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HomeMy WebLinkAboutWPO201800049 Calculations 2023-02-22SHIMP ENGINEERING, P.C. Design Focused Engineering 8.Computations Energy Balance Equation Proposed Energy Balance Equation As -Built As -Built HydroCAD Report As -Built HydroCAD Report (10-yr Clog) Stormwater Analysis Summary APPROVED by the Albemarle County Community Development Department Date 02/22/2023 File WP0201800049 see summary, last pg. 912 E. High Sr. Charlottesville, VA 22902 1434.227.51401 chimp-engineering.com Oak Hill Convenience Store Energy Balance Equation 24 Hr 1 year Storm: Qtleveloped� I.F. (Qpre-developed RVPre-Developed) Redeveloped nn �tleveloped� (Qforested RVforested) Redeveloped Opre-developed RVPre-Developed = O.OS7 M� aXQdeveloped = 0.61 cfs r RVDeveloped = 0.1 `4leveloped = 0.26 cfs Site Detention RV + Creek Only RV = 0.095+0.006 = 0.1 POA 2 Outflow - Offsite Detention Outflow = 0.78 - 0.52 = 0.26 PreDevelopment PostDevelopment 10 yr 1 3.15 2.92 Oak Hill Convenience Store Energy Balance Equation 24 Hr 1 year Storm: ASBUILT Qdeveloped� I.F. (Qpre-developed RVPre-Developed) Redeveloped Qn developed� (Qforested RVforested) Redeveloped Opre-developed RVPre-Developed = 0.057 MaXQdeveloped = 0.61 cfs RVDeveloped = O.1 Qdeveloped = 0.34 cfs Site Detention RV + Creek Only RV = 0.095+0.006 = 0.1 POA 2 Outflow - Offsite Detention Outflow = 0.86 - 0.52 = 0.34 PreDevelopment PostDevelopment 10 yr 1 3.15 2.89 AS -BUILT HYDROCAD REPORT OAKHILL CONVENIECE STORE 7S Offsite Deten ion DA (Not in Energy alance) Site WA Point of Analysis 1 Subcat Reach Pon Link Detention 'pe AB 4L Point of Analysis 2 970 AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by {enter your company name here} Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 2 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Road DA Runoff Area=3,846 sf 79.98% Impervious Runoff Depth>2.12" Tc=5.0 min CN=91 Runoff=0.32 cfs 0.016 of Subcatchment 2S: Site Detention DA Runoff Area=18,347 sf 98.04% Impervious Runoff Depth>2.71" Tc=5.0 min CN=97 Runoff=1.81 cfs 0.095 of Subcatchment 5S: Creek Only DA Runoff Area=6,480 sf 4.20% Impervious Runoff Depth>0.45" Tc=5.0 min CN=63 Runoff=0.10 cfs 0.006 of Subcatchment 7S: Offsite Detention DA Runoff Area=8,120 sf 61.33% Impervious Runoff Depth>1.56" Tc=5.0 min CN=84 Runoff=0.52 cfs 0.024 of Pond 7P: Detention Pipe AB Peak Elev=471.96' Storage=0.031 of Inflow=2.33 cfs 0.119 of Outflow=0.81 cfs 0.119 of Link 4L: Point of Analysis 2 Inflow=0.86 cfs 0.125 of Primary=0.86 cfs 0.125 of Link 6L: Point of Analysis 1 Inflow=0.32 cfs 0.016 of Primary=0.32 cfs 0.016 of Total Runoff Area = 0.845 ac Runoff Volume = 0.140 of Average Runoff Depth =1.99" 28.48% Pervious = 0.241 ac 71.52% Impervious = 0.604 ac AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by (enter your company name here) Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 1S: Road DA Runoff = 0.32 cfs @ 11.95 hrs, Volume= 0.016 af, Depth> 2.12" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05 Area (sf) CN Description 770 61 >75% Grass cover. Good. HSG B 3,846 91 Weighted Average 770 20.02% Pervious Area 3,076 79.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: Site Detention DA Runoff = 1.81 cfs @ 11.95 hrs, Volume= 0.095 af, Depth> 2.71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05 Area (sfl CN Description 17,988 98 359 61 >75% Grass cover, Good, HSG B 18,347 97 Weighted Average 359 1.96% Pervious Area 17,988 98.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: Creek Only DA Runoff = 0.10 cfs @ 11.98 hrs, Volume= 0.006 af, Depth> 0.45" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05 Area (so CN Description 6,208 61 >75% Grass cover, Good, HSG B 272 98 6,480 63 Weighted Average 6,208 95.80% Pervious Area 272 4.20% Impervious Area AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by (enter your company name here) Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 @ 2010 HydroCAD Software Solutions LLC Page 4 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Offsite Detention DA (Not in Energy Balance) Runoff = 0.52 cfs @ 11.96 hrs, Volume= 0.024 af, Depth> 1.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05" Area (sf) CN Description 4,980 98 3,140 61 >75% Grass cover, Good, HSG B 8,120 84 Weighted Average 3,140 38.67% Pervious Area 4,980 61.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 7P: Detention Pipe AB Inflow Area = 0.608 ac, 86.78% Impervious, Inflow Depth > 2.35" for 1 yr, 24 hr event Inflow = 2.33 cfs @ 11.95 hrs, Volume= 0.119 of Outflow = 0.81 cfs @ 12.07 hrs, Volume= 0.119 af, Atten= 65%, Lag= 7.2 min Primary = 0.81 cfs @ 12.07 hrs, Volume= 0.119 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 471.96' @ 12.07 hrs Surf.Area= 0.012 ac Storage= 0.031 of Plug -Flow detention time= 14.7 min calculated for 0.119 of (100% of inflow) Center -of -Mass det. time= 13.6 min ( 789.0 - 775.4 ) Volume Invert Avail.Storage Storage Description #1 468.95' 0.050 of 60.0" D x 110.0'L Pipe Storage Device Routing Invert Outlet Devices #1 Primary 468.95' 15.0" Round Culvert L= 47.7' Ke= 0.600 Inlet / Outlet Invert= 468.95' / 461.15' S= 0.1635 '/' Cc= 0.900 n= 0.010 #2 Device 1 468.95' 4.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 471.78' 10.0" Vert. Orifice/Grate C= 0.600 #4 Primary 473.37' 4.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) 4.4' Crest Height AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by {enter your company name here} Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 @ 2010 HydroCAD Software Solutions LLC Page 5 Primary OutFlow Max=0.79 cfs @ 12.07 hrs HW=471.93' (Free Discharge) I=Culvert (Passes 0.79 cfs of 8.50 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.70 cfs @ 8.08 fps) 3=Orifice/Grate (Orifice Controls 0.09 cfs @ 1.32 fps) 4=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Link 4L: Point of Analysis 2 Inflow Area = 0.756 ac, 70.54% Impervious, Inflow Depth > 1.98" for 1 yr, 24 hr event Inflow = 0.86 cfs @ 12.06 hrs, Volume= 0.125 of Primary = 0.86 cfs @ 12.06 hrs, Volume= 0.125 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Summary for Link 6L: Point of Analysis 1 Inflow Area = 0.088 ac, 79.98% Impervious, Inflow Depth > 2.12" for 1 yr, 24 hr event Inflow = 0.32 cfs @ 11.95 hrs, Volume= 0.016 of Primary = 0.32 cfs @ 11.95 hrs, Volume= 0.016 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by {enter your company name here} Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 6 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Road DA Runoff Area=3,846 sf 79.98% Impervious Runoff Depth>4.54" Tc=5.0 min CN=91 Runoff=0.66 cfs 0.033 of Subcatchment 2S: Site Detention DA Runoff Area=18,347 sf 98.04% Impervious Runoff Depth>5.22" Tc=5.0 min CN=97 Runoff=3.37 cfs 0.183 of Subcatchment 5S: Creek Only DA Runoff Area=6,480 sf 4.20% Impervious Runoff Depth>1.89" Tc=5.0 min CN=63 Runoff=0.50 cfs 0.023 of Subcatchment 7S: Offsite Detention DA Runoff Area=8,120 sf 61.33% Impervious Runoff Depth>3.80" Tc=5.0 min CN=84 Runoff=1.23 cfs 0.059 of Pond 7P: Detention Pipe AB Peak Elev=473.34' Storage=0.046 of Inflow=4.60 cfs 0.242 of Outflow=3.67 cfs 0.242 of Link 4L: Point of Analysis 2 Inflow=4.12 cfs 0.265 of Primary=4.12 cfs 0.265 of Link 6L: Point of Analysis 1 Inflow=0.66 cfs 0.033 of Primary=0.66 cfs 0.033 of Total Runoff Area = 0.845 ac Runoff Volume = 0.299 of Average Runoff Depth = 4.25" 28.48% Pervious = 0.241 ac 71.52% Impervious = 0.604 ac AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by (enter your company name here) Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 1S: Road DA Runoff = 0.66 cfs @ 11.95 hrs, Volume= 0.033 af, Depth> 4.54" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (sf) CN Description 770 61 >75% Grass cover. Good. HSG B 3,846 91 Weighted Average 770 20.02% Pervious Area 3,076 79.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: Site Detention DA Runoff = 3.37 cfs @ 11.95 hrs, Volume= 0.183 af, Depth> 5.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (sfl CN Description 17,988 98 359 61 >75% Grass cover, Good, HSG B 18,347 97 Weighted Average 359 1.96% Pervious Area 17,988 98.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: Creek Only DA Runoff = 0.50 cfs @ 11.96 hrs, Volume= 0.023 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (so CN Description 6,208 61 >75% Grass cover, Good, HSG B 272 98 6,480 63 Weighted Average 6,208 95.80% Pervious Area 272 4.20% Impervious Area AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by (enter your company name here) Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 @ 2010 HydroCAD Software Solutions LLC Page 8 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Offsite Detention DA (Not in Energy Balance) Runoff = 1.23 cfs @ 11.95 hrs, Volume= 0.059 af, Depth> 3.80" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (sfl CN Description 4,980 98 3,140 61 >75% Grass cover, Good, HSG B 8,120 84 Weighted Average 3,140 38.67% Pervious Area 4,980 61.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 7P: Detention Pipe AB Inflow Area = 0.608 ac, 86.78% Impervious, Inflow Depth > 4.79" for 10 yr, 24 hr event Inflow = 4.60 cfs @ 11.95 hrs, Volume= 0.242 of Outflow = 3.67 cfs @ 12.01 hrs, Volume= 0.242 af, Atten= 20%, Lag= 3.3 min Primary = 3.67 cfs @ 12.01 hrs, Volume= 0.242 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 473.34' @ 12.01 hrs Surf.Area= 0.008 ac Storage= 0.046 of Plug -Flow detention time= 12.4 min calculated for 0.242 of (100% of inflow) Center -of -Mass det. time= 11.4 min ( 772.7 - 761.3 ) Volume Invert Avail.Storage Storage Description #1 468.95' 0.050 of 60.0" D x 110.0'L Pipe Storage Device Routing Invert Outlet Devices #1 Primary 468.95' 15.0" Round Culvert L= 47.7' Ke= 0.600 Inlet / Outlet Invert= 468.95' / 461.15' S= 0.1635 '/' Cc= 0.900 n= 0.010 #2 Device 1 468.95' 4.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 471.78' 10.0" Vert. Orifice/Grate C= 0.600 #4 Primary 473.37' 4.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) 4.4' Crest Height AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by {enter your company name here} Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 @ 2010 HydroCAD Software Solutions LLC Page 9 Primary OutFlow Max=3.62 cfs @ 12.01 hrs HW=473.30' (Free Discharge) I=Culvert (Passes 3.62 cfs of 10.70 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.86 cfs @ 9.85 fps) 3=Orifice/Grate (Orifice Controls 2.76 cfs @ 5.07 fps) 4=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Link 4L: Point of Analysis 2 Inflow Area = 0.756 ac, 70.54% Impervious, Inflow Depth > 4.21" for 10 yr, 24 hr event Inflow = 4.12 cfs @ 12.00 hrs, Volume= 0.265 of Primary = 4.12 cfs @ 12.00 hrs, Volume= 0.265 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Summary for Link 6L: Point of Analysis 1 Inflow Area = 0.088 ac, 79.98% Impervious, Inflow Depth > 4.54" for 10 yr, 24 hr event Inflow = 0.66 cfs @ 11.95 hrs, Volume= 0.033 of Primary = 0.66 cfs @ 11.95 hrs, Volume= 0.033 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by {enter your company name here} Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 10 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Road DA Runoff Area=3,846 sf 79.98% Impervious Runoff Depth>8.07" Tc=5.0 min CN=91 Runoff=1.13 cfs 0.059 of Subcatchment 2S: Site Detention DA Runoff Area=18,347 sf 98.04% Impervious Runoff Depth>8.79" Tc=5.0 min CN=97 Runoff=5.56 cfs 0.309 of Subcatchment 5S: Creek Only DA Runoff Area=6,480 sf 4.20% Impervious Runoff Depth>4.60" Tc=5.0 min CN=63 Runoff=1.23 cfs 0.057 of Subcatchment 7S: Offsite Detention DA Runoff Area=8,120 sf 61.33% Impervious Runoff Depth>7.21" Tc=5.0 min CN=84 Runoff=2.25 cfs 0.112 of Pond 7P: Detention Pipe AB Peak Elev=473.82' Storage=0.049 of Inflow=7.81 cfs 0.421 of Outflow=8.22 cfs 0.420 of Link 4L: Point of Analysis 2 Inflow=9.45 cfs 0.477 of Primary=9.45 cfs 0.477 of Link 6L: Point of Analysis 1 Inflow=1.13 cfs 0.059 of Primary=1.13 cfs 0.059 of Total Runoff Area = 0.845 ac Runoff Volume = 0.537 of Average Runoff Depth = 7.63" 28.48% Pervious = 0.241 ac 71.52% Impervious = 0.604 ac AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by (enter your company name here) Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 1S: Road DA Runoff = 1.13 cfs @ 11.95 hrs, Volume= 0.059 af, Depth> 8.07" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (sf) CN Description 770 61 >75% Grass cover. Good. HSG B 3,846 91 Weighted Average 770 20.02% Pervious Area 3,076 79.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: Site Detention DA Runoff = 5.56 cfs @ 11.95 hrs, Volume= 0.309 af, Depth> 8.79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (sfl CN Description 17,988 98 359 61 >75% Grass cover, Good, HSG B 18,347 97 Weighted Average 359 1.96% Pervious Area 17,988 98.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: Creek Only DA Runoff = 1.23 cfs @ 11.96 hrs, Volume= 0.057 af, Depth> 4.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (so CN Description 6,208 61 >75% Grass cover, Good, HSG B 272 98 6,480 63 Weighted Average 6,208 95.80% Pervious Area 272 4.20% Impervious Area AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by (enter your company name here) Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 @ 2010 HydroCAD Software Solutions LLC Page 12 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Offsite Detention DA (Not in Energy Balance) Runoff = 2.25 cfs @ 11.95 hrs, Volume= 0.112 af, Depth> 7.21" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (sfl CN Description 4,980 98 3,140 61 >75% Grass cover, Good, HSG B 8,120 84 Weighted Average 3,140 38.67% Pervious Area 4,980 61.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 7P: Detention Pipe AB Inflow Area = 0.608 ac, 86.78% Impervious, Inflow Depth > 8.31" for 100 yr, 24 hr event Inflow = 7.81 cfs @ 11.95 hrs, Volume= 0.421 of Outflow = 8.22 cfs @ 11.96 hrs, Volume= 0.420 af, Atten= 0%, Lag= 0.3 min Primary = 8.22 cfs @ 11.96 hrs, Volume= 0.420 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 473.82' @ 11.96 hrs Surf.Area= 0.004 ac Storage= 0.049 of Plug -Flow detention time= 11.0 min calculated for 0.420 of (100% of inflow) Center -of -Mass det. time= 10.1 min ( 761.5 - 751.3 ) Volume Invert Avail.Storage Storage Description #1 468.95' 0.050 of 60.0" D x 110.0'L Pipe Storage Device Routing Invert Outlet Devices #1 Primary 468.95' 15.0" Round Culvert L= 47.7' Ke= 0.600 Inlet / Outlet Invert= 468.95' / 461.15' S= 0.1635 '/' Cc= 0.900 n= 0.010 #2 Device 1 468.95' 4.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 471.78' 10.0" Vert. Orifice/Grate C= 0.600 #4 Primary 473.37' 4.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) 4.4' Crest Height AS -BUILT Hydrocad Analysis PostDevelopment AS -BUILT Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by {enter your company name here} Printed 7/6/2022 HydroCAD® 9.10 s/n 07054 @ 2010 HydroCAD Software Solutions LLC Page 13 Primary OutFlow Max=8.00 cfs @ 11.96 hrs HW=473.81' (Free Discharge) I=Culvert (Passes 4.24 cfs of 11.40 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.91 cfs @ 10.43 fps) 3=Orifice/Grate (Orifice Controls 3.33 cfs @ 6.11 fps) 4=Sharp-Crested Rectangular Weir (Weir Controls 3.76 cfs @ 2.19 fps) Summary for Link 4L: Point of Analysis 2 Inflow Area = 0.756 ac, 70.54% Impervious, Inflow Depth > 7.57" for 100 yr, 24 hr event Inflow = 9.45 cfs @ 11.96 hrs, Volume= 0.477 of Primary = 9.45 cfs @ 11.96 hrs, Volume= 0.477 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Summary for Link 6L: Point of Analysis 1 Inflow Area = 0.088 ac, 79.98% Impervious, Inflow Depth > 8.07" for 100 yr, 24 hr event Inflow = 1.13 cfs @ 11.95 hrs, Volume= 0.059 of Primary = 1.13 cfs @ 11.95 hrs, Volume= 0.059 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Post Development HydroCAD Report As -Built 10-yr Clog Note: The 10" 10-yr orifice has been removed from this model to evaluate the a completely clogged condition. 7S 2S Offsite Detent n DA Site etention DA (Not in Energy B lance) 1S Roa i DA 5S 7P Cr ek Only DA Detention Pi a AB (10-yr Clo 41 6L 4L a Point of Analysis 1 Point of Analysis 2 Subcat Reach on Link Drainage Diagram for PostDevelopment AS -BUILT (10-yr Clog) Prepared by (enter your company name here), Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 0 2010 HydroCAD Software Solutions LLC AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 2 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Road DA Runoff Area=3,846 sf 79.98% Impervious Runoff Depth>2.12" Tc=5.0 min CN=91 Runoff=0.32 cfs 0.016 of Subcatchment 2S: Site Detention DA Runoff Area=18,347 sf 98.04% Impervious Runoff Depth>2.71" Tc=5.0 min CN=97 Runoff=1.81 cfs 0.095 of Subcatchment 5S: Creek Only DA Runoff Area=6,480 sf 4.20% Impervious Runoff Depth>0.45" Tc=5.0 min CN=63 Runoff=0.10 cfs 0.006 of Subcatchment 7S: Offsite Detention DA Runoff Area=8,120 sf 61.33% Impervious Runoff Depth>1.56" Tc=5.0 min CN=84 Runoff=0.52 cfs 0.024 of Pond 7P: Detention Pipe AB (10-yr Clog) Peak Elev=471.98' Storage=0.031 of Inflow=2.33 cfs 0.119 of Outflow=0.71 cfs 0.119 of Link 4L: Point of Analysis 2 Inflow=0.78 cfs 0.125 of Primary=0.78 cfs 0.125 of Link 6L: Point of Analysis 1 Inflow=0.32 cfs 0.016 of Primary=0.32 cfs 0.016 of Total Runoff Area = 0.845 ac Runoff Volume = 0.140 of Average Runoff Depth = 1.99" 28.48% Pervious = 0.241 ac 71.52% Impervious = 0.604 ac AB Post-Dev (10-yrClog) PostDevelopment AS -BUILT (10-yr Clog) Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 1S: Road DA Runoff = 0.32 cfs @ 11.95 hrs, Volume= 0.016 af, Depth> 2.12" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05 Area (sf) CN Description 770 61 >75% Grass cover. Good. HSG B 3,846 91 Weighted Average 770 20.02% Pervious Area 3,076 79.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: Site Detention DA Runoff = 1.81 cfs @ 11.95 hrs, Volume= 0.095 af, Depth> 2.71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05 Area (sfl CN Description 17,988 98 359 61 >75% Grass cover, Good, HSG B 18,347 97 Weighted Average 359 1.96% Pervious Area 17,988 98.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: Creek Only DA Runoff = 0.10 cfs @ 11.98 hrs, Volume= 0.006 af, Depth> 0.45" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05 Area (so CN Description 6,208 61 >75% Grass cover, Good, HSG B 272 98 6,480 63 Weighted Average 6,208 95.80% Pervious Area 272 4.20% Impervious Area AB Post-Dev (10-yrClog) PostDevelopment AS -BUILT (10-yr Clog) Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 4 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Offsite Detention DA (Not in Energy Balance) Runoff = 0.52 cfs @ 11.96 hrs, Volume= 0.024 af, Depth> 1.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.05" Area (sf) CN Description 4,980 98 3,140 61 >75% Grass cover, Good, HSG B 8,120 84 Weighted Average 3,140 38.67% Pervious Area 4,980 61.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 7P: Detention Pipe AB (10-yr Clog) Inflow Area = 0.608 ac, 86.78% Impervious, Inflow Depth > 2.35" for 1 yr, 24 hr event Inflow = 2.33 cfs @ 11.95 hrs, Volume= 0.119 of Outflow = 0.71 cfs @ 12.09 hrs, Volume= 0.119 af, Atten= 69%, Lag= 8.0 min Primary = 0.71 cfs @ 12.09 hrs, Volume= 0.119 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 471.98' @ 12.09 hrs Surf.Area= 0.012 ac Storage= 0.031 of Plug -Flow detention time= 15.3 min calculated for 0.119 of (100% of inflow) Center -of -Mass det. time= 13.9 min ( 789.3 - 775.4 ) Volume Invert Avail.Storage Storage Description #1 468.95' 0.050 of 60.0" D x 110.0'L Pipe Storage Device Routing Invert Outlet Devices #1 Primary 468.95' 15.0" Round Culvert L= 20.0' Ke= 0.600 Inlet / Outlet Invert= 468.95'/468.95' S= 0.0000 '/' Cc= 0.900 n= 0.010 #2 Device 1 468.95' 4.0" Vert. Orifice/Grate C= 0.600 #3 Primary 473.37' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads AB Post-Dev (10-yrClog) PostDevelopment AS -BUILT (10-yr Clog) Type // 24-hr 1 yr, 24 hr Rainfall=3.05" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 5 Primary OutFlow Max=0.71 cfs @ 12.09 hrs HW=471.97' (Free Discharge) 1'�--3=Orif 7=Culvert (Passes 0.71 cfs of 8.56 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.71 cfs @ 8.13 fps) ice/Grate ( Controls 0.00 cfs) Summary for Link 4L: Point of Analysis 2 Inflow Area = 0.756 ac, 70.54% Impervious, Inflow Depth > 1.98" for 1 yr, 24 hr event Inflow = 0.78 cfs @ 12.02 hrs, Volume= 0.125 of Primary = 0.78 cfs @ 12.02 hrs, Volume= 0.125 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Summary for Link 6L: Point of Analysis 1 Inflow Area = 0.088 ac, 79.98% Impervious, Inflow Depth > 2.12" for 1 yr, 24 hr event Inflow = 0.32 cfs @ 11.95 hrs, Volume= 0.016 of Primary = 0.32 cfs @ 11.95 hrs, Volume= 0.016 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 6 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Road DA Runoff Area=3,846 sf 79.98% Impervious Runoff Depth>4.54" Tc=5.0 min CN=91 Runoff=0.66 cfs 0.033 of Subcatchment 2S: Site Detention DA Runoff Area=18,347 sf 98.04% Impervious Runoff Depth>5.22" Tc=5.0 min CN=97 Runoff=3.37 cfs 0.183 of Subcatchment 5S: Creek Only DA Runoff Area=6,480 sf 4.20% Impervious Runoff Depth>1.89" Tc=5.0 min CN=63 Runoff=0.50 cfs 0.023 of Subcatchment 7S: Offsite Detention DA Runoff Area=8,120 sf 61.33% Impervious Runoff Depth>3.80" Tc=5.0 min CN=84 Runoff=1.23 cfs 0.059 of Pond 7P: Detention Pipe AB (10-yr Clog) Peak Elev=473.54' Storage=0.048 of Inflow=4.60 cfs 0.242 of Outflow=3.64 cfs 0.240 of Link 4L: Point of Analysis 2 Inflow=4.29 cfs 0.264 of Primary=4.29 cfs 0.264 of Link 6L: Point of Analysis 1 Inflow=0.66 cfs 0.033 of Primary=0.66 cfs 0.033 of Total Runoff Area = 0.845 ac Runoff Volume = 0.299 of Average Runoff Depth = 4.25" 28.48% Pervious = 0.241 ac 71.52% Impervious = 0.604 ac AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 1S: Road DA Runoff = 0.66 cfs @ 11.95 hrs, Volume= 0.033 af, Depth> 4.54" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (sf) CN Description 770 61 >75% Grass cover. Good. HSG B 3,846 91 Weighted Average 770 20.02% Pervious Area 3,076 79.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: Site Detention DA Runoff = 3.37 cfs @ 11.95 hrs, Volume= 0.183 af, Depth> 5.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (sfl CN Description 17,988 98 359 61 >75% Grass cover, Good, HSG B 18,347 97 Weighted Average 359 1.96% Pervious Area 17,988 98.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: Creek Only DA Runoff = 0.50 cfs @ 11.96 hrs, Volume= 0.023 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (so CN Description 6,208 61 >75% Grass cover, Good, HSG B 272 98 6,480 63 Weighted Average 6,208 95.80% Pervious Area 272 4.20% Impervious Area AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 8 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Offsite Detention DA (Not in Energy Balance) Runoff = 1.23 cfs @ 11.95 hrs, Volume= 0.059 af, Depth> 3.80" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.58" Area (sfl CN Description 4,980 98 3,140 61 >75% Grass cover, Good, HSG B 8,120 84 Weighted Average 3,140 38.67% Pervious Area 4,980 61.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 7P: Detention Pipe AB (10-yr Clog) Inflow Area = 0.608 ac, 86.78% Impervious, Inflow Depth > 4.79" for 10 yr, 24 hr event Inflow = 4.60 cfs @ 11.95 hrs, Volume= 0.242 of Outflow = 3.64 cfs @ 11.98 hrs, Volume= 0.240 af, Atten= 21 %, Lag= 1.5 min Primary = 3.64 cfs @ 11.98 hrs, Volume= 0.240 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 473.54' @ 11.98 hrs Surf.Area= 0.007 ac Storage= 0.048 of Plug -Flow detention time= 20.9 min calculated for 0.240 of (99% of inflow) Center -of -Mass det. time= 15.1 min ( 776.4 - 761.3 ) Volume Invert Avail.Storage Storage Description #1 468.95' 0.050 of 60.0" D x 110.0'L Pipe Storage Device Routing Invert Outlet Devices #1 Primary 468.95' 15.0" Round Culvert L= 20.0' Ke= 0.600 Inlet / Outlet Invert= 468.95'/468.95' S= 0.0000 '/' Cc= 0.900 n= 0.010 #2 Device 1 468.95' 4.0" Vert. Orifice/Grate C= 0.600 #3 Primary 473.37' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 10 yr, 24 hr Rainfall=5.58" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 9 Primary OutFlow Max=3.44 cfs @ 11.98 hrs HW=473.53' (Free Discharge) 1'�--3=Orif 7=Culvert (Passes 0.88 cfs of 11.01 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.88 cfs @ 10.11 fps) ice/Grate (Weir Controls 2.55 cfs @ 1.30 fps) Summary for Link 4L: Point of Analysis 2 Inflow Area = 0.756 ac, 70.54% Impervious, Inflow Depth > 4.18" for 10 yr, 24 hr event Inflow = 4.29 cfs @ 11.97 hrs, Volume= 0.264 of Primary = 4.29 cfs @ 11.97 hrs, Volume= 0.264 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Summary for Link 6L: Point of Analysis 1 Inflow Area = 0.088 ac, 79.98% Impervious, Inflow Depth > 4.54" for 10 yr, 24 hr event Inflow = 0.66 cfs @ 11.95 hrs, Volume= 0.033 of Primary = 0.66 cfs @ 11.95 hrs, Volume= 0.033 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Paoe 10 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Road DA Runoff Area=3,846 sf 79.98% Impervious Runoff Depth>8.07" Tc=5.0 min CN=91 Runoff=1.13 cfs 0.059 of Subcatchment 2S: Site Detention DA Runoff Area=18,347 sf 98.04% Impervious Runoff Depth>8.79" Tc=5.0 min CN=97 Runoff=5.56 cfs 0.309 of Subcatchment 5S: Creek Only DA Runoff Area=6,480 sf 4.20% Impervious Runoff Depth>4.60" Tc=5.0 min CN=63 Runoff=1.23 cfs 0.057 of Subcatchment 7S: Offsite Detention DA Runoff Area=8,120 sf 61.33% Impervious Runoff Depth>7.21" Tc=5.0 min CN=84 Runoff=2.25 cfs 0.112 of Pond 7P: Detention Pipe AB (10-yr Clog) Peak Elev=473.67' Storage=0.048 of Inflow=7.81 cfs 0.421 of Outflow=7.63 cfs 0.420 of Link 4L: Point of Analysis 2 Inflow=8.86 cfs 0.477 of Primary=8.86 cfs 0.477 of Link 6L: Point of Analysis 1 Inflow=1.13 cfs 0.059 of Primary=1.13 cfs 0.059 of Total Runoff Area = 0.845 ac Runoff Volume = 0.537 of Average Runoff Depth = 7.63" 28.48% Pervious = 0.241 ac 71.52% Impervious = 0.604 ac AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 1S: Road DA Runoff = 1.13 cfs @ 11.95 hrs, Volume= 0.059 af, Depth> 8.07" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (sf) CN Description 770 61 >75% Grass cover. Good. HSG B 3,846 91 Weighted Average 770 20.02% Pervious Area 3,076 79.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: Site Detention DA Runoff = 5.56 cfs @ 11.95 hrs, Volume= 0.309 af, Depth> 8.79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (sfl CN Description 17,988 98 359 61 >75% Grass cover, Good, HSG B 18,347 97 Weighted Average 359 1.96% Pervious Area 17,988 98.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: Creek Only DA Runoff = 1.23 cfs @ 11.96 hrs, Volume= 0.057 af, Depth> 4.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (so CN Description 6,208 61 >75% Grass cover, Good, HSG B 272 98 6,480 63 Weighted Average 6,208 95.80% Pervious Area 272 4.20% Impervious Area AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 12 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Offsite Detention DA (Not in Energy Balance) Runoff = 2.25 cfs @ 11.95 hrs, Volume= 0.112 af, Depth> 7.21" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.16" Area (sfl CN Description 4,980 98 3,140 61 >75% Grass cover, Good, HSG B 8,120 84 Weighted Average 3,140 38.67% Pervious Area 4,980 61.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 7P: Detention Pipe AB (10-yr Clog) Inflow Area = 0.608 ac, 86.78% Impervious, Inflow Depth > 8.31" for 100 yr, 24 hr event Inflow = 7.81 cfs @ 11.95 hrs, Volume= 0.421 of Outflow = 7.63 cfs @ 11.95 hrs, Volume= 0.420 af, Atten= 2%, Lag= 0.2 min Primary = 7.63 cfs @ 11.95 hrs, Volume= 0.420 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 473.67' @ 11.95 hrs Surf.Area= 0.006 ac Storage= 0.048 of Plug -Flow detention time= 13.1 min calculated for 0.420 of (100% of inflow) Center -of -Mass det. time= 12.6 min ( 763.9 - 751.3 ) Volume Invert Avail.Storage Storage Description #1 468.95' 0.050 of 60.0" D x 110.0'L Pipe Storage Device Routing Invert Outlet Devices #1 Primary 468.95' 15.0" Round Culvert L= 20.0' Ke= 0.600 Inlet / Outlet Invert= 468.95'/468.95' S= 0.0000 '/' Cc= 0.900 n= 0.010 #2 Device 1 468.95' 4.0" Vert. Orifice/Grate C= 0.600 #3 Primary 473.37' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads AB Post-Dev (10-yr Clog) PostDevelopment AS -BUILT (10-yr Clog) Type 11 24-hr 100 yr, 24 hr Rainfall=9.16" Prepared by (enter your company name here) Printed 2/16/2023 HydroCAD® 9.10 s/n 07054 © 2010 HydroCAD Software Solutions LLC Page 13 Primary OutFlow Max=7.54 cfs @ 11.95 hrs HW=473.67' (Free Discharge) 1'�--3=Orif 7=Culvert (Passes 0.90 cfs of 11.21 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.90 cfs @ 10.27 fps) ice/Grate (Weir Controls 6.64 cfs @ 1.78 fps) Summary for Link 4L: Point of Analysis 2 Inflow Area = 0.756 ac, 70.54% Impervious, Inflow Depth > 7.57" for 100 yr, 24 hr event Inflow = 8.86 cfs @ 11.95 hrs, Volume= 0.477 of Primary = 8.86 cfs @ 11.95 hrs, Volume= 0.477 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Summary for Link 6L: Point of Analysis 1 Inflow Area = 0.088 ac, 79.98% Impervious, Inflow Depth > 8.07" for 100 yr, 24 hr event Inflow = 1.13 cfs @ 11.95 hrs, Volume= 0.059 of Primary = 1.13 cfs @ 11.95 hrs, Volume= 0.059 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Stormwater Analysis Summary Oak Hill Convenience Store PROPOSED Elev Flow Offsite POA 1-YR 472.03 0.78 0.52 0.26 10-YR 473.61 4.15 1.23 2.92 100-YR 473.83 ASBUILT Elev Flow Offsite POA 1-YR 471.96 0.86 0.52 0.34 10-YR 473.34 4.12 1.23 2.89 100-YR 473.59 ASBUILT (10-YR CLOG) Elev Flow Offsite POA 1-YR 471.98 0.78 0.52 0.26 10-YR 473.54 4.29 1.23 3.06 100-YR 473.67 Max QI = 0.61 cfs Max Q10 = 3.15 cfs 'Offiste flow removed for evaluation at POA