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 15 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 30S: Basin 8 - Perv Runoff = 0.76 cfs @ 12.16 hrs, Volume= Routed to Pond 48P : Basin 8 2,632 cf, Depth= 1.39" 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) 11,542 11,245 22,787 22,787 Tc (min) 8.3 Length (feet) 100 0.3 65 8.6 165 CN 80 74 77 Description >75% Grass cover, Good, HSG D >75% Grass cover, Good, HSG C Weighted Average 100.00% Pervious Area Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.0700 0.20 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" 0.0600 3.94 Shallow Concentrated Flow, SCF (B-C) Unpaved Kv= 16.1 fps Total Subcatchment 30S: Basin 8 - Perv Hydrograph 0.85 0.8 0.75 0.7 0.65 0.6 Flow (cfs) 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 Runoff 0.76 cfs NOAA 24-hr D 2-Year Rainfall=3.44" Runoff Area=22,787 sf Runoff Volume=2,632 cf Runoff Depth=1.39" Flow Length=165' Tc=8.6 min CN=77 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)