250701_42 ERW_Stormwater Report

NOAA 24-hr D 25-Year Rainfall=6.44" 250624_42 ERW Waymaker Prepared by Colliers Engineering & Design HydroCAD® 10.20-5c s/n 04431 © 2023 HydroCAD Software Solutions LLC Printed 7/1/2025 Page 25 Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment PR 1A-P: Runoff Area=13,167 sf 0.00% Impervious Runoff Depth=3.97" Flow Length=203' Tc=5.9 min CN=78 Runoff=1.36 cfs 0.100 af Subcatchment PR 1B-I: Runoff Area=36,906 sf 100.00% Impervious Runoff Depth=6.20" Flow Length=136' Tc=1.5 min CN=98 Runoff=5.73 cfs 0.438 af Subcatchment PR 1B-P: Runoff Area=77,195 sf 0.00% Impervious Runoff Depth=4.07" Flow Length=180' Tc=7.5 min CN=79 Runoff=7.82 cfs 0.602 af Reach 10R: Inflow=12.08 cfs 1.040 af Outflow=12.08 cfs 1.040 af Reach DP1-PR: Inflow=5.28 cfs 0.551 af Outflow=5.28 cfs 0.551 af Pond BASIN: Peak Elev=18.32' Storage=0.253 af Inflow=12.08 cfs 1.040 af Discarded=0.87 cfs 0.589 af Primary=4.37 cfs 0.451 af Outflow=5.24 cfs 1.040 af Total Runoff Area = 2.922 ac Runoff Volume = 1.140 af Average Runoff Depth = 4.68" 71.00% Pervious = 2.074 ac 29.00% Impervious = 0.847 ac