J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 30 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC 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 21S: PO-DA 1 Pond 21P: O-2 Runoff Area=52,807 sf 14.94% Impervious Runoff Depth>6.76" Flow Length=341' Tc=3.7 min CN=WQ Runoff=9.80 cfs 0.682 af Inflow=9.80 cfs 0.682 af Primary=9.80 cfs 0.682 af Total Runoff Area = 1.212 ac Runoff Volume = 0.682 af Average Runoff Depth = 6.76" 85.06% Pervious = 1.031 ac 14.94% Impervious = 0.181 ac

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 31 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 21S: PO-DA 1 Runoff = 9.80 cfs @ 12.11 hrs, Volume= Routed to Pond 21P : O-2 0.682 af, Depth> 6.76" 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) 7,888 19,498 2,304 23,117 52,807 44,919 7,888 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 85.06% Pervious Area 14.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 23 0.0352 1.33 Sheet Flow, Sheet Flow Smooth surfaces n= 0.011 P2= 3.45" 0.2 31 0.2437 2.47 Shallow Concentrated Flow, Shallow Concentrated Flow Woodland Kv= 5.0 fps 3.2 287 0.0462 1.50 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 3.7 341 Total

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 32 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Subcatchment 21S: PO-DA 1 Hydrograph Runoff 9.80 cfs 10 NOAA 24-hr D 100-Year_Current Rainfall=9.23" P2=3.45" Runoff Area=52,807 sf Runoff Volume=0.682 af Runoff Depth>6.76" Flow Length=341' Tc=3.7 min CN=WQ 9 8 Flow (cfs) 7 6 5 4 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-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 33 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 21S: PO-DA 1 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 0.00 4.00 0.48 0.00 4.50 0.56 0.00 5.00 0.63 0.01 5.50 0.71 0.02 6.00 0.79 0.03 6.50 0.88 0.05 7.00 0.97 0.08 7.50 1.08 0.11 8.00 1.20 0.15 8.50 1.33 0.21 9.00 1.46 0.27 9.50 1.63 0.35 10.00 1.83 0.46 10.50 2.07 0.60 11.00 2.40 0.82 11.50 2.93 1.19 12.00 4.42 2.40 12.50 6.30 4.06 13.00 6.83 4.54 13.50 7.16 4.84 14.00 7.40 5.07 14.50 7.60 5.25 15.00 7.77 5.41 15.50 7.90 5.54 16.00 8.03 5.66 16.50 8.15 5.77 17.00 8.26 5.87 17.50 8.35 5.96 18.00 8.44 6.04 18.50 8.52 6.12 19.00 8.60 6.19 19.50 8.67 6.26 20.00 8.75 6.33 20.50 8.82 6.39 21.00 8.88 6.46 21.50 8.95 6.52 22.00 9.01 6.58 22.50 9.07 6.63 23.00 9.12 6.69 23.50 9.18 6.74 24.00 9.23 6.79 Runoff (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.02 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.08 0.10 0.12 0.14 0.17 0.23 0.30 0.37 0.61 1.08 5.55 1.83 0.97 0.63 0.50 0.42 0.34 0.30 0.28 0.26 0.24 0.21 0.19 0.18 0.17 0.17 0.16 0.16 0.15 0.15 0.14 0.13 0.13 0.12 0.12

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 34 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Pond 21P: O-2 Inflow Area = Inflow = Primary = 1.212 ac, 14.94% Impervious, Inflow Depth > 6.76" for 100-Year_Current event 9.80 cfs @ 12.11 hrs, Volume= 0.682 af 9.80 cfs @ 12.11 hrs, Volume= 0.682 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 21P: O-2 Hydrograph Inflow Primary 9.80 cfs Inflow Area=1.212 ac 9.80 cfs 10 9 8 Flow (cfs) 7 6 5 4 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-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 35 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 21P: 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 0.01 0.01 0.02 0.02 0.02 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.08 0.10 0.12 0.14 0.17 0.23 0.30 0.37 0.61 1.08 5.55 1.83 0.97 0.63 0.50 0.42 0.34 0.30 0.28 0.26 0.24 0.21 0.19 0.18 0.17 0.17 0.16 0.16 0.15 0.15 0.14 0.13 0.13 0.12 0.12 Primary (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.02 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.08 0.10 0.12 0.14 0.17 0.23 0.30 0.37 0.61 1.08 5.55 1.83 0.97 0.63 0.50 0.42 0.34 0.30 0.28 0.26 0.24 0.21 0.19 0.18 0.17 0.17 0.16 0.16 0.15 0.15 0.14 0.13 0.13 0.12 0.12

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" Prepared by Burns & McDonnell Printed 5/13/2024 Page 36 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC 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 21S: PO-DA 1 Pond 21P: O-2 Runoff Area=52,807 sf 14.94% Impervious Runoff Depth>8.99" Flow Length=341' Tc=3.7 min CN=WQ Runoff=12.86 cfs 0.908 af Inflow=12.86 cfs 0.908 af Primary=12.86 cfs 0.908 af Total Runoff Area = 1.212 ac Runoff Volume = 0.908 af Average Runoff Depth = 8.99" 85.06% Pervious = 1.031 ac 14.94% Impervious = 0.181 ac

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" Prepared by Burns & McDonnell Printed 5/13/2024 Page 37 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 21S: PO-DA 1 Runoff = 12.86 cfs @ 12.11 hrs, Volume= Routed to Pond 21P : O-2 0.908 af, Depth> 8.99" 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) 7,888 19,498 2,304 23,117 52,807 44,919 7,888 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 85.06% Pervious Area 14.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 23 0.0352 1.45 Sheet Flow, Sheet Flow Smooth surfaces n= 0.011 P2= 4.07" 0.2 31 0.2437 2.47 Shallow Concentrated Flow, Shallow Concentrated Flow Woodland Kv= 5.0 fps 3.2 287 0.0462 1.50 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 3.7 341 Total

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" Prepared by Burns & McDonnell Printed 5/13/2024 Page 38 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Subcatchment 21S: PO-DA 1 Hydrograph Runoff 14 12.86 cfs 13 NOAA 24-hr D 100-Year_Future Rainfall=11.58" P2=4.07" Runoff Area=52,807 sf Runoff Volume=0.908 af Runoff Depth>8.99" Flow Length=341' Tc=3.7 min CN=WQ 12 11 10 Flow (cfs) 9 8 7 6 5 4 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-2) West Orange HydroCAD_Pre NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" Prepared by Burns & McDonnell Printed 5/13/2024 Page 39 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 21S: PO-DA 1 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 0.00 3.50 0.52 0.00 4.00 0.61 0.00 4.50 0.70 0.01 5.00 0.79 0.03 5.50 0.89 0.05 6.00 0.99 0.08 6.50 1.10 0.12 7.00 1.22 0.16 7.50 1.35 0.22 8.00 1.50 0.29 8.50 1.66 0.37 9.00 1.84 0.47 9.50 2.04 0.59 10.00 2.30 0.75 10.50 2.59 0.95 11.00 3.01 1.26 11.50 3.67 1.77 12.00 5.55 3.38 12.50 7.91 5.54 13.00 8.57 6.16 13.50 8.99 6.56 14.00 9.28 6.84 14.50 9.54 7.08 15.00 9.74 7.28 15.50 9.92 7.44 16.00 10.08 7.59 16.50 10.23 7.74 17.00 10.36 7.87 17.50 10.48 7.98 18.00 10.59 8.09 18.50 10.69 8.18 19.00 10.79 8.28 19.50 10.88 8.37 20.00 10.97 8.45 20.50 11.06 8.54 21.00 11.14 8.62 21.50 11.22 8.70 22.00 11.30 8.77 22.50 11.38 8.84 23.00 11.45 8.91 23.50 11.52 8.98 24.00 11.58 9.04 Runoff (cfs) 0.00 0.00 0.01 0.02 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.07 0.08 0.10 0.13 0.15 0.18 0.21 0.25 0.33 0.42 0.53 0.85 1.48 7.37 2.37 1.25 0.81 0.64 0.54 0.44 0.39 0.36 0.33 0.30 0.27 0.24 0.23 0.22 0.22 0.21 0.20 0.19 0.19 0.18 0.17 0.16 0.16 0.15