Drainage Report and Supplement 82625

2025-08-13_Stormwater Calculations NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Stonefield Engineering & Design HydroCAD® 10.20-5c s/n 10626 © 2023 HydroCAD Software Solutions LLC Printed 8/13/2025 Page 20 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=7.33" Flow Length=147' Tc=2.6 min CN=74/98 Runoff=6.29 cfs 19,599 cf Subcatchment E-1: Existing Drainage to Runoff Area=143,746 sf 24.72% Impervious Runoff Depth=7.00" Flow Length=408' Tc=2.8 min CN=77/98 Runoff=27.67 cfs 83,884 cf Subcatchment E-2: Existing Drainage to Subcatchment P-1: Proposed Drainage to Runoff Area=32,238 sf 36.29% Impervious Runoff Depth=7.06" Flow Length=178' Tc=2.6 min CN=74/98 Runoff=6.19 cfs 18,973 cf Subcatchment P-2: Proposed Drainage to Runoff Area=143,609 sf 24.31% Impervious Runoff Depth=6.99" Flow Length=408' Tc=2.8 min CN=77/98 Runoff=27.62 cfs 83,679 cf Total Runoff Area = 351,694 sf Runoff Volume = 206,135 cf Average Runoff Depth = 7.03" 72.51% Pervious = 255,029 sf 27.49% Impervious = 96,665 sf