J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 10-Year_Current Rainfall=5.37", 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 0.03 0.00 1.00 0.06 0.00 1.50 0.09 0.00 2.00 0.13 0.00 2.50 0.16 0.00 3.00 0.20 0.00 3.50 0.24 0.00 4.00 0.28 0.00 4.50 0.32 0.00 5.00 0.37 0.01 5.50 0.41 0.01 6.00 0.46 0.02 6.50 0.51 0.03 7.00 0.57 0.05 7.50 0.63 0.07 8.00 0.70 0.10 8.50 0.77 0.13 9.00 0.85 0.17 9.50 0.95 0.22 10.00 1.06 0.29 10.50 1.20 0.38 11.00 1.40 0.51 11.50 1.70 0.73 12.00 2.57 1.44 12.50 3.67 2.42 13.00 3.97 2.70 13.50 4.17 2.88 14.00 4.31 3.01 14.50 4.42 3.12 15.00 4.52 3.21 15.50 4.60 3.29 16.00 4.67 3.36 16.50 4.74 3.42 17.00 4.80 3.48 17.50 4.86 3.54 18.00 4.91 3.58 18.50 4.96 3.63 19.00 5.00 3.67 19.50 5.05 3.71 20.00 5.09 3.75 20.50 5.13 3.79 21.00 5.17 3.83 21.50 5.21 3.86 22.00 5.24 3.90 22.50 5.28 3.93 23.00 5.31 3.96 23.50 5.34 3.99 24.00 5.37 4.02 Runoff (cfs) 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 0.03 0.04 0.05 0.06 0.09 0.16 0.46 0.50 0.20 0.13 0.09 0.08 0.06 0.05 0.05 0.05 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 0.02 0.02 Printed 5/13/2024 Page 132

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 133 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 9S: PO-DA G Runoff = 1.05 cfs @ 12.33 hrs, Volume= Routed to Pond 3P : BR-03 0.130 af, Depth> 4.02" 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 10-Year_Current Rainfall=5.37", 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 1.05 cfs NOAA 24-hr D 10-Year_Current Rainfall=5.37" P2=3.45" Runoff Area=16,902 sf Runoff Volume=0.130 af Runoff Depth>4.02" Flow Length=175' Tc=23.3 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_Current Rainfall=5.37", 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 0.03 0.00 1.00 0.06 0.00 1.50 0.09 0.00 2.00 0.13 0.00 2.50 0.16 0.00 3.00 0.20 0.00 3.50 0.24 0.00 4.00 0.28 0.00 4.50 0.32 0.00 5.00 0.37 0.01 5.50 0.41 0.01 6.00 0.46 0.02 6.50 0.51 0.03 7.00 0.57 0.05 7.50 0.63 0.07 8.00 0.70 0.10 8.50 0.77 0.13 9.00 0.85 0.17 9.50 0.95 0.22 10.00 1.06 0.29 10.50 1.20 0.38 11.00 1.40 0.51 11.50 1.70 0.73 12.00 2.57 1.44 12.50 3.67 2.42 13.00 3.97 2.70 13.50 4.17 2.88 14.00 4.31 3.01 14.50 4.42 3.12 15.00 4.52 3.21 15.50 4.60 3.29 16.00 4.67 3.36 16.50 4.74 3.42 17.00 4.80 3.48 17.50 4.86 3.54 18.00 4.91 3.58 18.50 4.96 3.63 19.00 5.00 3.67 19.50 5.05 3.71 20.00 5.09 3.75 20.50 5.13 3.79 21.00 5.17 3.83 21.50 5.21 3.86 22.00 5.24 3.90 22.50 5.28 3.93 23.00 5.31 3.96 23.50 5.34 3.99 24.00 5.37 4.02 Runoff (cfs) 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 0.03 0.04 0.05 0.06 0.09 0.15 0.37 0.78 0.27 0.15 0.11 0.09 0.07 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 Printed 5/13/2024 Page 134

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 135 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 11S: PO-DA I Runoff = 1.04 cfs @ 12.14 hrs, Volume= Routed to Pond 5P : BR-05 0.081 af, Depth> 4.02" 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 10-Year_Current Rainfall=5.37", 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 1.04 cfs NOAA 24-hr D 10-Year_Current Rainfall=5.37" P2=3.45" Runoff Area=10,507 sf Runoff Volume=0.081 af Runoff Depth>4.02" Flow Length=120' Tc=6.5 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_Current Rainfall=5.37", 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 0.03 0.00 1.00 0.06 0.00 1.50 0.09 0.00 2.00 0.13 0.00 2.50 0.16 0.00 3.00 0.20 0.00 3.50 0.24 0.00 4.00 0.28 0.00 4.50 0.32 0.00 5.00 0.37 0.01 5.50 0.41 0.01 6.00 0.46 0.02 6.50 0.51 0.03 7.00 0.57 0.05 7.50 0.63 0.07 8.00 0.70 0.10 8.50 0.77 0.13 9.00 0.85 0.17 9.50 0.95 0.22 10.00 1.06 0.29 10.50 1.20 0.38 11.00 1.40 0.51 11.50 1.70 0.73 12.00 2.57 1.44 12.50 3.67 2.42 13.00 3.97 2.70 13.50 4.17 2.88 14.00 4.31 3.01 14.50 4.42 3.12 15.00 4.52 3.21 15.50 4.60 3.29 16.00 4.67 3.36 16.50 4.74 3.42 17.00 4.80 3.48 17.50 4.86 3.54 18.00 4.91 3.58 18.50 4.96 3.63 19.00 5.00 3.67 19.50 5.05 3.71 20.00 5.09 3.75 20.50 5.13 3.79 21.00 5.17 3.83 21.50 5.21 3.86 22.00 5.24 3.90 22.50 5.28 3.93 23.00 5.31 3.96 23.50 5.34 3.99 24.00 5.37 4.02 Runoff (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 0.04 0.07 0.12 0.54 0.22 0.12 0.08 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 0.01 0.01 0.01 Printed 5/13/2024 Page 136

Post-Developed (O-1B) NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 137 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: PO-DA J Runoff = 1.44 cfs @ 12.12 hrs, Volume= Routed to Pond 6P : BR-04 0.109 af, Depth> 4.12" 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_Current Rainfall=5.37", 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 Runoff 1.44 cfs NOAA 24-hr D 10-Year_Current Rainfall=5.37" P2=3.45" Runoff Area=13,809 sf Runoff Volume=0.109 af Runoff Depth>4.12" Flow Length=96' Slope=0.0336 '/' Tc=5.4 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_Current Rainfall=5.37", 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 0.03 0.00 1.00 0.06 0.00 1.50 0.09 0.00 2.00 0.13 0.00 2.50 0.16 0.00 3.00 0.20 0.00 3.50 0.24 0.00 4.00 0.28 0.00 4.50 0.32 0.00 5.00 0.37 0.01 5.50 0.41 0.02 6.00 0.46 0.03 6.50 0.51 0.05 7.00 0.57 0.07 7.50 0.63 0.09 8.00 0.70 0.12 8.50 0.77 0.16 9.00 0.85 0.20 9.50 0.95 0.25 10.00 1.06 0.33 10.50 1.20 0.42 11.00 1.40 0.55 11.50 1.70 0.79 12.00 2.57 1.52 12.50 3.67 2.51 13.00 3.97 2.80 13.50 4.17 2.98 14.00 4.31 3.11 14.50 4.42 3.22 15.00 4.52 3.31 15.50 4.60 3.39 16.00 4.67 3.46 16.50 4.74 3.53 17.00 4.80 3.58 17.50 4.86 3.64 18.00 4.91 3.69 18.50 4.96 3.73 19.00 5.00 3.77 19.50 5.05 3.82 20.00 5.09 3.86 20.50 5.13 3.90 21.00 5.17 3.93 21.50 5.21 3.97 22.00 5.24 4.00 22.50 5.28 4.04 23.00 5.31 4.07 23.50 5.34 4.10 24.00 5.37 4.13 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 0.01 0.02 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.10 0.17 0.79 0.29 0.15 0.10 0.08 0.06 0.05 0.05 0.04 0.04 0.04 0.03 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 Printed 5/13/2024 Page 138

Post-Developed (O-1B) West Orange HydroCAD_Post NOAA 24-hr D 10-Year_Current Rainfall=5.37", P2=3.45" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Printed 5/13/2024 Page 139 Summary for Pond 1P: BR-01 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth > 3.90" for 10-Year_Current event Inflow = 1.67 cfs @ 12.27 hrs, Volume= 0.184 af Outflow = 0.33 cfs @ 13.03 hrs, Volume= 0.182 af, Atten= 80%, Lag= 45.6 min Primary = 0.33 cfs @ 13.03 hrs, Volume= 0.182 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= 600.08' @ 13.03 hrs Surf.Area= 5,277 sf Storage= 2,990 cf Plug-Flow detention time= 98.9 min calculated for 0.182 af (99% of inflow) Center-of-Mass det. time= 90.8 min ( 898.3 - 807.5 ) 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_Current Rainfall=5.37", P2=3.45" West Orange HydroCAD_Post Printed 5/13/2024 Page 140 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.33 cfs @ 13.03 hrs HW=600.08' TW=590.89' (Dynamic Tailwater) 1=SD-21 Outlet (Elevation F) (Passes 0.33 cfs of 10.70 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.33 cfs @ 9.60 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 1.67 cfs Flow (cfs) Inflow Area=0.567 ac Peak Elev=600.08' Storage=2,990 cf 1 0.33 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_Current Rainfall=5.37", 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 0.00 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 0.04 0.04 0.05 0.07 0.09 0.14 0.23 0.63 0.93 0.34 0.21 0.15 0.12 0.10 0.09 0.08 0.07 0.07 0.06 0.05 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.03 0.03 Storage Elevation (cubic-feet) (feet) 0 596.00 0 596.00 0 596.00 2 596.00 6 596.01 12 596.02 18 596.03 24 596.03 30 596.04 34 596.05 38 596.05 42 596.06 47 596.07 54 596.08 62 596.09 72 596.10 84 596.12 96 596.13 108 596.15 123 596.17 149 596.21 189 596.26 254 596.35 403 596.56 812 597.14 2,597 599.86 2,989 600.08 2,876 600.02 2,606 599.86 2,284 599.68 1,936 599.43 1,602 598.55 1,325 597.90 1,087 597.54 879 597.24 698 596.98 543 596.76 414 596.58 315 596.44 244 596.34 195 596.27 163 596.23 143 596.20 131 596.18 123 596.17 118 596.16 114 596.16 111 596.15 107 596.15 Primary (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 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.08 0.11 0.17 0.32 0.33 0.32 0.32 0.31 0.30 0.26 0.22 0.20 0.17 0.15 0.13 0.11 0.09 0.08 0.07 0.06 0.05 0.05 0.04 0.04 0.04 0.04 0.03 Printed 5/13/2024 Page 141