Drainage Report

Basin 2-1 Proposed Basin 2-1 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 Pond 41P: Pond 2-1 Inflow Area = 0.599 ac, Inflow Depth = 1.36" for 2-Year event Inflow = 0.79 cfs @ 12.18 hrs, Volume= 0.068 af Outflow = 0.04 cfs @ 16.51 hrs, Volume= 0.024 af, Atten= 95%, Lag= 259.5 min Primary = 0.04 cfs @ 16.51 hrs, Volume= 0.024 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 547.05' @ 16.51 hrs Surf.Area= 2,020 sf Storage= 2,121 cf Plug-Flow detention time= 503.1 min calculated for 0.024 af (35% of inflow) Center-of-Mass det. time= 355.4 min ( 1,217.1 - 861.6 ) Volume Invert Avail.Storage Storage Description #1 546.00' 4,040 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 546.00 2,020 0 0 548.00 2,020 4,040 4,040 Device Routing Invert Outlet Devices #1 Primary 546.95' 8.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 547.20' 10.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.04 cfs @ 16.51 hrs HW=547.05' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.04 cfs @ 1.08 fps) 2=Orifice/Grate ( Controls 0.00 cfs)

Basin 2-1 Proposed Basin 2-1 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 Pond 41P: Pond 2-1 Hydrograph Inflow 0.79 cfs Primary 0.85 0.8 Inflow Area=0.599 ac 0.75 0.7 Peak Elev=547.05' 0.65 0.6 Storage=2,121 cf 0.55 0.5 Flow (cfs) 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.04 cfs 0.05 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 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 13 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 33S: All basin's 2 undetained Runoff Area=34,308 sf Runoff Depth=2.54" Flow Length=36' Slope=0.1600 '/' Tc=10.0 min CN=74/0 Runoff=1.98 cfs 0.167 af Subcatchment 34S: Pre-dev basin 2 All Runoff Area=465,453 sf Runoff Depth=2.20" Flow Length=1,360' Tc=31.9 min CN=70/0 Runoff=13.90 cfs 1.960 af Subcatchment 40S: Basin 2-1 Runoff Area=26,074 sf Runoff Depth=2.76" Flow Length=190' Tc=10.0 min CN=76/98 Runoff=1.62 cfs 0.138 af Pond 41P: Pond 2-1 Peak Elev=547.31' Storage=2,643 cf Inflow=1.62 cfs 0.138 af Outflow=0.44 cfs 0.094 af Total Runoff Area = 12.072 ac Runoff Volume = 2.264 af Average Runoff Depth = 2.25"

Basin 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment 33S: All basin's 2 undetained Runoff = 1.98 cfs @ 12.18 hrs, Volume= 0.167 af, Depth= 2.54" 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 10-Year Rainfall=5.22" Area (sf) CN Description 34,308 74 >75% Grass cover, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.0 36 0.1600 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 4.0 36 Total, Increased to minimum Tc = 10.0 min Subcatchment 33S: All basin's 2 undetained Hydrograph Runoff 1.98 cfs 2 NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=34,308 sf Runoff Volume=0.167 af Flow (cfs) Runoff Depth=2.54" 1 Flow Length=36'

Runoff Depth=2.54" 1 Flow Length=36' Slope=0.1600 '/' Tc=10.0 min CN=74/0 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 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 15 Summary for Subcatchment 34S: Pre-dev basin 2 All Runoff = 13.90 cfs @ 12.46 hrs, Volume= 1.960 af, Depth= 2.20" 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 10-Year Rainfall=5.22" Area (sf) CN Description 465,453 70 Woods, Good, HSG C Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.4 100 0.0500 0.12 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.44" 17.6 1,260 0.0570 1.19 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 31.9 1,360 Total Subcatchment 34S: Pre-dev basin 2 All Hydrograph Runoff 15 13.90 cfs 14 13 NOAA 24-hr D 12 10-Year Rainfall=5.22" 11 Runoff Area=465,453 sf 10 Runoff Volume=1.960 af 9 Flow (cfs) 8 Runoff Depth=2.20"

Runoff Volume=1.960 af 9 Flow (cfs) 8 Runoff Depth=2.20" 7 Flow Length=1,360' 6 Tc=31.9 min 5 4 CN=70/0 3 2 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 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 16 Summary for Subcatchment 40S: Basin 2-1 Runoff = 1.62 cfs @ 12.18 hrs, Volume= 0.138 af, Depth= 2.76" Routed to Pond 41P : Pond 2-1 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 10-Year Rainfall=5.22" Area (sf) CN Description 23,447 74 >75% Grass cover, Good, HSG C 607 98 Roofs, HSG C 2,020 98 Water Surface, 0% imp, HSG C 26,074 76 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.1 100 0.0600 0.27 Sheet Flow, Grass: Short n= 0.150 P2= 3.44" 0.5 90 0.0340 2.77 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.6 190 Total, Increased to minimum Tc = 10.0 min Subcatchment 40S: Basin 2-1 Hydrograph Runoff 1.62 cfs NOAA 24-hr D 10-Year Rainfall=5.22" Runoff Area=26,074 sf

10-Year Rainfall=5.22" Runoff Area=26,074 sf Runoff Volume=0.138 af Flow (cfs) 1 Runoff Depth=2.76" Flow Length=190' Tc=10.0 min CN=76/98 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 2-1 Proposed Basin 2-1 R5 NOAA 24-hr D 10-Year Rainfall=5.22" Prepared by Anderson Consulting Services Printed 10/29/2023 HydroCAD® 10.20-3f s/n 06666 © 2023 HydroCAD Software Solutions LLC Page 17 Summary for Pond 41P: Pond 2-1 Inflow Area = 0.599 ac, Inflow Depth = 2.76" for 10-Year event Inflow = 1.62 cfs @ 12.18 hrs, Volume= 0.138 af Outflow = 0.44 cfs @ 12.57 hrs, Volume= 0.094 af, Atten= 73%, Lag= 23.4 min Primary = 0.44 cfs @ 12.57 hrs, Volume= 0.094 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 547.31' @ 12.57 hrs Surf.Area= 2,020 sf Storage= 2,643 cf Plug-Flow detention time= 239.7 min calculated for 0.094 af (68% of inflow) Center-of-Mass det. time= 132.1 min ( 972.5 - 840.4 ) Volume Invert Avail.Storage Storage Description #1 546.00' 4,040 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 546.00 2,020 0 0 548.00 2,020 4,040 4,040 Device Routing Invert Outlet Devices #1 Primary 546.95' 8.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #2 Primary 547.20' 10.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.44 cfs @ 12.57 hrs HW=547.31' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.39 cfs @ 2.04 fps) 2=Orifice/Grate (Orifice Controls 0.05 cfs @ 1.12 fps)