J_2024 05 09_West Orange Stormwater Management Plan

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 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 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.04 0.05 0.06 0.08 0.11 0.14 0.20 0.33 0.68 0.71 0.65 0.58 0.51 0.45 0.39 0.33 0.27 0.22 0.18 0.15 0.12 0.10 0.09 0.08 0.08 0.07 0.07 0.07 0.07 0.06 0.06 0.06 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 0.000 586.82 0.000 586.82 0.000 586.83 0.000 586.84 0.000 586.84 0.000 586.85 0.000 586.85 0.000 586.86 0.000 586.86 0.000 586.87 0.000 586.88 0.000 586.89 0.000 586.90 0.000 586.91 0.000 586.93 0.000 586.95 0.000 586.97 0.000 587.01 0.000 587.06 0.000 587.19 0.000 587.19 0.000 587.18 0.000 587.15 0.000 587.13 0.000 587.11 0.000 587.09 0.000 587.06 0.000 587.04 0.000 587.02 0.000 586.99 0.000 586.98 0.000 586.96 0.000 586.94 0.000 586.94 0.000 586.93 0.000 586.93 0.000 586.92 0.000 586.92 0.000 586.92 0.000 586.92 0.000 586.91 0.000 586.91 0.000 586.91 Primary (cfs) 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 0.02 0.03 0.04 0.05 0.06 0.08 0.11 0.14 0.20 0.33 0.68 0.71 0.65 0.58 0.51 0.45 0.39 0.33 0.27 0.22 0.18 0.15 0.12 0.10 0.09 0.08 0.08 0.07 0.07 0.07 0.07 0.06 0.06 0.06 Printed 5/13/2024 Page 122

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 123 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 > 2.72" for 2-Year_Future event Inflow = 0.52 cfs @ 12.74 hrs, Volume= 0.208 af Outflow = 0.52 cfs @ 12.74 hrs, Volume= 0.208 af, Atten= 0%, Lag= 0.1 min Primary = 0.52 cfs @ 12.74 hrs, Volume= 0.208 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= 588.81' @ 12.74 hrs Surf.Area= 0.000 ac Storage= 0.000 af Plug-Flow detention time= 0.1 min calculated for 0.208 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 875.0 - 875.0 ) 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=0.52 cfs @ 12.74 hrs HW=588.81' TW=587.20' (Dynamic Tailwater) 1=SD-22 (Orifice Controls 0.52 cfs @ 2.04 fps) Pond 18P: SD-22 Hydrograph Inflow Primary 0.52 cfs 0.55 Inflow Area=0.917 ac Peak Elev=588.81' Storage=0.000 af 0.52 cfs 0.5 0.45 Flow (cfs) 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-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 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 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.06 0.08 0.10 0.15 0.24 0.50 0.51 0.46 0.40 0.35 0.31 0.26 0.22 0.18 0.15 0.12 0.10 0.08 0.07 0.06 0.06 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 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 0.000 588.47 0.000 588.47 0.000 588.48 0.000 588.48 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 0.000 588.54 0.000 588.55 0.000 588.56 0.000 588.58 0.000 588.60 0.000 588.63 0.000 588.69 0.000 588.80 0.000 588.81 0.000 588.79 0.000 588.76 0.000 588.74 0.000 588.72 0.000 588.70 0.000 588.68 0.000 588.66 0.000 588.64 0.000 588.62 0.000 588.60 0.000 588.59 0.000 588.58 0.000 588.57 0.000 588.56 0.000 588.56 0.000 588.56 0.000 588.56 0.000 588.55 0.000 588.55 0.000 588.55 0.000 588.55 0.000 588.55 Primary (cfs) 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 0.03 0.04 0.06 0.08 0.10 0.15 0.24 0.50 0.51 0.46 0.40 0.35 0.31 0.26 0.22 0.18 0.15 0.12 0.10 0.08 0.07 0.06 0.06 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 Printed 5/13/2024 Page 124

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 125 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 > 2.66" for 2-Year_Future event Inflow = 0.30 cfs @ 12.82 hrs, Volume= 0.125 af Outflow = 0.30 cfs @ 12.82 hrs, Volume= 0.125 af, Atten= 0%, Lag= 0.1 min Primary = 0.30 cfs @ 12.82 hrs, Volume= 0.125 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= 590.88' @ 12.82 hrs Surf.Area= 0.000 ac Storage= 0.000 af Plug-Flow detention time= 0.1 min calculated for 0.125 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 887.5 - 887.5 ) 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=0.30 cfs @ 12.82 hrs HW=590.88' TW=588.81' (Dynamic Tailwater) 1=SD-21 (Orifice Controls 0.30 cfs @ 1.76 fps) Pond 19P: SD-21 Hydrograph Inflow Primary 0.30 cfs 0.32 Inflow Area=0.567 ac Peak Elev=590.88' Storage=0.000 af 0.30 cfs 0.3 0.28 0.26 0.24 0.22 Flow (cfs) 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 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 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 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.06 0.08 0.13 0.28 0.29 0.27 0.24 0.21 0.19 0.17 0.15 0.13 0.11 0.09 0.07 0.06 0.05 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 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 0.000 590.62 0.000 590.62 0.000 590.62 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 0.000 590.65 0.000 590.66 0.000 590.67 0.000 590.67 0.000 590.68 0.000 590.70 0.000 590.71 0.000 590.72 0.000 590.75 0.000 590.78 0.000 590.87 0.000 590.88 0.000 590.86 0.000 590.85 0.000 590.83 0.000 590.82 0.000 590.81 0.000 590.80 0.000 590.78 0.000 590.77 0.000 590.75 0.000 590.74 0.000 590.73 0.000 590.71 0.000 590.71 0.000 590.70 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 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 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.06 0.08 0.13 0.28 0.29 0.27 0.24 0.21 0.19 0.17 0.15 0.13 0.11 0.09 0.07 0.06 0.05 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 Printed 5/13/2024 Page 126

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 127 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>3.90" Flow Length=164' Tc=18.5 min CN=WQ Runoff=1.67 cfs 0.184 af Subcatchment 7S: PO-DA E Runoff Area=15,246 sf 31.71% Impervious Runoff Depth>4.08" Flow Length=175' Tc=15.6 min CN=WQ Runoff=1.14 cfs 0.119 af Subcatchment 9S: PO-DA G Runoff Area=16,902 sf 28.87% Impervious Runoff Depth>4.02" Flow Length=175' Tc=23.3 min CN=WQ Runoff=1.05 cfs 0.130 af Subcatchment 11S: PO-DA I Runoff Area=10,507 sf 27.64% Impervious Runoff Depth>4.02" Flow Length=120' Tc=6.5 min CN=WQ Runoff=1.04 cfs 0.081 af Runoff Area=13,809 sf 38.48% Impervious Runoff Depth>4.12" Flow Length=96' Slope=0.0336 '/' Tc=5.4 min CN=WQ Runoff=1.44 cfs 0.109 af Subcatchment 12S: PO-DA J Pond 1P: BR-01 Peak Elev=600.08' Storage=2,990 cf Inflow=1.67 cfs 0.184 af Outflow=0.33 cfs 0.182 af Pond 2P: BR-02 Peak Elev=601.13' Storage=1,649 cf Inflow=1.14 cfs 0.119 af Outflow=0.33 cfs 0.117 af Pond 3P: BR-03 Peak Elev=596.66' Storage=2,048 cf Inflow=1.05 cfs 0.130 af Outflow=0.26 cfs 0.127 af Pond 5P: BR-05 Peak Elev=595.55' Storage=1,100 cf Inflow=1.04 cfs 0.081 af Outflow=0.21 cfs 0.079 af Pond 6P: BR-04 Peak Elev=596.26' Storage=1,813 cf Inflow=1.44 cfs 0.109 af Outflow=0.20 cfs 0.106 af Pond 8P: O-1B Inflow=1.31 cfs 0.612 af Primary=1.31 cfs 0.612 af Pond 13P: SD-25, SD-26 Peak Elev=580.97' Storage=0.000 af Inflow=1.31 cfs 0.612 af 18.0" Round Culvert n=0.011 L=29.4' S=0.0099 '/' Outflow=1.31 cfs 0.612 af Pond 14P: SD-24 Peak Elev=585.38' Storage=0.000 af Inflow=1.10 cfs 0.532 af Outflow=1.10 cfs 0.532 af Pond 17P: SD-23 Peak Elev=587.25' Storage=0.000 af Inflow=0.90 cfs 0.426 af Outflow=0.90 cfs 0.426 af Pond 18P: SD-22 Peak Elev=588.86' Storage=0.000 af Inflow=0.65 cfs 0.299 af Outflow=0.65 cfs 0.299 af Pond 19P: SD-21 Peak Elev=590.89' Storage=0.000 af Inflow=0.33 cfs 0.182 af Outflow=0.33 cfs 0.182 af

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 128 Total Runoff Area = 1.863 ac Runoff Volume = 0.623 af Average Runoff Depth = 4.01" 72.59% Pervious = 1.353 ac 27.41% Impervious = 0.511 ac

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 129 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PO-DA C Runoff = 1.67 cfs @ 12.27 hrs, Volume= Routed to Pond 1P : BR-01 0.184 af, Depth> 3.90" 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 10-Year_Current Rainfall=5.37", P2=3.45" 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) 17.9 100 0.0018 0.09 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.45" 0.6 64 0.0106 1.66 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 18.5 164 Total Subcatchment 5S: PO-DA C Hydrograph Runoff Flow (cfs) 1.67 cfs NOAA 24-hr D 10-Year_Current Rainfall=5.37" P2=3.45" Runoff Area=24,698 sf Runoff Volume=0.184 af Runoff Depth>3.90" Flow Length=164' Tc=18.5 min CN=WQ 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 10-Year_Current Rainfall=5.37", P2=3.45" 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 0.03 0.00 1.00 0.06 0.00 1.50 0.09 0.00 2.00 0.13 0.00 2.50 0.16 0.00 3.00 0.20 0.00 3.50 0.24 0.00 4.00 0.28 0.00 4.50 0.32 0.00 5.00 0.37 0.00 5.50 0.41 0.01 6.00 0.46 0.02 6.50 0.51 0.03 7.00 0.57 0.04 7.50 0.63 0.06 8.00 0.70 0.08 8.50 0.77 0.11 9.00 0.85 0.15 9.50 0.95 0.20 10.00 1.06 0.26 10.50 1.20 0.34 11.00 1.40 0.46 11.50 1.70 0.68 12.00 2.57 1.37 12.50 3.67 2.33 13.00 3.97 2.61 13.50 4.17 2.79 14.00 4.31 2.92 14.50 4.42 3.03 15.00 4.52 3.12 15.50 4.60 3.19 16.00 4.67 3.26 16.50 4.74 3.32 17.00 4.80 3.38 17.50 4.86 3.44 18.00 4.91 3.48 18.50 4.96 3.53 19.00 5.00 3.57 19.50 5.05 3.61 20.00 5.09 3.65 20.50 5.13 3.69 21.00 5.17 3.73 21.50 5.21 3.76 22.00 5.24 3.79 22.50 5.28 3.83 23.00 5.31 3.86 23.50 5.34 3.89 24.00 5.37 3.92 Runoff (cfs) 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 0.01 0.02 0.02 0.03 0.04 0.04 0.05 0.07 0.09 0.14 0.23 0.63 0.93 0.34 0.21 0.15 0.12 0.10 0.09 0.08 0.07 0.07 0.06 0.05 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.03 0.03 Printed 5/13/2024 Page 130

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 131 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: PO-DA E Runoff = 1.14 cfs @ 12.23 hrs, Volume= Routed to Pond 2P : BR-02 0.119 af, Depth> 4.08" 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 10-Year_Current Rainfall=5.37", P2=3.45" 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) 14.6 100 0.0030 0.11 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.45" 1.0 75 0.0055 1.19 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 15.6 175 Total Subcatchment 7S: PO-DA E Hydrograph Runoff 1.14 cfs NOAA 24-hr D 10-Year_Current Rainfall=5.37" P2=3.45" Runoff Area=15,246 sf Runoff Volume=0.119 af Runoff Depth>4.08" Flow Length=175' Tc=15.6 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