Drainage Report and Supplement 82625

NOAA 24-hr D 25-Year Rainfall=6.44" 2025-08-21_Pipe Capacity Calculations Prepared by Stonefield Engineering & Design HydroCAD® 10.20-5c s/n 06682 © 2023 HydroCAD Software Solutions LLC Printed 8/21/2025 Page 5 Summary for Subcatchment PIPE 3: Pipe 3 Drainage Runoff = 2.80 cfs @ 12.09 hrs, Volume= 7,549 cf, Depth= 3.58" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs NOAA 24-hr D 25-Year Rainfall=6.44" Area (sf) 188 2,557 22,575 25,320 25,132 188 * * CN 98 74 74 74 74 98 Description Impervious Area >75% Grass cover, Good, HSG C Sand Riding Area Weighted Average 99.26% Pervious Area 0.74% Impervious Area Subcatchment PIPE 3: Pipe 3 Drainage Hydrograph Runoff 3 2.80 cfs Flow (cfs) 2 1 0 0 2 4 NOAA 24-hr D 25-Year Rainfall=6.44" Runoff Area=25,320 sf Runoff Volume=7,549 cf Runoff Depth=3.58" Tc=0.0 min CN=74/98 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 Time (hours)