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 byTRC Engineers, Inc. HvdroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Printed 3/4/2012 Page 48 Summary for Subcatchment 4S: EX-DA 4 11.40 cfs @ 12.19 hrs, Volume= Runoff Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" UH=SCS, Split 1.143 af, Depth= 7.57" Pervious/lmperv., Time Span= Area (sf) CN Description 31,370 5,072 12,803 8,134 21,568 98 98 91 85 80 Paved road, HSG D Gravel road, HSG D Gravel, HSG D Yard stone, HSG D Grass, Good, HSG D 78,947 42,505 36,442 91 84 98 Weighted Average 53.84% Pervious Area 46.16% Impervious Area Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec) 12.3 150 0.0600 0.20 Sheet Flow, 0.7 135 0.0460 3.22 Shallow Concentrated Flow, 1.2 310 0.0470 4.40 * ★ * ★ * Capacity (cfs) 0.00-30.00 hrs, dt= 0.01 Description Grass: Dense n= 0.240 P2= 3.42" Grassed Waterway Kv= 15.0 fps Shallow Concentrated Flow, Paved Kv= 20.3 fps 595 14.2 Total Subcatchment 4S: EX-DA 4 Hydrograph | ■ Runoff j 11 40 cfs rr: 7 112 /- 10- • J _ - I _________ X _ - J _ - I - U — 4 _____________ I - _ & - 4- - U _ 1, _ J--- L,1, L _ i._ _X- ._L_ . _ X ______ Type III 24-hr HOOiyr Rainfall=8.72" Runoff Area=78,947 sf Runoff Volume=1.143 af Runoff Depth=t.57" Flow Length-595' 1 J X-i J Tc=14.2 rhirt I i;_L _ i _1 ;CN=84/98 J. - -I _ X _ J _ -I- - J .. . - - - -1- _ _ i_l___ | i i _ „ X _ ~ 1 2 3 4 5 __X 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) hrs