J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Type III 24-hr 100 yr Rainfall=8.72" Prepared by TRC Engineers, Inc. HydroCAD® 9,10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Printed 3/4/2012 Page 55 Summary for Subcatchment 9B: EX-DA 9B Runoff = 4.85 cfs@ 12.40 hrs, Vo!ume= Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" UH=SCS, 0.678 af, Depth= 7.76" Split Pervious/lmperv., Time Span= 0.00-30.00 hrs, dt= 0.01 -r ~ i hrs Area (sf) CN Description * * * 24,703 670 20,336 98 Impervious, HSG D 91 Gravel, HSG D 85 Yard stone, HSG D 45,709 21,006 24,703 92 Weighted Average 85 45.96% Pervious Area 98 54.04% Impervious Area Tc (min) Length (feet) Slope Velocity Capacity (ft/ft) (ft/sec) 30.0 150 0.0070 0.08 Sheet Flow, Yard Stone 1.0 160 0.0190 2.80 Shallow Concentrated Flow, 31.0 310 Total Description (cfs) n= 0.250 P2= 3.42" Paved Kv= 20.3 fps Subcatchment 9B: EX-DA 9B Hydrograph t i l 4.85 cfs 5- i—:—i---1—i--i—r l - ■ ■ -r i -H—r-h-—i—— —•— •— -ri & 3- i a 1 - 1 i 1 i i 1 i 1 1 ” i 1 1 1 1 - i ” i i i 1 i * 1 i i i Rainfall=8.72" Runoff Area=45,709 sf Runoff; Volume=0.678 af Runoff Depth=7.76" Flow Length=310' Tc=31;0 min CN=85/98 L _ 1_ J 8 i 9 10 11 12 13 14 15 18 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) WMWr — i — r - r