J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Prepared by TRC Engineers, Inc. Type III 24-hr 100 yr Rainfall=8.72" Printed 3/4/2012 HvdroCAD® 9.10 s/n 06401 © 2009 HydroCAD Software Solutions LLC Page 50 Summary for Subcatchment 6S: EX-DA 6 Runoff = 18.00 cfs@ 12.22 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 100 yr Rainfall=8.72" UH=SCS, Split 1.832 af, Depth= 6.57" Pervious/lmperv., Area (sf) CN Description 9,501 8,481 43,082 57,041 27,592 98 98 85 80 73 Paved road, HSG D Gravel road, HSG D Yard stone, HSG D Grass cover, Good, HSG D Brush, Good, HSG D 145,697 127,715 17,982 82 80 98 Weighted Average 87.66% Pervious Area 12.34% Impervious Area Tc (min) Length (feet) Velocity (ft/sec) 13.2 150 Slope (ft/ft) 0.0500 0.1 30 0.0880 4.45 0.2 40 0.3130 2.80 * * * * 0.19 Capacity (cfs) Time Span= 0.00-30.00 Description Sheet Flow, Grass: Dense n= 0.240 P2= 3.42" Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 30 0.0330 2.92 Shallow Concentrated Flow, 3.2 240 0.0060 1.25 Shallow Concentrated Flow, Yard Stone Unpaved Kv= 16.1 fps Unpaved Kv= 16.1 fps 16.9 490 Total hrs, dt= 0.01 hrs