Drainage Report

Basin 4 without exfiltration Proposed basin 4 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 Subcatchment 19S: pre-dev basin 4 Runoff = 4.06 cfs @ 12.25 hrs, Volume= 0.408 af, Depth= 2.20" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.03 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) CN Description 96,981 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" 1.5 90 0.0400 1.00 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 15.9 190 Total Subcatchment 19S: pre-dev basin 4 Hydrograph Runoff 4.06 cfs 4 NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=96,981 sf 3 Runoff Volume=0.408 af Flow (cfs) Runoff Depth=2.20" 2

8 af Flow (cfs) Runoff Depth=2.20" 2 Flow Length=190' Tc=15.9 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)