250701_42 ERW_Stormwater Report

NOAA 24-hr D 50-Year Rainfall=7.49" 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 52 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=4.92" Flow Length=203' Tc=5.9 min CN=78 Runoff=1.67 cfs 0.124 af Subcatchment PR 1B-I: Runoff Area=36,906 sf 100.00% Impervious Runoff Depth=7.25" Flow Length=136' Tc=1.5 min CN=98 Runoff=6.66 cfs 0.512 af Subcatchment PR 1B-P: Runoff Area=77,195 sf 0.00% Impervious Runoff Depth=5.03" Flow Length=180' Tc=7.5 min CN=79 Runoff=9.58 cfs 0.744 af Reach 10R: Inflow=14.51 cfs 1.255 af Outflow=14.51 cfs 1.255 af Reach DP1-PR: Inflow=6.31 cfs 0.720 af Outflow=6.31 cfs 0.720 af Pond BASIN: Peak Elev=19.07' Storage=0.303 af Inflow=14.51 cfs 1.255 af Discarded=0.99 cfs 0.660 af Primary=5.40 cfs 0.596 af Outflow=6.39 cfs 1.255 af Total Runoff Area = 2.922 ac Runoff Volume = 1.379 af Average Runoff Depth = 5.67" 71.00% Pervious = 2.074 ac 29.00% Impervious = 0.847 ac