J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) 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 Pond 17P: SD-23 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.06 0.08 0.11 0.16 0.27 0.56 0.59 0.55 0.49 0.43 0.37 0.31 0.25 0.20 0.16 0.13 0.11 0.09 0.08 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 Storage Elevation (acre-feet) (feet) 0.000 586.80 0.000 586.80 0.000 586.80 0.000 586.80 0.000 586.80 0.000 586.81 0.000 586.81 0.000 586.82 0.000 586.82 0.000 586.83 0.000 586.84 0.000 586.84 0.000 586.85 0.000 586.85 0.000 586.85 0.000 586.86 0.000 586.86 0.000 586.87 0.000 586.88 0.000 586.89 0.000 586.91 0.000 586.92 0.000 586.95 0.000 586.98 0.000 587.04 0.000 587.15 0.000 587.16 0.000 587.14 0.000 587.12 0.000 587.10 0.000 587.08 0.000 587.05 0.000 587.03 0.000 587.00 0.000 586.98 0.000 586.96 0.000 586.95 0.000 586.93 0.000 586.92 0.000 586.92 0.000 586.92 0.000 586.91 0.000 586.91 0.000 586.91 0.000 586.91 0.000 586.91 0.000 586.90 0.000 586.90 0.000 586.90 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.06 0.08 0.11 0.16 0.27 0.56 0.59 0.55 0.49 0.43 0.37 0.31 0.25 0.20 0.16 0.13 0.11 0.09 0.08 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 Printed 5/13/2024 Page 82

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 83 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Pond 18P: SD-22 Inflow Area = 0.917 ac, 22.90% Impervious, Inflow Depth > 2.17" for 2-Year_Current event Inflow = 0.42 cfs @ 12.79 hrs, Volume= 0.166 af Outflow = 0.42 cfs @ 12.79 hrs, Volume= 0.166 af, Atten= 0%, Lag= 0.1 min Primary = 0.42 cfs @ 12.79 hrs, Volume= 0.166 af Routed to Pond 17P : SD-23 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 588.77' @ 12.79 hrs Surf.Area= 0.000 ac Storage= 0.000 af Plug-Flow detention time= 0.1 min calculated for 0.165 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 876.4 - 876.4 ) Volume #1 Device #1 Invert 588.45' Avail.Storage 0.002 af Routing Primary Invert 588.45' Storage Description 12.0" Round SD-22 L= 127.3' S= 0.0150 '/' Outlet Devices 12.0" Vert. SD-22 C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.42 cfs @ 12.79 hrs HW=588.77' TW=587.16' (Dynamic Tailwater) 1=SD-22 (Orifice Controls 0.42 cfs @ 1.93 fps) Pond 18P: SD-22 Flow (cfs) Hydrograph Inflow Primary 0.42 cfs 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 Area=0.917 ac Peak Elev=588.77' Storage=0.000 af 0.42 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) 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 Pond 18P: SD-22 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.08 0.12 0.20 0.40 0.42 0.38 0.34 0.30 0.25 0.21 0.17 0.14 0.11 0.09 0.07 0.06 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.03 Storage Elevation (acre-feet) (feet) 0.000 588.45 0.000 588.45 0.000 588.45 0.000 588.45 0.000 588.45 0.000 588.46 0.000 588.46 0.000 588.47 0.000 588.47 0.000 588.48 0.000 588.48 0.000 588.49 0.000 588.49 0.000 588.49 0.000 588.50 0.000 588.50 0.000 588.51 0.000 588.51 0.000 588.52 0.000 588.53 0.000 588.55 0.000 588.56 0.000 588.58 0.000 588.61 0.000 588.66 0.000 588.76 0.000 588.77 0.000 588.76 0.000 588.74 0.000 588.72 0.000 588.70 0.000 588.67 0.000 588.65 0.000 588.63 0.000 588.61 0.000 588.59 0.000 588.58 0.000 588.57 0.000 588.56 0.000 588.56 0.000 588.55 0.000 588.55 0.000 588.55 0.000 588.55 0.000 588.54 0.000 588.54 0.000 588.54 0.000 588.54 0.000 588.54 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.08 0.12 0.19 0.40 0.42 0.38 0.34 0.30 0.25 0.21 0.17 0.14 0.11 0.09 0.07 0.06 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.03 Printed 5/13/2024 Page 84

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 85 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Pond 19P: SD-21 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth > 2.11" for 2-Year_Current event Inflow = 0.24 cfs @ 12.86 hrs, Volume= 0.099 af Outflow = 0.24 cfs @ 12.86 hrs, Volume= 0.099 af, Atten= 0%, Lag= 0.1 min Primary = 0.24 cfs @ 12.86 hrs, Volume= 0.099 af Routed to Pond 18P : SD-22 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 590.85' @ 12.86 hrs Surf.Area= 0.000 ac Storage= 0.000 af Plug-Flow detention time= 0.1 min calculated for 0.099 af (100% of inflow) Center-of-Mass det. time= 0.0 min ( 888.7 - 888.6 ) Volume #1 Device #1 Invert 590.61' Avail.Storage 0.001 af Routing Primary Invert 590.61' Storage Description 12.0" Round SD-21 L= 64.5' S= 0.0150 '/' Outlet Devices 12.0" Vert. SD-21 C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.24 cfs @ 12.86 hrs HW=590.85' TW=588.77' (Dynamic Tailwater) 1=SD-21 (Orifice Controls 0.24 cfs @ 1.66 fps) Pond 19P: SD-21 Hydrograph 0.26 Inflow Primary 0.24 cfs Inflow Area=0.567 ac Peak Elev=590.85' Storage=0.000 af 0.24 cfs 0.24 0.22 0.2 Flow (cfs) 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 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 Pond 19P: SD-21 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.06 0.11 0.22 0.24 0.22 0.20 0.18 0.16 0.14 0.12 0.10 0.08 0.06 0.05 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 0.02 Storage Elevation (acre-feet) (feet) 0.000 590.61 0.000 590.61 0.000 590.61 0.000 590.61 0.000 590.61 0.000 590.61 0.000 590.62 0.000 590.62 0.000 590.62 0.000 590.63 0.000 590.63 0.000 590.63 0.000 590.64 0.000 590.64 0.000 590.64 0.000 590.64 0.000 590.65 0.000 590.66 0.000 590.66 0.000 590.67 0.000 590.68 0.000 590.69 0.000 590.71 0.000 590.73 0.000 590.77 0.000 590.84 0.000 590.85 0.000 590.84 0.000 590.83 0.000 590.82 0.000 590.80 0.000 590.79 0.000 590.77 0.000 590.76 0.000 590.74 0.000 590.73 0.000 590.72 0.000 590.70 0.000 590.70 0.000 590.69 0.000 590.69 0.000 590.69 0.000 590.69 0.000 590.69 0.000 590.68 0.000 590.68 0.000 590.68 0.000 590.68 0.000 590.68 Primary (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 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.06 0.11 0.22 0.24 0.22 0.20 0.18 0.16 0.14 0.12 0.10 0.08 0.06 0.05 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 0.02 Printed 5/13/2024 Page 86

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 87 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 Subcatchment 5S: PO-DA C Runoff Area=24,698 sf 17.46% Impervious Runoff Depth>2.70" Flow Length=164' Tc=17.1 min CN=WQ Runoff=1.21 cfs 0.128 af Subcatchment 7S: PO-DA E Runoff Area=15,246 sf 31.71% Impervious Runoff Depth>2.87" Flow Length=175' Tc=14.4 min CN=WQ Runoff=0.84 cfs 0.084 af Subcatchment 9S: PO-DA G Runoff Area=16,902 sf 28.87% Impervious Runoff Depth>2.82" Flow Length=175' Tc=21.5 min CN=WQ Runoff=0.77 cfs 0.091 af Subcatchment 11S: PO-DA I Runoff Area=10,507 sf 27.64% Impervious Runoff Depth>2.81" Flow Length=120' Tc=6.0 min CN=WQ Runoff=0.75 cfs 0.056 af Runoff Area=13,809 sf 38.48% Impervious Runoff Depth>2.91" Flow Length=96' Slope=0.0336 '/' Tc=4.9 min CN=WQ Runoff=1.05 cfs 0.077 af Subcatchment 12S: PO-DA J Pond 1P: BR-01 Peak Elev=599.34' Storage=1,902 cf Inflow=1.21 cfs 0.128 af Outflow=0.30 cfs 0.125 af Pond 2P: BR-02 Peak Elev=600.04' Storage=1,120 cf Inflow=0.84 cfs 0.084 af Outflow=0.23 cfs 0.082 af Pond 3P: BR-03 Peak Elev=595.56' Storage=1,373 cf Inflow=0.77 cfs 0.091 af Outflow=0.20 cfs 0.089 af Pond 5P: BR-05 Peak Elev=594.95' Storage=729 cf Inflow=0.75 cfs 0.056 af Outflow=0.17 cfs 0.055 af Pond 6P: BR-04 Peak Elev=595.75' Storage=1,229 cf Inflow=1.05 cfs 0.077 af Outflow=0.16 cfs 0.074 af Pond 8P: O-1B Inflow=1.04 cfs 0.427 af Primary=1.04 cfs 0.427 af Pond 13P: SD-25, SD-26 Peak Elev=580.90' Storage=0.000 af Inflow=1.04 cfs 0.427 af 18.0" Round Culvert n=0.011 L=29.4' S=0.0099 '/' Outflow=1.04 cfs 0.427 af Pond 14P: SD-24 Peak Elev=585.32' Storage=0.000 af Inflow=0.88 cfs 0.371 af Outflow=0.88 cfs 0.371 af Pond 17P: SD-23 Peak Elev=587.20' Storage=0.000 af Inflow=0.72 cfs 0.297 af Outflow=0.72 cfs 0.297 af Pond 18P: SD-22 Peak Elev=588.81' Storage=0.000 af Inflow=0.52 cfs 0.208 af Outflow=0.52 cfs 0.208 af Pond 19P: SD-21 Peak Elev=590.88' Storage=0.000 af Inflow=0.30 cfs 0.125 af Outflow=0.30 cfs 0.125 af

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 88 Total Runoff Area = 1.863 ac Runoff Volume = 0.436 af Average Runoff Depth = 2.81" 72.59% Pervious = 1.353 ac 27.41% Impervious = 0.511 ac

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 89 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PO-DA C Runoff = 1.21 cfs @ 12.25 hrs, Volume= Routed to Pond 1P : BR-01 0.128 af, Depth> 2.70" 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_Future Rainfall=4.07", P2=4.07" Area (sf) 4,312 2,396 17,990 24,698 20,386 4,312 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 82.54% Pervious Area 17.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 16.5 100 0.0018 0.10 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 4.07" 0.6 64 0.0106 1.66 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 17.1 164 Total Subcatchment 5S: PO-DA C Hydrograph Runoff 1.21 cfs NOAA 24-hr D 2-Year_Future Rainfall=4.07" P2=4.07" Runoff Area=24,698 sf Runoff Volume=0.128 af Runoff Depth>2.70" Flow Length=164' Tc=17.1 min CN=WQ Flow (cfs) 1 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 NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 5S: PO-DA C Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.02 0.00 1.00 0.05 0.00 1.50 0.07 0.00 2.00 0.10 0.00 2.50 0.12 0.00 3.00 0.15 0.00 3.50 0.18 0.00 4.00 0.21 0.00 4.50 0.25 0.00 5.00 0.28 0.00 5.50 0.31 0.00 6.00 0.35 0.00 6.50 0.39 0.00 7.00 0.43 0.01 7.50 0.48 0.02 8.00 0.53 0.03 8.50 0.58 0.05 9.00 0.65 0.07 9.50 0.72 0.09 10.00 0.81 0.13 10.50 0.91 0.18 11.00 1.06 0.26 11.50 1.29 0.40 12.00 1.95 0.87 12.50 2.78 1.55 13.00 3.01 1.75 13.50 3.16 1.88 14.00 3.26 1.97 14.50 3.35 2.05 15.00 3.42 2.11 15.50 3.49 2.17 16.00 3.54 2.22 16.50 3.59 2.27 17.00 3.64 2.31 17.50 3.68 2.35 18.00 3.72 2.38 18.50 3.76 2.42 19.00 3.79 2.45 19.50 3.82 2.48 20.00 3.86 2.51 20.50 3.89 2.53 21.00 3.92 2.56 21.50 3.95 2.59 22.00 3.97 2.61 22.50 4.00 2.64 23.00 4.02 2.66 23.50 4.05 2.68 24.00 4.07 2.70 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.04 0.06 0.09 0.16 0.45 0.61 0.23 0.15 0.11 0.09 0.07 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.02 Printed 5/13/2024 Page 90

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 91 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: PO-DA E Runoff = 0.84 cfs @ 12.22 hrs, Volume= Routed to Pond 2P : BR-02 0.084 af, Depth> 2.87" 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_Future Rainfall=4.07", P2=4.07" Area (sf) 4,835 2,047 8,364 15,246 10,411 4,835 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 68.29% Pervious Area 31.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.4 100 0.0030 0.12 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 4.07" 1.0 75 0.0055 1.19 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 14.4 175 Total Subcatchment 7S: PO-DA E Hydrograph Runoff 0.9 0.84 cfs 0.85 NOAA 24-hr D 2-Year_Future Rainfall=4.07" P2=4.07" Runoff Area=15,246 sf Runoff Volume=0.084 af Runoff Depth>2.87" Flow Length=175' Tc=14.4 min CN=WQ 0.8 0.75 0.7 0.65 Flow (cfs) 0.6 0.55 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