent capacity or forebay. This is a concession by the City from the full project area, and the minimum area that is acceptable to be detained.  Post-construction 10-year allowable release rate shall be 0.7 times the existing 100-year release rate for the tennis/pickleball court area post- construction detention.  The proposed detention system cannot meet the existing condition allowable release rates using an orifice of 6-inches or larger. Carmel will allow an orifice of 2-inches or larger in order to meet the allowable 04/17/2023 107 9339 Priority Way West Drive, Suite 100 Indianapolis, IN 46240 Ph: 317.844.6777 Fax: 317.706.6451 www.cripe.biz Page 3 of 3 release rates.  It is cost prohibitive to require detailed topographic survey of more than 5 acres of area beyond the project limits (and more than double the disturbed area) for an existing model of the ajacent existing parking lot detention.  GIS information will be acceptable for an approximated model of the existing conditions of the parking lot detention area.  An existing model of ajacent areas other than the parking lot detention area will not be provided with this project.  The underground storm pipe is is a private utility within private property. It shall be maintained by the owner.  The underground storm pipe is is a private utility within private property. The requirement for a 15’ horizontal easement in each direction (30 ft min) shall be waived for the private utility.  It is the City’s preference for the added detention (oversized pipe) to be combined with the existing storm system, so that the entire system can receive the benefit of the added detention for the court area. Water Quality  Carmel’s expectation is that the project will provide post-construction water quality for the added tennis/pickleball court area. This is a concession by the City from the full project area, and the minimum area that is acceptable to be treated.  A 20 ft wide water quality easement will be provided agacent to the proposed access easement and east of the proposed tennis court fencing. Stormwater Conveyance and Flood Routing  The existing concrete drainage ditch on the east side of the site shall be maintained.  GIS information will be acceptable for an approximated location of existing flood routing at the limits of the site.  The existing drainage flood routes for the site shall be maintained.  The 30 foot drainage easement requirement shall be waived for the existing concrete drainage ditch. Cripe may not have been copied on all correspondence and there may be other items unrelated to the drainage design that are not listed above. 04/17/2023 108