J_2024 05 09_West Orange Stormwater Management Plan

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", 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 22 Summary for Pond 2P: BR-02 Inflow Area = 0.350 ac, 31.71% Impervious, Inflow Depth = 0.52" for WQ event Inflow = 0.37 cfs @ 1.23 hrs, Volume= 0.015 af Outflow = 0.11 cfs @ 1.60 hrs, Volume= 0.015 af, Atten= 70%, Lag= 22.0 min Primary = 0.11 cfs @ 1.60 hrs, Volume= 0.015 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= 598.55' @ 1.60 hrs Surf.Area= 1,578 sf Storage= 357 cf Plug-Flow detention time= 56.9 min calculated for 0.015 af (100% of inflow) Center-of-Mass det. time= 57.2 min ( 139.9 - 82.7 ) 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 (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 23 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.11 cfs @ 1.60 hrs HW=598.55' TW=588.68' (Dynamic Tailwater) 1=SD-22 Outlet (Elevation F) (Passes 0.11 cfs of 10.50 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.11 cfs @ 3.23 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 2P: BR-02 Flow (cfs) Hydrograph 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Primary 0.37 cfs Inflow Area=0.350 ac Peak Elev=598.55' Storage=357 cf 0.11 cfs 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) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 2P: BR-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 0.07 0.15 0.04 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 0.00 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 0.00 0.00 0.00 0.00 Storage Elevation (cubic-feet) (feet) 0 598.00 0 598.00 35 598.05 352 598.55 313 598.48 184 598.28 93 598.14 56 598.09 38 598.06 29 598.05 23 598.04 19 598.03 17 598.03 14 598.02 13 598.02 11 598.02 10 598.02 10 598.01 9 598.01 8 598.01 8 598.01 7 598.01 7 598.01 6 598.01 6 598.01 6 598.01 5 598.01 5 598.01 5 598.01 5 598.01 4 598.01 4 598.01 4 598.01 4 598.01 4 598.01 4 598.01 4 598.01 3 598.01 3 598.01 3 598.01 3 598.00 3 598.00 3 598.00 3 598.00 3 598.00 3 598.00 3 598.00 3 598.00 3 598.00 Primary (cfs) 0.00 0.00 0.01 0.11 0.10 0.07 0.03 0.01 0.01 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 0.00 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 Printed 5/13/2024 Page 24

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", 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 25 Summary for Pond 3P: BR-03 Inflow Area = 0.388 ac, 28.87% Impervious, Inflow Depth = 0.49" for WQ event Inflow = 0.31 cfs @ 1.33 hrs, Volume= 0.016 af Outflow = 0.10 cfs @ 1.87 hrs, Volume= 0.016 af, Atten= 69%, Lag= 32.4 min Primary = 0.10 cfs @ 1.87 hrs, Volume= 0.016 af Routed to Pond 17P : SD-23 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 594.44' @ 1.87 hrs Surf.Area= 2,175 sf Storage= 405 cf Plug-Flow detention time= 78.2 min calculated for 0.016 af (99% of inflow) Center-of-Mass det. time= 78.2 min ( 168.5 - 90.3 ) Volume #1 #2 Invert 596.00' 595.50' Avail.Storage 8,864 cf 408 cf #3 594.00' 1,305 cf #4 594.00' 22 cf 10,599 cf Storage Description Filter Media Layer (Prismatic)Listed below (Recalc) Sand Layer (Prismatic)Listed below (Recalc) 1,088 cf Overall x 37.5% Voids Gravel Layer (Prismatic)Listed below (Recalc) 3,263 cf Overall x 40.0% Voids 4.0" Round Pipe Storage L= 254.1' S= 0.0001 '/' Total Available Storage Elevation (feet) 596.00 597.50 601.25 Surf.Area Voids (sq-ft) (%) 2,175 0.0 2,175 21.7 2,175 100.0 Elevation (feet) 595.50 596.00 Surf.Area (sq-ft) 2,175 2,175 Inc.Store (cubic-feet) 0 1,088 Cum.Store (cubic-feet) 0 1,088 Elevation (feet) 594.00 595.50 Surf.Area (sq-ft) 2,175 2,175 Inc.Store (cubic-feet) 0 3,263 Cum.Store (cubic-feet) 0 3,263 Device #1 Routing Primary Invert 588.19' #2 Device 1 594.00' #3 Device 1 598.50' #4 Device 1 601.15' Inc.Store (cubic-feet) 0 708 8,156 Cum.Store (cubic-feet) 0 708 8,864 Outlet Devices 15.0" Vert. SD-23 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 2.5" 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) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 26 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.10 cfs @ 1.87 hrs HW=594.44' TW=587.06' (Dynamic Tailwater) 1=SD-23 Outlet (Elevation F) (Passes 0.10 cfs of 14.01 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.10 cfs @ 2.79 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 3P: BR-03 Hydrograph 0.34 Inflow Primary 0.31 cfs Inflow Area=0.388 ac Peak Elev=594.44' Storage=405 cf 0.32 0.3 0.28 0.26 0.24 Flow (cfs) 0.22 0.2 0.18 0.16 0.14 0.12 0.10 cfs 0.1 0.08 0.06 0.04 0.02 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) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 3P: BR-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 0.04 0.23 0.07 0.01 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 0.00 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 0.00 0.00 0.00 Storage Elevation (cubic-feet) (feet) 0 594.00 0 594.00 22 594.02 333 594.36 400 594.43 302 594.32 190 594.20 120 594.13 83 594.09 63 594.07 50 594.06 41 594.05 35 594.04 30 594.03 27 594.03 24 594.03 21 594.02 19 594.02 18 594.02 16 594.02 15 594.02 14 594.02 13 594.02 13 594.01 12 594.01 11 594.01 11 594.01 10 594.01 10 594.01 9 594.01 9 594.01 8 594.01 8 594.01 8 594.01 8 594.01 7 594.01 7 594.01 7 594.01 7 594.01 6 594.01 6 594.01 6 594.01 6 594.01 6 594.01 6 594.01 5 594.01 5 594.01 5 594.01 5 594.01 Primary (cfs) 0.00 0.00 0.00 0.08 0.09 0.08 0.05 0.03 0.01 0.01 0.01 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 0.00 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 Printed 5/13/2024 Page 27

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", 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 28 Summary for Pond 5P: BR-05 Inflow Area = 0.241 ac, 27.64% Impervious, Inflow Depth = 0.48" for WQ event Inflow = 0.33 cfs @ 1.13 hrs, Volume= 0.010 af Outflow = 0.08 cfs @ 1.35 hrs, Volume= 0.010 af, Atten= 75%, Lag= 13.4 min Primary = 0.08 cfs @ 1.35 hrs, Volume= 0.010 af Routed to Pond 13P : SD-25, SD-26 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 594.16' @ 1.35 hrs Surf.Area= 1,575 sf Storage= 233 cf Plug-Flow detention time= 58.5 min calculated for 0.010 af (99% of inflow) Center-of-Mass det. time= 58.2 min ( 132.9 - 74.7 ) Volume #1 #2 Invert 595.80' 595.30' Avail.Storage 4,371 cf 295 cf #3 593.80' 941 cf #4 593.80' 11 cf 5,618 cf Storage Description Filter Media Layer (Prismatic)Listed below (Recalc) Sand Layer (Prismatic)Listed below (Recalc) 788 cf Overall x 37.5% Voids Gravel Layer (Prismatic)Listed below (Recalc) 2,363 cf Overall - 11 cf Embedded = 2,352 cf x 40.0% Voids 4.0" Round 4" Underdrain Pipe Inside #3 L= 125.2' S= 0.0001 '/' Total Available Storage Elevation (feet) 595.80 597.30 599.75 Surf.Area Voids (sq-ft) (%) 1,575 0.0 1,575 21.7 1,575 100.0 Elevation (feet) 595.30 595.80 Surf.Area (sq-ft) 1,575 1,575 Inc.Store (cubic-feet) 0 788 Cum.Store (cubic-feet) 0 788 Elevation (feet) 593.80 595.30 Surf.Area (sq-ft) 1,575 1,575 Inc.Store (cubic-feet) 0 2,363 Cum.Store (cubic-feet) 0 2,363 Device #1 Routing Primary Invert 584.63' #2 Device 1 593.80' #3 Device 1 598.20' #4 Device 1 599.65' Inc.Store (cubic-feet) 0 513 3,859 Cum.Store (cubic-feet) 0 513 4,371 Outlet Devices 18.0" Vert. SD-25 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) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 29 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.08 cfs @ 1.35 hrs HW=594.16' TW=580.72' (Dynamic Tailwater) 1=SD-25 Outlet (Elevation F) (Passes 0.08 cfs of 25.21 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.08 cfs @ 2.43 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 5P: BR-05 Hydrograph 0.36 Inflow Primary 0.33 cfs Inflow Area=0.241 ac Peak Elev=594.16' Storage=233 cf 0.34 0.32 0.3 0.28 0.26 Flow (cfs) 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 cfs 0.08 0.06 0.04 0.02 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) NJ DEP 2-hr WQ Rainfall=1.25", P2=3.42" West Orange HydroCAD_Post Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Pond 5P: BR-05 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 0.13 0.06 0.02 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 0.00 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 0.00 0.00 0.00 0.00 Storage Elevation (cubic-feet) (feet) 0 593.80 1 593.80 46 593.87 224 594.15 164 594.05 86 593.93 52 593.88 37 593.86 28 593.84 23 593.84 19 593.83 16 593.83 14 593.82 13 593.82 11 593.82 10 593.82 9 593.81 9 593.81 8 593.81 7 593.81 7 593.81 7 593.81 6 593.81 6 593.81 6 593.81 5 593.81 5 593.81 5 593.81 5 593.81 4 593.81 4 593.81 4 593.81 4 593.81 4 593.81 4 593.81 4 593.81 3 593.81 3 593.81 3 593.81 3 593.80 3 593.80 3 593.80 3 593.80 3 593.80 3 593.80 3 593.80 3 593.80 3 593.80 2 593.80 Primary (cfs) 0.00 0.00 0.01 0.08 0.06 0.03 0.01 0.01 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 0.00 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 0.00 Printed 5/13/2024 Page 30

Post-Developed (O-1B) NJ DEP 2-hr WQ Rainfall=1.25", 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 31 Summary for Pond 6P: BR-04 Inflow Area = 0.317 ac, 38.48% Impervious, Inflow Depth = 0.55" for WQ event Inflow = 0.50 cfs @ 1.11 hrs, Volume= 0.015 af Outflow = 0.08 cfs @ 1.54 hrs, Volume= 0.014 af, Atten= 84%, Lag= 25.9 min Primary = 0.08 cfs @ 1.54 hrs, Volume= 0.014 af Routed to Pond 14P : SD-24 Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.0100 hrs Peak Elev= 595.04' @ 1.54 hrs Surf.Area= 2,894 sf Storage= 410 cf Plug-Flow detention time= 101.6 min calculated for 0.014 af (99% of inflow) Center-of-Mass det. time= 100.9 min ( 173.5 - 72.6 ) Volume #1 #2 Invert 596.70' 596.20' Avail.Storage 5,428 cf 543 cf #3 594.70' 1,727 cf #4 594.70' 24 cf 7,721 cf Storage Description Filter Media Layer (Prismatic)Listed below (Recalc) Sand Layer (Prismatic)Listed below (Recalc) 1,447 cf Overall x 37.5% Voids Gravel Layer (Prismatic)Listed below (Recalc) 4,341 cf Overall - 24 cf Embedded = 4,317 cf x 40.0% Voids 4.0" Round 4" Underdrain Pipe Inside #3 L= 271.7' S= 0.0001 '/' Total Available Storage Elevation (feet) 596.70 598.20 599.75 Surf.Area Voids (sq-ft) (%) 2,894 0.0 2,894 21.7 2,894 100.0 Elevation (feet) 596.20 596.70 Surf.Area (sq-ft) 2,894 2,894 Inc.Store (cubic-feet) 0 1,447 Cum.Store (cubic-feet) 0 1,447 Elevation (feet) 594.70 596.20 Surf.Area (sq-ft) 2,894 2,894 Inc.Store (cubic-feet) 0 4,341 Cum.Store (cubic-feet) 0 4,341 Device #1 Routing Primary Invert 586.53' #2 Device 1 594.70' #3 Device 1 598.30' #4 Device 1 599.65' Inc.Store (cubic-feet) 0 942 4,486 Cum.Store (cubic-feet) 0 942 5,428 Outlet Devices 15.0" Vert. SD-24 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 2.5" 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