Revised Stormwater Management Report

POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 35 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 54S: Basin 9 - Perv Runoff = 0.33 cfs @ 12.15 hrs, Volume= Routed to Pond 42P : Basin 9 1,079 cf, Depth= 1.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-80.00 hrs, dt= 0.04 hrs NOAA 24-hr D 2-Year Rainfall=3.44" Area (sf) 2,537 6,379 8,916 8,916 Tc (min) 7.2 Length (feet) 100 0.2 40 7.4 140 CN 74 80 78 Description >75% Grass cover, Good, HSG C >75% Grass cover, Good, HSG D Weighted Average 100.00% Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.1000 0.23 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" 0.0750 4.41 Shallow Concentrated Flow, SCF (B-C) Unpaved Kv= 16.1 fps Total Subcatchment 54S: Basin 9 - Perv Hydrograph 0.36 0.34 0.32 0.3 0.28 0.26 0.24 Flow (cfs) 0.22 0.2 0.18 0.16 0.14 0.12 0.1 Runoff 0.33 cfs NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=8,916 sf Runoff Volume=1,079 cf Runoff Depth=1.45" Flow Length=140' Tc=7.4 min CN=78 0.08 0.06 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 74 76 78 80 Time (hours)