Drainage Report

Basin 5 witout exfiltration Proposed basin 5 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 25S: overland 5-A Runoff = 2.94 cfs @ 12.15 hrs, Volume= 0.243 af, Depth= 1.85" 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 22,200 98 Paved parking, HSG C 46,435 74 >75% Grass cover, Good, HSG C 68,635 82 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.7 100 0.1200 0.25 Sheet Flow, Grass: Dense n= 0.240 P2= 3.44" 0.1 20 0.0500 3.35 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.4 118 0.0550 4.76 Shallow Concentrated Flow, gutter flow Paved Kv= 20.3 fps 0.4 156 0.0349 6.80 3.82 Pipe Channel, 15.0" Round w/ 8.0" inside fill Area= 0.6 sf Perim= 3.1' r= 0.18' n= 0.013 Corrugated PE, smooth interior 7.6 394 Total Subcatchment 25S: overland 5-A Hydrograph Runoff

Hydrograph Runoff 2.94 cfs 3 NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=68,635 sf 2 Runoff Volume=0.243 af Flow (cfs) Runoff Depth=1.85" Flow Length=394' Tc=7.6 min 1 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)