Revised Stormwater Management Report

PA-3 Existing and Proposed 2024-05-12 HydroCad - Proposed 11-12 NOAA 24-hr D 100-Year Rainfall=8.66" Prepared by Anderson Consulting Services Printed 6/13/2024 Page 25 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 27S: Basin 12 - Imp Runoff = 0.51 cfs @ 12.11 hrs, Volume= Routed to Pond 30 : Basin 12 0.040 af, Depth= 8.42" 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 100-Year Rainfall=8.66" Area (sf) 2,500 2,500 Tc (min) 3.8 Length (feet) 50 0.2 60 4.0 110 CN 98 Description Paved parking, HSG C 100.00% Impervious 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 27S: Basin 12 - Imp Hydrograph Runoff 0.55 0.51 cfs 0.5 0.45 0.4 Flow (cfs) 0.35 0.3 0.25 0.2 0.15 0.1 NOAA 24-hr D 100-Year Rainfall=8.66" Runoff Area=2,500 sf Runoff Volume=0.040 af Runoff Depth=8.42" Flow Length=110' Slope=0.1200 '/' Tc=4.0 min CN=98 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)