J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1A) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 40 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Pond 20P: SD-11, SD-12 Flow (cfs) Hydrograph Inflow Primary 0.11 cfs 0.12 0.115 0.11 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=1.308 ac Peak Elev=591.14' Storage=12 cf 0.11 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-1A) 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 20P: SD-11, SD-12 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 0.00 0.06 0.05 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) 0 590.26 0 590.26 0 590.26 11 591.10 11 591.09 10 591.02 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 10 591.00 Primary (cfs) 0.00 0.00 0.00 0.06 0.05 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 41

Post-Developed (O-1A) 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 42 Summary for Pond 23P: SD-01, SD-02 Inflow Area = 0.656 ac, 0.00% Impervious, Inflow Depth = 0.07" for WQ event Inflow = 0.08 cfs @ 1.31 hrs, Volume= 0.004 af Outflow = 0.05 cfs @ 1.53 hrs, Volume= 0.002 af, Atten= 29%, Lag= 13.0 min Primary = 0.05 cfs @ 1.53 hrs, Volume= 0.002 af Routed to Pond 12P : SD-03, SD-04, SD-05 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 597.15' @ 1.53 hrs Surf.Area= 16 sf Storage= 85 cf Plug-Flow detention time= 27.1 min calculated for 0.002 af (53% of inflow) Center-of-Mass det. time= 13.8 min ( 108.0 - 94.2 ) Volume #1 #2 #3 Invert 602.00' 591.82' 598.38' Avail.Storage 5,354,109 cf 163 cf 25 cf #4 #5 598.06' 597.81' 118 cf 61 cf 5,354,476 cf Elevation (feet) 602.00 603.00 Surf.Area (sq-ft) 696,960 12,422,876 Elevation (feet) 591.82 602.00 Surf.Area (sq-ft) 16 16 Inc.Store (cubic-feet) 0 163 Cum.Store (cubic-feet) 0 163 Elevation (feet) 598.06 607.15 Surf.Area (sq-ft) 13 13 Inc.Store (cubic-feet) 0 118 Cum.Store (cubic-feet) 0 118 Device #1 Routing Primary Perim. (feet) 16.0 130.1 Storage Description Drainage Ditch Storage (Irregular)Listed below (Recalc) CB-1 (Prismatic) Listed below (Recalc) 12.0" Round SD-01 L= 31.6' S= 0.0100 '/' MH-01 (Prismatic) Listed below (Recalc) 12.0" Round SD-02 L= 78.0' S= 0.0100 '/' Total Available Storage Invert 597.04' Inc.Store (cubic-feet) 0 5,354,109 Cum.Store (cubic-feet) 0 5,354,109 Wet.Area (sq-ft) 696,960 698,289 Outlet Devices 12.0" Vert. SD-02 C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.05 cfs @ 1.53 hrs HW=597.15' TW=596.07' (Dynamic Tailwater) 1=SD-02 (Orifice Controls 0.05 cfs @ 1.14 fps)

Post-Developed (O-1A) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 43 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Pond 23P: SD-01, SD-02 Hydrograph 0.085 Inflow Primary 0.08 cfs Inflow Area=0.656 ac Peak Elev=597.15' Storage=85 cf 0.08 0.075 0.07 0.065 0.06 0.05 cfs Flow (cfs) 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Time (hours) 16 17 18 19 20 21 22 23 24

Post-Developed (O-1A) 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 23P: SD-01, SD-02 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 0.00 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 Storage Elevation (cubic-feet) (feet) 0 591.82 0 591.82 0 591.82 83 596.98 85 597.11 84 597.05 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 84 597.04 Primary (cfs) 0.00 0.00 0.00 0.00 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 44

Post-Developed (O-1A) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 45 Time span=0.00-24.00 hrs, dt=0.0100 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=28,575 sf 0.00% Impervious Runoff Depth>1.19" Flow Length=298' Tc=13.3 min CN=WQ Runoff=0.68 cfs 0.065 af Subcatchment 4S: PO-DA B Runoff Area=6,403 sf 0.00% Impervious Runoff Depth>1.40" Flow Length=85' Slope=0.1773 '/' Tc=7.6 min CN=WQ Runoff=0.23 cfs 0.017 af Subcatchment 6S: PO-DA D Runoff Area=3,746 sf 0.00% Impervious Runoff Depth>1.29" Flow Length=66' Slope=0.2264 '/' Tc=5.6 min CN=WQ Runoff=0.13 cfs 0.009 af Subcatchment 8S: PO-DA F Runoff Area=10,281 sf 0.00% Impervious Runoff Depth>1.16" Flow Length=82' Slope=0.1736 '/' Tc=7.4 min CN=WQ Runoff=0.30 cfs 0.023 af Subcatchment 10S: PO-DA H Subcatchment 13S: PO-DA K Runoff Area=4,400 sf 30.68% Impervious Runoff Depth>1.89" Flow Length=239' Tc=14.3 min CN=WQ Runoff=0.16 cfs 0.016 af Subcatchment 14S: PO-DA L Runoff Area=7,972 sf 0.00% Impervious Runoff Depth>1.22" Flow Length=116' Tc=11.1 min CN=WQ Runoff=0.21 cfs 0.019 af Reach 3R: TD-01 Avg. Flow Depth=0.05' Max Vel=2.88 fps Inflow=0.23 cfs 0.017 af n=0.012 L=67.2' S=0.0298 '/' Capacity=30.28 cfs Outflow=0.23 cfs 0.017 af Reach 4R: TD-02 Avg. Flow Depth=0.04' Max Vel=2.31 fps Inflow=0.13 cfs 0.009 af n=0.012 L=34.0' S=0.0279 '/' Capacity=29.34 cfs Outflow=0.13 cfs 0.009 af Reach 5R: TD-03 Avg. Flow Depth=0.11' Max Vel=1.75 fps Inflow=0.30 cfs 0.023 af n=0.012 L=133.7' S=0.0044 '/' Capacity=11.66 cfs Outflow=0.29 cfs 0.023 af Reach 6R: TD-04 Avg. Flow Depth=0.06' Max Vel=2.32 fps Inflow=0.21 cfs 0.019 af n=0.012 L=54.6' S=0.0163 '/' Capacity=22.41 cfs Outflow=0.21 cfs 0.019 af Pond 7P: O-1A Inflow=1.59 cfs 0.146 af Primary=1.59 cfs 0.146 af Pond 12P: SD-03, SD-04, SD-05 Peak Elev=596.37' Storage=16 cf Inflow=0.86 cfs 0.080 af Outflow=0.86 cfs 0.080 af Pond 15P: SD-06, SD-07, SD-08 Peak Elev=594.36' Storage=13 cf Inflow=0.95 cfs 0.089 af Outflow=0.95 cfs 0.089 af Pond 16P: SD-09, SD-10 Peak Elev=593.33' Storage=27 cf Inflow=1.23 cfs 0.112 af Outflow=1.23 cfs 0.112 af Pond 20P: SD-11, SD-12 Peak Elev=591.54'

nflow=0.95 cfs 0.089 af Outflow=0.95 cfs 0.089 af Pond 16P: SD-09, SD-10 Peak Elev=593.33' Storage=27 cf Inflow=1.23 cfs 0.112 af Outflow=1.23 cfs 0.112 af Pond 20P: SD-11, SD-12 Peak Elev=591.54' Storage=30 cf Inflow=1.44 cfs 0.131 af Outflow=1.44 cfs 0.130 af Pond 23P: SD-01, SD-02 Peak Elev=597.46' Storage=90 cf Inflow=0.68 cfs 0.065 af Outflow=0.68 cfs 0.063 af

Post-Developed (O-1A) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 46 Total Runoff Area = 1.409 ac Runoff Volume = 0.149 af Average Runoff Depth = 1.27" 97.80% Pervious = 1.378 ac 2.20% Impervious = 0.031 ac

Post-Developed (O-1A) NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 47 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 4S: PO-DA B Runoff = 0.68 cfs @ 12.22 hrs, Volume= Routed to Pond 23P : SD-01, SD-02 0.065 af, Depth> 1.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Area (sf) 1,873 610 26,092 28,575 28,575 * CN 80 85 73 Description >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Brush, Good, HSG D Weighted Average 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.3 100 0.0900 0.15 Sheet Flow, Sheet Flow Woods: Light underbrush n= 0.400 P2= 3.45" 0.3 64 0.1920 3.07 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 1.7 134 0.0094 1.34 8.07 Channel Flow, North Channel Area= 6.0 sf Perim= 9.3' r= 0.65' n= 0.080 Earth, long dense weeds 13.3 298 Total Subcatchment 4S: PO-DA B Hydrograph 0.75 Runoff 0.68 cfs 0.7 NOAA 24-hr D 2-Year_Current Rainfall=3.45" P2=3.45" Runoff Area=28,575 sf Runoff Volume=0.065 af Runoff Depth>1.19" Flow Length=298' Tc=13.3 min CN=WQ 0.65 0.6 0.55 Flow (cfs) 0.5 0.45 0.4 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-1A) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 4S: PO-DA B Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.02 0.00 1.00 0.04 0.00 1.50 0.06 0.00 2.00 0.08 0.00 2.50 0.11 0.00 3.00 0.13 0.00 3.50 0.16 0.00 4.00 0.18 0.00 4.50 0.21 0.00 5.00 0.24 0.00 5.50 0.26 0.00 6.00 0.29 0.00 6.50 0.33 0.00 7.00 0.36 0.00 7.50 0.40 0.00 8.00 0.45 0.00 8.50 0.50 0.00 9.00 0.55 0.00 9.50 0.61 0.00 10.00 0.68 0.00 10.50 0.77 0.00 11.00 0.90 0.01 11.50 1.09 0.04 12.00 1.65 0.20 12.50 2.36 0.53 13.00 2.55 0.64 13.50 2.68 0.71 14.00 2.77 0.76 14.50 2.84 0.81 15.00 2.90 0.85 15.50 2.95 0.88 16.00 3.00 0.91 16.50 3.05 0.94 17.00 3.09 0.96 17.50 3.12 0.99 18.00 3.16 1.01 18.50 3.19 1.03 19.00 3.21 1.05 19.50 3.24 1.07 20.00 3.27 1.08 20.50 3.29 1.10 21.00 3.32 1.12 21.50 3.34 1.13 22.00 3.37 1.15 22.50 3.39 1.16 23.00 3.41 1.18 23.50 3.43 1.19 24.00 3.45 1.21 Runoff (cfs) 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 0.01 0.04 0.21 0.29 0.14 0.09 0.07 0.06 0.05 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 Printed 5/13/2024 Page 48