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 Page 39 HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Summary for Subcatchment 3B: 3B Runoff = 1.97 cfs @ 12.08 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" * * UH=SCS, Split 0.156 af, Depth= 7.62" Pervious/lmperv., Area (sf) CN Description 5,785 1,111 3,792 98 98 78 Impervious, HSG D Gravel Road, HSG D Meadow, non-qrazed, HSG D 10,688 3,792 6,896 91 78 98 Weighted Average 35.48% Pervious Area 64.52% Impervious Area Tc (min) Length (feet) 1.3 100 0.0150 1.27 0.8 150 0.0400 3.00 2.1 250 Total, Time Span= 0.00-30.00 hrs, Slope Velocity Capacity Description (ft/ft) (ft/sec) (cfs) Sheet Flow, Smooth surfaces n= 0.011 P2=3.42" Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps Increased to minimum Tc = 6.0 min Subcatchment 3B: 3B Hydrograph 0 ___L______J--1______U _ L . 1 97cfs 2- '^ 1 2 34 5678 : ! ; Type III 24-hr 100 yr Rainfall=8.72" Runoff Area=10,688 sf Runoff Volume=0.156 af Runoff Depth=7.62* Flow Length=250' Tc=6.0 min CN=78/98 9 10 11 12 13 14 15 18 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) dt= 0.01 hrs