Drainage Report

Basin 2-6 without exfiltration Proposed basin 2-6 R5 Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 7 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Width Diam/Height Inside-Fill Node Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) Name 1 36S 0.00 0.00 1,622.0 0.0370 0.013 0.0 12.0 7.0

Basin 2-6 without exfiltration Proposed basin 2-6 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 8 Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 36S: Basin 2-6 Runoff Area=80,223 sf Runoff Depth=3.21" Flow Length=1,762' Tc=10.0 min CN=98/98 Runoff=5.13 cfs 0.492 af Subcatchment 42S: basin 2-6 pre-development Runoff Area=80,223 sf Runoff Depth=0.97" Flow Length=230' Tc=17.3 min CN=70/0 Runoff=1.32 cfs 0.149 af Pond 37P: Pond 2-6 Peak Elev=542.06' Storage=16,822 cf Inflow=5.13 cfs 0.492 af Outflow=0.18 cfs 0.167 af Total Runoff Area = 3.683 ac Runoff Volume = 0.641 af Average Runoff Depth = 2.09"

Basin 2-6 without exfiltration Proposed basin 2-6 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 36S: Basin 2-6 [47] Hint: Peak is 294% of capacity of segment #3 Runoff = 5.13 cfs @ 12.17 hrs, Volume= 0.492 af, Depth= 3.21" Routed to Pond 37P : Pond 2-6 Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 2-Year Rainfall=3.44" Area (sf) CN Description 69,441 98 Roofs, HSG C 10,782 98 Water Surface, 0% imp, HSG C 80,223 98 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 100 0.0100 1.08 Sheet Flow, Smooth surfaces n= 0.011 P2= 3.44" 0.3 40 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 4.8 1,622 0.0370 5.63 1.74 Pipe Channel, 12.0" Round w/ 7.0" inside fill Area= 0.3 sf Perim= 2.4' r= 0.13' n= 0.013 6.7 1,762 Total, Increased to minimum Tc = 10.0 min Subcatchment 36S: Basin 2-6 Hydrograph Runoff 5.13 cfs 5

Runoff 5.13 cfs 5 NOAA 24-hr D 2-Year Rainfall=3.44" 4 Runoff Area=80,223 sf Runoff Volume=0.492 af Flow (cfs) 3 Runoff Depth=3.21" Flow Length=1,762' 2 Tc=10.0 min CN=98/98 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

Basin 2-6 without exfiltration Proposed basin 2-6 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 10 Hydrograph for Subcatchment 36S: Basin 2-6 Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.11 0.02 0.02 0.03 5.00 0.24 0.09 0.09 0.08 7.50 0.40 0.23 0.23 0.13 10.00 0.68 0.49 0.49 0.27 12.50 2.35 2.12 2.12 1.37 15.00 2.89 2.66 2.66 0.22 17.50 3.11 2.88 2.88 0.13 20.00 3.26 3.03 3.03 0.10 22.50 3.38 3.15 3.15 0.08 25.00 3.44 3.21 3.21 0.00 27.50 3.44 3.21 3.21 0.00 30.00 3.44 3.21 3.21 0.00 32.50 3.44 3.21 3.21 0.00 35.00 3.44 3.21 3.21 0.00 37.50 3.44 3.21 3.21 0.00 40.00 3.44 3.21 3.21 0.00 42.50 3.44 3.21 3.21 0.00 45.00 3.44 3.21 3.21 0.00 47.50 3.44 3.21 3.21 0.00 50.00 3.44 3.21 3.21 0.00 52.50 3.44 3.21 3.21 0.00 55.00 3.44 3.21 3.21 0.00 57.50 3.44 3.21 3.21 0.00 60.00 3.44 3.21 3.21 0.00 62.50 3.44 3.21 3.21 0.00 65.00 3.44 3.21 3.21 0.00 67.50 3.44 3.21 3.21 0.00 70.00 3.44 3.21 3.21 0.00

Basin 2-6 without exfiltration Proposed basin 2-6 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 42S: basin 2-6 pre-development Runoff = 1.32 cfs @ 12.28 hrs, Volume= 0.149 af, Depth= 0.97" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.05 hrs NOAA 24-hr D 2-Year Rainfall=3.44" Area (sf) CN Description 80,223 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.7 100 0.0400 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 1.6 130 0.0700 1.32 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 17.3 230 Total Subcatchment 42S: basin 2-6 pre-development Hydrograph Runoff 1.32 cfs NOAA 24-hr D 2-Year Rainfall=3.44" 1 Runoff Area=80,223 sf Runoff Volume=0.149 af Flow (cfs) Runoff Depth=0.97"

e=0.149 af Flow (cfs) Runoff Depth=0.97" Flow Length=230' Tc=17.3 min CN=70/0 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

Basin 2-6 without exfiltration Proposed basin 2-6 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 12 Hydrograph for Subcatchment 42S: basin 2-6 pre-development Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 2.50 0.11 0.00 0.00 0.00 5.00 0.24 0.00 0.00 0.00 7.50 0.40 0.00 0.00 0.00 10.00 0.68 0.00 0.00 0.00 12.50 2.35 0.39 0.00 0.80 15.00 2.89 0.66 0.00 0.12 17.50 3.11 0.78 0.00 0.08 20.00 3.26 0.86 0.00 0.06 22.50 3.38 0.93 0.00 0.05 25.00 3.44 0.97 0.00 0.00 27.50 3.44 0.97 0.00 0.00 30.00 3.44 0.97 0.00 0.00 32.50 3.44 0.97 0.00 0.00 35.00 3.44 0.97 0.00 0.00 37.50 3.44 0.97 0.00 0.00 40.00 3.44 0.97 0.00 0.00 42.50 3.44 0.97 0.00 0.00 45.00 3.44 0.97 0.00 0.00 47.50 3.44 0.97 0.00 0.00 50.00 3.44 0.97 0.00 0.00 52.50 3.44 0.97 0.00 0.00 55.00 3.44 0.97 0.00 0.00 57.50 3.44 0.97 0.00 0.00 60.00 3.44 0.97 0.00 0.00 62.50 3.44 0.97 0.00 0.00 65.00 3.44 0.97 0.00 0.00 67.50 3.44 0.97 0.00 0.00 70.00 3.44 0.97 0.00 0.00

Basin 2-6 without exfiltration Proposed basin 2-6 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 13 Summary for Pond 37P: Pond 2-6 Inflow Area = 1.842 ac, Inflow Depth = 3.21" for 2-Year event Inflow = 5.13 cfs @ 12.17 hrs, Volume= 0.492 af Outflow = 0.18 cfs @ 15.80 hrs, Volume= 0.167 af, Atten= 96%, Lag= 217.8 min Primary = 0.18 cfs @ 15.80 hrs, Volume= 0.167 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 542.06' @ 15.80 hrs Surf.Area= 10,782 sf Storage= 16,822 cf Plug-Flow detention time= 738.3 min calculated for 0.167 af (34% of inflow) Center-of-Mass det. time= 551.4 min ( 1,311.9 - 760.4 ) Volume Invert Avail.Storage Storage Description #1 540.50' 37,737 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 540.50 10,782 0 0 544.00 10,782 37,737 37,737 Device Routing Invert Outlet Devices #1 Primary 541.80' 6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.18 cfs @ 15.80 hrs HW=542.06' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.18 cfs @ 1.74 fps)

Basin 2-6 without exfiltration Proposed basin 2-6 R5 NOAA 24-hr D 2-Year Rainfall=3.44" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 14 Pond 37P: Pond 2-6 Hydrograph Inflow 5.13 cfs Primary 5 Inflow Area=1.842 ac Peak Elev=542.06' 4 Storage=16,822 cf Flow (cfs) 3 2 1 0.18 cfs 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)