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WAKEBY RD-DRAFT SW DRAINAGE ADDENDUM #1STORMWATER DRAINAGE ANALYSIS ADDENDUM #1 For Wakeby Road Solar Project 810 Wakeby Road, Marston Mills-Barnstable, MA Prepared for: TJA Clean Energy 150 John Vertente Boulevard New Bedford, MA Prepared by: Atlantic Design Engineers, Inc. P.O. Box 1051 Sandwich, Massachusetts 02563 May 18, 2023 ADE Project No. 3064.04DRAFT Stormwater Drainage Analysis Addendum #1 Wakeby Road Solar Project Marstons Mills-Barnstable, Massachusetts May 18, 2023 Page 1 TABLE OF CONTENTS 1.0 Summary APPENDICES A. Revised HydroCAD Stormwater Modeling Calculations B. Revised Post-Development Watershed Plan DRAFT Stormwater Drainage Analysis Addendum #1 Wakeby Road Solar Project Marstons Mills-Barnstable, Massachusetts May 18, 2023 Page 2 1.0 SUMMARY This Addendum #1 to the original stormwater report dated 02/01/2023 addresses changes to the stormwater/drainage due to the widening of the proposed gravel access way from 12-feet wide to 20- feet wide and associated proposed grading. Total pervious gravel increased by approximately 17,349 S.F. The following is a summary of the revisions incorporated into this Stormwater Report Addendum #1: • A revised HydroCAD Stormwater Modeling Calculations for Post-Development applying increased pervious gravel ground-cover due to widening of gravel access way width. • A revised Post-Development Watershed Plan dated May 18, 2023. DRAFT APPENDIX A Revised HydroCAD Stormwater Modeling Calculations DRAFT 1S 2S 3S 1P 2P 3P Routing Diagram for 3064.04-POST_REV 1 Prepared by {enter your company name here}, Printed 5/18/2023 HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond LinkDRAFT 3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 2HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Project Notes Defined 5 rainfall events from MA-BARNSTABLE IDF DRAFT 3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 3HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 241,172 39 >75% Grass cover, Good, HSG A (1S, 2S) 410,485 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S) 106,953 72 Dirt roads, HSG A (1S, 2S) 38,000 82 Dirt roads, HSG B (1S, 2S) 5,228 98 Roofs, HSG A (1S, 2S) 121,642 36 Woods, Fair, HSG A (1S, 2S) 144,045 60 Woods, Fair, HSG B (1S, 2S, 3S) 1,067,525 55 TOTAL AREA DRAFT 3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 4HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Notes Listing (all nodes) Line# Node Number Notes 1 Project Defined 5 rainfall events from MA-BARNSTABLE IDF DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 5HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=510,711 sf 0.66% Impervious Runoff Depth=0.23"Subcatchment 1S: Flow Length=483' Tc=11.7 min CN=52 Runoff=0.94 cfs 9,872 cf Runoff Area=488,472 sf 0.38% Impervious Runoff Depth=0.43"Subcatchment 2S: Flow Length=555' Tc=12.9 min CN=58 Runoff=2.54 cfs 17,333 cf Runoff Area=68,342 sf 0.00% Impervious Runoff Depth=0.54"Subcatchment 3S: Tc=6.0 min CN=61 Runoff=0.70 cfs 3,085 cf Peak Elev=68.01' Storage=305 cf Inflow=0.94 cfs 9,872 cfPond 1P: Outflow=0.85 cfs 9,872 cf Peak Elev=62.14' Storage=5,274 cf Inflow=2.54 cfs 17,333 cfPond 2P: Outflow=0.45 cfs 17,333 cf Peak Elev=66.09' Storage=827 cf Inflow=0.70 cfs 3,085 cfPond 3P: Outflow=0.11 cfs 3,085 cf Total Runoff Area = 1,067,525 sf Runoff Volume = 30,290 cf Average Runoff Depth = 0.34" 99.51% Pervious = 1,062,297 sf 0.49% Impervious = 5,228 sf DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 6HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 0.94 cfs @ 12.45 hrs, Volume= 9,872 cf, Depth= 0.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr Rainfall=3.43" Area (sf) CN Description 80,556 36 Woods, Fair, HSG A 98,588 72 Dirt roads, HSG A 180,032 39 >75% Grass cover, Good, HSG A 77,953 60 Woods, Fair, HSG B 64,282 61 >75% Grass cover, Good, HSG B 5,930 82 Dirt roads, HSG B 3,370 98 Roofs, HSG A 510,711 52 Weighted Average 507,341 99.34% Pervious Area 3,370 0.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 50 0.0600 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 0.5 40 0.0830 1.44 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 2.3 252 0.0130 1.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.9 141 0.0280 2.51 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 11.7 483 Total DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 7HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 1S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 2-yr Rainfall=3.43" Runoff Area=510,711 sf Runoff Volume=9,872 cf Runoff Depth=0.23" Flow Length=483' Tc=11.7 min CN=52 0.94 cfs DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 8HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Runoff = 2.54 cfs @ 12.28 hrs, Volume= 17,333 cf, Depth= 0.43" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr Rainfall=3.43" Area (sf) CN Description 41,086 36 Woods, Fair, HSG A 8,365 72 Dirt roads, HSG A 61,140 39 >75% Grass cover, Good, HSG A 50,235 60 Woods, Fair, HSG B 32,070 82 Dirt roads, HSG B 293,718 61 >75% Grass cover, Good, HSG B 1,858 98 Roofs, HSG A 488,472 58 Weighted Average 486,614 99.62% Pervious Area 1,858 0.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.5 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 1.3 86 0.0500 1.12 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 344 0.0640 3.79 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.2 20 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.4 55 0.0270 2.46 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 12.9 555 Total DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 9HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Type III 24-hr 2-yr Rainfall=3.43" Runoff Area=488,472 sf Runoff Volume=17,333 cf Runoff Depth=0.43" Flow Length=555' Tc=12.9 min CN=58 2.54 cfs DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 10HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Runoff = 0.70 cfs @ 12.11 hrs, Volume= 3,085 cf, Depth= 0.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 2-yr Rainfall=3.43" Area (sf) CN Description 15,857 60 Woods, Fair, HSG B 52,485 61 >75% Grass cover, Good, HSG B 68,342 61 Weighted Average 68,342 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 2-yr Rainfall=3.43" Runoff Area=68,342 sf Runoff Volume=3,085 cf Runoff Depth=0.54" Tc=6.0 min CN=61 0.70 cfs DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 11HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: Inflow Area = 510,711 sf, 0.66% Impervious, Inflow Depth = 0.23" for 2-yr event Inflow = 0.94 cfs @ 12.45 hrs, Volume= 9,872 cf Outflow = 0.85 cfs @ 12.55 hrs, Volume= 9,872 cf, Atten= 9%, Lag= 5.7 min Discarded = 0.85 cfs @ 12.55 hrs, Volume= 9,872 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 68.01' @ 12.55 hrs Surf.Area= 23,249 sf Storage= 305 cf Plug-Flow detention time= 6.0 min calculated for 9,871 cf (100% of inflow) Center-of-Mass det. time= 6.0 min ( 978.1 - 972.1 ) Volume Invert Avail.Storage Storage Description #1 68.00' 61,922 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 68.00 23,156 0 0 23,156 70.00 39,488 61,922 61,922 39,535 Device Routing Invert Outlet Devices #1 Discarded 68.00'2.410 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=1.30 cfs @ 12.55 hrs HW=68.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.30 cfs) Pond 1P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=510,711 sf Peak Elev=68.01' Storage=305 cf 0.94 cfs 0.85 cfs DRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 12HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 2P: Inflow Area = 488,472 sf, 0.38% Impervious, Inflow Depth = 0.43" for 2-yr event Inflow = 2.54 cfs @ 12.28 hrs, Volume= 17,333 cf Outflow = 0.45 cfs @ 15.18 hrs, Volume= 17,333 cf, Atten= 82%, Lag= 173.7 min Discarded = 0.45 cfs @ 15.18 hrs, Volume= 17,333 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 62.14' @ 15.18 hrs Surf.Area= 37,765 sf Storage= 5,274 cf Plug-Flow detention time= 124.6 min calculated for 17,330 cf (100% of inflow) Center-of-Mass det. time= 124.6 min ( 1,053.2 - 928.6 ) Volume Invert Avail.Storage Storage Description #1 62.00' 85,850 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 62.00 36,959 0 0 36,959 64.00 49,182 85,850 85,850 49,270 Device Routing Invert Outlet Devices #1 Discarded 62.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.45 cfs @ 15.18 hrs HW=62.14' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.45 cfs) Pond 2P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Inflow Area=488,472 sf Peak Elev=62.14' Storage=5,274 cf 2.54 cfs 0.45 cfsDRAFT Type III 24-hr 2-yr Rainfall=3.43"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 13HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 3P: Inflow Area = 68,342 sf, 0.00% Impervious, Inflow Depth = 0.54" for 2-yr event Inflow = 0.70 cfs @ 12.11 hrs, Volume= 3,085 cf Outflow = 0.11 cfs @ 13.48 hrs, Volume= 3,085 cf, Atten= 84%, Lag= 81.8 min Discarded = 0.11 cfs @ 13.48 hrs, Volume= 3,085 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 66.09' @ 13.48 hrs Surf.Area= 9,313 sf Storage= 827 cf Plug-Flow detention time= 74.6 min calculated for 3,084 cf (100% of inflow) Center-of-Mass det. time= 74.6 min ( 980.9 - 906.3 ) Volume Invert Avail.Storage Storage Description #1 66.00' 25,671 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 66.00 9,003 0 0 9,003 68.00 17,097 25,671 25,671 17,136 Device Routing Invert Outlet Devices #1 Discarded 66.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.11 cfs @ 13.48 hrs HW=66.09' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.11 cfs) Pond 3P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=68,342 sf Peak Elev=66.09' Storage=827 cf 0.70 cfs 0.11 cfsDRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 14HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=510,711 sf 0.66% Impervious Runoff Depth=0.80"Subcatchment 1S: Flow Length=483' Tc=11.7 min CN=52 Runoff=6.37 cfs 34,182 cf Runoff Area=488,472 sf 0.38% Impervious Runoff Depth=1.17"Subcatchment 2S: Flow Length=555' Tc=12.9 min CN=58 Runoff=10.50 cfs 47,576 cf Runoff Area=68,342 sf 0.00% Impervious Runoff Depth=1.37"Subcatchment 3S: Tc=6.0 min CN=61 Runoff=2.29 cfs 7,797 cf Peak Elev=68.33' Storage=8,126 cf Inflow=6.37 cfs 34,182 cfPond 1P: Outflow=1.43 cfs 34,182 cf Peak Elev=62.73' Storage=28,653 cf Inflow=10.50 cfs 47,576 cfPond 2P: Outflow=0.50 cfs 47,576 cf Peak Elev=66.41' Storage=3,996 cf Inflow=2.29 cfs 7,797 cfPond 3P: Outflow=0.13 cfs 7,797 cf Total Runoff Area = 1,067,525 sf Runoff Volume = 89,555 cf Average Runoff Depth = 1.01" 99.51% Pervious = 1,062,297 sf 0.49% Impervious = 5,228 sf DRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 15HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 6.37 cfs @ 12.21 hrs, Volume= 34,182 cf, Depth= 0.80" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr Rainfall=5.00" Area (sf) CN Description 80,556 36 Woods, Fair, HSG A 98,588 72 Dirt roads, HSG A 180,032 39 >75% Grass cover, Good, HSG A 77,953 60 Woods, Fair, HSG B 64,282 61 >75% Grass cover, Good, HSG B 5,930 82 Dirt roads, HSG B 3,370 98 Roofs, HSG A 510,711 52 Weighted Average 507,341 99.34% Pervious Area 3,370 0.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 50 0.0600 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 0.5 40 0.0830 1.44 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 2.3 252 0.0130 1.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.9 141 0.0280 2.51 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 11.7 483 Total DRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 16HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 1S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 10-yr Rainfall=5.00" Runoff Area=510,711 sf Runoff Volume=34,182 cf Runoff Depth=0.80" Flow Length=483' Tc=11.7 min CN=52 6.37 cfs DRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 17HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Runoff = 10.50 cfs @ 12.20 hrs, Volume= 47,576 cf, Depth= 1.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr Rainfall=5.00" Area (sf) CN Description 41,086 36 Woods, Fair, HSG A 8,365 72 Dirt roads, HSG A 61,140 39 >75% Grass cover, Good, HSG A 50,235 60 Woods, Fair, HSG B 32,070 82 Dirt roads, HSG B 293,718 61 >75% Grass cover, Good, HSG B 1,858 98 Roofs, HSG A 488,472 58 Weighted Average 486,614 99.62% Pervious Area 1,858 0.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.5 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 1.3 86 0.0500 1.12 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 344 0.0640 3.79 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.2 20 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.4 55 0.0270 2.46 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 12.9 555 Total DRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 18HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-yr Rainfall=5.00" Runoff Area=488,472 sf Runoff Volume=47,576 cf Runoff Depth=1.17" Flow Length=555' Tc=12.9 min CN=58 10.50 cfs DRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 19HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Runoff = 2.29 cfs @ 12.10 hrs, Volume= 7,797 cf, Depth= 1.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 10-yr Rainfall=5.00" Area (sf) CN Description 15,857 60 Woods, Fair, HSG B 52,485 61 >75% Grass cover, Good, HSG B 68,342 61 Weighted Average 68,342 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Type III 24-hr 10-yr Rainfall=5.00" Runoff Area=68,342 sf Runoff Volume=7,797 cf Runoff Depth=1.37" Tc=6.0 min CN=61 2.29 cfs DRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 20HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: Inflow Area = 510,711 sf, 0.66% Impervious, Inflow Depth = 0.80" for 10-yr event Inflow = 6.37 cfs @ 12.21 hrs, Volume= 34,182 cf Outflow = 1.43 cfs @ 13.14 hrs, Volume= 34,182 cf, Atten= 78%, Lag= 55.8 min Discarded = 1.43 cfs @ 13.14 hrs, Volume= 34,182 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 68.33' @ 13.14 hrs Surf.Area= 25,579 sf Storage= 8,126 cf Plug-Flow detention time= 49.6 min calculated for 34,177 cf (100% of inflow) Center-of-Mass det. time= 49.6 min ( 960.1 - 910.5 ) Volume Invert Avail.Storage Storage Description #1 68.00' 61,922 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 68.00 23,156 0 0 23,156 70.00 39,488 61,922 61,922 39,535 Device Routing Invert Outlet Devices #1 Discarded 68.00'2.410 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=1.43 cfs @ 13.14 hrs HW=68.33' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.43 cfs) Pond 1P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=510,711 sf Peak Elev=68.33' Storage=8,126 cf 6.37 cfs 1.43 cfsDRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 21HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 2P: Inflow Area = 488,472 sf, 0.38% Impervious, Inflow Depth = 1.17" for 10-yr event Inflow = 10.50 cfs @ 12.20 hrs, Volume= 47,576 cf Outflow = 0.50 cfs @ 18.00 hrs, Volume= 47,576 cf, Atten= 95%, Lag= 347.8 min Discarded = 0.50 cfs @ 18.00 hrs, Volume= 47,576 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 62.73' @ 18.00 hrs Surf.Area= 41,238 sf Storage= 28,653 cf Plug-Flow detention time= 640.4 min calculated for 47,576 cf (100% of inflow) Center-of-Mass det. time= 640.3 min ( 1,528.6 - 888.3 ) Volume Invert Avail.Storage Storage Description #1 62.00' 85,850 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 62.00 36,959 0 0 36,959 64.00 49,182 85,850 85,850 49,270 Device Routing Invert Outlet Devices #1 Discarded 62.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.50 cfs @ 18.00 hrs HW=62.73' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.50 cfs) Pond 2P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=488,472 sf Peak Elev=62.73' Storage=28,653 cf 10.50 cfs 0.50 cfsDRAFT Type III 24-hr 10-yr Rainfall=5.00"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 22HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 3P: Inflow Area = 68,342 sf, 0.00% Impervious, Inflow Depth = 1.37" for 10-yr event Inflow = 2.29 cfs @ 12.10 hrs, Volume= 7,797 cf Outflow = 0.13 cfs @ 15.83 hrs, Volume= 7,797 cf, Atten= 95%, Lag= 223.7 min Discarded = 0.13 cfs @ 15.83 hrs, Volume= 7,797 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 66.41' @ 15.83 hrs Surf.Area= 10,457 sf Storage= 3,996 cf Plug-Flow detention time= 362.3 min calculated for 7,797 cf (100% of inflow) Center-of-Mass det. time= 362.3 min ( 1,234.6 - 872.3 ) Volume Invert Avail.Storage Storage Description #1 66.00' 25,671 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 66.00 9,003 0 0 9,003 68.00 17,097 25,671 25,671 17,136 Device Routing Invert Outlet Devices #1 Discarded 66.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.13 cfs @ 15.83 hrs HW=66.41' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.13 cfs) Pond 3P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Inflow Area=68,342 sf Peak Elev=66.41' Storage=3,996 cf 2.29 cfs 0.13 cfsDRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 23HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=510,711 sf 0.66% Impervious Runoff Depth=1.28"Subcatchment 1S: Flow Length=483' Tc=11.7 min CN=52 Runoff=11.97 cfs 54,418 cf Runoff Area=488,472 sf 0.38% Impervious Runoff Depth=1.74"Subcatchment 2S: Flow Length=555' Tc=12.9 min CN=58 Runoff=16.84 cfs 71,006 cf Runoff Area=68,342 sf 0.00% Impervious Runoff Depth=1.99"Subcatchment 3S: Tc=6.0 min CN=61 Runoff=3.49 cfs 11,346 cf Peak Elev=68.73' Storage=18,814 cf Inflow=11.97 cfs 54,418 cfPond 1P: Outflow=1.60 cfs 54,418 cf Peak Elev=63.20' Storage=48,601 cf Inflow=16.84 cfs 71,006 cfPond 2P: Outflow=0.53 cfs 71,006 cf Peak Elev=66.65' Storage=6,657 cf Inflow=3.49 cfs 11,346 cfPond 3P: Outflow=0.14 cfs 11,346 cf Total Runoff Area = 1,067,525 sf Runoff Volume = 136,770 cf Average Runoff Depth = 1.54" 99.51% Pervious = 1,062,297 sf 0.49% Impervious = 5,228 sf DRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 24HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 11.97 cfs @ 12.19 hrs, Volume= 54,418 cf, Depth= 1.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr Rainfall=5.98" Area (sf) CN Description 80,556 36 Woods, Fair, HSG A 98,588 72 Dirt roads, HSG A 180,032 39 >75% Grass cover, Good, HSG A 77,953 60 Woods, Fair, HSG B 64,282 61 >75% Grass cover, Good, HSG B 5,930 82 Dirt roads, HSG B 3,370 98 Roofs, HSG A 510,711 52 Weighted Average 507,341 99.34% Pervious Area 3,370 0.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 50 0.0600 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 0.5 40 0.0830 1.44 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 2.3 252 0.0130 1.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.9 141 0.0280 2.51 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 11.7 483 Total DRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 25HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 1S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-yr Rainfall=5.98" Runoff Area=510,711 sf Runoff Volume=54,418 cf Runoff Depth=1.28" Flow Length=483' Tc=11.7 min CN=52 11.97 cfs DRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 26HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Runoff = 16.84 cfs @ 12.20 hrs, Volume= 71,006 cf, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr Rainfall=5.98" Area (sf) CN Description 41,086 36 Woods, Fair, HSG A 8,365 72 Dirt roads, HSG A 61,140 39 >75% Grass cover, Good, HSG A 50,235 60 Woods, Fair, HSG B 32,070 82 Dirt roads, HSG B 293,718 61 >75% Grass cover, Good, HSG B 1,858 98 Roofs, HSG A 488,472 58 Weighted Average 486,614 99.62% Pervious Area 1,858 0.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.5 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 1.3 86 0.0500 1.12 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 344 0.0640 3.79 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.2 20 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.4 55 0.0270 2.46 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 12.9 555 Total DRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 27HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-yr Rainfall=5.98" Runoff Area=488,472 sf Runoff Volume=71,006 cf Runoff Depth=1.74" Flow Length=555' Tc=12.9 min CN=58 16.84 cfs DRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 28HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Runoff = 3.49 cfs @ 12.10 hrs, Volume= 11,346 cf, Depth= 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 25-yr Rainfall=5.98" Area (sf) CN Description 15,857 60 Woods, Fair, HSG B 52,485 61 >75% Grass cover, Good, HSG B 68,342 61 Weighted Average 68,342 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)3 2 1 0 Type III 24-hr 25-yr Rainfall=5.98" Runoff Area=68,342 sf Runoff Volume=11,346 cf Runoff Depth=1.99" Tc=6.0 min CN=61 3.49 cfs DRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 29HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: Inflow Area = 510,711 sf, 0.66% Impervious, Inflow Depth = 1.28" for 25-yr event Inflow = 11.97 cfs @ 12.19 hrs, Volume= 54,418 cf Outflow = 1.60 cfs @ 14.01 hrs, Volume= 54,418 cf, Atten= 87%, Lag= 109.6 min Discarded = 1.60 cfs @ 14.01 hrs, Volume= 54,418 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 68.73' @ 14.01 hrs Surf.Area= 28,602 sf Storage= 18,814 cf Plug-Flow detention time= 124.0 min calculated for 54,411 cf (100% of inflow) Center-of-Mass det. time= 123.9 min ( 1,016.5 - 892.6 ) Volume Invert Avail.Storage Storage Description #1 68.00' 61,922 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 68.00 23,156 0 0 23,156 70.00 39,488 61,922 61,922 39,535 Device Routing Invert Outlet Devices #1 Discarded 68.00'2.410 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=1.60 cfs @ 14.01 hrs HW=68.73' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.60 cfs) Pond 1P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=510,711 sf Peak Elev=68.73' Storage=18,814 cf 11.97 cfs 1.60 cfsDRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 30HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 2P: Inflow Area = 488,472 sf, 0.38% Impervious, Inflow Depth = 1.74" for 25-yr event Inflow = 16.84 cfs @ 12.20 hrs, Volume= 71,006 cf Outflow = 0.53 cfs @ 20.21 hrs, Volume= 71,006 cf, Atten= 97%, Lag= 481.0 min Discarded = 0.53 cfs @ 20.21 hrs, Volume= 71,006 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 63.20' @ 20.21 hrs Surf.Area= 44,089 sf Storage= 48,601 cf Plug-Flow detention time= 979.3 min calculated for 71,006 cf (100% of inflow) Center-of-Mass det. time= 979.2 min ( 1,854.1 - 874.9 ) Volume Invert Avail.Storage Storage Description #1 62.00' 85,850 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 62.00 36,959 0 0 36,959 64.00 49,182 85,850 85,850 49,270 Device Routing Invert Outlet Devices #1 Discarded 62.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.53 cfs @ 20.21 hrs HW=63.20' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.53 cfs) Pond 2P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=488,472 sf Peak Elev=63.20' Storage=48,601 cf 16.84 cfs 0.53 cfsDRAFT Type III 24-hr 25-yr Rainfall=5.98"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 31HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 3P: Inflow Area = 68,342 sf, 0.00% Impervious, Inflow Depth = 1.99" for 25-yr event Inflow = 3.49 cfs @ 12.10 hrs, Volume= 11,346 cf Outflow = 0.14 cfs @ 16.69 hrs, Volume= 11,346 cf, Atten= 96%, Lag= 275.7 min Discarded = 0.14 cfs @ 16.69 hrs, Volume= 11,346 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 66.65' @ 16.69 hrs Surf.Area= 11,370 sf Storage= 6,657 cf Plug-Flow detention time= 547.8 min calculated for 11,344 cf (100% of inflow) Center-of-Mass det. time= 547.8 min ( 1,408.2 - 860.4 ) Volume Invert Avail.Storage Storage Description #1 66.00' 25,671 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 66.00 9,003 0 0 9,003 68.00 17,097 25,671 25,671 17,136 Device Routing Invert Outlet Devices #1 Discarded 66.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.14 cfs @ 16.69 hrs HW=66.65' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.14 cfs) Pond 3P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)3 2 1 0 Inflow Area=68,342 sf Peak Elev=66.65' Storage=6,657 cf 3.49 cfs 0.14 cfsDRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 32HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=510,711 sf 0.66% Impervious Runoff Depth=2.14"Subcatchment 1S: Flow Length=483' Tc=11.7 min CN=52 Runoff=22.28 cfs 91,138 cf Runoff Area=488,472 sf 0.38% Impervious Runoff Depth=2.75"Subcatchment 2S: Flow Length=555' Tc=12.9 min CN=58 Runoff=27.84 cfs 111,862 cf Runoff Area=68,342 sf 0.00% Impervious Runoff Depth=3.06"Subcatchment 3S: Tc=6.0 min CN=61 Runoff=5.53 cfs 17,432 cf Peak Elev=69.44' Storage=41,131 cf Inflow=22.28 cfs 91,138 cfPond 1P: Outflow=1.92 cfs 91,138 cf Peak Elev=63.98' Storage=85,060 cf Inflow=27.84 cfs 111,862 cfPond 2P: Outflow=0.59 cfs 111,859 cf Peak Elev=67.05' Storage=11,398 cf Inflow=5.53 cfs 17,432 cfPond 3P: Outflow=0.16 cfs 17,432 cf Total Runoff Area = 1,067,525 sf Runoff Volume = 220,431 cf Average Runoff Depth = 2.48" 99.51% Pervious = 1,062,297 sf 0.49% Impervious = 5,228 sf DRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 33HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 22.28 cfs @ 12.18 hrs, Volume= 91,138 cf, Depth= 2.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr Rainfall=7.49" Area (sf) CN Description 80,556 36 Woods, Fair, HSG A 98,588 72 Dirt roads, HSG A 180,032 39 >75% Grass cover, Good, HSG A 77,953 60 Woods, Fair, HSG B 64,282 61 >75% Grass cover, Good, HSG B 5,930 82 Dirt roads, HSG B 3,370 98 Roofs, HSG A 510,711 52 Weighted Average 507,341 99.34% Pervious Area 3,370 0.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 50 0.0600 0.10 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 0.5 40 0.0830 1.44 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 2.3 252 0.0130 1.84 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.9 141 0.0280 2.51 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 11.7 483 Total DRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 34HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 1S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100-yr Rainfall=7.49" Runoff Area=510,711 sf Runoff Volume=91,138 cf Runoff Depth=2.14" Flow Length=483' Tc=11.7 min CN=52 22.28 cfs DRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 35HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Runoff = 27.84 cfs @ 12.19 hrs, Volume= 111,862 cf, Depth= 2.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr Rainfall=7.49" Area (sf) CN Description 41,086 36 Woods, Fair, HSG A 8,365 72 Dirt roads, HSG A 61,140 39 >75% Grass cover, Good, HSG A 50,235 60 Woods, Fair, HSG B 32,070 82 Dirt roads, HSG B 293,718 61 >75% Grass cover, Good, HSG B 1,858 98 Roofs, HSG A 488,472 58 Weighted Average 486,614 99.62% Pervious Area 1,858 0.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.5 50 0.0400 0.09 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.12" 1.3 86 0.0500 1.12 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 344 0.0640 3.79 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.2 20 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.4 55 0.0270 2.46 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 12.9 555 Total DRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 36HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Subcatchment 2S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 100-yr Rainfall=7.49" Runoff Area=488,472 sf Runoff Volume=111,862 cf Runoff Depth=2.75" Flow Length=555' Tc=12.9 min CN=58 27.84 cfs DRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 37HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Runoff = 5.53 cfs @ 12.09 hrs, Volume= 17,432 cf, Depth= 3.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type III 24-hr 100-yr Rainfall=7.49" Area (sf) CN Description 15,857 60 Woods, Fair, HSG B 52,485 61 >75% Grass cover, Good, HSG B 68,342 61 Weighted Average 68,342 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)6 5 4 3 2 1 0 Type III 24-hr 100-yr Rainfall=7.49" Runoff Area=68,342 sf Runoff Volume=17,432 cf Runoff Depth=3.06" Tc=6.0 min CN=61 5.53 cfs DRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 38HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: Inflow Area = 510,711 sf, 0.66% Impervious, Inflow Depth = 2.14" for 100-yr event Inflow = 22.28 cfs @ 12.18 hrs, Volume= 91,138 cf Outflow = 1.92 cfs @ 14.99 hrs, Volume= 91,138 cf, Atten= 91%, Lag= 168.9 min Discarded = 1.92 cfs @ 14.99 hrs, Volume= 91,138 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 69.44' @ 14.99 hrs Surf.Area= 34,454 sf Storage= 41,131 cf Plug-Flow detention time= 250.2 min calculated for 91,138 cf (100% of inflow) Center-of-Mass det. time= 250.2 min ( 1,125.2 - 875.0 ) Volume Invert Avail.Storage Storage Description #1 68.00' 61,922 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 68.00 23,156 0 0 23,156 70.00 39,488 61,922 61,922 39,535 Device Routing Invert Outlet Devices #1 Discarded 68.00'2.410 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=1.92 cfs @ 14.99 hrs HW=69.44' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.92 cfs) Pond 1P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)24 23 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=510,711 sf Peak Elev=69.44' Storage=41,131 cf 22.28 cfs 1.92 cfsDRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 39HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 2P: Inflow Area = 488,472 sf, 0.38% Impervious, Inflow Depth = 2.75" for 100-yr event Inflow = 27.84 cfs @ 12.19 hrs, Volume= 111,862 cf Outflow = 0.59 cfs @ 22.87 hrs, Volume= 111,859 cf, Atten= 98%, Lag= 640.7 min Discarded = 0.59 cfs @ 22.87 hrs, Volume= 111,859 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 63.98' @ 22.87 hrs Surf.Area= 49,077 sf Storage= 85,060 cf Plug-Flow detention time= 1,487.8 min calculated for 111,843 cf (100% of inflow) Center-of-Mass det. time= 1,488.0 min ( 2,348.8 - 860.8 ) Volume Invert Avail.Storage Storage Description #1 62.00' 85,850 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 62.00 36,959 0 0 36,959 64.00 49,182 85,850 85,850 49,270 Device Routing Invert Outlet Devices #1 Discarded 62.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.59 cfs @ 22.87 hrs HW=63.98' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.59 cfs) Pond 2P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=488,472 sf Peak Elev=63.98' Storage=85,060 cf 27.84 cfs 0.59 cfsDRAFT Type III 24-hr 100-yr Rainfall=7.49"3064.04-POST_REV 1 Printed 5/18/2023Prepared by {enter your company name here} Page 40HydroCAD® 10.00-25 s/n 00480 © 2019 HydroCAD Software Solutions LLC Summary for Pond 3P: Inflow Area = 68,342 sf, 0.00% Impervious, Inflow Depth = 3.06" for 100-yr event Inflow = 5.53 cfs @ 12.09 hrs, Volume= 17,432 cf Outflow = 0.16 cfs @ 17.63 hrs, Volume= 17,432 cf, Atten= 97%, Lag= 332.0 min Discarded = 0.16 cfs @ 17.63 hrs, Volume= 17,432 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 67.05' @ 17.63 hrs Surf.Area= 12,914 sf Storage= 11,398 cf Plug-Flow detention time= 810.2 min calculated for 17,429 cf (100% of inflow) Center-of-Mass det. time= 810.3 min ( 1,657.7 - 847.4 ) Volume Invert Avail.Storage Storage Description #1 66.00' 25,671 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (cubic-feet) (cubic-feet)(sq-ft) 66.00 9,003 0 0 9,003 68.00 17,097 25,671 25,671 17,136 Device Routing Invert Outlet Devices #1 Discarded 66.00'0.520 in/hr Exfiltration over Wetted area Phase-In= 0.01' Discarded OutFlow Max=0.16 cfs @ 17.63 hrs HW=67.05' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.16 cfs) Pond 3P: Inflow Discarded Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow (cfs)6 5 4 3 2 1 0 Inflow Area=68,342 sf Peak Elev=67.05' Storage=11,398 cf 5.53 cfs 0.16 cfsDRAFT APPENDIX B Revised Post-Development Watershed Plan DRAFT DRAFT