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 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 0.00 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 0.07 0.08 0.12 0.20 0.57 0.62 0.24 0.15 0.11 0.09 0.08 0.06 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 0.02 Storage Elevation (cubic-feet) (feet) 0 598.00 0 598.00 1 598.00 4 598.01 11 598.02 19 598.03 27 598.04 33 598.05 38 598.06 42 598.06 46 598.07 50 598.08 54 598.08 59 598.09 66 598.10 73 598.11 82 598.13 90 598.14 99 598.15 111 598.17 132 598.20 162 598.25 214 598.33 336 598.52 683 599.08 1,805 601.23 1,634 601.12 1,467 601.01 1,220 600.34 997 599.68 806 599.28 632 598.99 485 598.76 369 598.57 278 598.43 211 598.32 164 598.25 131 598.20 113 598.17 104 598.16 100 598.15 97 598.15 94 598.15 92 598.14 90 598.14 88 598.13 85 598.13 83 598.13 81 598.12 Primary (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 0.03 0.04 0.04 0.05 0.06 0.08 0.11 0.16 0.72 0.31 0.28 0.25 0.21 0.18 0.15 0.13 0.11 0.09 0.08 0.06 0.05 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 Printed 5/13/2024 Page 44

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 45 Summary for Pond 3P: BR-03 Inflow Area = 0.388 ac, 28.87% Impervious, Inflow Depth > 5.03" for 25-Year event Inflow = 1.30 cfs @ 12.33 hrs, Volume= 0.163 af Outflow = 0.31 cfs @ 13.06 hrs, Volume= 0.160 af, Atten= 76%, Lag= 43.7 min Primary = 0.31 cfs @ 13.06 hrs, Volume= 0.160 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= 597.59' @ 13.06 hrs Surf.Area= 6,525 sf Storage= 2,630 cf Plug-Flow detention time= 105.4 min calculated for 0.160 af (98% of inflow) Center-of-Mass det. time= 94.6 min ( 893.0 - 798.4 ) 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 (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 46 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.31 cfs @ 13.06 hrs HW=597.59' TW=587.28' (Dynamic Tailwater) 1=SD-23 Outlet (Elevation F) (Passes 0.31 cfs of 17.50 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.31 cfs @ 8.98 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 3P: BR-03 Hydrograph Inflow Primary 1.30 cfs Inflow Area=0.388 ac Peak Elev=597.59' Storage=2,630 cf Flow (cfs) 1 0.31 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 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 0.00 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 0.07 0.08 0.12 0.20 0.47 0.97 0.33 0.19 0.13 0.11 0.09 0.07 0.07 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 Storage Elevation (cubic-feet) (feet) 0 594.00 0 594.00 0 594.00 3 594.00 10 594.01 18 594.02 28 594.03 37 594.04 44 594.05 51 594.06 58 594.06 65 594.07 71 594.08 79 594.09 88 594.10 99 594.11 111 594.12 125 594.13 138 594.15 154 594.17 180 594.19 219 594.23 279 594.30 406 594.44 724 594.81 2,156 596.89 2,627 597.58 2,524 597.54 2,267 597.13 1,991 596.54 1,733 596.00 1,488 595.70 1,259 595.42 1,052 595.18 868 594.97 706 594.79 566 594.63 447 594.49 352 594.38 281 594.30 230 594.25 194 594.21 170 594.18 155 594.17 145 594.16 138 594.15 133 594.14 129 594.14 125 594.14 Primary (cfs) 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 0.02 0.03 0.03 0.04 0.05 0.06 0.07 0.10 0.14 0.27 0.31 0.30 0.29 0.26 0.23 0.21 0.19 0.17 0.15 0.14 0.12 0.10 0.09 0.07 0.06 0.05 0.05 0.04 0.04 0.03 0.03 0.03 0.03 Printed 5/13/2024 Page 47

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 48 Summary for Pond 5P: BR-05 Inflow Area = 0.241 ac, 27.64% Impervious, Inflow Depth > 5.03" for 25-Year event Inflow = 1.30 cfs @ 12.13 hrs, Volume= 0.101 af Outflow = 0.25 cfs @ 12.56 hrs, Volume= 0.100 af, Atten= 80%, Lag= 25.2 min Primary = 0.25 cfs @ 12.56 hrs, Volume= 0.100 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= 596.30' @ 12.56 hrs Surf.Area= 4,725 sf Storage= 1,417 cf Plug-Flow detention time= 68.8 min calculated for 0.100 af (99% of inflow) Center-of-Mass det. time= 59.6 min ( 845.5 - 785.9 ) 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 (25-Year) NOAA 24-hr D 25-Year Rainfall=6.44", P2=3.42" West Orange HydroCAD_Post Printed 5/13/2024 Page 49 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.25 cfs @ 12.56 hrs HW=596.30' TW=581.07' (Dynamic Tailwater) 1=SD-25 Outlet (Elevation F) (Passes 0.25 cfs of 28.11 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.25 cfs @ 7.45 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 5P: BR-05 Hydrograph Inflow Primary 1.30 cfs Inflow Area=0.241 ac Peak Elev=596.30' Storage=1,417 cf Flow (cfs) 1 0.25 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 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 0.00 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 0.04 0.05 0.06 0.09 0.16 0.68 0.27 0.14 0.09 0.07 0.06 0.05 0.04 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 Storage Elevation (cubic-feet) (feet) 0 593.80 0 593.80 1 593.80 4 593.81 8 593.81 14 593.82 19 593.83 23 593.84 27 593.84 31 593.85 34 593.85 38 593.86 41 593.86 46 593.87 51 593.88 57 593.89 64 593.90 71 593.91 78 593.92 87 593.94 102 593.96 120 593.99 157 594.04 248 594.18 591 594.73 1,415 596.29 1,312 595.99 1,117 595.58 899 595.22 702 594.90 527 594.63 380 594.39 270 594.22 192 594.10 142 594.02 112 593.97 95 593.95 87 593.93 82 593.93 80 593.92 78 593.92 76 593.92 74 593.92 73 593.91 71 593.91 70 593.91 68 593.91 66 593.90 65 593.90 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 0.01 0.02 0.02 0.02 0.03 0.04 0.05 0.06 0.09 0.15 0.25 0.24 0.21 0.19 0.16 0.14 0.11 0.09 0.07 0.06 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 Printed 5/13/2024 Page 50

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 51 Summary for Pond 6P: BR-04 Inflow Area = 0.317 ac, 38.48% Impervious, Inflow Depth > 5.14" for 25-Year event Inflow = 1.79 cfs @ 12.12 hrs, Volume= 0.136 af Outflow = 0.23 cfs @ 12.78 hrs, Volume= 0.132 af, Atten= 87%, Lag= 39.1 min Primary = 0.23 cfs @ 12.78 hrs, Volume= 0.132 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= 596.75' @ 12.78 hrs Surf.Area= 8,682 sf Storage= 2,324 cf Plug-Flow detention time= 125.0 min calculated for 0.132 af (98% of inflow) Center-of-Mass det. time= 109.8 min ( 888.7 - 778.9 ) 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

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 52 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Primary OutFlow Max=0.23 cfs @ 12.78 hrs HW=596.75' TW=585.44' (Dynamic Tailwater) 1=SD-24 Outlet (Elevation F) (Passes 0.23 cfs of 18.30 cfs potential flow) 2=Water Quatity (Elevation G) (Orifice Controls 0.23 cfs @ 6.71 fps) 3=Water Quantity (Elevation H) ( Controls 0.00 cfs) 4=Overflow Grate (Elevation I) ( Controls 0.00 cfs) Pond 6P: BR-04 Hydrograph Inflow Primary 1.79 cfs Flow (cfs) Inflow Area=0.317 ac Peak Elev=596.75' Storage=2,324 cf 1 0.23 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 6P: BR-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 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.03 0.03 0.03 0.04 0.05 0.06 0.08 0.13 0.22 0.98 0.35 0.19 0.12 0.09 0.08 0.06 0.06 0.05 0.05 0.04 0.04 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.02 0.02 0.02 Storage Elevation (cubic-feet) (feet) 0 594.70 0 594.70 1 594.70 7 594.71 16 594.71 26 594.72 38 594.73 49 594.74 59 594.75 68 594.76 76 594.76 84 594.77 92 594.78 101 594.78 111 594.79 124 594.80 137 594.82 151 594.83 166 594.84 186 594.86 217 594.88 256 594.91 330 594.97 492 595.11 1,052 595.60 2,275 596.68 2,307 596.72 2,174 596.59 1,976 596.41 1,770 596.22 1,559 596.03 1,351 595.86 1,160 595.69 985 595.54 828 595.40 687 595.28 563 595.17 457 595.08 372 595.01 305 594.95 255 594.91 219 594.88 194 594.86 178 594.85 167 594.84 159 594.83 153 594.83 148 594.82 143 594.82 Primary (cfs) 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 0.02 0.03 0.03 0.04 0.05 0.05 0.07 0.09 0.15 0.22 0.23 0.22 0.21 0.20 0.18 0.17 0.15 0.14 0.13 0.11 0.10 0.09 0.07 0.06 0.05 0.05 0.04 0.03 0.03 0.03 0.03 0.03 0.02 Printed 5/13/2024 Page 53