Revised Stormwater Management Report

POA 2 proposed 2024-05-12 HydroCad - Proposed POA 2 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 6/29/2024 Page 115 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 54S: Basin 9 - Perv Runoff = 0.65 cfs @ 12.15 hrs, Volume= Routed to Pond 42P : Basin 9 2,154 cf, Depth= 2.90" 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 10-Year Rainfall=5.22" 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 Runoff 0.7 0.65 cfs 0.65 0.6 0.55 0.5 Flow (cfs) 0.45 0.4 0.35 0.3 0.25 0.2 NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=8,916 sf Runoff Volume=2,154 cf Runoff Depth=2.90" Flow Length=140' Tc=7.4 min CN=78 0.15 0.1 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 74 76 78 80 Time (hours)