Drainage Report and Supplement 82625

NOAA 24-hr D 10-Year-2050 Rainfall=6.37", P2=4.09" Printed 8/13/2025 Prepared by Stonefield Engineering & Design 2025-08-13_Stormwater Calculations HydroCAD® 10.20-5c s/n 10626 © 2023 HydroCAD Software Solutions LLC Page 38 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=32,101 sf 45.25% Impervious Runoff Depth=4.69" Flow Length=147' Tc=2.5 min CN=74/98 Runoff=4.07 cfs 12,546 cf Subcatchment E-1: Existing Drainage to Runoff Area=143,746 sf 24.72% Impervious Runoff Depth=4.38" Flow Length=408' Tc=2.8 min CN=77/98 Runoff=17.67 cfs 52,460 cf Subcatchment E-2: Existing Drainage to Subcatchment P-1: Proposed Drainage to Runoff Area=32,238 sf 36.29% Impervious Runoff Depth=4.45" Flow Length=178' Tc=2.5 min CN=74/98 Runoff=3.95 cfs 11,965 cf Subcatchment P-2: Proposed Drainage to Runoff Area=143,609 sf 24.31% Impervious Runoff Depth=4.37" Flow Length=408' Tc=2.8 min CN=77/98 Runoff=17.63 cfs 52,297 cf Total Runoff Area = 351,694 sf Runoff Volume = 129,268 cf Average Runoff Depth = 4.41" 72.51% Pervious = 255,029 sf 27.49% Impervious = 96,665 sf