J_2024 05 09_West Orange Stormwater Management Plan

PRE-DEVELOPED: OUTFALL = O-2 21S 21P PO-DA 1 O-2 Subcat Reach Pond Link Routing Diagram for West Orange HydroCAD_Pre Prepared by Burns & McDonnell, Printed 5/13/2024 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC

Post-Developed (O-2) West Orange HydroCAD_Pre Table of Contents Prepared by Burns & McDonnell Printed 5/13/2024 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC TABLE OF CONTENTS Project Reports 1 Routing Diagram 2 Rainfall Events Listing 3 Area Listing (selected nodes) 4 Soil Listing (selected nodes) 5 Ground Covers (selected nodes) 2-Year_Current Event 6 Node Listing 7 Subcat 21S: PO-DA 1 10 Pond 21P: O-2 2-Year_Future Event 12 Node Listing 13 Subcat 21S: PO-DA 1 16 Pond 21P: O-2 10-Year_Current Event 18 Node Listing 19 Subcat 21S: PO-DA 1 22 Pond 21P: O-2 10-Year_Future Event 24 Node Listing 25 Subcat 21S: PO-DA 1 28 Pond 21P: O-2 100-Year_Current Event 30 Node Listing 31 Subcat 21S: PO-DA 1 34 Pond 21P: O-2 100-Year_Future Event 36 Node Listing 37 Subcat 21S: PO-DA 1 40 Pond 21P: O-2

Post-Developed (O-2) West Orange HydroCAD_Pre Printed 5/13/2024 Page 2 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing Event# 1 2 3 4 5 6 Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) 2-Year_Current 2-Year_Future 10-Year_Current 10-Year_Future 100-Year_Current 100-Year_Future NOAA 24-hr NOAA 24-hr NOAA 24-hr NOAA 24-hr NOAA 24-hr NOAA 24-hr D D D D D D Default Default Default Default Default Default 24.00 24.00 24.00 24.00 24.00 24.00 1 1 1 1 1 1 3.45 4.07 5.37 6.36 9.23 11.58 AMC 2 2 2 2 2 2 P2 (inches) 3.45 4.07 3.45 4.07 3.45 4.07

Post-Developed (O-2) West Orange HydroCAD_Pre Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 0.448 0.531 0.181 0.053 1.212 80 73 98 85 80 >75% Grass cover, Good, HSG D (21S) Brush, Good, HSG D (21S) Impervious, Pavement, HSG D (21S) Yard Stone/Gravel Pad, HSG D (21S) TOTAL AREA Printed 5/13/2024 Page 3

Post-Developed (O-2) West Orange HydroCAD_Pre Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Soil Listing (selected nodes) Area (acres) Soil Group 0.000 0.000 0.000 1.212 0.000 1.212 HSG A HSG B HSG C HSG D Other Subcatchment Numbers 21S TOTAL AREA Printed 5/13/2024 Page 4

Post-Developed (O-2) West Orange HydroCAD_Pre Printed 5/13/2024 Page 5 Prepared by Burns & McDonnell HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Ground Covers (selected nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.448 0.531 0.181 0.053 1.212 0.000 0.000 0.000 0.000 0.000 0.448 0.531 0.181 0.053 1.212 >75% Grass cover, Good Brush, Good Impervious, Pavement Yard Stone/Gravel Pad TOTAL AREA 21S 21S 21S 21S

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 6 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.0100 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 21S: PO-DA 1 Pond 21P: O-2 Runoff Area=52,807 sf 14.94% Impervious Runoff Depth>1.66" Flow Length=341' Tc=3.7 min CN=WQ Runoff=2.45 cfs 0.167 af Inflow=2.45 cfs 0.167 af Primary=2.45 cfs 0.167 af Total Runoff Area = 1.212 ac Runoff Volume = 0.167 af Average Runoff Depth = 1.66" 85.06% Pervious = 1.031 ac 14.94% Impervious = 0.181 ac

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 7 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment 21S: PO-DA 1 Runoff = 2.45 cfs @ 12.11 hrs, Volume= Routed to Pond 21P : O-2 0.167 af, Depth> 1.66" 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 2-Year_Current Rainfall=3.45", P2=3.45" * Area (sf) 7,888 19,498 2,304 23,117 52,807 44,919 7,888 CN 98 80 85 73 Description Impervious, Pavement, HSG D >75% Grass cover, Good, HSG D Yard Stone/Gravel Pad, HSG D Brush, Good, HSG D Weighted Average 85.06% Pervious Area 14.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 23 0.0352 1.33 Sheet Flow, Sheet Flow Smooth surfaces n= 0.011 P2= 3.45" 0.2 31 0.2437 2.47 Shallow Concentrated Flow, Shallow Concentrated Flow Woodland Kv= 5.0 fps 3.2 287 0.0462 1.50 Shallow Concentrated Flow, Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 3.7 341 Total

Post-Developed (O-2) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 8 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Subcatchment 21S: PO-DA 1 Hydrograph Runoff 2.45 cfs NOAA 24-hr D 2-Year_Current Rainfall=3.45" P2=3.45" Runoff Area=52,807 sf Runoff Volume=0.167 af Runoff Depth>1.66" Flow Length=341' Tc=3.7 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-2) West Orange HydroCAD_Pre NOAA 24-hr D 2-Year_Current Rainfall=3.45", P2=3.45" Prepared by Burns & McDonnell Printed 5/13/2024 Page 9 HydroCAD® 10.20-4b s/n 08510 © 2023 HydroCAD Software Solutions LLC Hydrograph for Subcatchment 21S: PO-DA 1 Time Precip. Excess (hours) (inches) (inches) 0.00 0.00 0.00 0.50 0.02 0.00 1.00 0.04 0.00 1.50 0.06 0.00 2.00 0.08 0.00 2.50 0.11 0.00 3.00 0.13 0.00 3.50 0.16 0.00 4.00 0.18 0.00 4.50 0.21 0.00 5.00 0.24 0.00 5.50 0.26 0.00 6.00 0.29 0.00 6.50 0.33 0.00 7.00 0.36 0.00 7.50 0.40 0.00 8.00 0.45 0.00 8.50 0.50 0.00 9.00 0.55 0.00 9.50 0.61 0.00 10.00 0.68 0.01 10.50 0.77 0.03 11.00 0.90 0.05 11.50 1.09 0.11 12.00 1.65 0.36 12.50 2.36 0.79 13.00 2.55 0.93 13.50 2.68 1.01 14.00 2.77 1.08 14.50 2.84 1.13 15.00 2.90 1.18 15.50 2.95 1.22 16.00 3.00 1.25 16.50 3.05 1.28 17.00 3.09 1.32 17.50 3.12 1.34 18.00 3.16 1.37 18.50 3.19 1.39 19.00 3.21 1.41 19.50 3.24 1.43 20.00 3.27 1.46 20.50 3.29 1.48 21.00 3.32 1.49 21.50 3.34 1.51 22.00 3.37 1.53 22.50 3.39 1.55 23.00 3.41 1.57 23.50 3.43 1.58 24.00 3.45 1.60 Runoff (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 0.01 0.02 0.02 0.02 0.03 0.04 0.05 0.10 0.20 1.28 0.50 0.27 0.18 0.14 0.12 0.10 0.09 0.08 0.08 0.07 0.06 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