Revised Stormwater Management Report

PA-3 Existing and Proposed 2024-05-12 HydroCad - Proposed 11-12 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/13/2024 Page 12 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 26S: Basin 12 pre-dev Runoff = 0.30 cfs @ 12.15 hrs, Volume= 0.023 af, Depth= 2.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs NOAA 24-hr D 10-Year Rainfall=5.22" Area (sf) 5,000 5,000 Tc (min) 7.6 Length (feet) 70 0.4 40 8.0 110 CN 72 Description Woods/grass comb., Good, HSG C 100.00% Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.1200 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.47" 0.1200 1.73 Shallow Concentrated Flow, Woodland Kv= 5.0 fps Total Subcatchment 26S: Basin 12 pre-dev Hydrograph Runoff 0.32 0.30 cfs 0.3 0.28 0.26 0.24 0.22 Flow (cfs) 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=5,000 sf Runoff Volume=0.023 af Runoff Depth=2.37" Flow Length=110' Slope=0.1200 '/' Tc=8.0 min CN=72 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)