J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-2) West Orange HydroCAD_Post Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Soil Listing (selected nodes) Area (acres) Soil Group 0.000 0.000 0.000 1.319 0.000 1.319 HSG A HSG B HSG C HSG D Other Subcatchment Numbers 16S TOTAL AREA Printed 5/13/2024 Page 4

Post-Developed (O-2) West Orange HydroCAD_Post Printed 5/13/2024 Page 5 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Ground Covers (selected nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.428 0.528 0.210 0.153 1.319 0.000 0.000 0.000 0.000 0.000 0.428 0.528 0.210 0.153 1.319 >75% Grass cover, Good Brush, Good Impervious, Pavement Yard Stone/Gravel Pad TOTAL AREA 16S 16S 16S 16S

Post-Developed (O-2) West Orange HydroCAD_Post NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 6 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=0.28" Flow Length=452' Tc=11.6 min CN=WQ Runoff=0.79 cfs 0.031 af Inflow=0.79 cfs 0.031 af Primary=0.79 cfs 0.031 af Total Runoff Area = 1.319 ac Runoff Volume = 0.031 af Average Runoff Depth = 0.28" 84.08% Pervious = 1.109 ac 15.92% Impervious = 0.210 ac

Post-Developed (O-2) West Orange HydroCAD_Post NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 7 Summary for Subcatchment 16S: PO-DA N Runoff = 0.79 cfs @ Routed to Pond 25P : O-2 1.19 hrs, Volume= 0.031 af, Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" * 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) 7.9 100 0.0139 0.21 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.42" 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 11.6 452 Total

Post-Developed (O-2) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 8 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Subcatchment 16S: PO-DA N Hydrograph Runoff 0.85 0.79 cfs 0.8 NJ DEP 2-hr WQ Rainfall=1.25" P2=3.42" Runoff Area=57,457 sf Runoff Volume=0.031 af Runoff Depth=0.28" Flow Length=452' Tc=11.6 min CN=WQ 0.75 0.7 0.65 0.6 Flow (cfs) 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 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 NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" 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 0.10 0.00 1.00 0.63 0.01 1.50 1.15 0.15 2.00 1.25 0.20 2.50 1.25 0.20 3.00 1.25 0.20 3.50 1.25 0.20 4.00 1.25 0.20 4.50 1.25 0.20 5.00 1.25 0.20 5.50 1.25 0.20 6.00 1.25 0.20 6.50 1.25 0.20 7.00 1.25 0.20 7.50 1.25 0.20 8.00 1.25 0.20 8.50 1.25 0.20 9.00 1.25 0.20 9.50 1.25 0.20 10.00 1.25 0.20 10.50 1.25 0.20 11.00 1.25 0.20 11.50 1.25 0.20 12.00 1.25 0.20 12.50 1.25 0.20 13.00 1.25 0.20 13.50 1.25 0.20 14.00 1.25 0.20 14.50 1.25 0.20 15.00 1.25 0.20 15.50 1.25 0.20 16.00 1.25 0.20 16.50 1.25 0.20 17.00 1.25 0.20 17.50 1.25 0.20 18.00 1.25 0.20 18.50 1.25 0.20 19.00 1.25 0.20 19.50 1.25 0.20 20.00 1.25 0.20 20.50 1.25 0.20 21.00 1.25 0.20 21.50 1.25 0.20 22.00 1.25 0.20 22.50 1.25 0.20 23.00 1.25 0.20 23.50 1.25 0.20 24.00 1.25 0.20 Runoff (cfs) 0.00 0.01 0.19 0.25 0.08 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 0.00 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 0.00 0.00 0.00 0.00 0.00 0.00 Printed 5/13/2024 Page 9

Post-Developed (O-2) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 10 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 = 0.28" for WQ event 0.79 cfs @ 1.19 hrs, Volume= 0.031 af 0.79 cfs @ 1.19 hrs, Volume= 0.031 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 0.79 cfs 0.85 Inflow Area=1.319 ac 0.79 cfs 0.8 0.75 0.7 0.65 0.6 Flow (cfs) 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 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 NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" 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 0.01 0.19 0.25 0.08 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 0.00 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 0.00 0.00 0.00 0.00 0.00 0.00 Primary (cfs) 0.00 0.01 0.19 0.25 0.08 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 0.00 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 0.00 0.00 0.00 0.00 0.00 0.00 Printed 5/13/2024 Page 11

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 Printed 5/13/2024 Page 12 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>1.71" Flow Length=452' Tc=11.6 min CN=WQ Runoff=2.06 cfs 0.188 af Inflow=2.06 cfs 0.188 af Primary=2.06 cfs 0.188 af Total Runoff Area = 1.319 ac Runoff Volume = 0.188 af Average Runoff Depth = 1.71" 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_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 13 Summary for Subcatchment 16S: PO-DA N Runoff = 2.06 cfs @ 12.19 hrs, Volume= Routed to Pond 25P : O-2 0.188 af, Depth> 1.71" 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_Current Rainfall=3.45", P2=3.45" * 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) 7.9 100 0.0139 0.21 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.45" 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 11.6 452 Total