J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" 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 0.05 0.00 1.00 0.11 0.00 1.50 0.16 0.00 2.00 0.22 0.00 2.50 0.28 0.00 3.00 0.35 0.00 3.50 0.41 0.01 4.00 0.48 0.03 4.50 0.56 0.05 5.00 0.63 0.07 5.50 0.71 0.11 6.00 0.79 0.14 6.50 0.88 0.18 7.00 0.97 0.24 7.50 1.08 0.30 8.00 1.20 0.37 8.50 1.33 0.46 9.00 1.46 0.56 9.50 1.63 0.68 10.00 1.83 0.83 10.50 2.07 1.02 11.00 2.40 1.30 11.50 2.93 1.75 12.00 4.42 3.12 12.50 6.30 4.92 13.00 6.83 5.43 13.50 7.16 5.75 14.00 7.40 5.98 14.50 7.60 6.18 15.00 7.77 6.34 15.50 7.90 6.47 16.00 8.03 6.60 16.50 8.15 6.71 17.00 8.26 6.82 17.50 8.35 6.92 18.00 8.44 7.00 18.50 8.52 7.08 19.00 8.60 7.15 19.50 8.67 7.23 20.00 8.75 7.30 20.50 8.82 7.37 21.00 8.88 7.43 21.50 8.95 7.50 22.00 9.01 7.56 22.50 9.07 7.61 23.00 9.12 7.67 23.50 9.18 7.72 24.00 9.23 7.77 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 0.09 0.11 0.13 0.19 0.32 0.88 0.93 0.36 0.23 0.16 0.14 0.11 0.09 0.09 0.08 0.07 0.07 0.06 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 Printed 5/13/2024 Page 212

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 213 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: PO-DA G Runoff = 1.97 cfs @ 12.32 hrs, Volume= Routed to Pond 3P : BR-03 0.250 af, Depth> 7.72" 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_Current Rainfall=9.23", P2=3.45" 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) 22.6 100 0.0010 0.07 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.45" 0.7 75 0.0121 1.77 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 23.3 175 Total Subcatchment 9S: PO-DA G Hydrograph Runoff 1.97 cfs Flow (cfs) 2 NOAA 24-hr D 100-Year_Current Rainfall=9.23" P2=3.45" Runoff Area=16,902 sf Runoff Volume=0.250 af Runoff Depth>7.72" Flow Length=175' Tc=23.3 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 100-Year_Current Rainfall=9.23", P2=3.45" 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 0.05 0.00 1.00 0.11 0.00 1.50 0.16 0.00 2.00 0.22 0.00 2.50 0.28 0.00 3.00 0.35 0.00 3.50 0.41 0.01 4.00 0.48 0.03 4.50 0.56 0.05 5.00 0.63 0.07 5.50 0.71 0.11 6.00 0.79 0.14 6.50 0.88 0.18 7.00 0.97 0.24 7.50 1.08 0.30 8.00 1.20 0.37 8.50 1.33 0.46 9.00 1.46 0.56 9.50 1.63 0.68 10.00 1.83 0.83 10.50 2.07 1.02 11.00 2.40 1.30 11.50 2.93 1.75 12.00 4.42 3.12 12.50 6.30 4.92 13.00 6.83 5.43 13.50 7.16 5.75 14.00 7.40 5.98 14.50 7.60 6.18 15.00 7.77 6.34 15.50 7.90 6.47 16.00 8.03 6.60 16.50 8.15 6.71 17.00 8.26 6.82 17.50 8.35 6.92 18.00 8.44 7.00 18.50 8.52 7.08 19.00 8.60 7.15 19.50 8.67 7.23 20.00 8.75 7.30 20.50 8.82 7.37 21.00 8.88 7.43 21.50 8.95 7.50 22.00 9.01 7.56 22.50 9.07 7.61 23.00 9.12 7.67 23.50 9.18 7.72 24.00 9.23 7.77 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 0.06 0.06 0.07 0.09 0.11 0.14 0.19 0.31 0.72 1.45 0.49 0.28 0.19 0.16 0.13 0.11 0.10 0.09 0.08 0.08 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 214

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 215 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 11S: PO-DA I Runoff = 1.96 cfs @ 12.13 hrs, Volume= Routed to Pond 5P : BR-05 0.155 af, Depth> 7.73" 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_Current Rainfall=9.23", P2=3.45" 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) 6.4 100 0.0237 0.26 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.45" 0.1 20 0.0320 2.88 Shallow Concentrated Flow, Shallow Concentrated Flow Unpaved Kv= 16.1 fps 6.5 120 Total Subcatchment 11S: PO-DA I Hydrograph Runoff 1.96 cfs Flow (cfs) 2 NOAA 24-hr D 100-Year_Current Rainfall=9.23" P2=3.45" Runoff Area=10,507 sf Runoff Volume=0.155 af Runoff Depth>7.73" Flow Length=120' Tc=6.5 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 100-Year_Current Rainfall=9.23", P2=3.45" 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 0.05 0.00 1.00 0.11 0.00 1.50 0.16 0.00 2.00 0.22 0.00 2.50 0.28 0.00 3.00 0.35 0.00 3.50 0.41 0.01 4.00 0.48 0.03 4.50 0.56 0.05 5.00 0.63 0.07 5.50 0.71 0.11 6.00 0.79 0.14 6.50 0.88 0.18 7.00 0.97 0.24 7.50 1.08 0.30 8.00 1.20 0.37 8.50 1.33 0.46 9.00 1.46 0.56 9.50 1.63 0.68 10.00 1.83 0.83 10.50 2.07 1.02 11.00 2.40 1.30 11.50 2.93 1.75 12.00 4.42 3.12 12.50 6.30 4.92 13.00 6.83 5.43 13.50 7.16 5.75 14.00 7.40 5.98 14.50 7.60 6.18 15.00 7.77 6.34 15.50 7.90 6.47 16.00 8.03 6.60 16.50 8.15 6.71 17.00 8.26 6.82 17.50 8.35 6.92 18.00 8.44 7.00 18.50 8.52 7.08 19.00 8.60 7.15 19.50 8.67 7.23 20.00 8.75 7.30 20.50 8.82 7.37 21.00 8.88 7.43 21.50 8.95 7.50 22.00 9.01 7.56 22.50 9.07 7.61 23.00 9.12 7.67 23.50 9.18 7.72 24.00 9.23 7.77 Runoff (cfs) 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.06 0.08 0.09 0.15 0.25 1.04 0.40 0.21 0.14 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 216

Post-Developed (O-1B) NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 217 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: PO-DA J Runoff = 2.68 cfs @ 12.12 hrs, Volume= Routed to Pond 6P : BR-04 0.207 af, Depth> 7.84" 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_Current Rainfall=9.23", P2=3.45" 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) 5.4 96 0.0336 0.30 Sheet Flow, Gravel Sheet Flow n= 0.100 P2= 3.45" Subcatchment 12S: PO-DA J Hydrograph 3 Runoff 2.68 cfs NOAA 24-hr D 100-Year_Current Rainfall=9.23" P2=3.45" Runoff Area=13,809 sf Runoff Volume=0.207 af Runoff Depth>7.84" Flow Length=96' Slope=0.0336 '/' Tc=5.4 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_Current Rainfall=9.23", P2=3.45" 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 0.05 0.00 1.00 0.11 0.00 1.50 0.16 0.00 2.00 0.22 0.00 2.50 0.28 0.00 3.00 0.35 0.01 3.50 0.41 0.02 4.00 0.48 0.04 4.50 0.56 0.06 5.00 0.63 0.09 5.50 0.71 0.13 6.00 0.79 0.16 6.50 0.88 0.21 7.00 0.97 0.27 7.50 1.08 0.34 8.00 1.20 0.41 8.50 1.33 0.50 9.00 1.46 0.60 9.50 1.63 0.73 10.00 1.83 0.89 10.50 2.07 1.08 11.00 2.40 1.37 11.50 2.93 1.83 12.00 4.42 3.22 12.50 6.30 5.03 13.00 6.83 5.54 13.50 7.16 5.87 14.00 7.40 6.10 14.50 7.60 6.30 15.00 7.77 6.46 15.50 7.90 6.59 16.00 8.03 6.72 16.50 8.15 6.83 17.00 8.26 6.94 17.50 8.35 7.04 18.00 8.44 7.12 18.50 8.52 7.20 19.00 8.60 7.28 19.50 8.67 7.35 20.00 8.75 7.42 20.50 8.82 7.49 21.00 8.88 7.55 21.50 8.95 7.62 22.00 9.01 7.68 22.50 9.07 7.74 23.00 9.12 7.79 23.50 9.18 7.85 24.00 9.23 7.90 Runoff (cfs) 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 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 0.34 1.49 0.52 0.27 0.18 0.14 0.12 0.09 0.08 0.08 0.07 0.06 0.06 0.05 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.03 0.03 0.03 Printed 5/13/2024 Page 218

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 100-Year_Current Rainfall=9.23", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 219 Summary for Pond 1P: BR-01 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth > 7.59" for 100-Year_Current event Inflow = 3.18 cfs @ 12.27 hrs, Volume= 0.359 af Outflow = 1.24 cfs @ 12.62 hrs, Volume= 0.354 af, Atten= 61%, Lag= 21.1 min Primary = 1.24 cfs @ 12.62 hrs, Volume= 0.354 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= 601.35' @ 12.62 hrs Surf.Area= 5,277 sf Storage= 5,218 cf Plug-Flow detention time= 99.5 min calculated for 0.354 af (99% of inflow) Center-of-Mass det. time= 91.3 min ( 881.9 - 790.6 ) 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_Current Rainfall=9.23", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 220 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=1.24 cfs @ 12.62 hrs HW=601.35' TW=591.19' (Dynamic Tailwater) 1=SD-21 Outlet (Elevation F) (Passes 1.24 cfs of 11.52 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.38 cfs @ 11.03 fps) 3=Water Quantity (Elevation H) (Orifice Controls 0.87 cfs @ 4.15 fps) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 1P: BR-01 Hydrograph Inflow Primary 3.18 cfs Inflow Area=0.567 ac Peak Elev=601.35' Storage=5,218 cf Flow (cfs) 3 2 1.24 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_Current Rainfall=9.23", P2=3.45" 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 0.01 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 0.09 0.10 0.13 0.16 0.20 0.29 0.49 1.24 1.74 0.62 0.38 0.27 0.22 0.18 0.15 0.14 0.13 0.12 0.11 0.10 0.09 0.09 0.08 0.08 0.08 0.07 0.07 0.07 0.07 0.06 0.06 0.06 Storage Elevation (cubic-feet) (feet) 0 596.00 0 596.00 2 596.00 10 596.01 20 596.03 31 596.04 40 596.06 48 596.07 58 596.08 69 596.10 81 596.11 93 596.13 104 596.14 115 596.16 131 596.18 152 596.21 178 596.25 210 596.29 248 596.34 298 596.41 381 596.53 500 596.70 681 596.96 1,054 597.49 1,955 599.48 5,115 601.29 4,778 601.10 4,075 600.70 3,792 600.54 3,608 600.43 3,366 600.30 3,067 600.13 2,749 599.95 2,423 599.76 2,092 599.57 1,766 598.98 1,485 598.24 1,247 597.78 1,041 597.47 865 597.22 716 597.01 592 596.83 490 596.69 409 596.57 344 596.48 294 596.41 256 596.35 226 596.31 203 596.28 Primary (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.05 0.05 0.06 0.07 0.08 0.09 0.11 0.13 0.15 0.19 0.30 1.20 1.07 0.64 0.37 0.34 0.34 0.33 0.32 0.31 0.31 0.28 0.24 0.21 0.19 0.17 0.16 0.14 0.13 0.11 0.10 0.09 0.08 0.07 0.07 Printed 5/13/2024 Page 221