J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 10-Year_Future Rainfall=6.36", 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 0.01 0.01 0.02 0.02 0.02 0.03 0.04 0.04 0.05 0.07 0.08 0.10 0.12 0.14 0.17 0.20 0.25 0.34 0.50 1.30 1.02 0.93 0.86 0.78 0.72 0.67 0.62 0.55 0.47 0.41 0.36 0.31 0.26 0.23 0.20 0.17 0.15 0.14 0.12 0.11 0.11 0.10 0.10 Storage Elevation (acre-feet) (feet) 0.000 586.80 0.000 586.80 0.000 586.80 0.000 586.81 0.000 586.82 0.000 586.83 0.000 586.84 0.000 586.85 0.000 586.86 0.000 586.86 0.000 586.87 0.000 586.88 0.000 586.89 0.000 586.89 0.000 586.91 0.000 586.92 0.000 586.93 0.000 586.94 0.000 586.95 0.000 586.97 0.000 586.99 0.000 587.00 0.000 587.03 0.000 587.07 0.000 587.13 0.000 587.35 0.000 587.28 0.000 587.26 0.000 587.24 0.000 587.22 0.000 587.20 0.000 587.18 0.000 587.17 0.000 587.14 0.000 587.12 0.000 587.10 0.000 587.08 0.000 587.05 0.000 587.04 0.000 587.02 0.000 587.00 0.000 586.99 0.000 586.98 0.000 586.97 0.000 586.96 0.000 586.95 0.000 586.95 0.000 586.94 0.000 586.94 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.02 0.02 0.03 0.04 0.04 0.05 0.07 0.08 0.10 0.12 0.14 0.17 0.20 0.25 0.34 0.50 1.30 1.02 0.93 0.86 0.79 0.72 0.67 0.62 0.55 0.47 0.41 0.36 0.31 0.26 0.23 0.20 0.17 0.15 0.14 0.12 0.11 0.11 0.10 0.10 Printed 5/13/2024 Page 202

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Future Rainfall=6.36", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 203 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 > 4.84" for 10-Year_Future event Inflow = 1.08 cfs @ 12.43 hrs, Volume= 0.370 af Outflow = 1.08 cfs @ 12.43 hrs, Volume= 0.370 af, Atten= 0%, Lag= 0.1 min Primary = 1.08 cfs @ 12.43 hrs, Volume= 0.370 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= 588.99' @ 12.43 hrs Surf.Area= 0.001 ac Storage= 0.000 af Plug-Flow detention time= 0.1 min calculated for 0.370 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 883.0 - 882.9 ) 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=1.08 cfs @ 12.43 hrs HW=588.99' TW=587.35' (Dynamic Tailwater) 1=SD-22 (Orifice Controls 1.08 cfs @ 2.50 fps) Pond 18P: SD-22 Hydrograph Inflow Primary 1.08 cfs Inflow Area=0.917 ac Peak Elev=588.99' Storage=0.000 af 1.08 cfs 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 10-Year_Future Rainfall=6.36", 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 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.07 0.08 0.10 0.12 0.14 0.18 0.24 0.36 1.02 0.71 0.63 0.58 0.53 0.50 0.47 0.44 0.38 0.32 0.28 0.24 0.21 0.18 0.16 0.14 0.12 0.11 0.10 0.09 0.08 0.08 0.07 0.07 Storage Elevation (acre-feet) (feet) 0.000 588.45 0.000 588.45 0.000 588.45 0.000 588.46 0.000 588.46 0.000 588.48 0.000 588.49 0.000 588.49 0.000 588.50 0.000 588.51 0.000 588.51 0.000 588.52 0.000 588.53 0.000 588.53 0.000 588.54 0.000 588.55 0.000 588.57 0.000 588.58 0.000 588.59 0.000 588.60 0.000 588.62 0.000 588.63 0.000 588.66 0.000 588.69 0.000 588.75 0.000 588.97 0.000 588.88 0.000 588.85 0.000 588.83 0.000 588.82 0.000 588.80 0.000 588.79 0.000 588.78 0.000 588.76 0.000 588.73 0.000 588.71 0.000 588.69 0.000 588.67 0.000 588.66 0.000 588.64 0.000 588.63 0.000 588.62 0.000 588.61 0.000 588.60 0.000 588.59 0.000 588.59 0.000 588.58 0.000 588.58 0.000 588.57 Primary (cfs) 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 0.03 0.04 0.05 0.06 0.07 0.08 0.10 0.12 0.14 0.18 0.24 0.36 1.02 0.72 0.63 0.58 0.54 0.50 0.47 0.44 0.38 0.32 0.28 0.24 0.21 0.18 0.16 0.14 0.12 0.11 0.10 0.09 0.08 0.08 0.07 0.07 Printed 5/13/2024 Page 204

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Future Rainfall=6.36", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 205 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 > 4.77" for 10-Year_Future event Inflow = 0.42 cfs @ 12.96 hrs, Volume= 0.225 af Outflow = 0.42 cfs @ 12.96 hrs, Volume= 0.225 af, Atten= 0%, Lag= 0.1 min Primary = 0.42 cfs @ 12.96 hrs, Volume= 0.225 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= 590.93' @ 12.96 hrs Surf.Area= 0.000 ac Storage= 0.000 af Plug-Flow detention time= 0.1 min calculated for 0.225 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 906.9 - 906.8 ) 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=0.42 cfs @ 12.96 hrs HW=590.93' TW=588.88' (Dynamic Tailwater) 1=SD-21 (Orifice Controls 0.42 cfs @ 1.93 fps) Pond 19P: SD-21 Flow (cfs) Hydrograph 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 0.42 cfs Inflow Area=0.567 ac Peak Elev=590.93' Storage=0.000 af 0 1 2 3 4 5 6 7 8 9 10 0.42 cfs 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_Future Rainfall=6.36", 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 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.07 0.08 0.10 0.14 0.20 0.34 0.42 0.35 0.34 0.33 0.32 0.31 0.31 0.27 0.23 0.20 0.18 0.16 0.14 0.12 0.10 0.09 0.07 0.06 0.06 0.05 0.05 0.04 0.04 Storage Elevation (acre-feet) (feet) 0.000 590.61 0.000 590.61 0.000 590.61 0.000 590.61 0.000 590.62 0.000 590.63 0.000 590.63 0.000 590.64 0.000 590.64 0.000 590.65 0.000 590.65 0.000 590.66 0.000 590.66 0.000 590.67 0.000 590.68 0.000 590.69 0.000 590.70 0.000 590.71 0.000 590.71 0.000 590.72 0.000 590.73 0.000 590.75 0.000 590.76 0.000 590.79 0.000 590.83 0.000 590.90 0.000 590.93 0.000 590.90 0.000 590.90 0.000 590.89 0.000 590.89 0.000 590.89 0.000 590.88 0.000 590.87 0.000 590.84 0.000 590.83 0.000 590.82 0.000 590.80 0.000 590.79 0.000 590.78 0.000 590.76 0.000 590.75 0.000 590.74 0.000 590.73 0.000 590.72 0.000 590.72 0.000 590.71 0.000 590.71 0.000 590.71 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 0.03 0.03 0.04 0.05 0.06 0.07 0.08 0.10 0.14 0.20 0.34 0.42 0.35 0.34 0.33 0.32 0.31 0.31 0.27 0.23 0.20 0.18 0.16 0.14 0.12 0.10 0.09 0.07 0.06 0.06 0.05 0.05 0.04 0.04 Printed 5/13/2024 Page 206

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 207 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>7.59" Flow Length=164' Tc=18.5 min CN=WQ Runoff=3.18 cfs 0.359 af Subcatchment 7S: PO-DA E Runoff Area=15,246 sf 31.71% Impervious Runoff Depth>7.80" Flow Length=175' Tc=15.6 min CN=WQ Runoff=2.14 cfs 0.228 af Subcatchment 9S: PO-DA G Runoff Area=16,902 sf 28.87% Impervious Runoff Depth>7.72" Flow Length=175' Tc=23.3 min CN=WQ Runoff=1.97 cfs 0.250 af Subcatchment 11S: PO-DA I Runoff Area=10,507 sf 27.64% Impervious Runoff Depth>7.73" Flow Length=120' Tc=6.5 min CN=WQ Runoff=1.96 cfs 0.155 af Runoff Area=13,809 sf 38.48% Impervious Runoff Depth>7.84" Flow Length=96' Slope=0.0336 '/' Tc=5.4 min CN=WQ Runoff=2.68 cfs 0.207 af Subcatchment 12S: PO-DA J Pond 1P: BR-01 Peak Elev=601.35' Storage=5,218 cf Inflow=3.18 cfs 0.359 af Outflow=1.24 cfs 0.354 af Pond 2P: BR-02 Peak Elev=601.42' Storage=2,112 cf Inflow=2.14 cfs 0.228 af Outflow=1.85 cfs 0.225 af Pond 3P: BR-03 Peak Elev=598.43' Storage=4,464 cf Inflow=1.97 cfs 0.250 af Outflow=0.34 cfs 0.246 af Pond 5P: BR-05 Peak Elev=597.66' Storage=2,328 cf Inflow=1.96 cfs 0.155 af Outflow=0.32 cfs 0.154 af Pond 6P: BR-04 Peak Elev=598.36' Storage=3,691 cf Inflow=2.68 cfs 0.207 af Outflow=0.32 cfs 0.203 af Pond 8P: O-1B Inflow=3.61 cfs 1.181 af Primary=3.61 cfs 1.181 af Pond 13P: SD-25, SD-26 Peak Elev=581.41' Storage=0.000 af Inflow=3.61 cfs 1.181 af 18.0" Round Culvert n=0.011 L=29.4' S=0.0099 '/' Outflow=3.61 cfs 1.181 af Pond 14P: SD-24 Peak Elev=585.82' Storage=0.001 af Inflow=3.29 cfs 1.028 af Outflow=3.29 cfs 1.028 af Pond 17P: SD-23 Peak Elev=587.69' Storage=0.001 af Inflow=2.99 cfs 0.825 af Outflow=2.99 cfs 0.825 af Pond 18P: SD-22 Peak Elev=589.45' Storage=0.001 af Inflow=2.68 cfs 0.579 af Outflow=2.68 cfs 0.579 af Pond 19P: SD-21 Peak Elev=591.19' Storage=0.000 af Inflow=1.24 cfs 0.354 af Outflow=1.24 cfs 0.354 af

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 208 Total Runoff Area = 1.863 ac Runoff Volume = 1.199 af Average Runoff Depth = 7.72" 72.59% Pervious = 1.353 ac 27.41% Impervious = 0.511 ac

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 209 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PO-DA C Runoff = 3.18 cfs @ 12.27 hrs, Volume= Routed to Pond 1P : BR-01 0.359 af, Depth> 7.59" 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 100-Year_Current Rainfall=9.23", 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 3.18 cfs NOAA 24-hr D 100-Year_Current Rainfall=9.23" P2=3.45" Runoff Area=24,698 sf Runoff Volume=0.359 af Runoff Depth>7.59" Flow Length=164' Tc=18.5 min CN=WQ Flow (cfs) 3 2 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 100-Year_Current Rainfall=9.23", 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 0.05 0.00 1.00 0.11 0.00 1.50 0.16 0.00 2.00 0.22 0.00 2.50 0.28 0.00 3.00 0.35 0.00 3.50 0.41 0.01 4.00 0.48 0.02 4.50 0.56 0.04 5.00 0.63 0.06 5.50 0.71 0.09 6.00 0.79 0.12 6.50 0.88 0.16 7.00 0.97 0.21 7.50 1.08 0.27 8.00 1.20 0.34 8.50 1.33 0.42 9.00 1.46 0.51 9.50 1.63 0.63 10.00 1.83 0.77 10.50 2.07 0.96 11.00 2.40 1.23 11.50 2.93 1.67 12.00 4.42 3.03 12.50 6.30 4.81 13.00 6.83 5.32 13.50 7.16 5.64 14.00 7.40 5.87 14.50 7.60 6.06 15.00 7.77 6.22 15.50 7.90 6.36 16.00 8.03 6.48 16.50 8.15 6.60 17.00 8.26 6.70 17.50 8.35 6.80 18.00 8.44 6.88 18.50 8.52 6.96 19.00 8.60 7.03 19.50 8.67 7.11 20.00 8.75 7.18 20.50 8.82 7.25 21.00 8.88 7.31 21.50 8.95 7.37 22.00 9.01 7.43 22.50 9.07 7.49 23.00 9.12 7.55 23.50 9.18 7.60 24.00 9.23 7.65 Runoff (cfs) 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 0.05 0.06 0.07 0.08 0.09 0.10 0.13 0.16 0.20 0.29 0.49 1.24 1.74 0.62 0.38 0.27 0.22 0.18 0.15 0.14 0.13 0.12 0.11 0.10 0.09 0.09 0.08 0.08 0.08 0.07 0.07 0.07 0.07 0.06 0.06 0.06 Printed 5/13/2024 Page 210

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 211 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: PO-DA E Runoff = 2.14 cfs @ 12.23 hrs, Volume= Routed to Pond 2P : BR-02 0.228 af, Depth> 7.80" 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 100-Year_Current Rainfall=9.23", 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 2.14 cfs NOAA 24-hr D 100-Year_Current Rainfall=9.23" P2=3.45" Runoff Area=15,246 sf Runoff Volume=0.228 af Runoff Depth>7.80" Flow Length=175' Tc=15.6 min CN=WQ Flow (cfs) 2 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