Drainage Report

Basin 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 34 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 28S: Basin 1 Runoff Area=314,926 sf Runoff Depth=7.30" Flow Length=1,759' Tc=30.2 min CN=74/98 Runoff=29.62 cfs 4.400 af Subcatchment 32S: Basin 1 Undetained Runoff Area=51,560 sf Runoff Depth=5.52" Flow Length=70' Slope=0.0800 '/' Tc=10.0 min CN=74/0 Runoff=6.40 cfs 0.544 af Subcatchment 36S: Basin 1 Predevelopment Runoff Area=368,926 sf Runoff Depth=5.04" Flow Length=1,360' Tc=31.9 min CN=70/0 Runoff=25.64 cfs 3.555 af Pond 29P: Basin 1 Peak Elev=544.77' Storage=136,068 cf Inflow=29.62 cfs 4.400 af Outflow=2.09 cfs 2.848 af Total Runoff Area = 16.883 ac Runoff Volume = 8.499 af Average Runoff Depth = 6.04"

Basin 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment 28S: Basin 1 [47] Hint: Peak is 754% of capacity of segment #4 Runoff = 29.62 cfs @ 12.41 hrs, Volume= 4.400 af, Depth= 7.30" Routed to Pond 29P : Basin 1 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 100-Year Rainfall=8.66" Area (sf) CN Description 193,625 98 Paved parking, HSG C 121,301 74 >75% Grass cover, Good, HSG C 314,926 89 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 24.0 100 0.0050 0.07 Sheet Flow, grass Grass: Dense n= 0.240 P2= 3.44" 0.6 144 0.0690 3.94 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.7 642 0.0206 2.91 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.9 873 0.0520 7.62 3.93 Pipe Channel, 18.0" Round w/ 12.0" inside fill Area= 0.5 sf Perim= 3.3' r= 0.16' n= 0.013 Corrugated PE, smooth interior 30.2 1,759 Total

Basin 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 36 Subcatchment 28S: Basin 1 Hydrograph 32 Runoff 29.62 cfs 30 28 NOAA 24-hr D 26 100-Year Rainfall=8.66" 24 Runoff Area=314,926 sf 22 20 Runoff Volume=4.400 af Flow (cfs) 18 Runoff Depth=7.30" 16 14 Flow Length=1,759' 12 Tc=30.2 min 10 8 CN=74/98 6 4 2 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 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 37 Hydrograph for Subcatchment 28S: Basin 1 Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.27 0.00 0.12 0.36 5.00 0.59 0.00 0.40 0.56 7.50 1.01 0.03 0.80 0.90 10.00 1.72 0.23 1.49 1.88 12.50 5.91 3.11 5.68 27.90 15.00 7.29 4.29 7.05 2.35 17.50 7.84 4.78 7.60 1.33 20.00 8.21 5.11 7.97 0.96 22.50 8.51 5.38 8.27 0.79 25.00 8.66 5.52 8.42 0.02 27.50 8.66 5.52 8.42 0.00 30.00 8.66 5.52 8.42 0.00 32.50 8.66 5.52 8.42 0.00 35.00 8.66 5.52 8.42 0.00 37.50 8.66 5.52 8.42 0.00 40.00 8.66 5.52 8.42 0.00 42.50 8.66 5.52 8.42 0.00 45.00 8.66 5.52 8.42 0.00 47.50 8.66 5.52 8.42 0.00 50.00 8.66 5.52 8.42 0.00 52.50 8.66 5.52 8.42 0.00 55.00 8.66 5.52 8.42 0.00 57.50 8.66 5.52 8.42 0.00 60.00 8.66 5.52 8.42 0.00 62.50 8.66 5.52 8.42 0.00 65.00 8.66 5.52 8.42 0.00 67.50 8.66 5.52 8.42 0.00 70.00 8.66 5.52 8.42 0.00

Basin 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 38 Summary for Subcatchment 32S: Basin 1 Undetained Runoff = 6.40 cfs @ 12.17 hrs, Volume= 0.544 af, Depth= 5.52" 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 100-Year Rainfall=8.66" Area (sf) CN Description 51,560 74 >75% Grass cover, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.9 70 0.0800 0.20 Sheet Flow, Grass: Dense n= 0.240 P2= 3.44" 5.9 70 Total, Increased to minimum Tc = 10.0 min Subcatchment 32S: Basin 1 Undetained Hydrograph 7 Runoff 6.40 cfs 6 NOAA 24-hr D 100-Year Rainfall=8.66" 5 Runoff Area=51,560 sf Runoff Volume=0.544 af Flow (cfs) 4 Runoff Depth=5.52" 3 Flow Length=70'

Runoff Depth=5.52" 3 Flow Length=70' Slope=0.0800 '/' 2 Tc=10.0 min CN=74/0 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 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 39 Hydrograph for Subcatchment 32S: Basin 1 Undetained Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.27 0.00 0.00 0.00 5.00 0.59 0.00 0.00 0.00 7.50 1.01 0.03 0.00 0.03 10.00 1.72 0.23 0.00 0.18 12.50 5.91 3.11 0.00 1.83 15.00 7.29 4.29 0.00 0.31 17.50 7.84 4.78 0.00 0.19 20.00 8.21 5.11 0.00 0.14 22.50 8.51 5.38 0.00 0.12 25.00 8.66 5.52 0.00 0.00 27.50 8.66 5.52 0.00 0.00 30.00 8.66 5.52 0.00 0.00 32.50 8.66 5.52 0.00 0.00 35.00 8.66 5.52 0.00 0.00 37.50 8.66 5.52 0.00 0.00 40.00 8.66 5.52 0.00 0.00 42.50 8.66 5.52 0.00 0.00 45.00 8.66 5.52 0.00 0.00 47.50 8.66 5.52 0.00 0.00 50.00 8.66 5.52 0.00 0.00 52.50 8.66 5.52 0.00 0.00 55.00 8.66 5.52 0.00 0.00 57.50 8.66 5.52 0.00 0.00 60.00 8.66 5.52 0.00 0.00 62.50 8.66 5.52 0.00 0.00 65.00 8.66 5.52 0.00 0.00 67.50 8.66 5.52 0.00 0.00 70.00 8.66 5.52 0.00 0.00

Basin 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 40 Summary for Subcatchment 36S: Basin 1 Predevelopment Runoff = 25.64 cfs @ 12.45 hrs, Volume= 3.555 af, Depth= 5.04" 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 100-Year Rainfall=8.66" Area (sf) CN Description 368,926 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.4 100 0.0500 0.12 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 17.6 1,260 0.0570 1.19 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 31.9 1,360 Total Subcatchment 36S: Basin 1 Predevelopment Hydrograph 28 Runoff 25.64 cfs 26 24 NOAA 24-hr D 22 100-Year Rainfall=8.66" 20 Runoff Area=368,926 sf 18 Runoff Volume=3.555 af Flow (cfs) 16 Runoff Depth=5.04"

Runoff Volume=3.555 af Flow (cfs) 16 Runoff Depth=5.04" 14 12 Flow Length=1,360' 10 Tc=31.9 min 8 CN=70/0 6 4 2 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 1 without exfiltration Proposed basin 1 R5 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 41 Hydrograph for Subcatchment 36S: Basin 1 Predevelopment Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.27 0.00 0.00 0.00 5.00 0.59 0.00 0.00 0.00 7.50 1.01 0.01 0.00 0.05 10.00 1.72 0.14 0.00 0.75 12.50 5.91 2.74 0.00 25.13 15.00 7.29 3.86 0.00 2.44 17.50 7.84 4.33 0.00 1.40 20.00 8.21 4.64 0.00 1.01 22.50 8.51 4.90 0.00 0.84 25.00 8.66 5.04 0.00 0.03 27.50 8.66 5.04 0.00 0.00 30.00 8.66 5.04 0.00 0.00 32.50 8.66 5.04 0.00 0.00 35.00 8.66 5.04 0.00 0.00 37.50 8.66 5.04 0.00 0.00 40.00 8.66 5.04 0.00 0.00 42.50 8.66 5.04 0.00 0.00 45.00 8.66 5.04 0.00 0.00 47.50 8.66 5.04 0.00 0.00 50.00 8.66 5.04 0.00 0.00 52.50 8.66 5.04 0.00 0.00 55.00 8.66 5.04 0.00 0.00 57.50 8.66 5.04 0.00 0.00 60.00 8.66 5.04 0.00 0.00 62.50 8.66 5.04 0.00 0.00 65.00 8.66 5.04 0.00 0.00 67.50 8.66 5.04 0.00 0.00 70.00 8.66 5.04 0.00 0.00