J_2024 05 09_West Orange Stormwater Management Plan

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 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 0.01 0.01 0.02 0.03 0.03 0.05 0.06 0.07 0.08 0.09 0.11 0.13 0.15 0.17 0.20 0.22 0.26 0.31 0.37 0.48 0.72 2.80 1.84 1.27 0.99 0.92 0.88 0.83 0.80 0.76 0.71 0.63 0.55 0.49 0.44 0.39 0.35 0.31 0.28 0.25 0.23 0.20 0.19 0.17 0.16 Storage Elevation (acre-feet) (feet) 0.000 586.80 0.000 586.80 0.000 586.80 0.000 586.82 0.000 586.83 0.000 586.85 0.000 586.86 0.000 586.87 0.000 586.88 0.000 586.90 0.000 586.91 0.000 586.92 0.000 586.93 0.000 586.94 0.000 586.95 0.000 586.96 0.000 586.98 0.000 586.99 0.000 587.00 0.000 587.02 0.000 587.03 0.000 587.06 0.000 587.08 0.000 587.12 0.000 587.20 0.001 587.65 0.000 587.46 0.000 587.34 0.000 587.27 0.000 587.25 0.000 587.24 0.000 587.23 0.000 587.22 0.000 587.21 0.000 587.19 0.000 587.17 0.000 587.14 0.000 587.12 0.000 587.11 0.000 587.09 0.000 587.07 0.000 587.06 0.000 587.04 0.000 587.03 0.000 587.02 0.000 587.01 0.000 587.00 0.000 586.99 0.000 586.98 Primary (cfs) 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.03 0.03 0.05 0.06 0.07 0.08 0.09 0.11 0.13 0.15 0.17 0.20 0.22 0.26 0.31 0.37 0.48 0.72 2.81 1.84 1.27 0.99 0.92 0.88 0.83 0.80 0.77 0.71 0.63 0.55 0.49 0.44 0.39 0.35 0.32 0.28 0.25 0.23 0.20 0.19 0.17 0.16 Printed 5/13/2024 Page 242

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 243 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 > 7.58" for 100-Year_Current event Inflow = 2.68 cfs @ 12.34 hrs, Volume= 0.579 af Outflow = 2.68 cfs @ 12.35 hrs, Volume= 0.579 af, Atten= 0%, Lag= 0.5 min Primary = 2.68 cfs @ 12.35 hrs, Volume= 0.579 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= 589.45' @ 12.35 hrs Surf.Area= 0.001 ac Storage= 0.001 af Plug-Flow detention time= 0.1 min calculated for 0.579 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 861.5 - 861.4 ) 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=2.68 cfs @ 12.35 hrs HW=589.45' TW=587.69' (Dynamic Tailwater) 1=SD-22 (Orifice Controls 2.68 cfs @ 3.41 fps) Pond 18P: SD-22 Hydrograph 3 Inflow Primary 2.68 cfs Inflow Area=0.917 ac Peak Elev=589.45' Storage=0.001 af 2.68 cfs 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

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 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 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.11 0.12 0.14 0.16 0.19 0.22 0.27 0.34 0.54 2.46 1.49 0.93 0.65 0.59 0.55 0.51 0.49 0.46 0.44 0.39 0.34 0.30 0.26 0.24 0.21 0.19 0.18 0.16 0.15 0.13 0.12 0.11 0.11 Storage Elevation (acre-feet) (feet) 0.000 588.45 0.000 588.45 0.000 588.45 0.000 588.47 0.000 588.48 0.000 588.49 0.000 588.51 0.000 588.51 0.000 588.52 0.000 588.54 0.000 588.55 0.000 588.56 0.000 588.56 0.000 588.57 0.000 588.59 0.000 588.60 0.000 588.61 0.000 588.62 0.000 588.63 0.000 588.64 0.000 588.66 0.000 588.68 0.000 588.70 0.000 588.74 0.000 588.82 0.001 589.37 0.000 589.10 0.000 588.94 0.000 588.86 0.000 588.83 0.000 588.82 0.000 588.81 0.000 588.80 0.000 588.79 0.000 588.78 0.000 588.76 0.000 588.74 0.000 588.72 0.000 588.70 0.000 588.69 0.000 588.68 0.000 588.66 0.000 588.65 0.000 588.64 0.000 588.63 0.000 588.63 0.000 588.62 0.000 588.61 0.000 588.61 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.11 0.12 0.14 0.16 0.19 0.22 0.27 0.34 0.54 2.47 1.50 0.93 0.65 0.59 0.55 0.51 0.49 0.46 0.44 0.39 0.34 0.30 0.26 0.24 0.21 0.19 0.18 0.16 0.15 0.13 0.12 0.11 0.11 Printed 5/13/2024 Page 244

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 245 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 > 7.49" for 100-Year_Current event Inflow = 1.24 cfs @ 12.62 hrs, Volume= 0.354 af Outflow = 1.24 cfs @ 12.62 hrs, Volume= 0.354 af, Atten= 0%, Lag= 0.1 min Primary = 1.24 cfs @ 12.62 hrs, Volume= 0.354 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= 591.19' @ 12.62 hrs Surf.Area= 0.001 ac Storage= 0.000 af Plug-Flow detention time= 0.1 min calculated for 0.354 af (100% of inflow) Center-of-Mass det. time= 0.1 min ( 882.0 - 881.9 ) 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=1.24 cfs @ 12.62 hrs HW=591.19' TW=589.26' (Dynamic Tailwater) 1=SD-21 (Orifice Controls 1.24 cfs @ 2.60 fps) Pond 19P: SD-21 Hydrograph Inflow Primary 1.24 cfs Inflow Area=0.567 ac Peak Elev=591.19' Storage=0.000 af 1.24 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 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 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 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.05 0.05 0.06 0.07 0.08 0.09 0.11 0.13 0.15 0.19 0.30 1.20 1.07 0.64 0.37 0.34 0.34 0.33 0.32 0.31 0.31 0.28 0.24 0.21 0.19 0.17 0.16 0.14 0.13 0.11 0.10 0.09 0.08 0.07 0.07 Storage Elevation (acre-feet) (feet) 0.000 590.61 0.000 590.61 0.000 590.61 0.000 590.62 0.000 590.63 0.000 590.64 0.000 590.65 0.000 590.65 0.000 590.66 0.000 590.67 0.000 590.68 0.000 590.69 0.000 590.70 0.000 590.70 0.000 590.71 0.000 590.72 0.000 590.73 0.000 590.74 0.000 590.75 0.000 590.76 0.000 590.77 0.000 590.78 0.000 590.80 0.000 590.82 0.000 590.88 0.000 591.18 0.000 591.15 0.000 591.01 0.000 590.91 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 0.000 590.85 0.000 590.83 0.000 590.82 0.000 590.81 0.000 590.80 0.000 590.79 0.000 590.78 0.000 590.77 0.000 590.76 0.000 590.75 0.000 590.75 0.000 590.74 0.000 590.74 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.05 0.05 0.06 0.07 0.08 0.09 0.11 0.13 0.15 0.19 0.30 1.20 1.07 0.64 0.37 0.34 0.34 0.33 0.32 0.31 0.31 0.28 0.24 0.21 0.19 0.17 0.16 0.14 0.13 0.11 0.10 0.09 0.08 0.07 0.07 Printed 5/13/2024 Page 246

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 247 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>9.89" Flow Length=164' Tc=17.1 min CN=WQ Runoff=4.23 cfs 0.467 af Subcatchment 7S: PO-DA E Runoff Area=15,246 sf 31.71% Impervious Runoff Depth>10.10" Flow Length=175' Tc=14.4 min CN=WQ Runoff=2.83 cfs 0.295 af Subcatchment 9S: PO-DA G Runoff Area=16,902 sf 28.87% Impervious Runoff Depth>10.02" Flow Length=175' Tc=21.5 min CN=WQ Runoff=2.63 cfs 0.324 af Subcatchment 11S: PO-DA I Runoff Area=10,507 sf 27.64% Impervious Runoff Depth>10.03" Flow Length=120' Tc=6.0 min CN=WQ Runoff=2.55 cfs 0.202 af Runoff Area=13,809 sf 38.48% Impervious Runoff Depth>10.15" Flow Length=96' Slope=0.0336 '/' Tc=4.9 min CN=WQ Runoff=3.49 cfs 0.268 af Subcatchment 12S: PO-DA J Pond 1P: BR-01 Peak Elev=602.16' Storage=6,639 cf Inflow=4.23 cfs 0.467 af Outflow=1.65 cfs 0.460 af Pond 2P: BR-02 Peak Elev=601.47' Storage=2,187 cf Inflow=2.83 cfs 0.295 af Outflow=2.78 cfs 0.292 af Pond 3P: BR-03 Peak Elev=599.05' Storage=5,822 cf Inflow=2.63 cfs 0.324 af Outflow=0.50 cfs 0.317 af Pond 5P: BR-05 Peak Elev=598.22' Storage=3,203 cf Inflow=2.55 cfs 0.202 af Outflow=0.35 cfs 0.200 af Pond 6P: BR-04 Peak Elev=598.73' Storage=4,782 cf Inflow=3.49 cfs 0.268 af Outflow=0.44 cfs 0.261 af Pond 8P: O-1B Inflow=5.00 cfs 1.530 af Primary=5.00 cfs 1.530 af Pond 13P: SD-25, SD-26 Peak Elev=581.63' Storage=0.001 af Inflow=5.00 cfs 1.530 af 18.0" Round Culvert n=0.011 L=29.4' S=0.0099 '/' Outflow=5.00 cfs 1.530 af Pond 14P: SD-24 Peak Elev=586.13' Storage=0.001 af Inflow=4.68 cfs 1.331 af Outflow=4.67 cfs 1.331 af Pond 17P: SD-23 Peak Elev=587.94' Storage=0.001 af Inflow=4.27 cfs 1.069 af Outflow=4.26 cfs 1.069 af Pond 18P: SD-22 Peak Elev=590.04' Storage=0.001 af Inflow=3.95 cfs 0.752 af Outflow=3.95 cfs 0.752 af Pond 19P: SD-21 Peak Elev=591.31' Storage=0.000 af Inflow=1.65 cfs 0.460 af Outflow=1.65 cfs 0.460 af

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 248 Total Runoff Area = 1.863 ac Runoff Volume = 1.556 af Average Runoff Depth = 10.02" 72.59% Pervious = 1.353 ac 27.41% Impervious = 0.511 ac

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 249 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PO-DA C Runoff = 4.23 cfs @ 12.25 hrs, Volume= Routed to Pond 1P : BR-01 0.467 af, Depth> 9.89" 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_Future Rainfall=11.58", 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 4.23 cfs NOAA 24-hr D 100-Year_Future Rainfall=11.58" P2=4.07" Runoff Area=24,698 sf Runoff Volume=0.467 af Runoff Depth>9.89" Flow Length=164' Tc=17.1 min CN=WQ 4 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_Future Rainfall=11.58", 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 0.06 0.00 1.00 0.13 0.00 1.50 0.20 0.00 2.00 0.28 0.00 2.50 0.36 0.00 3.00 0.44 0.01 3.50 0.52 0.03 4.00 0.61 0.05 4.50 0.70 0.08 5.00 0.79 0.12 5.50 0.89 0.17 6.00 0.99 0.22 6.50 1.10 0.28 7.00 1.22 0.35 7.50 1.35 0.44 8.00 1.50 0.54 8.50 1.66 0.65 9.00 1.84 0.78 9.50 2.04 0.94 10.00 2.30 1.14 10.50 2.59 1.39 11.00 3.01 1.75 11.50 3.67 2.34 12.00 5.55 4.09 12.50 7.91 6.36 13.00 8.57 7.01 13.50 8.99 7.41 14.00 9.28 7.70 14.50 9.54 7.95 15.00 9.74 8.15 15.50 9.92 8.32 16.00 10.08 8.48 16.50 10.23 8.63 17.00 10.36 8.76 17.50 10.48 8.88 18.00 10.59 8.99 18.50 10.69 9.09 19.00 10.79 9.18 19.50 10.88 9.27 20.00 10.97 9.36 20.50 11.06 9.45 21.00 11.14 9.53 21.50 11.22 9.61 22.00 11.30 9.69 22.50 11.38 9.76 23.00 11.45 9.83 23.50 11.52 9.90 24.00 11.58 9.96 Runoff (cfs) 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.05 0.06 0.07 0.08 0.10 0.11 0.13 0.14 0.18 0.23 0.28 0.40 0.65 1.71 2.07 0.76 0.47 0.34 0.28 0.23 0.20 0.18 0.17 0.15 0.14 0.12 0.11 0.11 0.11 0.10 0.10 0.09 0.09 0.09 0.08 0.08 0.08 0.07 Printed 5/13/2024 Page 250

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 251 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: PO-DA E Runoff = 2.83 cfs @ 12.21 hrs, Volume= Routed to Pond 2P : BR-02 0.295 af, Depth>10.10" 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_Future Rainfall=11.58", 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 3 2.83 cfs NOAA 24-hr D 100-Year_Future Rainfall=11.58" P2=4.07" Runoff Area=15,246 sf Runoff Volume=0.295 af Runoff Depth>10.10" Flow Length=175' Tc=14.4 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