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 23 Summary for Subcatchment 18S: OL-4 Runoff = 0.70 cfs @ 12.16 hrs, Volume= 0.056 af, Depth= 2.61" 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 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 Runoff 0.75 0.70 cfs 0.7 NOAA 24-hr D 0.65 0.6 10-Year Rainfall=5.22" 0.55 Runoff Area=11,273 sf 0.5 Runoff Volume=0.056 af 0.45 Flow (cfs) 0.4 Runoff

Runoff Volume=0.056 af 0.45 Flow (cfs) 0.4 Runoff Depth=2.61" 0.35 Flow Length=96' 0.3 Slope=0.0573 '/' 0.25 0.2 Tc=8.7 min 0.15 CN=74/98 0.1 0.05 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)