J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 10-Year_Future Rainfall=6.36", 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 0.04 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 0.33 0.00 4.50 0.38 0.01 5.00 0.43 0.02 5.50 0.49 0.03 6.00 0.54 0.04 6.50 0.60 0.06 7.00 0.67 0.09 7.50 0.74 0.12 8.00 0.83 0.16 8.50 0.91 0.20 9.00 1.01 0.26 9.50 1.12 0.33 10.00 1.26 0.42 10.50 1.42 0.53 11.00 1.65 0.69 11.50 2.02 0.98 12.00 3.05 1.86 12.50 4.34 3.05 13.00 4.71 3.39 13.50 4.94 3.61 14.00 5.10 3.76 14.50 5.24 3.90 15.00 5.35 4.00 15.50 5.45 4.09 16.00 5.53 4.18 16.50 5.62 4.26 17.00 5.69 4.33 17.50 5.76 4.39 18.00 5.82 4.45 18.50 5.87 4.50 19.00 5.93 4.55 19.50 5.98 4.60 20.00 6.03 4.65 20.50 6.07 4.70 21.00 6.12 4.74 21.50 6.16 4.78 22.00 6.21 4.83 22.50 6.25 4.87 23.00 6.29 4.90 23.50 6.32 4.94 24.00 6.36 4.97 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 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.07 0.08 0.12 0.20 0.59 0.57 0.23 0.15 0.11 0.09 0.07 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 Printed 5/13/2024 Page 172

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Future Rainfall=6.36", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 173 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: PO-DA G Runoff = 1.34 cfs @ 12.30 hrs, Volume= Routed to Pond 3P : BR-03 0.160 af, Depth> 4.96" 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 10-Year_Future Rainfall=6.36", 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 Runoff 1.34 cfs NOAA 24-hr D 10-Year_Future Rainfall=6.36" P2=4.07" Runoff Area=16,902 sf Runoff Volume=0.160 af Runoff Depth>4.96" Flow Length=175' Tc=21.5 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

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 10-Year_Future Rainfall=6.36", 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 0.04 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 0.33 0.00 4.50 0.38 0.01 5.00 0.43 0.02 5.50 0.49 0.03 6.00 0.54 0.04 6.50 0.60 0.06 7.00 0.67 0.09 7.50 0.74 0.12 8.00 0.83 0.16 8.50 0.91 0.20 9.00 1.01 0.26 9.50 1.12 0.33 10.00 1.26 0.42 10.50 1.42 0.53 11.00 1.65 0.69 11.50 2.02 0.98 12.00 3.05 1.86 12.50 4.34 3.05 13.00 4.71 3.39 13.50 4.94 3.61 14.00 5.10 3.76 14.50 5.24 3.90 15.00 5.35 4.00 15.50 5.45 4.09 16.00 5.53 4.18 16.50 5.62 4.26 17.00 5.69 4.33 17.50 5.76 4.39 18.00 5.82 4.45 18.50 5.87 4.50 19.00 5.93 4.55 19.50 5.98 4.60 20.00 6.03 4.65 20.50 6.07 4.70 21.00 6.12 4.74 21.50 6.16 4.78 22.00 6.21 4.83 22.50 6.25 4.87 23.00 6.29 4.90 23.50 6.32 4.94 24.00 6.36 4.97 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 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.07 0.08 0.12 0.20 0.49 0.89 0.31 0.18 0.13 0.10 0.09 0.07 0.07 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 Printed 5/13/2024 Page 174

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Future Rainfall=6.36", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 175 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 0.100 af, Depth> 4.96" 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 10-Year_Future Rainfall=6.36", 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 1.30 cfs NOAA 24-hr D 10-Year_Future Rainfall=6.36" P2=4.07" Runoff Area=10,507 sf Runoff Volume=0.100 af Runoff Depth>4.96" Flow Length=120' Tc=6.0 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 10-Year_Future Rainfall=6.36", 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 0.04 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 0.33 0.00 4.50 0.38 0.01 5.00 0.43 0.02 5.50 0.49 0.03 6.00 0.54 0.04 6.50 0.60 0.06 7.00 0.67 0.09 7.50 0.74 0.12 8.00 0.83 0.16 8.50 0.91 0.20 9.00 1.01 0.26 9.50 1.12 0.33 10.00 1.26 0.42 10.50 1.42 0.53 11.00 1.65 0.69 11.50 2.02 0.98 12.00 3.05 1.86 12.50 4.34 3.05 13.00 4.71 3.39 13.50 4.94 3.61 14.00 5.10 3.76 14.50 5.24 3.90 15.00 5.35 4.00 15.50 5.45 4.09 16.00 5.53 4.18 16.50 5.62 4.26 17.00 5.69 4.33 17.50 5.76 4.39 18.00 5.82 4.45 18.50 5.87 4.50 19.00 5.93 4.55 19.50 5.98 4.60 20.00 6.03 4.65 20.50 6.07 4.70 21.00 6.12 4.74 21.50 6.16 4.78 22.00 6.21 4.83 22.50 6.25 4.87 23.00 6.29 4.90 23.50 6.32 4.94 24.00 6.36 4.97 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 0.02 0.02 0.02 0.03 0.04 0.05 0.06 0.09 0.16 0.70 0.26 0.14 0.09 0.07 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 176

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Future Rainfall=6.36", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 177 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: PO-DA J Runoff = 1.79 cfs @ 12.12 hrs, Volume= Routed to Pond 6P : BR-04 0.134 af, Depth> 5.06" 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 10-Year_Future Rainfall=6.36", 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 2 Runoff Flow (cfs) 1.79 cfs NOAA 24-hr D 10-Year_Future Rainfall=6.36" P2=4.07" Runoff Area=13,809 sf Runoff Volume=0.134 af Runoff Depth>5.06" Flow Length=96' Slope=0.0336 '/' Tc=4.9 min CN=WQ 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 10-Year_Future Rainfall=6.36", 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 0.04 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 0.33 0.01 4.50 0.38 0.01 5.00 0.43 0.02 5.50 0.49 0.04 6.00 0.54 0.06 6.50 0.60 0.08 7.00 0.67 0.11 7.50 0.74 0.14 8.00 0.83 0.18 8.50 0.91 0.23 9.00 1.01 0.29 9.50 1.12 0.36 10.00 1.26 0.46 10.50 1.42 0.57 11.00 1.65 0.75 11.50 2.02 1.04 12.00 3.05 1.94 12.50 4.34 3.15 13.00 4.71 3.49 13.50 4.94 3.71 14.00 5.10 3.87 14.50 5.24 4.00 15.00 5.35 4.11 15.50 5.45 4.20 16.00 5.53 4.29 16.50 5.62 4.36 17.00 5.69 4.44 17.50 5.76 4.50 18.00 5.82 4.56 18.50 5.87 4.61 19.00 5.93 4.66 19.50 5.98 4.71 20.00 6.03 4.76 20.50 6.07 4.81 21.00 6.12 4.85 21.50 6.16 4.90 22.00 6.21 4.94 22.50 6.25 4.98 23.00 6.29 5.01 23.50 6.32 5.05 24.00 6.36 5.08 Runoff (cfs) 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 0.03 0.04 0.05 0.06 0.08 0.13 0.21 1.00 0.34 0.18 0.12 0.09 0.08 0.06 0.06 0.05 0.05 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 0.02 0.02 Printed 5/13/2024 Page 178

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Future Rainfall=6.36", 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 179 Summary for Pond 1P: BR-01 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth > 4.83" for 10-Year_Future event Inflow = 2.13 cfs @ 12.25 hrs, Volume= 0.228 af Outflow = 0.42 cfs @ 12.96 hrs, Volume= 0.225 af, Atten= 80%, Lag= 42.3 min Primary = 0.42 cfs @ 12.96 hrs, Volume= 0.225 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= 600.58' @ 12.96 hrs Surf.Area= 5,277 sf Storage= 3,860 cf Plug-Flow detention time= 113.5 min calculated for 0.225 af (99% of inflow) Center-of-Mass det. time= 105.9 min ( 906.8 - 801.0 ) 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 10-Year_Future Rainfall=6.36", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 180 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.42 cfs @ 12.96 hrs HW=600.58' TW=590.93' (Dynamic Tailwater) 1=SD-21 Outlet (Elevation F) (Passes 0.42 cfs of 11.03 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.35 cfs @ 10.18 fps) 3=Water Quantity (Elevation H) (Orifice Controls 0.07 cfs @ 0.90 fps) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 1P: BR-01 Hydrograph Inflow Primary 2.13 cfs Inflow Area=0.567 ac Peak Elev=600.58' Storage=3,860 cf Flow (cfs) 2 1 0.42 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 10-Year_Future Rainfall=6.36", 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 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.07 0.09 0.12 0.18 0.30 0.83 1.06 0.40 0.25 0.18 0.15 0.12 0.10 0.10 0.09 0.08 0.07 0.07 0.06 0.06 0.06 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 0.04 Storage Elevation (cubic-feet) (feet) 0 596.00 0 596.00 0 596.00 4 596.01 10 596.01 17 596.02 24 596.03 31 596.04 37 596.05 41 596.06 47 596.07 54 596.07 61 596.09 70 596.10 80 596.11 92 596.13 106 596.15 120 596.17 135 596.19 157 596.22 197 596.27 255 596.35 350 596.49 559 596.78 1,120 597.59 3,414 600.32 3,859 600.58 3,733 600.51 3,486 600.36 3,174 600.19 2,828 599.99 2,453 599.78 2,074 599.56 1,713 598.84 1,414 598.06 1,162 597.65 940 597.33 744 597.05 582 596.82 452 596.63 352 596.49 278 596.39 225 596.31 188 596.26 164 596.23 148 596.20 136 596.19 128 596.18 122 596.17 Primary (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 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.07 0.08 0.10 0.14 0.20 0.34 0.42 0.35 0.34 0.33 0.32 0.31 0.31 0.27 0.23 0.20 0.18 0.16 0.14 0.12 0.10 0.09 0.07 0.06 0.06 0.05 0.05 0.04 0.04 Printed 5/13/2024 Page 181