J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 6S: PO-DA D Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.04 0.00 1.00 0.07 0.00 1.50 0.11 0.00 2.00 0.15 0.00 2.50 0.20 0.00 3.00 0.24 0.00 3.50 0.29 0.00 4.00 0.34 0.00 4.50 0.39 0.00 5.00 0.44 0.00 5.50 0.49 0.00 6.00 0.55 0.00 6.50 0.61 0.00 7.00 0.68 0.00 7.50 0.75 0.01 8.00 0.84 0.02 8.50 0.93 0.03 9.00 1.02 0.05 9.50 1.14 0.08 10.00 1.28 0.13 10.50 1.44 0.19 11.00 1.67 0.29 11.50 2.04 0.47 12.00 3.09 1.13 12.50 4.40 2.13 13.00 4.77 2.43 13.50 5.00 2.62 14.00 5.16 2.76 14.50 5.30 2.88 15.00 5.42 2.98 15.50 5.51 3.06 16.00 5.60 3.14 16.50 5.69 3.21 17.00 5.76 3.27 17.50 5.83 3.33 18.00 5.89 3.38 18.50 5.95 3.43 19.00 6.00 3.48 19.50 6.05 3.52 20.00 6.10 3.57 20.50 6.15 3.61 21.00 6.20 3.65 21.50 6.24 3.69 22.00 6.29 3.73 22.50 6.33 3.77 23.00 6.37 3.80 23.50 6.40 3.83 24.00 6.44 3.87 Runoff (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 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.03 0.06 0.29 0.15 0.08 0.05 0.04 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Printed 5/13/2024 Page 14

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 15 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: PO-DA E Runoff = 1.42 cfs @ 12.23 hrs, Volume= Routed to Pond 2P : BR-02 0.149 af, Depth> 5.10" 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 25-Year Rainfall=6.44", P2=3.42" 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= 3.42" 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 1.42 cfs NOAA 24-hr D 25-Year Rainfall=6.44" P2=3.42" Runoff Area=15,246 sf Runoff Volume=0.149 af Runoff Depth>5.10" 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

Post-Developed (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 7S: PO-DA E Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.04 0.00 1.00 0.07 0.00 1.50 0.11 0.00 2.00 0.15 0.00 2.50 0.20 0.00 3.00 0.24 0.00 3.50 0.29 0.00 4.00 0.34 0.00 4.50 0.39 0.01 5.00 0.44 0.02 5.50 0.49 0.03 6.00 0.55 0.05 6.50 0.61 0.07 7.00 0.68 0.09 7.50 0.75 0.13 8.00 0.84 0.16 8.50 0.93 0.21 9.00 1.02 0.27 9.50 1.14 0.33 10.00 1.28 0.43 10.50 1.44 0.54 11.00 1.67 0.71 11.50 2.04 1.00 12.00 3.09 1.89 12.50 4.40 3.10 13.00 4.77 3.45 13.50 5.00 3.67 14.00 5.16 3.82 14.50 5.30 3.96 15.00 5.42 4.07 15.50 5.51 4.16 16.00 5.60 4.25 16.50 5.69 4.32 17.00 5.76 4.40 17.50 5.83 4.46 18.00 5.89 4.52 18.50 5.95 4.57 19.00 6.00 4.63 19.50 6.05 4.68 20.00 6.10 4.72 20.50 6.15 4.77 21.00 6.20 4.82 21.50 6.24 4.86 22.00 6.29 4.90 22.50 6.33 4.94 23.00 6.37 4.98 23.50 6.40 5.02 24.00 6.44 5.05 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 0.02 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.07 0.08 0.12 0.20 0.57 0.62 0.24 0.15 0.11 0.09 0.08 0.06 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 Printed 5/13/2024 Page 16

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 17 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 8S: PO-DA F Runoff = 0.38 cfs @ 12.13 hrs, Volume= Routed to Reach 4R : TD-02 0.026 af, Depth> 3.69" 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 25-Year Rainfall=6.44", P2=3.42" Area (sf) 1,220 2,526 3,746 3,746 CN 80 73 Description >75% Grass cover, Good, HSG D Brush, Good, HSG D Weighted Average 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 66 0.2264 0.19 Sheet Flow, Sheet Flow Woods: Light underbrush n= 0.400 P2= 3.42" Subcatchment 8S: PO-DA F Hydrograph Flow (cfs) 0.42 0.4 0.38 0.36 0.34 Runoff 0.38 cfs NOAA 24-hr D 25-Year Rainfall=6.44" P2=3.42" Runoff Area=3,746 sf Runoff Volume=0.026 af Runoff Depth>3.69" Flow Length=66' Slope=0.2264 '/' Tc=5.6 min CN=WQ 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 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 (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 8S: PO-DA F Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.04 0.00 1.00 0.07 0.00 1.50 0.11 0.00 2.00 0.15 0.00 2.50 0.20 0.00 3.00 0.24 0.00 3.50 0.29 0.00 4.00 0.34 0.00 4.50 0.39 0.00 5.00 0.44 0.00 5.50 0.49 0.00 6.00 0.55 0.00 6.50 0.61 0.00 7.00 0.68 0.00 7.50 0.75 0.00 8.00 0.84 0.01 8.50 0.93 0.02 9.00 1.02 0.03 9.50 1.14 0.06 10.00 1.28 0.09 10.50 1.44 0.15 11.00 1.67 0.23 11.50 2.04 0.40 12.00 3.09 1.02 12.50 4.40 1.97 13.00 4.77 2.26 13.50 5.00 2.45 14.00 5.16 2.58 14.50 5.30 2.70 15.00 5.42 2.79 15.50 5.51 2.87 16.00 5.60 2.95 16.50 5.69 3.02 17.00 5.76 3.08 17.50 5.83 3.14 18.00 5.89 3.19 18.50 5.95 3.24 19.00 6.00 3.28 19.50 6.05 3.33 20.00 6.10 3.37 20.50 6.15 3.41 21.00 6.20 3.45 21.50 6.24 3.49 22.00 6.29 3.53 22.50 6.33 3.56 23.00 6.37 3.60 23.50 6.40 3.63 24.00 6.44 3.66 Runoff (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 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.04 0.19 0.08 0.04 0.03 0.02 0.02 0.02 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Printed 5/13/2024 Page 18

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 19 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: PO-DA G Runoff = 1.30 cfs @ 12.33 hrs, Volume= Routed to Pond 3P : BR-03 0.163 af, Depth> 5.03" 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 25-Year Rainfall=6.44", P2=3.42" Area (sf) 4,879 2,788 9,235 16,902 12,023 4,879 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 71.13% Pervious Area 28.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22.7 100 0.0010 0.07 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.42" 0.7 75 0.0121 1.77 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 23.4 175 Total Subcatchment 9S: PO-DA G Hydrograph Runoff 1.30 cfs NOAA 24-hr D 25-Year Rainfall=6.44" P2=3.42" Runoff Area=16,902 sf Runoff Volume=0.163 af Runoff Depth>5.03" Flow Length=175' Tc=23.4 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

Post-Developed (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 9S: PO-DA G Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.04 0.00 1.00 0.07 0.00 1.50 0.11 0.00 2.00 0.15 0.00 2.50 0.20 0.00 3.00 0.24 0.00 3.50 0.29 0.00 4.00 0.34 0.00 4.50 0.39 0.01 5.00 0.44 0.02 5.50 0.49 0.03 6.00 0.55 0.05 6.50 0.61 0.07 7.00 0.68 0.09 7.50 0.75 0.13 8.00 0.84 0.16 8.50 0.93 0.21 9.00 1.02 0.27 9.50 1.14 0.33 10.00 1.28 0.43 10.50 1.44 0.54 11.00 1.67 0.71 11.50 2.04 1.00 12.00 3.09 1.89 12.50 4.40 3.10 13.00 4.77 3.45 13.50 5.00 3.67 14.00 5.16 3.82 14.50 5.30 3.96 15.00 5.42 4.07 15.50 5.51 4.16 16.00 5.60 4.25 16.50 5.69 4.32 17.00 5.76 4.40 17.50 5.83 4.46 18.00 5.89 4.52 18.50 5.95 4.57 19.00 6.00 4.63 19.50 6.05 4.68 20.00 6.10 4.72 20.50 6.15 4.77 21.00 6.20 4.82 21.50 6.24 4.86 22.00 6.29 4.90 22.50 6.33 4.94 23.00 6.37 4.98 23.50 6.40 5.02 24.00 6.44 5.05 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 0.02 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.07 0.08 0.12 0.20 0.47 0.97 0.33 0.19 0.13 0.11 0.09 0.07 0.07 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 Printed 5/13/2024 Page 20

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 21 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 10S: PO-DA H Runoff = 0.92 cfs @ 12.15 hrs, Volume= Routed to Reach 5R : TD-03 0.068 af, Depth> 3.48" 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 25-Year Rainfall=6.44", P2=3.42" Area (sf) 436 9,845 10,281 10,281 CN 80 73 Description >75% Grass cover, Good, HSG D Brush, Good, HSG D Weighted Average 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.5 82 0.1736 0.18 Sheet Flow, Sheet Flow Woods: Light underbrush n= 0.400 P2= 3.42" Subcatchment 10S: PO-DA H Hydrograph Runoff 1 0.92 cfs Flow (cfs) NOAA 24-hr D 25-Year Rainfall=6.44" P2=3.42" Runoff Area=10,281 sf Runoff Volume=0.068 af Runoff Depth>3.48" Flow Length=82' Slope=0.1736 '/' Tc=7.5 min CN=WQ 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 (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 10S: PO-DA H Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.04 0.00 1.00 0.07 0.00 1.50 0.11 0.00 2.00 0.15 0.00 2.50 0.20 0.00 3.00 0.24 0.00 3.50 0.29 0.00 4.00 0.34 0.00 4.50 0.39 0.00 5.00 0.44 0.00 5.50 0.49 0.00 6.00 0.55 0.00 6.50 0.61 0.00 7.00 0.68 0.00 7.50 0.75 0.00 8.00 0.84 0.00 8.50 0.93 0.01 9.00 1.02 0.02 9.50 1.14 0.04 10.00 1.28 0.07 10.50 1.44 0.11 11.00 1.67 0.19 11.50 2.04 0.34 12.00 3.09 0.91 12.50 4.40 1.82 13.00 4.77 2.10 13.50 5.00 2.28 14.00 5.16 2.41 14.50 5.30 2.52 15.00 5.42 2.61 15.50 5.51 2.69 16.00 5.60 2.76 16.50 5.69 2.83 17.00 5.76 2.89 17.50 5.83 2.95 18.00 5.89 3.00 18.50 5.95 3.04 19.00 6.00 3.09 19.50 6.05 3.13 20.00 6.10 3.17 20.50 6.15 3.21 21.00 6.20 3.25 21.50 6.24 3.29 22.00 6.29 3.33 22.50 6.33 3.36 23.00 6.37 3.39 23.50 6.40 3.43 24.00 6.44 3.46 Runoff (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 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.02 0.04 0.09 0.42 0.22 0.12 0.08 0.06 0.05 0.04 0.04 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01 Printed 5/13/2024 Page 22

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 23 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 11S: PO-DA I Runoff = 1.30 cfs @ 12.13 hrs, Volume= Routed to Pond 5P : BR-05 0.101 af, Depth> 5.03" 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 25-Year Rainfall=6.44", P2=3.42" Area (sf) 2,904 1,737 5,866 10,507 7,603 2,904 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 72.36% Pervious Area 27.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.4 100 0.0237 0.26 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.42" 0.1 20 0.0320 2.88 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 6.5 120 Total Subcatchment 11S: PO-DA I Hydrograph Runoff 1.30 cfs NOAA 24-hr D 25-Year Rainfall=6.44" P2=3.42" Runoff Area=10,507 sf Runoff Volume=0.101 af Runoff Depth>5.03" Flow Length=120' Tc=6.5 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