Drainage Report

Basin 2-4 without exfiltration Proposed Basin 2-4 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 38S: Basin 2-4 [47] Hint: Peak is 144% of capacity of segment #3 Runoff = 3.93 cfs @ 12.18 hrs, Volume= 0.354 af, Depth= 1.93" Routed to Pond 43P : pond 2-4 Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 2-Year Rainfall=3.44" Area (sf) CN Description 26,461 98 Roofs, HSG C 11,090 98 Water Surface, 0% imp, HSG C 58,486 74 >75% Grass cover, Good, HSG C 96,037 83 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 100 0.0800 0.31 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.9 120 0.0200 2.12 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.7 1,692 0.0390 7.60 2.72 Pipe Channel, pipe to basin 15.0" Round w/ 10.0" inside fill Area= 0.4 sf Perim= 2.7' r= 0.13' n= 0.010 10.1 1,912 Total