J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Future Rainfall=11.58", 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 0.06 0.00 1.00 0.13 0.00 1.50 0.20 0.00 2.00 0.28 0.00 2.50 0.36 0.00 3.00 0.44 0.02 3.50 0.52 0.04 4.00 0.61 0.07 4.50 0.70 0.10 5.00 0.79 0.14 5.50 0.89 0.19 6.00 0.99 0.25 6.50 1.10 0.31 7.00 1.22 0.39 7.50 1.35 0.48 8.00 1.50 0.58 8.50 1.66 0.70 9.00 1.84 0.84 9.50 2.04 1.00 10.00 2.30 1.21 10.50 2.59 1.46 11.00 3.01 1.83 11.50 3.67 2.43 12.00 5.55 4.19 12.50 7.91 6.48 13.00 8.57 7.13 13.50 8.99 7.53 14.00 9.28 7.83 14.50 9.54 8.08 15.00 9.74 8.28 15.50 9.92 8.45 16.00 10.08 8.61 16.50 10.23 8.75 17.00 10.36 8.89 17.50 10.48 9.01 18.00 10.59 9.11 18.50 10.69 9.21 19.00 10.79 9.31 19.50 10.88 9.40 20.00 10.97 9.49 20.50 11.06 9.58 21.00 11.14 9.66 21.50 11.22 9.74 22.00 11.30 9.82 22.50 11.38 9.89 23.00 11.45 9.96 23.50 11.52 10.03 24.00 11.58 10.09 Runoff (cfs) 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.03 0.04 0.04 0.05 0.06 0.07 0.07 0.08 0.09 0.12 0.15 0.18 0.26 0.43 1.20 1.10 0.45 0.28 0.20 0.17 0.14 0.12 0.11 0.10 0.09 0.08 0.08 0.07 0.07 0.06 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 0.04 Printed 5/13/2024 Page 252

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 253 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: PO-DA G Runoff = 2.63 cfs @ 12.30 hrs, Volume= Routed to Pond 3P : BR-03 0.324 af, Depth>10.02" 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 100-Year_Future Rainfall=11.58", 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 2.63 cfs NOAA 24-hr D 100-Year_Future Rainfall=11.58" P2=4.07" Runoff Area=16,902 sf Runoff Volume=0.324 af Runoff Depth>10.02" Flow Length=175' Tc=21.5 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-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Future Rainfall=11.58", 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 0.06 0.00 1.00 0.13 0.00 1.50 0.20 0.00 2.00 0.28 0.00 2.50 0.36 0.00 3.00 0.44 0.02 3.50 0.52 0.04 4.00 0.61 0.07 4.50 0.70 0.10 5.00 0.79 0.14 5.50 0.89 0.19 6.00 0.99 0.25 6.50 1.10 0.31 7.00 1.22 0.39 7.50 1.35 0.48 8.00 1.50 0.58 8.50 1.66 0.70 9.00 1.84 0.84 9.50 2.04 1.00 10.00 2.30 1.21 10.50 2.59 1.46 11.00 3.01 1.83 11.50 3.67 2.43 12.00 5.55 4.19 12.50 7.91 6.48 13.00 8.57 7.13 13.50 8.99 7.53 14.00 9.28 7.83 14.50 9.54 8.08 15.00 9.74 8.28 15.50 9.92 8.45 16.00 10.08 8.61 16.50 10.23 8.75 17.00 10.36 8.89 17.50 10.48 9.01 18.00 10.59 9.11 18.50 10.69 9.21 19.00 10.79 9.31 19.50 10.88 9.40 20.00 10.97 9.49 20.50 11.06 9.58 21.00 11.14 9.66 21.50 11.22 9.74 22.00 11.30 9.82 22.50 11.38 9.89 23.00 11.45 9.96 23.50 11.52 10.03 24.00 11.58 10.09 Runoff (cfs) 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.03 0.04 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.12 0.15 0.19 0.26 0.42 0.99 1.74 0.59 0.34 0.24 0.20 0.16 0.14 0.12 0.12 0.11 0.10 0.09 0.08 0.07 0.07 0.07 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 Printed 5/13/2024 Page 254

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 255 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 11S: PO-DA I Runoff = 2.55 cfs @ 12.13 hrs, Volume= Routed to Pond 5P : BR-05 0.202 af, Depth>10.03" 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 100-Year_Future Rainfall=11.58", 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 2.55 cfs NOAA 24-hr D 100-Year_Future Rainfall=11.58" P2=4.07" Runoff Area=10,507 sf Runoff Volume=0.202 af Runoff Depth>10.03" Flow Length=120' Tc=6.0 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-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Future Rainfall=11.58", 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 0.06 0.00 1.00 0.13 0.00 1.50 0.20 0.00 2.00 0.28 0.00 2.50 0.36 0.00 3.00 0.44 0.02 3.50 0.52 0.04 4.00 0.61 0.07 4.50 0.70 0.10 5.00 0.79 0.14 5.50 0.89 0.19 6.00 0.99 0.25 6.50 1.10 0.31 7.00 1.22 0.39 7.50 1.35 0.48 8.00 1.50 0.58 8.50 1.66 0.70 9.00 1.84 0.84 9.50 2.04 1.00 10.00 2.30 1.21 10.50 2.59 1.46 11.00 3.01 1.83 11.50 3.67 2.43 12.00 5.55 4.19 12.50 7.91 6.48 13.00 8.57 7.13 13.50 8.99 7.53 14.00 9.28 7.83 14.50 9.54 8.08 15.00 9.74 8.28 15.50 9.92 8.45 16.00 10.08 8.61 16.50 10.23 8.75 17.00 10.36 8.89 17.50 10.48 9.01 18.00 10.59 9.11 18.50 10.69 9.21 19.00 10.79 9.31 19.50 10.88 9.40 20.00 10.97 9.49 20.50 11.06 9.58 21.00 11.14 9.66 21.50 11.22 9.74 22.00 11.30 9.82 22.50 11.38 9.89 23.00 11.45 9.96 23.50 11.52 10.03 24.00 11.58 10.09 Runoff (cfs) 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.03 0.03 0.04 0.05 0.05 0.06 0.07 0.08 0.11 0.13 0.20 0.33 1.39 0.51 0.27 0.17 0.13 0.11 0.09 0.08 0.07 0.07 0.06 0.06 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.03 0.03 0.03 Printed 5/13/2024 Page 256

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 257 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: PO-DA J Runoff = 3.49 cfs @ 12.12 hrs, Volume= Routed to Pond 6P : BR-04 0.268 af, Depth>10.15" 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 100-Year_Future Rainfall=11.58", 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 3.49 cfs NOAA 24-hr D 100-Year_Future Rainfall=11.58" P2=4.07" Runoff Area=13,809 sf Runoff Volume=0.268 af Runoff Depth>10.15" Flow Length=96' Slope=0.0336 '/' Tc=4.9 min CN=WQ Flow (cfs) 3 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-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Future Rainfall=11.58", 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 0.06 0.00 1.00 0.13 0.00 1.50 0.20 0.00 2.00 0.28 0.00 2.50 0.36 0.01 3.00 0.44 0.03 3.50 0.52 0.05 4.00 0.61 0.08 4.50 0.70 0.12 5.00 0.79 0.17 5.50 0.89 0.22 6.00 0.99 0.28 6.50 1.10 0.35 7.00 1.22 0.43 7.50 1.35 0.52 8.00 1.50 0.63 8.50 1.66 0.76 9.00 1.84 0.89 9.50 2.04 1.06 10.00 2.30 1.28 10.50 2.59 1.54 11.00 3.01 1.91 11.50 3.67 2.52 12.00 5.55 4.30 12.50 7.91 6.60 13.00 8.57 7.25 13.50 8.99 7.66 14.00 9.28 7.95 14.50 9.54 8.20 15.00 9.74 8.40 15.50 9.92 8.57 16.00 10.08 8.73 16.50 10.23 8.88 17.00 10.36 9.01 17.50 10.48 9.13 18.00 10.59 9.24 18.50 10.69 9.34 19.00 10.79 9.43 19.50 10.88 9.53 20.00 10.97 9.62 20.50 11.06 9.70 21.00 11.14 9.79 21.50 11.22 9.87 22.00 11.30 9.94 22.50 11.38 10.02 23.00 11.45 10.09 23.50 11.52 10.15 24.00 11.58 10.22 Runoff (cfs) 0.00 0.00 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.07 0.08 0.09 0.11 0.14 0.17 0.27 0.44 1.99 0.66 0.35 0.22 0.18 0.15 0.12 0.11 0.10 0.09 0.08 0.07 0.07 0.06 0.06 0.06 0.06 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 Printed 5/13/2024 Page 258

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Future Rainfall=11.58", P2=4.07" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 259 Summary for Pond 1P: BR-01 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth > 9.89" for 100-Year_Future event Inflow = 4.23 cfs @ 12.25 hrs, Volume= 0.467 af Outflow = 1.65 cfs @ 12.58 hrs, Volume= 0.460 af, Atten= 61%, Lag= 19.6 min Primary = 1.65 cfs @ 12.58 hrs, Volume= 0.460 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= 602.16' @ 12.58 hrs Surf.Area= 5,277 sf Storage= 6,639 cf Plug-Flow detention time= 94.9 min calculated for 0.460 af (98% of inflow) Center-of-Mass det. time= 85.2 min ( 868.2 - 783.0 ) 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 100-Year_Future Rainfall=11.58", P2=4.07" West Orange HydroCAD_Post Printed 5/13/2024 Page 260 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=1.65 cfs @ 12.58 hrs HW=602.16' TW=591.31' (Dynamic Tailwater) 1=SD-21 Outlet (Elevation F) (Passes 1.65 cfs of 12.01 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.40 cfs @ 11.85 fps) 3=Water Quantity (Elevation H) (Orifice Controls 1.25 cfs @ 6.00 fps) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 1P: BR-01 Hydrograph Inflow Primary 4.23 cfs Inflow Area=0.567 ac Peak Elev=602.16' Storage=6,639 cf 4 Flow (cfs) 3 2 1.65 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 100-Year_Future Rainfall=11.58", 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 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.04 0.05 0.05 0.06 0.07 0.08 0.10 0.11 0.13 0.14 0.18 0.23 0.28 0.40 0.65 1.71 2.07 0.76 0.47 0.34 0.28 0.23 0.20 0.18 0.17 0.15 0.14 0.12 0.11 0.11 0.11 0.10 0.10 0.09 0.09 0.09 0.08 0.08 0.08 0.07 Storage Elevation (cubic-feet) (feet) 0 596.00 0 596.00 5 596.01 16 596.02 30 596.04 42 596.06 53 596.07 67 596.09 83 596.11 98 596.14 113 596.16 127 596.18 142 596.20 160 596.22 187 596.26 223 596.31 268 596.37 321 596.45 382 596.53 462 596.65 590 596.83 769 597.08 1,038 597.47 1,571 598.47 2,835 599.99 6,584 602.13 5,892 601.73 4,706 601.06 3,983 600.65 3,776 600.53 3,616 600.44 3,383 600.31 3,121 600.16 2,843 600.00 2,552 599.83 2,248 599.66 1,932 599.41 1,638 598.64 1,398 598.02 1,199 597.71 1,027 597.45 878 597.24 750 597.06 641 596.90 549 596.77 472 596.66 408 596.57 356 596.50 313 596.43 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.04 0.04 0.05 0.06 0.06 0.07 0.08 0.10 0.11 0.12 0.14 0.16 0.19 0.25 0.32 1.64 1.45 1.04 0.53 0.36 0.34 0.34 0.33 0.32 0.32 0.31 0.30 0.26 0.23 0.21 0.19 0.17 0.16 0.15 0.13 0.12 0.11 0.10 0.09 Printed 5/13/2024 Page 261