Drainage Report

Basin 4 without exfiltration Proposed basin 4 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 18S: OL-4 Runoff = 0.33 cfs @ 12.16 hrs, Volume= 0.027 af, Depth= 1.25" 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 2-Year Rainfall=3.44" Area (sf) CN Description 301 98 Paved roads w/curbs & sewers, HSG C 10,972 74 >75% Grass cover, Good, HSG C 11,273 75 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.7 96 0.0573 0.18 Sheet Flow, Grass: Dense n= 0.240 P2= 3.44" Subcatchment 18S: OL-4 Hydrograph 0.36 Runoff 0.34 0.33 cfs 0.32 NOAA 24-hr D 0.3 0.28 2-Year Rainfall=3.44" 0.26 Runoff Area=11,273 sf 0.24 0.22 Runoff Volume=0.027 af Flow (cfs) 0.2 Runoff Depth=1.25" 0.18 0.16

Runoff Volume=0.027 af Flow (cfs) 0.2 Runoff Depth=1.25" 0.18 0.16 Flow Length=96' 0.14 0.12 Slope=0.0573 '/' 0.1 Tc=8.7 min 0.08 0.06 CN=74/98 0.04 0.02 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)