1240815StormWaterManagementReport

1=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.65 cfs @ 12.11 hrs HW=412.72' (Free Discharge) 2=Culvert (Passes 0.65 cfs of 1.42 cfs potential flow) 3=Orifice (Orifice Controls 0.65 cfs @ 3.31 fps) 4=Grate ( Controls 0.00 cfs) 31

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 10-Year-2020 Rainfall=5.38", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Pond 5: Pipes Hydrograph 1 0.90 cfs Inflow Outflow Discarded Inflow Area=0.359 ac Primary 0.68 cfs 0.66 cfs Peak Elev=412.73' Storage=267 cf Flow (cfs) 0.03 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) 32

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 10-Year-2020 Rainfall=5.38", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 6: Bypass Runoff = 0.04 cfs @ 12.13 hrs, Volume= 0.003 af, Depth= 2.67" Routed to Link 7 : Proposed Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-72.00 hrs, dt= 0.05 NOAA 24-hr D 10-Year-2020 Rainfall=5.38", P2=3.47" Area (sf) CN Description 605 74 >75% Grass cover, Good, HSG C 605 74 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.9 100 0.0650 0.28 Sheet Flow, 1 Grass: Short n= 0.150 P2= 3.47" 0.1 28 0.0900 4.50 Shallow Concentrated Flow, 2 Grassed Waterway Kv= 15.0 fps 6.0 128 Total Subcatchment 6: Bypass Hydrograph 0.046 0.044 0.04 cfs Runoff 0.042 0.04 NOAA 24-hr D 0.038 0.036 10-Year-2020 Rainfall=5.38" 0.034 0.032 P2=3.47" 0.03 0.028 Runoff Area=605 sf

P2=3.47" 0.03 0.028 Runoff Area=605 sf Runoff Volume=0.003 af Flow (cfs) 0.026 0.024 0.022 Runoff Depth=2.67" 0.02 0.018 Flow Length=128' 0.016 0.014 Tc=6.0 min 0.012 CN=74/0 0.01 0.008 0.006 0.004 0.002 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) 33

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 10-Year-2020 Rainfall=5.38", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Summary for Link 7: Proposed Inflow Area = 0.373 ac, 69.07% Impervious, Inflow Depth = 1.18" for 10-Year-2020 event Inflow = 0.70 cfs @ 12.11 hrs, Volume= 0.037 af Primary = 0.70 cfs @ 12.11 hrs, Volume= 0.037 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Link 7: Proposed Hydrograph 0.75 0.70 cfs Inflow 0.7 Primary 0.65 Inflow Area=0.373 ac 0.6 0.55 0.5 0.45 Flow (cfs) 0.4 0.35 0.3 0.25 0.2 0.15 0.1 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) 34

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1: Exisiting Runoff Area=16,242 sf 68.64% Impervious Runoff Depth=8.02" Flow Length=141' Tc=5.9 min CN=74/98 Runoff=2.97 cfs 0.249 af Subcatchment 2: Parking Lot Runoff Area=7,305 sf 88.61% Impervious Runoff Depth=8.60" Flow Length=92' Tc=0.9 min CN=74/98 Runoff=1.58 cfs 0.120 af Pond 3: Pervious Pavers Peak Elev=415.25' Storage=1,132 cf Inflow=1.58 cfs 0.120 af Discarded=0.11 cfs 0.094 af Primary=0.64 cfs 0.027 af Outflow=0.74 cfs 0.120 af Subcatchment 4: Proposed Runoff Area=8,332 sf 56.96% Impervious Runoff Depth=7.67" Flow Length=92' Tc=0.9 min CN=74/98 Runoff=1.68 cfs 0.122 af Pond 5: Pipes Peak Elev=414.08' Storage=640 cf Inflow=2.19 cfs 0.149 af Discarded=0.03 cfs 0.045 af Primary=1.80 cfs 0.104 af Outflow=1.83 cfs 0.149 af Subcatchment 6: Bypass Runoff Area=605 sf 0.00% Impervious Runoff Depth=5.99" Flow Length=128' Tc=6.0 min CN=74/0 Runoff=0.09 cfs 0.007 af Link 7: Proposed Inflow=1.89 cfs 0.111 af Primary=1.89 cfs 0.111 af 35

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Exisiting Runoff = 2.97 cfs @ 12.13 hrs, Volume= 0.249 af, Depth= 8.02" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-72.00 hrs, dt= 0.05 NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description * 2,676 98 Buildings * 794 98 Walks/Steps & Patio 7,679 98 Paved parking, HSG C 5,093 74 >75% Grass cover, Good, HSG C 16,242 90 Weighted Average 5,093 74 31.36% Pervious Area 11,149 98 68.64% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.1 66 0.0680 0.27 Sheet Flow, 1 Grass: Short n= 0.150 P2= 3.47" 1.4 21 0.0950 0.24 Sheet Flow, 2 Grass: Short n= 0.150 P2= 3.47" 0.2 13 0.0390 1.24 Sheet Flow, 3 Smooth surfaces n= 0.011 P2= 3.47" 0.1 13 0.0390 4.01 Shallow Concentrated Flow, 4 Paved Kv= 20.3 fps 0.1 28 0.0360 3.85 Shallow Concentrated Flow, 5 Paved Kv= 20.3 fps 5.9 141 Total 36

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Subcatchment 1: Exisiting Hydrograph 2.97 cfs Runoff 3 NOAA 24-hr D 100-Year-2020 Rainfall=9.18" P2=3.47" 2 Runoff Area=16,242 sf Runoff Volume=0.249 af Flow (cfs) Runoff Depth=8.02" Flow Length=141' 1 Tc=5.9 min CN=74/98 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) 37

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 2: Parking Lot Runoff = 1.58 cfs @ 12.06 hrs, Volume= 0.120 af, Depth= 8.60" Routed to Pond 3 : Pervious Pavers Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-72.00 hrs, dt= 0.05 NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Area (sf) CN Description 6,473 98 Paved parking, HSG C 832 74 >75% Grass cover, Good, HSG C 7,305 95 Weighted Average 832 74 11.39% Pervious Area 6,473 98 88.61% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.1 8 0.0650 1.38 Sheet Flow, 1 Smooth surfaces n= 0.011 P2= 3.47" 0.1 15 0.6700 3.99 Sheet Flow, 2 Smooth surfaces n= 0.011 P2= 3.47" 0.5 59 0.0500 1.86 Sheet Flow, 3 Smooth surfaces n= 0.011 P2= 3.47" 0.2 10 0.0250 0.99 Sheet Flow, 4 Smooth surfaces n= 0.011 P2= 3.47" 0.9 92 Total 38

PLEASANT VALLEY WAY 1240815-pipes NOAA 24-hr D 100-Year-2020 Rainfall=9.18", P2=3.47" Prepared by Casey & Keller, Inc Printed 9/12/2025 HydroCAD® 10.20-7a s/n 03272 © 2025 HydroCAD Software Solutions LLC Subcatchment 2: Parking Lot Hydrograph 1.58 cfs Runoff NOAA 24-hr D 100-Year-2020 Rainfall=9.18" P2=3.47" Runoff Area=7,305 sf 1 Runoff Volume=0.120 af Flow (cfs) Runoff Depth=8.60" Flow Length=92' Tc=0.9 min CN=74/98 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) 39