Drainage Report

Basin 3 without exfiltration proposed basin 3 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 Summary for Subcatchment 34S: Basin 3 [47] Hint: Peak is 262% of capacity of segment #4 Runoff = 13.09 cfs @ 12.17 hrs, Volume= 1.188 af, Depth= 6.50" Routed to Pond 35P : Basin 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 100-Year Rainfall=8.66" Area (sf) CN Description 32,412 98 Paved parking, HSG C 63,013 74 >75% Grass cover, Good, HSG C 95,425 82 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.9 100 0.0800 0.21 Sheet Flow, Grass: Dense n= 0.240 P2= 3.44" 0.1 20 0.0800 4.24 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.4 100 0.0500 4.54 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 450 0.0600 8.91 5.00 Pipe Channel, 15.0" Round w/ 8.0" inside fill Area= 0.6 sf Perim= 3.1' r= 0.18' n= 0.013 Concrete sewer w/manholes & inlets 9.2 670 Total, Increased to minimum Tc = 10.0 min

Basin 3 without exfiltration proposed basin 3 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 Subcatchment 34S: Basin 3 Hydrograph Runoff 14 13.09 cfs 13 NOAA 24-hr D 12 11 100-Year Rainfall=8.66" 10 Runoff Area=95,425 sf 9 Runoff Volume=1.188 af Flow (cfs) 8 Runoff Depth=6.50" 7 6 Flow Length=670' 5 Tc=10.0 min 4 CN=74/98 3 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 3 without exfiltration proposed basin 3 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 Hydrograph for Subcatchment 34S: Basin 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 0.27 0.00 0.12 0.07 5.00 0.59 0.00 0.40 0.10 7.50 1.01 0.03 0.80 0.19 10.00 1.72 0.23 1.49 0.51 12.50 5.91 3.11 5.68 3.64 15.00 7.29 4.29 7.05 0.60 17.50 7.84 4.78 7.60 0.37 20.00 8.21 5.11 7.97 0.28 22.50 8.51 5.38 8.27 0.23 25.00 8.66 5.52 8.42 0.00 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 3 without exfiltration proposed basin 3 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 Summary for Subcatchment 36S: Basin 3 undetained Runoff = 2.56 cfs @ 12.17 hrs, Volume= 0.234 af, Depth= 6.57" 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 11,836 74 >75% Grass cover, Good, HSG C 6,737 98 Paved roads w/curbs & sewers, HSG C 18,573 83 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.8 45 0.1000 0.20 Sheet Flow, Grass: Dense n= 0.240 P2= 3.44" 3.8 45 Total, Increased to minimum Tc = 10.0 min Subcatchment 36S: Basin 3 undetained Hydrograph Runoff 2.56 cfs NOAA 24-hr D 100-Year Rainfall=8.66" 2 Runoff Area=18,573 sf Runoff Volume=0.234 af Flow (cfs) Runoff Depth=6.57"

Runoff Volume=0.234 af Flow (cfs) Runoff Depth=6.57" Flow Length=45' 1 Slope=0.1000 '/' Tc=10.0 min CN=74/98 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 3 without exfiltration proposed basin 3 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 Hydrograph for Subcatchment 36S: Basin 3 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 0.12 0.01 5.00 0.59 0.00 0.40 0.02 7.50 1.01 0.03 0.80 0.04 10.00 1.72 0.23 1.49 0.10 12.50 5.91 3.11 5.68 0.71 15.00 7.29 4.29 7.05 0.12 17.50 7.84 4.78 7.60 0.07 20.00 8.21 5.11 7.97 0.05 22.50 8.51 5.38 8.27 0.04 25.00 8.66 5.52 8.42 0.00 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 3 without exfiltration proposed basin 3 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 Summary for Subcatchment 37S: Basin 3 pre-development Runoff = 10.09 cfs @ 12.29 hrs, Volume= 1.098 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 113,998 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.7 100 0.0400 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 3.7 204 0.0340 0.92 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 19.4 304 Total Subcatchment 37S: Basin 3 pre-development Hydrograph 11 Runoff 10.09 cfs 10 NOAA 24-hr D 9 100-Year Rainfall=8.66" 8 Runoff Area=113,998 sf 7 Runoff Volume=1.098 af Flow (cfs) 6 Runoff Depth=5.04" 5

1.098 af Flow (cfs) 6 Runoff Depth=5.04" 5 Flow Length=304' 4 Tc=19.4 min 3 CN=70/0 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 3 without exfiltration proposed basin 3 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 Hydrograph for Subcatchment 37S: Basin 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 0.27 0.00 0.00 0.00 5.00 0.59 0.00 0.00 0.00 7.50 1.01 0.01 0.00 0.02 10.00 1.72 0.14 0.00 0.27 12.50 5.91 2.74 0.00 6.16 15.00 7.29 3.86 0.00 0.70 17.50 7.84 4.33 0.00 0.42 20.00 8.21 4.64 0.00 0.31 22.50 8.51 4.90 0.00 0.26 25.00 8.66 5.04 0.00 0.00 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

Basin 3 without exfiltration proposed basin 3 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 Summary for Pond 35P: Basin 3 Inflow Area = 2.191 ac, Inflow Depth = 6.50" for 100-Year event Inflow = 13.09 cfs @ 12.17 hrs, Volume= 1.188 af Outflow = 4.35 cfs @ 12.44 hrs, Volume= 0.924 af, Atten= 67%, Lag= 16.2 min Primary = 4.35 cfs @ 12.44 hrs, Volume= 0.924 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 531.69' @ 12.44 hrs Surf.Area= 9,634 sf Storage= 23,858 cf Plug-Flow detention time= 242.0 min calculated for 0.923 af (78% of inflow) Center-of-Mass det. time= 154.0 min ( 943.6 - 789.6 ) Volume Invert Avail.Storage Storage Description #1 528.00' 26,911 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 528.00 3,437 0 0 530.00 6,648 10,085 10,085 532.00 10,178 16,826 26,911 Device Routing Invert Outlet Devices #1 Primary 530.20' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 530.60' 18.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=4.35 cfs @ 12.44 hrs HW=531.69' (Free Discharge) 1=Orifice/Grate (Orifice Controls 1.05 cfs @ 5.36 fps) 2=Orifice/Grate (Orifice Controls 3.30 cfs @ 4.40 fps)