Drainage Report

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 19 Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 40S: Basin 2-3 Runoff Area=98,395 sf Runoff Depth=3.92" Flow Length=1,558' Tc=10.5 min CN=79/98 Runoff=7.90 cfs 0.737 af Subcatchment 45S: basin 2-3 pre-development Runoff Area=99,393 sf Runoff Depth=2.20" Flow Length=280' Tc=12.2 min CN=70/0 Runoff=4.62 cfs 0.418 af Pond 44P: pond 2-3 Peak Elev=543.93' Storage=20,108 cf Inflow=7.90 cfs 0.737 af Outflow=0.75 cfs 0.448 af Total Runoff Area = 4.541 ac Runoff Volume = 1.156 af Average Runoff Depth = 3.05"

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 40S: Basin 2-3 Runoff = 7.90 cfs @ 12.18 hrs, Volume= 0.737 af, Depth= 3.92" Routed to Pond 44P : pond 2-3 Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) CN Description 41,793 74 >75% Grass cover, Good, HSG C 46,190 98 Roofs, HSG C 10,412 98 Water Surface, 0% imp, HSG C 98,395 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 100 0.0300 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.4 60 0.0330 2.72 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.2 72 0.0800 5.74 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.9 1,326 0.0300 11.85 14.55 Pipe Channel, 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.010 10.5 1,558 Total

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 21 Subcatchment 40S: Basin 2-3 Hydrograph Runoff 7.90 cfs 8 NOAA 24-hr D 7 10-Year Rainfall=5.22" 6 Runoff Area=98,395 sf Runoff Volume=0.737 af 5 Flow (cfs) Runoff Depth=3.92" 4 Flow Length=1,558' 3 Tc=10.5 min CN=79/98 2 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 22 Hydrograph for Subcatchment 40S: Basin 2-3 Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.16 0.00 0.04 0.04 5.00 0.36 0.00 0.19 0.08 7.50 0.61 0.00 0.42 0.13 10.00 1.03 0.08 0.82 0.32 12.50 3.57 1.60 3.33 2.29 15.00 4.39 2.27 4.16 0.37 17.50 4.73 2.55 4.49 0.23 20.00 4.95 2.74 4.71 0.17 22.50 5.13 2.89 4.89 0.14 25.00 5.22 2.97 4.98 0.00 27.50 5.22 2.97 4.98 0.00 30.00 5.22 2.97 4.98 0.00 32.50 5.22 2.97 4.98 0.00 35.00 5.22 2.97 4.98 0.00 37.50 5.22 2.97 4.98 0.00 40.00 5.22 2.97 4.98 0.00 42.50 5.22 2.97 4.98 0.00 45.00 5.22 2.97 4.98 0.00 47.50 5.22 2.97 4.98 0.00 50.00 5.22 2.97 4.98 0.00 52.50 5.22 2.97 4.98 0.00 55.00 5.22 2.97 4.98 0.00 57.50 5.22 2.97 4.98 0.00 60.00 5.22 2.97 4.98 0.00 62.50 5.22 2.97 4.98 0.00 65.00 5.22 2.97 4.98 0.00 67.50 5.22 2.97 4.98 0.00 70.00 5.22 2.97 4.98 0.00

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment 45S: basin 2-3 pre-development Runoff = 4.62 cfs @ 12.21 hrs, Volume= 0.418 af, Depth= 2.20" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) CN Description 99,393 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.1 100 0.1200 0.16 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 2.1 180 0.0830 1.44 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 12.2 280 Total Subcatchment 45S: basin 2-3 pre-development Hydrograph 5 Runoff 4.62 cfs NOAA 24-hr D 4 10-Year Rainfall=5.22" Runoff Area=99,393 sf 3 Runoff Volume=0.418 af Flow (cfs) Runoff Depth=2.20"

e=0.418 af Flow (cfs) Runoff Depth=2.20" Flow Length=280' 2 Tc=12.2 min CN=70/0 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 24 Hydrograph for Subcatchment 45S: basin 2-3 pre-development Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.16 0.00 0.00 0.00 5.00 0.36 0.00 0.00 0.00 7.50 0.61 0.00 0.00 0.00 10.00 1.03 0.01 0.00 0.03 12.50 3.57 1.05 0.00 1.73 15.00 4.39 1.60 0.00 0.29 17.50 4.73 1.83 0.00 0.18 20.00 4.95 2.00 0.00 0.14 22.50 5.13 2.13 0.00 0.11 25.00 5.22 2.20 0.00 0.00 27.50 5.22 2.20 0.00 0.00 30.00 5.22 2.20 0.00 0.00 32.50 5.22 2.20 0.00 0.00 35.00 5.22 2.20 0.00 0.00 37.50 5.22 2.20 0.00 0.00 40.00 5.22 2.20 0.00 0.00 42.50 5.22 2.20 0.00 0.00 45.00 5.22 2.20 0.00 0.00 47.50 5.22 2.20 0.00 0.00 50.00 5.22 2.20 0.00 0.00 52.50 5.22 2.20 0.00 0.00 55.00 5.22 2.20 0.00 0.00 57.50 5.22 2.20 0.00 0.00 60.00 5.22 2.20 0.00 0.00 62.50 5.22 2.20 0.00 0.00 65.00 5.22 2.20 0.00 0.00 67.50 5.22 2.20 0.00 0.00 70.00 5.22 2.20 0.00 0.00

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 25 Summary for Pond 44P: pond 2-3 Inflow Area = 2.259 ac, Inflow Depth = 3.92" for 10-Year event Inflow = 7.90 cfs @ 12.18 hrs, Volume= 0.737 af Outflow = 0.75 cfs @ 13.44 hrs, Volume= 0.448 af, Atten= 91%, Lag= 75.8 min Primary = 0.75 cfs @ 13.44 hrs, Volume= 0.448 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 543.93' @ 13.44 hrs Surf.Area= 10,412 sf Storage= 20,108 cf Plug-Flow detention time= 446.8 min calculated for 0.448 af (61% of inflow) Center-of-Mass det. time= 326.4 min ( 1,112.9 - 786.4 ) Volume Invert Avail.Storage Storage Description #1 542.00' 41,648 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 542.00 10,412 0 0 546.00 10,412 41,648 41,648 Device Routing Invert Outlet Devices #1 Primary 543.20' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 543.75' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.75 cfs @ 13.44 hrs HW=543.93' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.66 cfs @ 3.34 fps) 2=Orifice/Grate (Orifice Controls 0.09 cfs @ 1.45 fps)

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 26 Pond 44P: pond 2-3 Hydrograph Inflow 7.90 cfs Primary 8 Inflow Area=2.259 ac 7 Peak Elev=543.93' 6 Storage=20,108 cf Flow (cfs) 5 4 3 2 0.75 cfs 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

Basin 2-3 without exfiltration Proposed Basin 2-3 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 27 Hydrograph for Pond 44P: pond 2-3 Time Inflow Storage Elevation Primary (hours) (cfs) (cubic-feet) (feet) (cfs) 0.00 0.00 0 542.00 0.00 2.50 0.04 144 542.01 0.00 5.00 0.08 694 542.07 0.00 7.50 0.13 1,547 542.15 0.00 10.00 0.32 3,319 542.32 0.00 12.50 2.29 18,207 543.75 0.52 15.00 0.37 19,115 543.84 0.61 17.50 0.23 17,125 543.64 0.42 20.00 0.17 15,857 543.52 0.26 22.50 0.14 15,277 543.47 0.19 25.00 0.00 14,613 543.40 0.12 27.50 0.00 13,898 543.33 0.05 30.00 0.00 13,532 543.30 0.03 32.50 0.00 13,313 543.28 0.02 35.00 0.00 13,166 543.26 0.01 37.50 0.00 13,059 543.25 0.01 40.00 0.00 12,980 543.25 0.01 42.50 0.00 12,923 543.24 0.01 45.00 0.00 12,879 543.24 0.00 47.50 0.00 12,839 543.23 0.00 50.00 0.00 12,804 543.23 0.00 52.50 0.00 12,772 543.23 0.00 55.00 0.00 12,743 543.22 0.00 57.50 0.00 12,718 543.22 0.00 60.00 0.00 12,695 543.22 0.00 62.50 0.00 12,674 543.22 0.00 65.00 0.00 12,656 543.22 0.00 67.50 0.00 12,639 543.21 0.00 70.00 0.00 12,624 543.21 0.00