J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Type III 24-hr 10yr Rainfall=5.21" Prepared by TRC Engineers, Inc. HydroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Printed 3/4/2012 Page 27 Summary for Subcatchment 4S: EX-DA 4 Runoff = 6.37 cfs @ 12.19 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 10 yr Rainfall=5.21" UH=SCS, Split 0.628 af, Depth= 4.16" Pervious/lmperv., Time Span= 0.00-30.00 hrs, Area (sf) CN Description * * * * * 31,370 5,072 12,803 8,134 21,568 98 Paved road, HSG D 98 Gravel road, HSG D 91 Gravel, HSG D 85 Yard stone, HSG D 80 Grass, Good, HSG D 78,947 42,505 36,442 91 Weighted Average 84 53.84% Pervious Area 98 46.16% Impervious Area Tc (min) Length (feet) Slope Velocity Capacity (ft/ft) (ft/sec) 12.3 150 0.0600 0.20 0.7 135 0.0460 3.22 1.2 310 0.0470 4.40 14.2 595 Total Description (cfs) Sheet Flow, Grass: Dense n= 0.240 P2= 3.42" Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps Shallow Concentrated Flow, Paved Kv= 20.3 fps Subcatchment 4S: EX-DA 4 Hydrograph -—i—. r ,----------- r—;—i------- 1—r7- 6.37cfs 6,__ I_*_1 _ J__ ___t ___J ____ I __ I __ L _ J £ 4.1 ___ |___ i - 01 2 34 — i— i- -I — t— u _ J 56 78 ------ ii ii Type III 24-hr 10 yr Rainfall=5.21" _ l L „ J • _ - I 4 - J ' I I l _ _ I 1 _ Runoff Area=78,947 sf Runoff Volume=0.628 af Runoff Depth=4.16" f Flow Length=595' i ii ii i w i i it Tc=14.2 min CN= 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) dt= 0.01 hrs