J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post Printed 5/13/2024 Page 2 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# 1 2 3 4 5 6 7 Event Name Storm Type WQ 2-Year_Current 2-Year_Future 10-Year_Current 10-Year_Future 100-Year_Current 100-Year_Future NJ DEP 2-hr NOAA 24-hr NOAA 24-hr NOAA 24-hr NOAA 24-hr NOAA 24-hr NOAA 24-hr Curve Mode Duration (hours) B/B Depth (inches) D D D D D D Default Default Default Default Default Default Default 2.00 24.00 24.00 24.00 24.00 24.00 24.00 1 1 1 1 1 1 1 1.25 3.45 4.07 5.37 6.36 9.23 11.58 AMC 2 2 2 2 2 2 2 P2 (inches) 3.42 3.45 4.07 3.45 4.07 3.45 4.07

Post-Developed (O-1B) West Orange HydroCAD_Post 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) 0.291 0.511 1.062 1.863 80 98 85 88 >75% Grass cover, Good, HSG D (5S, 7S, 9S, 11S, 12S) Impervious, Pavement, HSG D (5S, 7S, 9S, 11S, 12S) Yard Stone/Gravel Pad, HSG D (5S, 7S, 9S, 11S, 12S) TOTAL AREA Printed 5/13/2024 Page 3

Post-Developed (O-1B) 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 1.863 0.000 1.863 HSG A HSG B HSG C HSG D Other Subcatchment Numbers 5S, 7S, 9S, 11S, 12S TOTAL AREA Printed 5/13/2024 Page 4

Post-Developed (O-1B) 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 0.291 0.000 0.291 0.000 0.000 0.000 0.511 0.000 0.511 0.000 0.000 0.000 1.062 0.000 1.062 0.000 0.000 0.000 1.863 0.000 1.863 >75% Grass cover, Good 5S, 7S, 9S, 11S, 12S Impervious, Pavement 5S, 7S, 9S, 11S, 12S Yard Stone/Gravel Pad 5S, 7S, 9S, 11S, 12S TOTAL AREA

Post-Developed (O-1B) West Orange HydroCAD_Post Printed 5/13/2024 Page 6 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Pipe Listing (selected nodes) Line# 1 Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Width (inches) Diam/Height (inches) Inside-Fill (inches) 13P 580.44 580.15 29.4 0.0099 0.011 0.0 18.0 0.0 Node Name

Post-Developed (O-1B) 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 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 5S: PO-DA C Runoff Area=24,698 sf 17.46% Impervious Runoff Depth=0.42" Flow Length=164' Tc=18.6 min CN=WQ Runoff=0.44 cfs 0.020 af Subcatchment 7S: PO-DA E Runoff Area=15,246 sf 31.71% Impervious Runoff Depth=0.52" Flow Length=175' Tc=15.6 min CN=WQ Runoff=0.37 cfs 0.015 af Subcatchment 9S: PO-DA G Runoff Area=16,902 sf 28.87% Impervious Runoff Depth=0.49" Flow Length=175' Tc=23.4 min CN=WQ Runoff=0.31 cfs 0.016 af Subcatchment 11S: PO-DA I Runoff Area=10,507 sf 27.64% Impervious Runoff Depth=0.48" Flow Length=120' Tc=6.5 min CN=WQ Runoff=0.33 cfs 0.010 af Runoff Area=13,809 sf 38.48% Impervious Runoff Depth=0.55" Flow Length=96' Slope=0.0336 '/' Tc=5.4 min CN=WQ Runoff=0.50 cfs 0.015 af Subcatchment 12S: PO-DA J Pond 1P: BR-01 Peak Elev=596.68' Storage=487 cf Inflow=0.44 cfs 0.020 af Outflow=0.12 cfs 0.020 af Pond 2P: BR-02 Peak Elev=598.55' Storage=357 cf Inflow=0.37 cfs 0.015 af Outflow=0.11 cfs 0.015 af Pond 3P: BR-03 Peak Elev=594.44' Storage=405 cf Inflow=0.31 cfs 0.016 af Outflow=0.10 cfs 0.016 af Pond 5P: BR-05 Peak Elev=594.16' Storage=233 cf Inflow=0.33 cfs 0.010 af Outflow=0.08 cfs 0.010 af Pond 6P: BR-04 Peak Elev=595.04' Storage=410 cf Inflow=0.50 cfs 0.015 af Outflow=0.08 cfs 0.014 af Pond 8P: O-1B Inflow=0.48 cfs 0.074 af Primary=0.48 cfs 0.074 af Pond 13P: SD-25, SD-26 Peak Elev=580.74' Storage=0.000 af Inflow=0.48 cfs 0.074 af 18.0" Round Culvert n=0.011 L=29.4' S=0.0099 '/' Outflow=0.48 cfs 0.074 af Pond 14P: SD-24 Peak Elev=585.17' Storage=0.000 af Inflow=0.41 cfs 0.065 af Outflow=0.41 cfs 0.065 af Pond 17P: SD-23 Peak Elev=587.06' Storage=0.000 af Inflow=0.33 cfs 0.050 af Outflow=0.33 cfs 0.050 af Pond 18P: SD-22 Peak Elev=588.69' Storage=0.000 af Inflow=0.23 cfs 0.035 af Outflow=0.23 cfs 0.035 af Pond 19P: SD-21 Peak Elev=590.78' Storage=0.000 af Inflow=0.12 cfs 0.020 af Outflow=0.12 cfs 0.020 af

Post-Developed (O-1B) 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 8 Total Runoff Area = 1.863 ac Runoff Volume = 0.075 af Average Runoff Depth = 0.48" 72.59% Pervious = 1.353 ac 27.41% Impervious = 0.511 ac

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 9 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: PO-DA C Runoff = 0.44 cfs @ Routed to Pond 1P : BR-01 1.29 hrs, Volume= 0.020 af, Depth= 0.42" 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) 4,312 2,396 17,990 24,698 20,386 4,312 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 82.54% Pervious Area 17.46% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.0 100 0.0018 0.09 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.42" 0.6 64 0.0106 1.66 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 18.6 164 Total Subcatchment 5S: PO-DA C Flow (cfs) Hydrograph 0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 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 Runoff 0.44 cfs NJ DEP 2-hr WQ Rainfall=1.25" P2=3.42" Runoff Area=24,698 sf Runoff Volume=0.020 af Runoff Depth=0.42" Flow Length=164' Tc=18.6 min CN=WQ 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-1B) 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 5S: PO-DA C Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.10 0.00 1.00 0.63 0.06 1.50 1.15 0.31 2.00 1.25 0.37 2.50 1.25 0.37 3.00 1.25 0.37 3.50 1.25 0.37 4.00 1.25 0.37 4.50 1.25 0.37 5.00 1.25 0.37 5.50 1.25 0.37 6.00 1.25 0.37 6.50 1.25 0.37 7.00 1.25 0.37 7.50 1.25 0.37 8.00 1.25 0.37 8.50 1.25 0.37 9.00 1.25 0.37 9.50 1.25 0.37 10.00 1.25 0.37 10.50 1.25 0.37 11.00 1.25 0.37 11.50 1.25 0.37 12.00 1.25 0.37 12.50 1.25 0.37 13.00 1.25 0.37 13.50 1.25 0.37 14.00 1.25 0.37 14.50 1.25 0.37 15.00 1.25 0.37 15.50 1.25 0.37 16.00 1.25 0.37 16.50 1.25 0.37 17.00 1.25 0.37 17.50 1.25 0.37 18.00 1.25 0.37 18.50 1.25 0.37 19.00 1.25 0.37 19.50 1.25 0.37 20.00 1.25 0.37 20.50 1.25 0.37 21.00 1.25 0.37 21.50 1.25 0.37 22.00 1.25 0.37 22.50 1.25 0.37 23.00 1.25 0.37 23.50 1.25 0.37 24.00 1.25 0.37 Runoff (cfs) 0.00 0.00 0.05 0.24 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 10

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 11 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 7S: PO-DA E Runoff = 0.37 cfs @ Routed to Pond 2P : BR-02 1.23 hrs, Volume= 0.015 af, Depth= 0.52" 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) 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 0.4 0.37 cfs 0.38 0.36 NJ DEP 2-hr WQ Rainfall=1.25" P2=3.42" Runoff Area=15,246 sf Runoff Volume=0.015 af Runoff Depth=0.52" Flow Length=175' Tc=15.6 min CN=WQ 0.34 0.32 0.3 Flow (cfs) 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