J_2024 05 09_West Orange Stormwater Management Plan

Pre-Development West Orange with ponds 2 Type III 24-hr 10 yr Rainfall=5.21" Prepared by TRC Engineers, Inc. HydroCAD® 9.10 sIn 06401 © 2009 HydroCAD Software Solutions LLC Printed 3/4/2012 Page 29 Summary for Subcatchment 6S: EX-DA 6 Runoff = 9.18 cfs @ 12.23 hrs, Volume= Runoff by SCS TR-20 method, Type III 24-hr 10 yr Rainfall=5.21" UH=SCS, Split 0.923 af, Depth= 3.31" Pervious/lmperv., Time Span= 0.00-30.00 Area (sf) CN Description * * * * 9,501 8,481 43,082 57,041 27.592 98 Paved road, HSG D 98 Gravel road, HSG D 85 Yard stone, HSG D 80 Grass cover, Good, HSG D 73 Brush. Good, HSG D 145,697 127,715 17,982 82 Weighted Average 80 87.66% Pervious Area 98 12.34% Impervious Area Tc (min) Length (feet) Slope Velocity (ft/ft) (ft/sec) 13.2 150 0.0500 0.19 0.1 30 0.0880 4.45 0.2 40 0.3130 2.80 Capacity (cfs) 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