J_2024 05 09_West Orange Stormwater Management Plan

Post Development West Orange A_03 01 12 Prepared by TRC Engineers, Inc. Type III 24-hr 100 yr Rainfall=8.72" Printed 3/14/2012 HydroCAD® 9.10 s/n 06401 © 2009 HvdroCAD Software Solutions LLC Page 35 Summary for Subcatchment 1A: 1A Runoff = 2.08 cfs @ 12.09 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" UH=SCS, Split 0.154 af, Depth= 6.47" Pervious/lmperv., Time Span= 0.00-30.00 hrs, Area (sf) CN Description * 2,107 10.364 98 78 Impervious, HSG D Meadow, non-grazedf HSG D 12,471 10,364 2,107 81 78 98 Weighted Average 83.10% Pervious Area 16.90% Impervious Area Tc (min) Length (feet) Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) 4.3 70 0.1860 0.27 Sheet Flow, 0.4 70 0.0429 3.11 Shallow Concentrated Grass: Dense n= 0.240 P2= 3.42” Flow, Grassed Waterway Kv= 15.0 fps 4.7 140 Total, Increased to minimum Tc = 6.0 min Subcatchment 1A: 1A Hydrograph 2.08 cfs Type III 24-hr 100 yr Rainfall=8.72" Runoff Area=12,471 sf Runoff Volume=0.154 af Runoff Depth=6.47" Flow Length=140' Tc=6.0 min CN=78/98 U. 1. 78 9 10 11 12 13 14 15 18 1 7 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) dt= 0.01 hrs