J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1) West Orange HydroCAD_Pre Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.674 0.386 0.100 0.526 1.685 80 73 98 85 81 >75% Grass cover, Good, HSG D (24S) Brush, Good, HSG D (24S) Impervious, Pavement, HSG D (24S) Yard Stone/Gravel Pad, HSG D (24S) TOTAL AREA Printed 5/13/2024 Page 3

Post-Developed (O-1) West Orange HydroCAD_Pre 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 1.685 0.000 1.685 HSG A HSG B HSG C HSG D Other Subcatchment Numbers 24S TOTAL AREA Printed 5/13/2024 Page 4

Post-Developed (O-1) West Orange HydroCAD_Pre 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 0.674 0.386 0.100 0.526 1.685 0.000 0.000 0.000 0.000 0.000 0.674 0.386 0.100 0.526 1.685 >75% Grass cover, Good Brush, Good Impervious, Pavement Yard Stone/Gravel Pad TOTAL AREA 24S 24S 24S 24S

Post-Developed (O-1) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 6 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 24S: PO-DA 7 Pond 22P: O-1 Runoff Area=73,407 sf 5.92% Impervious Runoff Depth>1.70" Flow Length=439' Tc=12.1 min CN=WQ Runoff=2.66 cfs 0.239 af Inflow=2.66 cfs 0.239 af Primary=2.66 cfs 0.239 af Total Runoff Area = 1.685 ac Runoff Volume = 0.239 af Average Runoff Depth = 1.70" 94.08% Pervious = 1.585 ac 5.92% Impervious = 0.100 ac

Post-Developed (O-1) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 7 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 24S: PO-DA 7 Runoff = 2.66 cfs @ 12.20 hrs, Volume= Routed to Pond 22P : O-1 0.239 af, Depth> 1.70" 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) 4,346 29,340 22,892 16,829 73,407 69,061 4,346 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 94.08% Pervious Area 5.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.7 49 0.0791 0.12 Sheet Flow, Sheet Flow Woods: Light underbrush n= 0.400 P2= 3.45" 1.9 151 0.0071 1.36 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 3.5 239 0.0260 1.13 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 12.1 439 Total

Post-Developed (O-1) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 8 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Subcatchment 24S: PO-DA 7 Hydrograph Runoff 2.66 cfs NOAA 24-hr D 2-Year_Current Rainfall=3.45" P2=3.45" Runoff Area=73,407 sf Runoff Volume=0.239 af Runoff Depth>1.70" Flow Length=439' Tc=12.1 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-1) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 9 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 24S: PO-DA 7 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 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.05 0.07 0.13 0.25 1.01 0.94 0.45 0.29 0.22 0.19 0.15 0.13 0.12 0.11 0.10 0.09 0.08 0.08 0.08 0.07 0.07 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05

Post-Developed (O-1) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 10 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Pond 22P: O-1 Inflow Area = Inflow = Primary = 1.685 ac, 5.92% Impervious, Inflow Depth > 1.70" for 2-Year_Current event 2.66 cfs @ 12.20 hrs, Volume= 0.239 af 2.66 cfs @ 12.20 hrs, Volume= 0.239 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 22P: O-1 Hydrograph Inflow Primary 2.66 cfs Inflow Area=1.685 ac 2.66 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-1) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 11 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 22P: O-1 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 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.05 0.07 0.13 0.25 1.01 0.94 0.45 0.29 0.22 0.19 0.15 0.13 0.12 0.11 0.10 0.09 0.08 0.08 0.08 0.07 0.07 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 Primary (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 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.05 0.07 0.13 0.25 1.01 0.94 0.45 0.29 0.22 0.19 0.15 0.13 0.12 0.11 0.10 0.09 0.08 0.08 0.08 0.07 0.07 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05

Post-Developed (O-1) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" Prepared by Burns & McDonnell Printed 5/13/2024 Page 12 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 24S: PO-DA 7 Pond 22P: O-1 Runoff Area=73,407 sf 5.92% Impervious Runoff Depth>2.21" Flow Length=439' Tc=11.6 min CN=WQ Runoff=3.49 cfs 0.310 af Inflow=3.49 cfs 0.310 af Primary=3.49 cfs 0.310 af Total Runoff Area = 1.685 ac Runoff Volume = 0.310 af Average Runoff Depth = 2.21" 94.08% Pervious = 1.585 ac 5.92% Impervious = 0.100 ac