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 52 Summary for Subcatchment 7S: EX-DA 7 Runoff = 16.51 cfs@ 12.11 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" UH=SCS, Split 1.275 af, Depth= 6.37" Pervious/lmperv., Time Span= 0.00-30.00 hrs, dt= 0.01 Area (sf) CN Description * * * 805 2,198 10,157 86,177 5.402 98 Impervious, HSG D 98 Gravel road, HSG D 85 Yard stone, HSG D 80 >75% Grass cover, Good, HSG D 73 Brush, Good, HSG D 104,739 101,736 3,003 81 Weighted Average 80 97.13% Pervious Area 98 2.87% Impervious Area Tc (min) Length (feet) 4.5 70 0.1600 0.26 0.8 70 0.0857 2.4 310 0.0200 2.12 Description Slope Velocity Capacity (ft/ft) (ft/sec) (cfs) Sheet Flow, Grass: Dense n= 0.240 P2= 3.42" Shallow Concentrated Flow, 1.46 Woodland Kv= 5.0 fps Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 7.7 450 Total Subcatchment 7S: EX-DA 7 Hydrograph ---- r 18- -- 16.51 cfs 17- 1 / 15 / 1312 L.i »=, i 9u. 8 4- -- t —i----1--r- - »-- 1--i— - -i---i— 1--- 1 - ’:’:Type III 24-hr 100;yr -M Rainfall=8.72,> Runoff Area=104^739 sf RunpffV°lume=i:275! af - -j - Runoff Depth=0.37'' i i t Flow Length=450r 4 -..; -;Tci7.7 rrtirt ! CN=80/98 - L - J - -I----------------------------------------- 1------I------4 - -1 - ___1------X - L_ 0 1 2 3 4 5 6 7 8 nrr| 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) I ■ Runoff k hrs