J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" 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 0.02 0.00 1.00 0.05 0.00 1.50 0.07 0.00 2.00 0.10 0.00 2.50 0.12 0.00 3.00 0.15 0.00 3.50 0.18 0.00 4.00 0.21 0.00 4.50 0.25 0.00 5.00 0.28 0.00 5.50 0.31 0.00 6.00 0.35 0.00 6.50 0.39 0.01 7.00 0.43 0.02 7.50 0.48 0.03 8.00 0.53 0.04 8.50 0.58 0.06 9.00 0.65 0.08 9.50 0.72 0.11 10.00 0.81 0.15 10.50 0.91 0.20 11.00 1.06 0.29 11.50 1.29 0.43 12.00 1.95 0.93 12.50 2.78 1.62 13.00 3.01 1.83 13.50 3.16 1.96 14.00 3.26 2.05 14.50 3.35 2.13 15.00 3.42 2.20 15.50 3.49 2.26 16.00 3.54 2.31 16.50 3.59 2.35 17.00 3.64 2.40 17.50 3.68 2.44 18.00 3.72 2.47 18.50 3.76 2.50 19.00 3.79 2.54 19.50 3.82 2.57 20.00 3.86 2.60 20.50 3.89 2.62 21.00 3.92 2.65 21.50 3.95 2.68 22.00 3.97 2.70 22.50 4.00 2.73 23.00 4.02 2.75 23.50 4.05 2.77 24.00 4.07 2.79 Runoff (cfs) 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 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.04 0.06 0.11 0.33 0.34 0.14 0.09 0.07 0.06 0.05 0.04 0.04 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 0.02 0.01 Printed 5/13/2024 Page 92

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 93 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: PO-DA G Runoff = 0.77 cfs @ 12.30 hrs, Volume= Routed to Pond 3P : BR-03 0.091 af, Depth> 2.82" 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_Future Rainfall=4.07", P2=4.07" 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) 20.8 100 0.0010 0.08 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 4.07" 0.7 75 0.0121 1.77 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 21.5 175 Total Subcatchment 9S: PO-DA G Hydrograph 0.85 Runoff 0.8 0.77 cfs NOAA 24-hr D 2-Year_Future Rainfall=4.07" P2=4.07" Runoff Area=16,902 sf Runoff Volume=0.091 af Runoff Depth>2.82" Flow Length=175' Tc=21.5 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-1B) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" 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 0.02 0.00 1.00 0.05 0.00 1.50 0.07 0.00 2.00 0.10 0.00 2.50 0.12 0.00 3.00 0.15 0.00 3.50 0.18 0.00 4.00 0.21 0.00 4.50 0.25 0.00 5.00 0.28 0.00 5.50 0.31 0.00 6.00 0.35 0.00 6.50 0.39 0.01 7.00 0.43 0.02 7.50 0.48 0.03 8.00 0.53 0.04 8.50 0.58 0.06 9.00 0.65 0.08 9.50 0.72 0.11 10.00 0.81 0.15 10.50 0.91 0.20 11.00 1.06 0.29 11.50 1.29 0.43 12.00 1.95 0.93 12.50 2.78 1.62 13.00 3.01 1.83 13.50 3.16 1.96 14.00 3.26 2.05 14.50 3.35 2.13 15.00 3.42 2.20 15.50 3.49 2.26 16.00 3.54 2.31 16.50 3.59 2.35 17.00 3.64 2.40 17.50 3.68 2.44 18.00 3.72 2.47 18.50 3.76 2.50 19.00 3.79 2.54 19.50 3.82 2.57 20.00 3.86 2.60 20.50 3.89 2.62 21.00 3.92 2.65 21.50 3.95 2.68 22.00 3.97 2.70 22.50 4.00 2.73 23.00 4.02 2.75 23.50 4.05 2.77 24.00 4.07 2.79 Runoff (cfs) 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 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.04 0.06 0.11 0.27 0.52 0.18 0.11 0.08 0.06 0.05 0.04 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 Printed 5/13/2024 Page 94

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 95 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 11S: PO-DA I Runoff = 0.75 cfs @ 12.13 hrs, Volume= Routed to Pond 5P : BR-05 0.056 af, Depth> 2.81" 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_Future Rainfall=4.07", P2=4.07" 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) 5.9 100 0.0237 0.28 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 4.07" 0.1 20 0.0320 2.88 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 6.0 120 Total Subcatchment 11S: PO-DA I Hydrograph Runoff 0.8 0.75 cfs NOAA 24-hr D 2-Year_Future Rainfall=4.07" P2=4.07" Runoff Area=10,507 sf Runoff Volume=0.056 af Runoff Depth>2.81" Flow Length=120' Tc=6.0 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-1B) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 11S: PO-DA I Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.02 0.00 1.00 0.05 0.00 1.50 0.07 0.00 2.00 0.10 0.00 2.50 0.12 0.00 3.00 0.15 0.00 3.50 0.18 0.00 4.00 0.21 0.00 4.50 0.25 0.00 5.00 0.28 0.00 5.50 0.31 0.00 6.00 0.35 0.00 6.50 0.39 0.01 7.00 0.43 0.02 7.50 0.48 0.03 8.00 0.53 0.04 8.50 0.58 0.06 9.00 0.65 0.08 9.50 0.72 0.11 10.00 0.81 0.15 10.50 0.91 0.20 11.00 1.06 0.29 11.50 1.29 0.43 12.00 1.95 0.93 12.50 2.78 1.62 13.00 3.01 1.83 13.50 3.16 1.96 14.00 3.26 2.05 14.50 3.35 2.13 15.00 3.42 2.20 15.50 3.49 2.26 16.00 3.54 2.31 16.50 3.59 2.35 17.00 3.64 2.40 17.50 3.68 2.44 18.00 3.72 2.47 18.50 3.76 2.50 19.00 3.79 2.54 19.50 3.82 2.57 20.00 3.86 2.60 20.50 3.89 2.62 21.00 3.92 2.65 21.50 3.95 2.68 22.00 3.97 2.70 22.50 4.00 2.73 23.00 4.02 2.75 23.50 4.05 2.77 24.00 4.07 2.79 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 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.05 0.08 0.39 0.16 0.08 0.05 0.04 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 Printed 5/13/2024 Page 96

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 97 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: PO-DA J Runoff = 1.05 cfs @ 12.12 hrs, Volume= Routed to Pond 6P : BR-04 0.077 af, Depth> 2.91" 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_Future Rainfall=4.07", P2=4.07" Area (sf) 5,314 3,703 4,792 13,809 8,495 5,314 * CN 98 80 85 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Weighted Average 61.52% Pervious Area 38.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.9 96 0.0336 0.32 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 4.07" Subcatchment 12S: PO-DA J Hydrograph Runoff 1.05 cfs NOAA 24-hr D 2-Year_Future Rainfall=4.07" P2=4.07" Runoff Area=13,809 sf Runoff Volume=0.077 af Runoff Depth>2.91" Flow Length=96' Slope=0.0336 '/' Tc=4.9 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 (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 12S: PO-DA J Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.02 0.00 1.00 0.05 0.00 1.50 0.07 0.00 2.00 0.10 0.00 2.50 0.12 0.00 3.00 0.15 0.00 3.50 0.18 0.00 4.00 0.21 0.00 4.50 0.25 0.00 5.00 0.28 0.00 5.50 0.31 0.00 6.00 0.35 0.01 6.50 0.39 0.01 7.00 0.43 0.02 7.50 0.48 0.04 8.00 0.53 0.05 8.50 0.58 0.07 9.00 0.65 0.10 9.50 0.72 0.13 10.00 0.81 0.17 10.50 0.91 0.23 11.00 1.06 0.32 11.50 1.29 0.48 12.00 1.95 0.99 12.50 2.78 1.70 13.00 3.01 1.91 13.50 3.16 2.04 14.00 3.26 2.14 14.50 3.35 2.22 15.00 3.42 2.29 15.50 3.49 2.34 16.00 3.54 2.40 16.50 3.59 2.44 17.00 3.64 2.49 17.50 3.68 2.53 18.00 3.72 2.56 18.50 3.76 2.60 19.00 3.79 2.63 19.50 3.82 2.66 20.00 3.86 2.69 20.50 3.89 2.72 21.00 3.92 2.74 21.50 3.95 2.77 22.00 3.97 2.80 22.50 4.00 2.82 23.00 4.02 2.85 23.50 4.05 2.87 24.00 4.07 2.89 Runoff (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.07 0.12 0.57 0.21 0.11 0.07 0.06 0.05 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 0.01 Printed 5/13/2024 Page 98

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 99 Summary for Pond 1P: BR-01 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth > 2.70" for 2-Year_Future event Inflow = 1.21 cfs @ 12.25 hrs, Volume= 0.128 af Outflow = 0.30 cfs @ 12.82 hrs, Volume= 0.125 af, Atten= 76%, Lag= 34.1 min Primary = 0.30 cfs @ 12.82 hrs, Volume= 0.125 af Routed to Pond 19P : SD-21 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 599.34' @ 12.82 hrs Surf.Area= 5,277 sf Storage= 1,902 cf Plug-Flow detention time= 81.4 min calculated for 0.125 af (98% of inflow) Center-of-Mass det. time= 71.8 min ( 887.5 - 815.7 ) Volume #1 #2 Invert 598.00' 597.50' Avail.Storage 5,850 cf 330 cf #3 596.00' 1,051 cf #4 596.00' 11 cf 7,241 cf Storage Description Filter Media Layer (Prismatic)Listed below (Recalc) Sand Layer (Prismatic)Listed below (Recalc) 880 cf Overall x 37.5% Voids Gravel Layer (Prismatic)Listed below (Recalc) 2,639 cf Overall - 11 cf Embedded = 2,627 cf x 40.0% Voids 4.0" Round 4" Underdrain Pipe Inside #3 L= 127.3' S= 0.0001 '/' Total Available Storage Elevation (feet) 598.00 599.50 602.50 Surf.Area Voids (sq-ft) (%) 1,759 0.0 1,759 21.7 1,759 100.0 Elevation (feet) 597.50 598.00 Surf.Area (sq-ft) 1,759 1,759 Inc.Store (cubic-feet) 0 880 Cum.Store (cubic-feet) 0 880 Elevation (feet) 596.00 597.50 Surf.Area (sq-ft) 1,759 1,759 Inc.Store (cubic-feet) 0 2,639 Cum.Store (cubic-feet) 0 2,639 Device #1 Routing Primary Invert 591.57' #2 Device 1 596.00' #3 Device 1 600.50' #4 Device 1 602.40' Inc.Store (cubic-feet) 0 573 5,277 Cum.Store (cubic-feet) 0 573 5,850 Outlet Devices 12.0" Vert. SD-21 Outlet (Elevation F) C= 0.600 Limited to weir flow at low heads 2.5" Vert. Water Quatity (Elevation G) C= 0.600 Limited to weir flow at low heads 12.0" W x 2.5" H Vert. Water Quantity (Elevation H) C= 0.600 Limited to weir flow at low heads 48.0" x 48.0" Horiz. Overflow Grate (Elevation I) C= 0.600 Limited to weir flow at low heads

Post-Developed (O-1B) NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 100 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.30 cfs @ 12.82 hrs HW=599.34' TW=590.88' (Dynamic Tailwater) 1=SD-21 Outlet (Elevation F) (Passes 0.30 cfs of 10.19 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.30 cfs @ 8.66 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 1P: BR-01 Hydrograph Inflow Primary 1.21 cfs Inflow Area=0.567 ac Peak Elev=599.34' Storage=1,902 cf Flow (cfs) 1 0.30 cfs 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-1B) West Orange HydroCAD_Post NOAA 24-hr D 2-Year_Future Rainfall=4.07", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 1P: BR-01 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 (cfs) 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 0.01 0.01 0.02 0.02 0.02 0.03 0.04 0.06 0.09 0.16 0.45 0.61 0.23 0.15 0.11 0.09 0.07 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.02 Storage Elevation (cubic-feet) (feet) 0 596.00 0 596.00 0 596.00 1 596.00 3 596.00 6 596.01 11 596.02 15 596.02 20 596.03 25 596.03 28 596.04 32 596.04 34 596.05 37 596.05 41 596.06 48 596.07 56 596.08 65 596.09 75 596.10 86 596.12 104 596.14 126 596.17 162 596.22 252 596.35 520 596.73 1,748 598.93 1,881 599.28 1,705 598.82 1,466 598.20 1,240 597.77 1,024 597.45 821 597.16 645 596.91 498 596.70 379 596.53 286 596.40 216 596.30 167 596.23 136 596.19 119 596.17 111 596.15 106 596.15 103 596.14 100 596.14 98 596.14 96 596.13 93 596.13 91 596.13 88 596.12 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 0.01 0.02 0.02 0.03 0.04 0.06 0.08 0.13 0.28 0.29 0.27 0.24 0.21 0.19 0.17 0.15 0.13 0.11 0.09 0.07 0.06 0.05 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 Printed 5/13/2024 Page 101