J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach 4R: TD-02 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.04 0.19 0.08 0.04 0.03 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 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Storage (cubic-feet) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 2 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Elevation (feet) 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.26 604.26 604.27 604.30 604.28 604.27 604.27 604.26 604.26 604.26 604.26 604.26 604.26 604.26 604.26 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 604.25 Outflow (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 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.04 0.19 0.08 0.04 0.03 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 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Printed 5/13/2024 Page 34

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 35 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Reach 5R: TD-03 Inflow Area = 0.236 ac, 0.00% Impervious, Inflow Depth > 3.48" for 25-Year event Inflow = 0.92 cfs @ 12.15 hrs, Volume= 0.068 af Outflow = 0.91 cfs @ 12.16 hrs, Volume= 0.068 af, Atten= 1%, Lag= 0.6 min Routed to Pond 16P : SD-09, SD-10 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Max. Velocity= 2.60 fps, Min. Travel Time= 0.9 min Avg. Velocity = 0.76 fps, Avg. Travel Time= 2.9 min Peak Storage= 47 cf @ 12.16 hrs Average Depth at Peak Storage= 0.23' , Surface Width= 1.50' Bank-Full Depth= 1.50' Flow Area= 2.3 sf, Capacity= 11.66 cfs 1.50' x 1.50' deep channel, n= 0.012 Concrete pipe, finished Length= 133.7' Slope= 0.0044 '/' Inlet Invert= 601.81', Outlet Invert= 601.22' Reach 5R: TD-03 Hydrograph 1 Inflow Outflow 0.92 cfs Inflow Area=0.236 ac Avg. Flow Depth=0.23' Max Vel=2.60 fps n=0.012 L=133.7' S=0.0044 '/' Capacity=11.66 cfs Flow (cfs) 0.91 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 (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach 5R: TD-03 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.02 0.04 0.09 0.42 0.22 0.12 0.08 0.06 0.05 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 0.01 0.01 Storage Elevation (cubic-feet) (feet) 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 0 601.81 1 601.81 2 601.82 3 601.82 4 601.83 5 601.83 7 601.84 10 601.86 27 601.94 19 601.90 13 601.87 10 601.86 8 601.85 8 601.85 7 601.84 6 601.84 6 601.84 6 601.84 5 601.84 5 601.83 5 601.83 4 601.83 4 601.83 4 601.83 4 601.83 4 601.83 4 601.83 4 601.83 4 601.83 4 601.83 4 601.83 4 601.83 3 601.83 Outflow (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 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.02 0.04 0.08 0.39 0.22 0.12 0.08 0.06 0.05 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 0.02 0.01 Printed 5/13/2024 Page 36

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 37 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Reach 6R: TD-04 Inflow Area = 0.183 ac, 0.00% Impervious, Inflow Depth > 3.56" for 25-Year event Inflow = 0.63 cfs @ 12.19 hrs, Volume= 0.054 af Outflow = 0.63 cfs @ 12.19 hrs, Volume= 0.054 af, Atten= 0%, Lag= 0.2 min Routed to Pond 20P : SD-11, SD-12 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Max. Velocity= 3.49 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.13 fps, Avg. Travel Time= 0.8 min Peak Storage= 10 cf @ 12.19 hrs Average Depth at Peak Storage= 0.12' , Surface Width= 1.50' Bank-Full Depth= 1.50' Flow Area= 2.3 sf, Capacity= 22.41 cfs 1.50' x 1.50' deep channel, n= 0.012 Concrete pipe, finished Length= 54.6' Slope= 0.0163 '/' Inlet Invert= 600.77', Outlet Invert= 599.88' Reach 6R: TD-04 Hydrograph 0.7 Inflow Area=0.183 ac Avg. Flow Depth=0.12' Max Vel=3.49 fps n=0.012 L=54.6' S=0.0163 '/' Capacity=22.41 cfs 0.63 cfs 0.65 0.6 0.55 0.5 0.45 Flow (cfs) Inflow Outflow 0.63 cfs 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 (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Reach 6R: TD-04 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 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.03 0.07 0.26 0.20 0.10 0.06 0.05 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 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Storage (cubic-feet) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 2 2 6 5 3 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Elevation (feet) 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.77 600.78 600.78 600.78 600.79 600.80 600.84 600.83 600.81 600.80 600.79 600.79 600.79 600.79 600.79 600.79 600.79 600.78 600.78 600.78 600.78 600.78 600.78 600.78 600.78 600.78 600.78 600.78 600.78 600.78 600.78 Outflow (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 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.02 0.03 0.06 0.25 0.20 0.10 0.06 0.05 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 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Printed 5/13/2024 Page 38

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" 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 39 Summary for Pond 1P: BR-01 Inflow Area = 0.567 ac, 17.46% Impervious, Inflow Depth > 4.91" for 25-Year event Inflow = 2.09 cfs @ 12.26 hrs, Volume= 0.232 af Outflow = 0.45 cfs @ 12.95 hrs, Volume= 0.229 af, Atten= 79%, Lag= 40.9 min Primary = 0.45 cfs @ 12.95 hrs, Volume= 0.229 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= 600.60' @ 12.95 hrs Surf.Area= 5,277 sf Storage= 3,897 cf Plug-Flow detention time= 113.2 min calculated for 0.229 af (99% of inflow) Center-of-Mass det. time= 105.6 min ( 907.4 - 801.7 ) 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 (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 40 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.45 cfs @ 12.95 hrs HW=600.60' TW=590.94' (Dynamic Tailwater) 1=SD-21 Outlet (Elevation F) (Passes 0.45 cfs of 11.04 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.35 cfs @ 10.21 fps) 3=Water Quantity (Elevation H) (Orifice Controls 0.10 cfs @ 1.01 fps) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 1P: BR-01 Hydrograph Inflow Primary 2.09 cfs Inflow Area=0.567 ac Peak Elev=600.60' Storage=3,897 cf Flow (cfs) 2 1 0.45 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 (25-Year) West Orange HydroCAD_Post NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" 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 0.10 0.12 0.18 0.30 0.79 1.16 0.42 0.26 0.18 0.15 0.13 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 0.05 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 25 596.03 31 596.04 37 596.05 41 596.06 47 596.07 54 596.08 62 596.09 70 596.10 81 596.11 93 596.13 107 596.15 121 596.17 137 596.19 159 596.22 199 596.27 258 596.36 352 596.49 558 596.78 1,101 597.56 3,390 600.31 3,894 600.60 3,758 600.52 3,520 600.38 3,214 600.21 2,872 600.02 2,499 599.80 2,121 599.59 1,756 598.95 1,449 598.15 1,194 597.70 968 597.37 770 597.08 603 596.85 470 596.66 366 596.51 289 596.40 233 596.32 195 596.27 169 596.23 151 596.21 139 596.19 130 596.18 124 596.17 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 0.44 0.35 0.34 0.33 0.32 0.32 0.31 0.28 0.23 0.21 0.18 0.16 0.14 0.12 0.10 0.09 0.08 0.07 0.06 0.05 0.05 0.05 0.04 Printed 5/13/2024 Page 41

Post-Developed (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" 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 42 Summary for Pond 2P: BR-02 Inflow Area = 0.350 ac, 31.71% Impervious, Inflow Depth > 5.10" for 25-Year event Inflow = 1.42 cfs @ 12.23 hrs, Volume= 0.149 af Outflow = 0.77 cfs @ 12.44 hrs, Volume= 0.147 af, Atten= 46%, Lag= 12.4 min Primary = 0.77 cfs @ 12.44 hrs, Volume= 0.147 af Routed to Pond 18P : SD-22 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 601.23' @ 12.44 hrs Surf.Area= 4,734 sf Storage= 1,818 cf Plug-Flow detention time= 63.7 min calculated for 0.147 af (99% of inflow) Center-of-Mass det. time= 55.8 min ( 845.9 - 790.1 ) Volume #1 #2 Invert 599.50' 599.00' Avail.Storage 1,303 cf 296 cf #3 598.00' 627 cf #4 598.00' 12 cf 2,237 cf Storage Description Filter Media Layer (Prismatic)Listed below (Recalc) Sand Layer (Prismatic)Listed below (Recalc) 789 cf Overall x 37.5% Voids Gravel Layer (Prismatic)Listed below (Recalc) 1,578 cf Overall - 12 cf Embedded = 1,566 cf x 40.0% Voids 4.0" Round 4" Underdrain Pipe Inside #3 L= 133.4' S= 0.0001 '/' Total Available Storage Elevation (feet) 599.50 601.00 601.50 Surf.Area Voids (sq-ft) (%) 1,578 0.0 1,578 21.7 1,578 100.0 Elevation (feet) 599.00 599.50 Surf.Area (sq-ft) 1,578 1,578 Inc.Store (cubic-feet) 0 789 Cum.Store (cubic-feet) 0 789 Elevation (feet) 598.00 599.00 Surf.Area (sq-ft) 1,578 1,578 Inc.Store (cubic-feet) 0 1,578 Cum.Store (cubic-feet) 0 1,578 Device #1 Routing Primary Invert 590.35' #2 Device 1 598.00' #3 Device 1 601.10' #4 Device 1 601.40' Inc.Store (cubic-feet) 0 514 789 Cum.Store (cubic-feet) 0 514 1,303 Outlet Devices 12.0" Vert. SD-22 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 36.0" 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 (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 43 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.77 cfs @ 12.44 hrs HW=601.23' TW=588.99' (Dynamic Tailwater) 1=SD-22 Outlet (Elevation F) (Passes 0.77 cfs of 12.19 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.29 cfs @ 8.52 fps) 3=Water Quantity (Elevation H) (Orifice Controls 0.48 cfs @ 1.18 fps) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 2P: BR-02 Hydrograph Inflow Primary 1.42 cfs Inflow Area=0.350 ac Peak Elev=601.23' Storage=1,818 cf Flow (cfs) 1 0.77 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