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 89 HydroCAD® 10.20-5a s/n 06666 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 25S: Basin 2 - Perv Runoff = 5.11 cfs @ 12.18 hrs, Volume= Routed to Pond 27P : Basin 2 18,966 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) 47,097 31,398 78,495 78,495 Tc (min) 9.0 1.5 10.5 CN 80 74 78 Description >75% Grass cover, Good, HSG D >75% Grass cover, Good, HSG C Weighted Average 100.00% Pervious Area Length (feet) 93 Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 0.0500 0.17 Sheet Flow, Sheet Flow (A-B) Grass: Dense n= 0.240 P2= 3.47" Using McCuen-Spiess flow length 370 0.0650 4.10 Shallow Concentrated Flow, SCF (B-C) Unpaved Kv= 16.1 fps 463 Total Subcatchment 25S: Basin 2 - Perv Hydrograph Runoff 5.11 cfs 5 Flow (cfs) 4 3 2 NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=78,495 sf Runoff Volume=18,966 cf Runoff Depth=2.90" Flow Length=463' Tc=10.5 min CN=78 1 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)