J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-2) NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 14 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Subcatchment 16S: PO-DA N Hydrograph Runoff 2.06 cfs NOAA 24-hr D 2-Year_Current Rainfall=3.45" P2=3.45" Runoff Area=57,457 sf Runoff Volume=0.188 af Runoff Depth>1.71" Flow Length=452' Tc=11.6 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

Post-Developed (O-2) 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 16S: PO-DA N 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 0.01 10.00 0.68 0.02 10.50 0.77 0.03 11.00 0.90 0.07 11.50 1.09 0.13 12.00 1.65 0.40 12.50 2.36 0.84 13.00 2.55 0.98 13.50 2.68 1.07 14.00 2.77 1.14 14.50 2.84 1.19 15.00 2.90 1.24 15.50 2.95 1.28 16.00 3.00 1.32 16.50 3.05 1.35 17.00 3.09 1.38 17.50 3.12 1.41 18.00 3.16 1.43 18.50 3.19 1.46 19.00 3.21 1.48 19.50 3.24 1.50 20.00 3.27 1.52 20.50 3.29 1.54 21.00 3.32 1.56 21.50 3.34 1.58 22.00 3.37 1.60 22.50 3.39 1.62 23.00 3.41 1.64 23.50 3.43 1.65 24.00 3.45 1.67 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 0.01 0.02 0.02 0.02 0.02 0.03 0.04 0.06 0.10 0.20 0.80 0.70 0.34 0.22 0.17 0.14 0.12 0.10 0.09 0.09 0.08 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 Printed 5/13/2024 Page 15

Post-Developed (O-2) NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 16 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Pond 25P: O-2 Inflow Area = Inflow = Primary = 1.319 ac, 15.92% Impervious, Inflow Depth > 1.71" for 2-Year_Current event 2.06 cfs @ 12.19 hrs, Volume= 0.188 af 2.06 cfs @ 12.19 hrs, Volume= 0.188 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Pond 25P: O-2 Hydrograph Inflow Primary 2.06 cfs Inflow Area=1.319 ac 2.06 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-2) 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 25P: O-2 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 Elevation (cfs) (feet) 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 0.01 0.02 0.02 0.02 0.02 0.03 0.04 0.06 0.10 0.20 0.80 0.70 0.34 0.22 0.17 0.14 0.12 0.10 0.09 0.09 0.08 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 Primary (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 0.01 0.02 0.02 0.02 0.02 0.03 0.04 0.06 0.10 0.20 0.80 0.70 0.34 0.22 0.17 0.14 0.12 0.10 0.09 0.09 0.08 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 Printed 5/13/2024 Page 17

Post-Developed (O-2) 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 18 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 16S: PO-DA N Pond 25P: O-2 Runoff Area=57,457 sf 15.92% Impervious Runoff Depth>2.21" Flow Length=452' Tc=11.0 min CN=WQ Runoff=2.75 cfs 0.243 af Inflow=2.75 cfs 0.243 af Primary=2.75 cfs 0.243 af Total Runoff Area = 1.319 ac Runoff Volume = 0.243 af Average Runoff Depth = 2.21" 84.08% Pervious = 1.109 ac 15.92% Impervious = 0.210 ac

Post-Developed (O-2) 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 19 Summary for Subcatchment 16S: PO-DA N Runoff = 2.75 cfs @ 12.19 hrs, Volume= Routed to Pond 25P : O-2 0.243 af, Depth> 2.21" 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) 9,148 18,644 6,665 23,000 57,457 48,309 9,148 CN 98 80 85 73 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Brush, Good, HSG D Weighted Average 84.08% Pervious Area 15.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.3 100 0.0139 0.23 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 4.07" 0.1 19 0.0480 3.53 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 0.2 28 0.2178 2.33 Shallow Concentrated Flow, Shallow Concentrated Flow Woodland Kv= 5.0 fps 3.4 305 0.0468 1.51 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 11.0 452 Total

Post-Developed (O-2) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 20 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Subcatchment 16S: PO-DA N Hydrograph Runoff 3 2.75 cfs NOAA 24-hr D 2-Year_Future Rainfall=4.07" P2=4.07" Runoff Area=57,457 sf Runoff Volume=0.243 af Runoff Depth>2.21" Flow Length=452' Tc=11.0 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

Post-Developed (O-2) 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 16S: PO-DA N 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 0.00 7.50 0.48 0.00 8.00 0.53 0.00 8.50 0.58 0.01 9.00 0.65 0.01 9.50 0.72 0.02 10.00 0.81 0.04 10.50 0.91 0.07 11.00 1.06 0.12 11.50 1.29 0.21 12.00 1.95 0.57 12.50 2.78 1.15 13.00 3.01 1.32 13.50 3.16 1.44 14.00 3.26 1.52 14.50 3.35 1.59 15.00 3.42 1.65 15.50 3.49 1.70 16.00 3.54 1.74 16.50 3.59 1.78 17.00 3.64 1.82 17.50 3.68 1.86 18.00 3.72 1.89 18.50 3.76 1.92 19.00 3.79 1.95 19.50 3.82 1.97 20.00 3.86 2.00 20.50 3.89 2.03 21.00 3.92 2.05 21.50 3.95 2.08 22.00 3.97 2.10 22.50 4.00 2.12 23.00 4.02 2.14 23.50 4.05 2.16 24.00 4.07 2.18 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.03 0.05 0.06 0.09 0.15 0.28 1.11 0.86 0.42 0.28 0.21 0.18 0.14 0.13 0.12 0.11 0.10 0.09 0.08 0.07 0.07 0.07 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 Printed 5/13/2024 Page 21

Post-Developed (O-2) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 22 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Pond 25P: O-2 Inflow Area = Inflow = Primary = 1.319 ac, 15.92% Impervious, Inflow Depth > 2.21" for 2-Year_Future event 2.75 cfs @ 12.19 hrs, Volume= 0.243 af 2.75 cfs @ 12.19 hrs, Volume= 0.243 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Pond 25P: O-2 Hydrograph 3 Inflow Primary 2.75 cfs Inflow Area=1.319 ac 2.75 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-2) 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 25P: O-2 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 Elevation (cfs) (feet) 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.03 0.05 0.06 0.09 0.15 0.28 1.11 0.86 0.42 0.28 0.21 0.18 0.14 0.13 0.12 0.11 0.10 0.09 0.08 0.07 0.07 0.07 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.03 0.05 0.06 0.09 0.15 0.28 1.11 0.86 0.42 0.28 0.21 0.18 0.14 0.13 0.12 0.11 0.10 0.09 0.08 0.07 0.07 0.07 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 Printed 5/13/2024 Page 23