J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 7S: PO-DA E Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.10 0.00 1.00 0.63 0.07 1.50 1.15 0.34 2.00 1.25 0.41 2.50 1.25 0.41 3.00 1.25 0.41 3.50 1.25 0.41 4.00 1.25 0.41 4.50 1.25 0.41 5.00 1.25 0.41 5.50 1.25 0.41 6.00 1.25 0.41 6.50 1.25 0.41 7.00 1.25 0.41 7.50 1.25 0.41 8.00 1.25 0.41 8.50 1.25 0.41 9.00 1.25 0.41 9.50 1.25 0.41 10.00 1.25 0.41 10.50 1.25 0.41 11.00 1.25 0.41 11.50 1.25 0.41 12.00 1.25 0.41 12.50 1.25 0.41 13.00 1.25 0.41 13.50 1.25 0.41 14.00 1.25 0.41 14.50 1.25 0.41 15.00 1.25 0.41 15.50 1.25 0.41 16.00 1.25 0.41 16.50 1.25 0.41 17.00 1.25 0.41 17.50 1.25 0.41 18.00 1.25 0.41 18.50 1.25 0.41 19.00 1.25 0.41 19.50 1.25 0.41 20.00 1.25 0.41 20.50 1.25 0.41 21.00 1.25 0.41 21.50 1.25 0.41 22.00 1.25 0.41 22.50 1.25 0.41 23.00 1.25 0.41 23.50 1.25 0.41 24.00 1.25 0.41 Runoff (cfs) 0.00 0.00 0.07 0.15 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 5/13/2024 Page 12

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 13 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: PO-DA G Runoff = 0.31 cfs @ Routed to Pond 3P : BR-03 1.33 hrs, Volume= 0.016 af, Depth= 0.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Area (sf) 4,879 2,788 9,235 16,902 12,023 4,879 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 71.13% Pervious Area 28.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22.7 100 0.0010 0.07 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.42" 0.7 75 0.0121 1.77 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 23.4 175 Total Subcatchment 9S: PO-DA G Hydrograph Runoff 0.34 0.31 cfs 0.32 NJ DEP 2-hr WQ Rainfall=1.25" P2=3.42" Runoff Area=16,902 sf Runoff Volume=0.016 af Runoff Depth=0.49" Flow Length=175' Tc=23.4 min CN=WQ 0.3 0.28 0.26 0.24 Flow (cfs) 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Time (hours) 15 16 17 18 19 20 21 22 23 24

Post-Developed (O-1B) West Orange HydroCAD_Post NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 9S: PO-DA G Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.10 0.00 1.00 0.63 0.07 1.50 1.15 0.34 2.00 1.25 0.41 2.50 1.25 0.41 3.00 1.25 0.41 3.50 1.25 0.41 4.00 1.25 0.41 4.50 1.25 0.41 5.00 1.25 0.41 5.50 1.25 0.41 6.00 1.25 0.41 6.50 1.25 0.41 7.00 1.25 0.41 7.50 1.25 0.41 8.00 1.25 0.41 8.50 1.25 0.41 9.00 1.25 0.41 9.50 1.25 0.41 10.00 1.25 0.41 10.50 1.25 0.41 11.00 1.25 0.41 11.50 1.25 0.41 12.00 1.25 0.41 12.50 1.25 0.41 13.00 1.25 0.41 13.50 1.25 0.41 14.00 1.25 0.41 14.50 1.25 0.41 15.00 1.25 0.41 15.50 1.25 0.41 16.00 1.25 0.41 16.50 1.25 0.41 17.00 1.25 0.41 17.50 1.25 0.41 18.00 1.25 0.41 18.50 1.25 0.41 19.00 1.25 0.41 19.50 1.25 0.41 20.00 1.25 0.41 20.50 1.25 0.41 21.00 1.25 0.41 21.50 1.25 0.41 22.00 1.25 0.41 22.50 1.25 0.41 23.00 1.25 0.41 23.50 1.25 0.41 24.00 1.25 0.41 Runoff (cfs) 0.00 0.00 0.04 0.23 0.07 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 5/13/2024 Page 14

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 15 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 11S: PO-DA I Runoff = 0.33 cfs @ Routed to Pond 5P : BR-05 1.13 hrs, Volume= 0.010 af, Depth= 0.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Area (sf) 2,904 1,737 5,866 10,507 7,603 2,904 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 72.36% Pervious Area 27.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.4 100 0.0237 0.26 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.42" 0.1 20 0.0320 2.88 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 6.5 120 Total Subcatchment 11S: PO-DA I Hydrograph Runoff 0.36 0.33 cfs 0.34 NJ DEP 2-hr WQ Rainfall=1.25" P2=3.42" Runoff Area=10,507 sf Runoff Volume=0.010 af Runoff Depth=0.48" Flow Length=120' Tc=6.5 min CN=WQ 0.32 0.3 0.28 0.26 Flow (cfs) 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Time (hours) 15 16 17 18 19 20 21 22 23 24

Post-Developed (O-1B) West Orange HydroCAD_Post NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 11S: PO-DA I Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.10 0.00 1.00 0.63 0.07 1.50 1.15 0.34 2.00 1.25 0.41 2.50 1.25 0.41 3.00 1.25 0.41 3.50 1.25 0.41 4.00 1.25 0.41 4.50 1.25 0.41 5.00 1.25 0.41 5.50 1.25 0.41 6.00 1.25 0.41 6.50 1.25 0.41 7.00 1.25 0.41 7.50 1.25 0.41 8.00 1.25 0.41 8.50 1.25 0.41 9.00 1.25 0.41 9.50 1.25 0.41 10.00 1.25 0.41 10.50 1.25 0.41 11.00 1.25 0.41 11.50 1.25 0.41 12.00 1.25 0.41 12.50 1.25 0.41 13.00 1.25 0.41 13.50 1.25 0.41 14.00 1.25 0.41 14.50 1.25 0.41 15.00 1.25 0.41 15.50 1.25 0.41 16.00 1.25 0.41 16.50 1.25 0.41 17.00 1.25 0.41 17.50 1.25 0.41 18.00 1.25 0.41 18.50 1.25 0.41 19.00 1.25 0.41 19.50 1.25 0.41 20.00 1.25 0.41 20.50 1.25 0.41 21.00 1.25 0.41 21.50 1.25 0.41 22.00 1.25 0.41 22.50 1.25 0.41 23.00 1.25 0.41 23.50 1.25 0.41 24.00 1.25 0.41 Runoff (cfs) 0.00 0.00 0.13 0.06 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 5/13/2024 Page 16

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 17 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: PO-DA J Runoff = 0.50 cfs @ Routed to Pond 6P : BR-04 1.11 hrs, Volume= 0.015 af, Depth= 0.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Area (sf) 5,314 3,703 4,792 13,809 8,495 5,314 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 61.52% Pervious Area 38.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.4 96 0.0336 0.30 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.42" Subcatchment 12S: PO-DA J Hydrograph Runoff 0.55 0.50 cfs NJ DEP 2-hr WQ Rainfall=1.25" P2=3.42" Runoff Area=13,809 sf Runoff Volume=0.015 af Runoff Depth=0.55" Flow Length=96' Slope=0.0336 '/' Tc=5.4 min CN=WQ 0.5 0.45 0.4 Flow (cfs) 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Time (hours) 15 16 17 18 19 20 21 22 23 24

Post-Developed (O-1B) West Orange HydroCAD_Post NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 12S: PO-DA J Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.10 0.00 1.00 0.63 0.09 1.50 1.15 0.38 2.00 1.25 0.45 2.50 1.25 0.45 3.00 1.25 0.45 3.50 1.25 0.45 4.00 1.25 0.45 4.50 1.25 0.45 5.00 1.25 0.45 5.50 1.25 0.45 6.00 1.25 0.45 6.50 1.25 0.45 7.00 1.25 0.45 7.50 1.25 0.45 8.00 1.25 0.45 8.50 1.25 0.45 9.00 1.25 0.45 9.50 1.25 0.45 10.00 1.25 0.45 10.50 1.25 0.45 11.00 1.25 0.45 11.50 1.25 0.45 12.00 1.25 0.45 12.50 1.25 0.45 13.00 1.25 0.45 13.50 1.25 0.45 14.00 1.25 0.45 14.50 1.25 0.45 15.00 1.25 0.45 15.50 1.25 0.45 16.00 1.25 0.45 16.50 1.25 0.45 17.00 1.25 0.45 17.50 1.25 0.45 18.00 1.25 0.45 18.50 1.25 0.45 19.00 1.25 0.45 19.50 1.25 0.45 20.00 1.25 0.45 20.50 1.25 0.45 21.00 1.25 0.45 21.50 1.25 0.45 22.00 1.25 0.45 22.50 1.25 0.45 23.00 1.25 0.45 23.50 1.25 0.45 24.00 1.25 0.45 Runoff (cfs) 0.00 0.01 0.27 0.08 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 5/13/2024 Page 18

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 19 Summary for Pond 1P: BR-01 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth = 0.42" for WQ event Inflow = 0.44 cfs @ 1.29 hrs, Volume= 0.020 af Outflow = 0.12 cfs @ 1.80 hrs, Volume= 0.020 af, Atten= 71%, Lag= 30.6 min Primary = 0.12 cfs @ 1.80 hrs, Volume= 0.020 af Routed to Pond 19P : SD-21 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 596.68' @ 1.80 hrs Surf.Area= 1,759 sf Storage= 487 cf Plug-Flow detention time= 64.5 min calculated for 0.020 af (100% of inflow) Center-of-Mass det. time= 64.2 min ( 151.6 - 87.4 ) Volume #1 #2 Invert 598.00' 597.50' Avail.Storage 5,850 cf 330 cf #3 596.00' 1,051 cf #4 596.00' 11 cf 7,241 cf Storage Description Filter Media Layer (Prismatic)Listed below (Recalc) Sand Layer (Prismatic)Listed below (Recalc) 880 cf Overall x 37.5% Voids Gravel Layer (Prismatic)Listed below (Recalc) 2,639 cf Overall - 11 cf Embedded = 2,627 cf x 40.0% Voids 4.0" Round 4" Underdrain Pipe Inside #3 L= 127.3' S= 0.0001 '/' Total Available Storage Elevation (feet) 598.00 599.50 602.50 Surf.Area Voids (sq-ft) (%) 1,759 0.0 1,759 21.7 1,759 100.0 Elevation (feet) 597.50 598.00 Surf.Area (sq-ft) 1,759 1,759 Inc.Store (cubic-feet) 0 880 Cum.Store (cubic-feet) 0 880 Elevation (feet) 596.00 597.50 Surf.Area (sq-ft) 1,759 1,759 Inc.Store (cubic-feet) 0 2,639 Cum.Store (cubic-feet) 0 2,639 Device #1 Routing Primary Invert 591.57' #2 Device 1 596.00' #3 Device 1 600.50' #4 Device 1 602.40' Inc.Store (cubic-feet) 0 573 5,277 Cum.Store (cubic-feet) 0 573 5,850 Outlet Devices 12.0" Vert. SD-21 Outlet (Elevation F) C= 0.600 Limited to weir flow at low heads 2.5" Vert. Water Quatity (Elevation G) C= 0.600 Limited to weir flow at low heads 12.0" W x 2.5" H Vert. Water Quantity (Elevation H) C= 0.600 Limited to weir flow at low heads 48.0" x 48.0" Horiz. Overflow Grate (Elevation I) C= 0.600 Limited to weir flow at low heads

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 20 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.12 cfs @ 1.80 hrs HW=596.68' TW=590.78' (Dynamic Tailwater) 1=SD-21 Outlet (Elevation F) (Passes 0.12 cfs of 8.12 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.12 cfs @ 3.66 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 1P: BR-01 Flow (cfs) Hydrograph 0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Primary 0.44 cfs Inflow Area=0.567 ac Peak Elev=596.68' Storage=487 cf 0.12 cfs 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Time (hours) 15 16 17 18 19 20 21 22 23 24

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 1P: BR-01 Time (hours) 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 9.50 10.00 10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 15.00 15.50 16.00 16.50 17.00 17.50 18.00 18.50 19.00 19.50 20.00 20.50 21.00 21.50 22.00 22.50 23.00 23.50 24.00 Inflow (cfs) 0.00 0.00 0.05 0.24 0.08 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Storage Elevation (cubic-feet) (feet) 0 596.00 0 596.00 26 596.04 436 596.61 471 596.66 325 596.45 182 596.25 99 596.14 62 596.09 44 596.06 34 596.05 28 596.04 23 596.03 20 596.03 17 596.02 16 596.02 14 596.02 13 596.02 12 596.02 11 596.02 10 596.01 9 596.01 9 596.01 8 596.01 8 596.01 7 596.01 7 596.01 7 596.01 6 596.01 6 596.01 6 596.01 5 596.01 5 596.01 5 596.01 5 596.01 5 596.01 5 596.01 4 596.01 4 596.01 4 596.01 4 596.01 4 596.01 4 596.01 4 596.01 4 596.01 3 596.00 3 596.00 3 596.00 3 596.00 Primary (cfs) 0.00 0.00 0.00 0.12 0.12 0.10 0.06 0.03 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Printed 5/13/2024 Page 21