Revised Stormwater Management Report

PA-3 Existing and Proposed 2024-05-12 HydroCad - Proposed 11-12 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 6/13/2024 Page 5 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 29S: Basin 12 - Perv Runoff = 0.18 cfs @ 12.12 hrs, Volume= Routed to Pond 30 : Basin 12 0.012 af, Depth= 1.20" 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 2-Year Rainfall=3.44" Area (sf) 5,251 5,251 Tc (min) 3.8 Length (feet) 50 0.2 60 4.0 110 CN 74 Description >75% Grass cover, Good, HSG C 100.00% Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.1200 0.22 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" 0.1200 5.20 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps Total Subcatchment 29S: Basin 12 - Perv Hydrograph 0.2 Runoff 0.19 0.18 0.18 cfs 0.17 0.16 0.15 0.14 Flow (cfs) 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=5,251 sf Runoff Volume=0.012 af Runoff Depth=1.20" Flow Length=110' Tc=4.0 min CN=74 0.04 0.03 0.02 0.01 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)