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HomeMy WebLinkAboutWPO201900040 Calculations 2019-08-23Yancey Lumber Yard VSMP ALBEMARLE COUNTY, VIRGINIA VSMP PLAN DESIGN CALCULATIONS & NARRATIVE JULY 1, 2019 REVISED: AUGUST 21, 2019 TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Jonathan Showalter, PE Timmons Group 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 434.327.1681 �r��,AL7'H OF Li U�.%TF -IN M. SHOMLTCR I.ic. No. 0402057151 Table of Contents Section Title Project Narrative Pre- and Post -Developed HydroCAD Calculations Virginia Runoff Reduction Method ReDevelopment Worksheet Project Narrative: This project includes lower the grading of an asphalt roadway uphill of retaining wall and concrete pad to ensure loads on the wall are within the recommendations of the structural engineer. The concrete pad and wall were previously constructed without a permit. Therefore, the limits of disturbance from that previous work is being added into the limits of disturbance for the current work to account for stormwater quality and quantity requirements. The limits of disturbance are 0.98 acres. Water Quality: Currently, there exists 0.00 acres of forest, 0.06 acres of managed turf and 0.92 acres of impervious cover within the site limits. In the proposed condition, there will be 0.00 acres of forest, 0.10 acres of managed turf and 0.88 acres of impervious cover. Per the Virginia Runoff Reduction Redevelopment Spreadsheet, the required removal is 0.13 lb/yr. This removal will be achieved with the purchase of offsite nutrient credits from a DEQ approved credit bank. Water Quantity: No new impervious surface is being added as part of this project. Pre -developed flows will be maintained or reduced. See plan sheet C6.1 and HydroCAD Routing Calculations. 2S Pre -Developed rea of Concrete Pa Previously Constru ed 1S Pre -De eloped Area urre nt Work Pre -Developed S4 Each Pon L ink 4S 5S of Post -Developed rea of Post -De eloped Area of Concrete Pa C rrent Work Previously Co nstru ted 6L Post -Developed Yancey Pre Post Type 1124-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 1 S: Pre -Developed Area of Current Work Runoff = 2.12 cfs @ 11.96 hrs, Volume= 0.103 af, Depth> 2.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 Year Rainfall=3.05" Area (ac) CN Description 0.490 98 Paved parking, HSG B 0.060 61 >75% Grass cover, Good, HSG B 0.550 94 Weighted Average 0.060 10.91 % Pervious Area 0.490 89.09% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1 S: Pre -Developed Area of Current Work Hydrograph I I ❑Runoff 2.12 cfs r Type tl 24=hr 2 i 1Ypar Rainfall 3.05" Runoff Area=0.550 ac i Runoffs Volume-0.i103 of Runoff Depth>2.25" Tjc=6.0 min LL 1 CN=94 I a 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pace 3 Hydrograph for Subcatchment 1 S: Pre -Developed Area of Current Work Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.19 0.01 0.00 5.25 0.20 0.01 0.01 5.50 0.22 0.01 0.01 5.75 0.23 0.01 0.01 6.00 0.24 0.02 0.01 6.25 0.26 0.02 0.01 6.50 0.27 0.03 0.01 6.75 0.29 0.03 0.01 7.00 0.30 0.04 0.01 7.25 0.32 0.04 0.01 7.50 0.33 0.05 0.01 7.75 0.35 0.06 0.02 8.00 0.37 0.06 0.02 8.25 0.38 0.07 0.02 8.50 0.40 0.08 0.02 8.75 0.42 0.09 0.03 9.00 0.45 0.11 0.03 9.25 0.47 0.12 0.03 9.50 0.50 0.14 0.03 9.75 0.52 0.15 0.04 10.00 0.55 0.17 0.04 10.25 0.58 0.19 0.05 10.50 0.62 0.22 0.06 10.75 0.67 0.25 0.07 11.00 0.72 0.28 0.08 11.25 0.78 0.33 0.11 11.50 0.86 0.39 0.15 11.75 1.18 0.66 0.69 12.00 2.02 1.42 1.98 12.25 2.15 1.54 0.27 12.50 2.24 1.62 0.17 12.75 2.30 1.68 0.13 13.00 2.35 1.73 0.11 13.25 2.40 1.77 0.09 13.50 2.44 1.81 0.08 13.75 2.47 1.84 0.07 14.00 2.50 1.87 0.06 14.25 2.53 1.90 0.06 14.50 2.55 1.92 0.06 14.75 2.58 1.95 0.05 15.00 2.60 1.97 0.05 15.25 2.63 1.99 0.05 15.50 2.65 2.01 0.04 15.75 2.67 2.03 0.04 16.00 2.68 2.05 0.04 16.25 2.70 2.06 0.04 16.50 2.72 2.08 0.04 16.75 2.73 2.09 0.03 17.00 2.75 2.11 0.03 17.25 2.77 2.12 0.03 17.50 2.78 2.14 0.03 17.75 2.80 2.15 0.03 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 2.81 2.17 0.03 18.25 2.82 2.18 0.03 18.50 2.84 2.19 0.03 18.75 2.85 2.20 0.03 19.00 2.86 2.22 0.03 19.25 2.87 2.23 0.02 19.50 2.88 2.24 0.02 19.75 2.89 2.25 0.02 20.00 2.90 2.26 0.02 Yancey Pre Post Type 1124-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Runoff = 1.80 cfs @ 11.96 hrs, Volume= 0.093 af, Depth> 2.61" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 Year Rainfall=3.05" Area (ac) CN Description 0.430 98 Paved parking, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.430 98 Weighted Average 0.430 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Hydrograph 2 1.80 cfs I I I I I I I I I I I I I I I I I I I I N I I I I o LL Type II 24-hr 1Ypar Rainfall=3.05" Runoff Area=0.430 ac I Runoff) Volume=0.093 of Runoff Depth;>-2-.61 , Tc-6'.0 min CN=98 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pace 5 Hydrograph for Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.19 0.06 0.01 5.25 0.20 0.07 0.01 5.50 0.22 0.08 0.02 5.75 0.23 0.09 0.02 6.00 0.24 0.10 0.02 6.25 0.26 0.11 0.02 6.50 0.27 0.12 0.02 6.75 0.29 0.13 0.02 7.00 0.30 0.15 0.02 7.25 0.32 0.16 0.02 7.50 0.33 0.17 0.02 7.75 0.35 0.19 0.02 8.00 0.37 0.20 0.02 8.25 0.38 0.21 0.03 8.50 0.40 0.23 0.03 8.75 0.42 0.25 0.03 9.00 0.45 0.27 0.04 9.25 0.47 0.29 0.04 9.50 0.50 0.32 0.04 9.75 0.52 0.34 0.04 10.00 0.55 0.37 0.05 10.25 0.58 0.40 0.05 10.50 0.62 0.43 0.06 10.75 0.67 0.47 0.07 11.00 0.72 0.52 0.09 11.25 0.78 0.58 0.11 11.50 0.86 0.66 0.14 11.75 1.18 0.97 0.63 12.00 2.02 1.80 1.66 12.25 2.15 1.93 0.22 12.50 2.24 2.01 0.14 12.75 2.30 2.08 0.10 13.00 2.35 2.13 0.09 13.25 2.40 2.17 0.07 13.50 2.44 2.21 0.07 13.75 2.47 2.24 0.06 14.00 2.50 2.27 0.05 14.25 2.53 2.30 0.05 14.50 2.55 2.33 0.04 14.75 2.58 2.35 0.04 15.00 2.60 2.37 0.04 15.25 2.63 2.40 0.04 15.50 2.65 2.42 0.04 15.75 2.67 2.44 0.03 16.00 2.68 2.45 0.03 16.25 2.70 2.47 0.03 16.50 2.72 2.49 0.03 16.75 2.73 2.50 0.03 17.00 2.75 2.52 0.03 17.25 2.77 2.54 0.03 17.50 2.78 2.55 0.03 17.75 2.80 2.56 0.02 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 2.81 2.58 0.02 18.25 2.82 2.59 0.02 18.50 2.84 2.60 0.02 18.75 2.85 2.62 0.02 19.00 2.86 2.63 0.02 19.25 2.87 2.64 0.02 19.50 2.88 2.65 0.02 19.75 2.89 2.66 0.02 20.00 2.90 2.67 0.02 Yancey Pre Post Type 1124-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Runoff = 1.80 cfs @ 11.96 hrs, Volume= 0.093 af, Depth> 2.61" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 Year Rainfall=3.05" Area (ac) CN Description 0.430 98 Paved parking, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.430 98 Weighted Average 0.430 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Hydrograph 2 1.80 cfs I I I I I I I I I I I I I I I I I I I I N I I I I o LL Type II 24-hr 1Ypar Rainfall=3.05" Runoff Area=0.430 ac I Runoff) Volume=0.093 of Runoff Depth;>-2-.61 , Tc-6'.0 min CN=98 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pace 7 Hydrograph for Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.19 0.06 0.01 5.25 0.20 0.07 0.01 5.50 0.22 0.08 0.02 5.75 0.23 0.09 0.02 6.00 0.24 0.10 0.02 6.25 0.26 0.11 0.02 6.50 0.27 0.12 0.02 6.75 0.29 0.13 0.02 7.00 0.30 0.15 0.02 7.25 0.32 0.16 0.02 7.50 0.33 0.17 0.02 7.75 0.35 0.19 0.02 8.00 0.37 0.20 0.02 8.25 0.38 0.21 0.03 8.50 0.40 0.23 0.03 8.75 0.42 0.25 0.03 9.00 0.45 0.27 0.04 9.25 0.47 0.29 0.04 9.50 0.50 0.32 0.04 9.75 0.52 0.34 0.04 10.00 0.55 0.37 0.05 10.25 0.58 0.40 0.05 10.50 0.62 0.43 0.06 10.75 0.67 0.47 0.07 11.00 0.72 0.52 0.09 11.25 0.78 0.58 0.11 11.50 0.86 0.66 0.14 11.75 1.18 0.97 0.63 12.00 2.02 1.80 1.66 12.25 2.15 1.93 0.22 12.50 2.24 2.01 0.14 12.75 2.30 2.08 0.10 13.00 2.35 2.13 0.09 13.25 2.40 2.17 0.07 13.50 2.44 2.21 0.07 13.75 2.47 2.24 0.06 14.00 2.50 2.27 0.05 14.25 2.53 2.30 0.05 14.50 2.55 2.33 0.04 14.75 2.58 2.35 0.04 15.00 2.60 2.37 0.04 15.25 2.63 2.40 0.04 15.50 2.65 2.42 0.04 15.75 2.67 2.44 0.03 16.00 2.68 2.45 0.03 16.25 2.70 2.47 0.03 16.50 2.72 2.49 0.03 16.75 2.73 2.50 0.03 17.00 2.75 2.52 0.03 17.25 2.77 2.54 0.03 17.50 2.78 2.55 0.03 17.75 2.80 2.56 0.02 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 2.81 2.58 0.02 18.25 2.82 2.59 0.02 18.50 2.84 2.60 0.02 18.75 2.85 2.62 0.02 19.00 2.86 2.63 0.02 19.25 2.87 2.64 0.02 19.50 2.88 2.65 0.02 19.75 2.89 2.66 0.02 20.00 2.90 2.67 0.02 Yancey Pre Post Type 1124-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 5S: Post -Developed Area of Current Work Runoff = 1.94 cfs @ 11.97 hrs, Volume= 0.091 af, Depth> 1.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 Year Rainfall=3.05" Area (ac) CN Description 0.450 98 Paved parking, HSG B 0.100 61 >75% Grass cover, Good, HSG B 0.550 91 Weighted Average 0.100 18.18% Pervious Area 0.450 81.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: Post -Developed Area of Current Work Hydrograph � _ 1 ❑Runoff 2 1.94 cfs Type II 24-hr 1 Ypar Rainfall 3.05" Runoff Area=0.550 ac Runoff Volume=0.091 of 1 Runoff De�pth;1>1.98" LL 1 ' ' Tc-6'.0 min CN=91 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pace 9 Hydrograph for Subcatchment 5S: Post -Developed Area of Current Work Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.19 0.00 0.00 5.25 0.20 0.00 0.00 5.50 0.22 0.00 0.00 5.75 0.23 0.00 0.00 6.00 0.24 0.00 0.00 6.25 0.26 0.00 0.00 6.50 0.27 0.01 0.00 6.75 0.29 0.01 0.00 7.00 0.30 0.01 0.01 7.25 0.32 0.01 0.01 7.50 0.33 0.02 0.01 7.75 0.35 0.02 0.01 8.00 0.37 0.02 0.01 8.25 0.38 0.03 0.01 8.50 0.40 0.04 0.01 8.75 0.42 0.04 0.02 9.00 0.45 0.05 0.02 9.25 0.47 0.06 0.02 9.50 0.50 0.07 0.02 9.75 0.52 0.08 0.02 10.00 0.55 0.09 0.03 10.25 0.58 0.11 0.04 10.50 0.62 0.13 0.04 10.75 0.67 0.15 0.05 11.00 0.72 0.18 0.06 11.25 0.78 0.22 0.09 11.50 0.86 0.27 0.12 11.75 1.18 0.49 0.59 12.00 2.02 1.18 1.82 12.25 2.15 1.30 0.25 12.50 2.24 1.38 0.16 12.75 2.30 1.43 0.12 13.00 2.35 1.48 0.10 13.25 2.40 1.52 0.09 13.50 2.44 1.55 0.08 13.75 2.47 1.58 0.07 14.00 2.50 1.61 0.06 14.25 2.53 1.64 0.06 14.50 2.55 1.66 0.05 14.75 2.58 1.68 0.05 15.00 2.60 1.70 0.05 15.25 2.63 1.72 0.04 15.50 2.65 1.74 0.04 15.75 2.67 1.76 0.04 16.00 2.68 1.78 0.04 16.25 2.70 1.79 0.04 16.50 2.72 1.81 0.03 16.75 2.73 1.83 0.03 17.00 2.75 1.84 0.03 17.25 2.77 1.85 0.03 17.50 2.78 1.87 0.03 17.75 2.80 1.88 0.03 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 2.81 1.89 0.03 18.25 2.82 1.91 0.03 18.50 2.84 1.92 0.03 18.75 2.85 1.93 0.03 19.00 2.86 1.94 0.02 19.25 2.87 1.95 0.02 19.50 2.88 1.96 0.02 19.75 2.89 1.97 0.02 20.00 2.90 1.98 0.02 Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Link 3L: Pre -Developed Inflow Area = 0.980 ac, 93.88% Impervious, Inflow Depth > 2.41" for 1Year event Inflow = 3.92 cfs @ 11.96 hrs, Volume= 0.197 of Primary = 3.92 cfs @ 11.96 hrs, Volume= 0.197 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs N U 3 0 LL Link 3L: Pre -Developed Hydrograph 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Inflow ❑ Primary Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 11 Hydrograph for Link 3L: Pre -Developed Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 5.00 0.02 0.00 0.02 5.25 0.02 0.00 0.02 5.50 0.02 0.00 0.02 5.75 0.02 0.00 0.02 6.00 0.03 0.00 0.03 6.25 0.03 0.00 0.03 6.50 0.03 0.00 0.03 6.75 0.03 0.00 0.03 7.00 0.03 0.00 0.03 7.25 0.04 0.00 0.04 7.50 0.04 0.00 0.04 7.75 0.04 0.00 0.04 8.00 0.04 0.00 0.04 8.25 0.05 0.00 0.05 8.50 0.05 0.00 0.05 8.75 0.06 0.00 0.06 9.00 0.07 0.00 0.07 9.25 0.07 0.00 0.07 9.50 0.07 0.00 0.07 9.75 0.08 0.00 0.08 10.00 0.09 0.00 0.09 10.25 0.10 0.00 0.10 10.50 0.12 0.00 0.12 10.75 0.14 0.00 0.14 11.00 0.17 0.00 0.17 11.25 0.22 0.00 0.22 11.50 0.29 0.00 0.29 11.75 1.32 0.00 1.32 12.00 3.64 0.00 3.64 12.25 0.49 0.00 0.49 12.50 0.31 0.00 0.31 12.75 0.23 0.00 0.23 13.00 0.19 0.00 0.19 13.25 0.17 0.00 0.17 13.50 0.15 0.00 0.15 13.75 0.13 0.00 0.13 14.00 0.11 0.00 0.11 14.25 0.11 0.00 0.11 14.50 0.10 0.00 0.10 14.75 0.10 0.00 0.10 15.00 0.09 0.00 0.09 15.25 0.08 0.00 0.08 15.50 0.08 0.00 0.08 15.75 0.07 0.00 0.07 16.00 0.07 0.00 0.07 16.25 0.07 0.00 0.07 16.50 0.06 0.00 0.06 16.75 0.06 0.00 0.06 17.00 0.06 0.00 0.06 17.25 0.06 0.00 0.06 17.50 0.06 0.00 0.06 17.75 0.06 0.00 0.06 Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 18.00 0.05 0.00 0.05 18.25 0.05 0.00 0.05 18.50 0.05 0.00 0.05 18.75 0.05 0.00 0.05 19.00 0.05 0.00 0.05 19.25 0.04 0.00 0.04 19.50 0.04 0.00 0.04 19.75 0.04 0.00 0.04 20.00 0.04 0.00 0.04 Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 12 Summary for Link 6L: Post -Developed Inflow Area = 0.980 ac, 89.80% Impervious, Inflow Depth > 2.26" for 1 Year event Inflow = 3.73 cfs @ 11.96 hrs, Volume= 0.184 of Primary = 3.73 cfs @ 11.96 hrs, Volume= 0.184 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs N U 3 0 LL Link 6L: Post -Developed Hydrograph 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Inflow ❑ Primary Yancey Pre Post Type 11 24-hr 1 Year Rainfall=3.05" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 13 Hydrograph for Link 6L: Post -Developed Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 5.00 0.01 0.00 0.01 5.25 0.01 0.00 0.01 5.50 0.02 0.00 0.02 5.75 0.02 0.00 0.02 6.00 0.02 0.00 0.02 6.25 0.02 0.00 0.02 6.50 0.02 0.00 0.02 6.75 0.03 0.00 0.03 7.00 0.03 0.00 0.03 7.25 0.03 0.00 0.03 7.50 0.03 0.00 0.03 7.75 0.03 0.00 0.03 8.00 0.03 0.00 0.03 8.25 0.04 0.00 0.04 8.50 0.04 0.00 0.04 8.75 0.05 0.00 0.05 9.00 0.05 0.00 0.05 9.25 0.06 0.00 0.06 9.50 0.06 0.00 0.06 9.75 0.07 0.00 0.07 10.00 0.08 0.00 0.08 10.25 0.09 0.00 0.09 10.50 0.10 0.00 0.10 10.75 0.12 0.00 0.12 11.00 0.15 0.00 0.15 11.25 0.20 0.00 0.20 11.50 0.26 0.00 0.26 11.75 1.22 0.00 1.22 12.00 3.48 0.00 3.48 12.25 0.47 0.00 0.47 12.50 0.31 0.00 0.31 12.75 0.22 0.00 0.22 13.00 0.19 0.00 0.19 13.25 0.16 0.00 0.16 13.50 0.14 0.00 0.14 13.75 0.12 0.00 0.12 14.00 0.11 0.00 0.11 14.25 0.10 0.00 0.10 14.50 0.10 0.00 0.10 14.75 0.09 0.00 0.09 15.00 0.09 0.00 0.09 15.25 0.08 0.00 0.08 15.50 0.08 0.00 0.08 15.75 0.07 0.00 0.07 16.00 0.07 0.00 0.07 16.25 0.06 0.00 0.06 16.50 0.06 0.00 0.06 16.75 0.06 0.00 0.06 17.00 0.06 0.00 0.06 17.25 0.06 0.00 0.06 17.50 0.06 0.00 0.06 17.75 0.05 0.00 0.05 Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 18.00 0.05 0.00 0.05 18.25 0.05 0.00 0.05 18.50 0.05 0.00 0.05 18.75 0.05 0.00 0.05 19.00 0.05 0.00 0.05 19.25 0.04 0.00 0.04 19.50 0.04 0.00 0.04 19.75 0.04 0.00 0.04 20.00 0.04 0.00 0.04 Yancey Pre Post Type 1124-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 14 Summary for Subcatchment 1 S: Pre -Developed Area of Current Work Runoff = 2.63 cfs @ 11.96 hrs, Volume= 0.130 af, Depth> 2.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2Year Rainfall=3.69" Area (ac) CN Description 0.490 98 Paved parking, HSG B 0.060 61 >75% Grass cover, Good, HSG B 0.550 94 Weighted Average 0.060 10.91 % Pervious Area 0.490 89.09% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1 S: Pre -Developed Area of Current Work Hydrograph I I ❑Runoff 2.63 cfs Type II 24-hr ;2Year Rainfall-3.69" 2 — — -Runoff Area-o.550 ac i Runoffs Volume=0.i130 of Runoff Depth>2.83" ' ' Tc=6.0 min n LL -CN=94 I a 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 15 Hydrograph for Subcatchment 1 S: Pre -Developed Area of Current Work Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.23 0.01 0.01 5.25 0.25 0.02 0.01 5.50 0.26 0.02 0.01 5.75 0.28 0.03 0.01 6.00 0.30 0.03 0.01 6.25 0.31 0.04 0.01 6.50 0.33 0.05 0.02 6.75 0.35 0.06 0.02 7.00 0.37 0.06 0.02 7.25 0.38 0.07 0.02 7.50 0.40 0.08 0.02 7.75 0.42 0.09 0.02 8.00 0.44 0.10 0.02 8.25 0.46 0.12 0.03 8.50 0.49 0.13 0.03 8.75 0.51 0.15 0.04 9.00 0.54 0.16 0.04 9.25 0.57 0.18 0.04 9.50 0.60 0.20 0.04 9.75 0.63 0.22 0.05 10.00 0.67 0.25 0.06 10.25 0.71 0.28 0.06 10.50 0.75 0.31 0.08 10.75 0.81 0.35 0.09 11.00 0.87 0.40 0.11 11.25 0.94 0.46 0.14 11.50 1.04 0.54 0.19 11.75 1.43 0.87 0.88 12.00 2.45 1.82 2.45 12.25 2.61 1.97 0.33 12.50 2.71 2.07 0.21 12.75 2.79 2.14 0.16 13.00 2.85 2.20 0.13 13.25 2.90 2.26 0.11 13.50 2.95 2.30 0.10 13.75 2.99 2.34 0.09 14.00 3.03 2.38 0.08 14.25 3.06 2.41 0.07 14.50 3.09 2.44 0.07 14.75 3.12 2.47 0.06 15.00 3.15 2.49 0.06 15.25 3.18 2.52 0.06 15.50 3.20 2.55 0.05 15.75 3.23 2.57 0.05 16.00 3.25 2.59 0.05 16.25 3.27 2.61 0.04 16.50 3.29 2.63 0.04 16.75 3.31 2.65 0.04 17.00 3.33 2.67 0.04 17.25 3.35 2.69 0.04 17.50 3.36 2.70 0.04 17.75 3.38 2.72 0.04 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 3.40 2.74 0.04 18.25 3.41 2.75 0.04 18.50 3.43 2.77 0.03 18.75 3.45 2.78 0.03 19.00 3.46 2.80 0.03 19.25 3.47 2.81 0.03 19.50 3.49 2.82 0.03 19.75 3.50 2.84 0.03 20.00 3.51 2.85 0.03 Yancey Pre Post Type 1124-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 16 Summary for Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Runoff = 2.19 cfs @ 11.96 hrs, Volume= 0.114 af, Depth> 3.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2Year Rainfall=3.69" Area (ac) CN Description 0.430 98 Paved parking, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.430 98 Weighted Average 0.430 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Hydrograph ❑ Runoff 2.19 cfs Type 11 24ob r 2 � I 12Year Rainfall-3.69" Runoff Area=0.430 ac I Runoff) Vollume-0.1114 of Runoff Depth;>3.19" L Tc-6'.0 min LL 1 I I I I I I CN=98 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 17 Hydrograph for Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.23 0.09 0.02 5.25 0.25 0.10 0.02 5.50 0.26 0.12 0.02 5.75 0.28 0.13 0.02 6.00 0.30 0.14 0.02 6.25 0.31 0.15 0.02 6.50 0.33 0.17 0.02 6.75 0.35 0.18 0.03 7.00 0.37 0.20 0.03 7.25 0.38 0.22 0.03 7.50 0.40 0.23 0.03 7.75 0.42 0.25 0.03 8.00 0.44 0.27 0.03 8.25 0.46 0.29 0.03 8.50 0.49 0.31 0.04 8.75 0.51 0.33 0.04 9.00 0.54 0.36 0.05 9.25 0.57 0.38 0.05 9.50 0.60 0.41 0.05 9.75 0.63 0.44 0.05 10.00 0.67 0.47 0.06 10.25 0.71 0.51 0.07 10.50 0.75 0.55 0.08 10.75 0.81 0.60 0.09 11.00 0.87 0.66 0.10 11.25 0.94 0.74 0.13 11.50 1.04 0.83 0.17 11.75 1.43 1.21 0.77 12.00 2.45 2.22 2.02 12.25 2.61 2.38 0.27 12.50 2.71 2.48 0.17 12.75 2.79 2.56 0.13 13.00 2.85 2.62 0.10 13.25 2.90 2.67 0.09 13.50 2.95 2.72 0.08 13.75 2.99 2.76 0.07 14.00 3.03 2.79 0.06 14.25 3.06 2.83 0.06 14.50 3.09 2.86 0.05 14.75 3.12 2.89 0.05 15.00 3.15 2.92 0.05 15.25 3.18 2.94 0.05 15.50 3.20 2.97 0.04 15.75 3.23 2.99 0.04 16.00 3.25 3.01 0.04 16.25 3.27 3.04 0.04 16.50 3.29 3.06 0.04 16.75 3.31 3.08 0.03 17.00 3.33 3.09 0.03 17.25 3.35 3.11 0.03 17.50 3.36 3.13 0.03 17.75 3.38 3.15 0.03 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 3.40 3.17 0.03 18.25 3.41 3.18 0.03 18.50 3.43 3.20 0.03 18.75 3.45 3.21 0.03 19.00 3.46 3.23 0.03 19.25 3.47 3.24 0.02 19.50 3.49 3.25 0.02 19.75 3.50 3.27 0.02 20.00 3.51 3.28 0.02 Yancey Pre Post Type 1124-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 18 Summary for Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Runoff = 2.19 cfs @ 11.96 hrs, Volume= 0.114 af, Depth> 3.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2Year Rainfall=3.69" Area (ac) CN Description 0.430 98 Paved parking, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.430 98 Weighted Average 0.430 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Hydrograph ❑ Runoff 2.19 cfs Type 11 24ob r 2 � I 12Year Rainfall-3.69" Runoff Area=0.430 ac I Runoff) Vollume-0.1114 of Runoff Depth;>3.19" o _ - L Tc-6'.0 min LL 1 I I I I I I CN=98 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 19 Hydrograph for Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.23 0.09 0.02 5.25 0.25 0.10 0.02 5.50 0.26 0.12 0.02 5.75 0.28 0.13 0.02 6.00 0.30 0.14 0.02 6.25 0.31 0.15 0.02 6.50 0.33 0.17 0.02 6.75 0.35 0.18 0.03 7.00 0.37 0.20 0.03 7.25 0.38 0.22 0.03 7.50 0.40 0.23 0.03 7.75 0.42 0.25 0.03 8.00 0.44 0.27 0.03 8.25 0.46 0.29 0.03 8.50 0.49 0.31 0.04 8.75 0.51 0.33 0.04 9.00 0.54 0.36 0.05 9.25 0.57 0.38 0.05 9.50 0.60 0.41 0.05 9.75 0.63 0.44 0.05 10.00 0.67 0.47 0.06 10.25 0.71 0.51 0.07 10.50 0.75 0.55 0.08 10.75 0.81 0.60 0.09 11.00 0.87 0.66 0.10 11.25 0.94 0.74 0.13 11.50 1.04 0.83 0.17 11.75 1.43 1.21 0.77 12.00 2.45 2.22 2.02 12.25 2.61 2.38 0.27 12.50 2.71 2.48 0.17 12.75 2.79 2.56 0.13 13.00 2.85 2.62 0.10 13.25 2.90 2.67 0.09 13.50 2.95 2.72 0.08 13.75 2.99 2.76 0.07 14.00 3.03 2.79 0.06 14.25 3.06 2.83 0.06 14.50 3.09 2.86 0.05 14.75 3.12 2.89 0.05 15.00 3.15 2.92 0.05 15.25 3.18 2.94 0.05 15.50 3.20 2.97 0.04 15.75 3.23 2.99 0.04 16.00 3.25 3.01 0.04 16.25 3.27 3.04 0.04 16.50 3.29 3.06 0.04 16.75 3.31 3.08 0.03 17.00 3.33 3.09 0.03 17.25 3.35 3.11 0.03 17.50 3.36 3.13 0.03 17.75 3.38 3.15 0.03 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 3.40 3.17 0.03 18.25 3.41 3.18 0.03 18.50 3.43 3.20 0.03 18.75 3.45 3.21 0.03 19.00 3.46 3.23 0.03 19.25 3.47 3.24 0.02 19.50 3.49 3.25 0.02 19.75 3.50 3.27 0.02 20.00 3.51 3.28 0.02 Yancey Pre Post Type 1124-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 20 Summary for Subcatchment 5S: Post -Developed Area of Current Work Runoff = 2.45 cfs @ 11.97 hrs, Volume= 0.117 af, Depth> 2.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2Year Rainfall=3.69" Area (ac) CN Description 0.450 98 Paved parking, HSG B 0.100 61 >75% Grass cover, Good, HSG B 0.550 91 Weighted Average 0.100 18.18% Pervious Area 0.450 81.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: Post -Developed Area of Current Work Hydrograph I I I I 2.45 cfs I I I I Type II 24ohr + - + ;Vql r Rainfalll AT 2 I I 1 I I Runoff Area=0.550 ac I I I I Runoff) Vollume-0.1117 of Runoff Depth>2.55" I I Tc=6.0 min n LL CN=91 I a 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 21 Hydrograph for Subcatchment 5S: Post -Developed Area of Current Work Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.23 0.00 0.00 5.25 0.25 0.00 0.00 5.50 0.26 0.00 0.00 5.75 0.28 0.01 0.00 6.00 0.30 0.01 0.01 6.25 0.31 0.01 0.01 6.50 0.33 0.02 0.01 6.75 0.35 0.02 0.01 7.00 0.37 0.02 0.01 7.25 0.38 0.03 0.01 7.50 0.40 0.04 0.01 7.75 0.42 0.04 0.01 8.00 0.44 0.05 0.02 8.25 0.46 0.06 0.02 8.50 0.49 0.07 0.02 8.75 0.51 0.08 0.02 9.00 0.54 0.09 0.03 9.25 0.57 0.10 0.03 9.50 0.60 0.12 0.03 9.75 0.63 0.13 0.04 10.00 0.67 0.15 0.04 10.25 0.71 0.17 0.05 10.50 0.75 0.20 0.06 10.75 0.81 0.23 0.07 11.00 0.87 0.27 0.09 11.25 0.94 0.32 0.12 11.50 1.04 0.39 0.16 11.75 1.43 0.68 0.77 12.00 2.45 1.56 2.29 12.25 2.61 1.71 0.31 12.50 2.71 1.80 0.20 12.75 2.79 1.87 0.15 13.00 2.85 1.93 0.12 13.25 2.90 1.98 0.11 13.50 2.95 2.02 0.09 13.75 2.99 2.06 0.08 14.00 3.03 2.10 0.07 14.25 3.06 2.13 0.07 14.50 3.09 2.16 0.07 14.75 3.12 2.18 0.06 15.00 3.15 2.21 0.06 15.25 3.18 2.24 0.06 15.50 3.20 2.26 0.05 15.75 3.23 2.28 0.05 16.00 3.25 2.30 0.05 16.25 3.27 2.32 0.04 16.50 3.29 2.34 0.04 16.75 3.31 2.36 0.04 17.00 3.33 2.38 0.04 17.25 3.35 2.40 0.04 17.50 3.36 2.41 0.04 17.75 3.38 2.43 0.04 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 3.40 2.45 0.04 18.25 3.41 2.46 0.03 18.50 3.43 2.48 0.03 18.75 3.45 2.49 0.03 19.00 3.46 2.50 0.03 19.25 3.47 2.52 0.03 19.50 3.49 2.53 0.03 19.75 3.50 2.54 0.03 20.00 3.51 2.55 0.03 Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 22 Summary for Link 3L: Pre -Developed Inflow Area = 0.980 ac, 93.88% Impervious, Inflow Depth > 2.99" for 2Year event Inflow = 4.82 cfs @ 11.96 hrs, Volume= 0.244 of Primary = 4.82 cfs @ 11.96 hrs, Volume= 0.244 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs N V 3 0 LL Link 3L: Pre -Developed Hydrograph 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Inflow ❑ Primary Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 23 Hydrograph for Link 3L: Pre -Developed Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 5.00 0.03 0.00 0.03 5.25 0.03 0.00 0.03 5.50 0.03 0.00 0.03 5.75 0.03 0.00 0.03 6.00 0.04 0.00 0.04 6.25 0.04 0.00 0.04 6.50 0.04 0.00 0.04 6.75 0.04 0.00 0.04 7.00 0.05 0.00 0.05 7.25 0.05 0.00 0.05 7.50 0.05 0.00 0.05 7.75 0.05 0.00 0.05 8.00 0.06 0.00 0.06 8.25 0.06 0.00 0.06 8.50 0.07 0.00 0.07 8.75 0.08 0.00 0.08 9.00 0.09 0.00 0.09 9.25 0.09 0.00 0.09 9.50 0.09 0.00 0.09 9.75 0.10 0.00 0.10 10.00 0.11 0.00 0.11 10.25 0.13 0.00 0.13 10.50 0.15 0.00 0.15 10.75 0.18 0.00 0.18 11.00 0.21 0.00 0.21 11.25 0.28 0.00 0.28 11.50 0.36 0.00 0.36 11.75 1.65 0.00 1.65 12.00 4.46 0.00 4.46 12.25 0.60 0.00 0.60 12.50 0.38 0.00 0.38 12.75 0.28 0.00 0.28 13.00 0.23 0.00 0.23 13.25 0.20 0.00 0.20 13.50 0.18 0.00 0.18 13.75 0.16 0.00 0.16 14.00 0.14 0.00 0.14 14.25 0.13 0.00 0.13 14.50 0.12 0.00 0.12 14.75 0.12 0.00 0.12 15.00 0.11 0.00 0.11 15.25 0.10 0.00 0.10 15.50 0.10 0.00 0.10 15.75 0.09 0.00 0.09 16.00 0.08 0.00 0.08 16.25 0.08 0.00 0.08 16.50 0.08 0.00 0.08 16.75 0.08 0.00 0.08 17.00 0.07 0.00 0.07 17.25 0.07 0.00 0.07 17.50 0.07 0.00 0.07 17.75 0.07 0.00 0.07 Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 18.00 0.07 0.00 0.07 18.25 0.06 0.00 0.06 18.50 0.06 0.00 0.06 18.75 0.06 0.00 0.06 19.00 0.06 0.00 0.06 19.25 0.05 0.00 0.05 19.50 0.05 0.00 0.05 19.75 0.05 0.00 0.05 20.00 0.05 0.00 0.05 Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 24 Summary for Link 6L: Post -Developed Inflow Area = 0.980 ac, 89.80% Impervious, Inflow Depth > 2.83" for 2Year event Inflow = 4.64 cfs @ 11.96 hrs, Volume= 0.231 of Primary = 4.64 cfs @ 11.96 hrs, Volume= 0.231 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 6L: Post -Developed Hydrograph ❑ Inflow ❑ Primary 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 11 24-hr 2Year Rainfall=3.69" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 25 Hydrograph for Link 6L: Post -Developed Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 5.00 0.02 0.00 0.02 5.25 0.02 0.00 0.02 5.50 0.02 0.00 0.02 5.75 0.03 0.00 0.03 6.00 0.03 0.00 0.03 6.25 0.03 0.00 0.03 6.50 0.03 0.00 0.03 6.75 0.04 0.00 0.04 7.00 0.04 0.00 0.04 7.25 0.04 0.00 0.04 7.50 0.04 0.00 0.04 7.75 0.04 0.00 0.04 8.00 0.05 0.00 0.05 8.25 0.05 0.00 0.05 8.50 0.06 0.00 0.06 8.75 0.07 0.00 0.07 9.00 0.07 0.00 0.07 9.25 0.08 0.00 0.08 9.50 0.08 0.00 0.08 9.75 0.09 0.00 0.09 10.00 0.10 0.00 0.10 10.25 0.12 0.00 0.12 10.50 0.13 0.00 0.13 10.75 0.16 0.00 0.16 11.00 0.19 0.00 0.19 11.25 0.25 0.00 0.25 11.50 0.33 0.00 0.33 11.75 1.54 0.00 1.54 12.00 4.31 0.00 4.31 12.25 0.58 0.00 0.58 12.50 0.38 0.00 0.38 12.75 0.27 0.00 0.27 13.00 0.23 0.00 0.23 13.25 0.20 0.00 0.20 13.50 0.17 0.00 0.17 13.75 0.15 0.00 0.15 14.00 0.14 0.00 0.14 14.25 0.13 0.00 0.13 14.50 0.12 0.00 0.12 14.75 0.11 0.00 0.11 15.00 0.11 0.00 0.11 15.25 0.10 0.00 0.10 15.50 0.10 0.00 0.10 15.75 0.09 0.00 0.09 16.00 0.08 0.00 0.08 16.25 0.08 0.00 0.08 16.50 0.08 0.00 0.08 16.75 0.08 0.00 0.08 17.00 0.07 0.00 0.07 17.25 0.07 0.00 0.07 17.50 0.07 0.00 0.07 17.75 0.07 0.00 0.07 Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 18.00 0.06 0.00 0.06 18.25 0.06 0.00 0.06 18.50 0.06 0.00 0.06 18.75 0.06 0.00 0.06 19.00 0.06 0.00 0.06 19.25 0.05 0.00 0.05 19.50 0.05 0.00 0.05 19.75 0.05 0.00 0.05 20.00 0.05 0.00 0.05 Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 26 Summary for Subcatchment 1 S: Pre -Developed Area of Current Work Runoff = 4.10 cfs @ 11.96 hrs, Volume= 0.208 af, Depth> 4.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10Year Rainfall=5.55" Area (ac) CN Description 0.490 98 Paved parking, HSG B 0.060 61 >75% Grass cover, Good, HSG B 0.550 94 Weighted Average 0.060 10.91 % Pervious Area 0.490 89.09% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1 S: Pre -Developed Area of Current Work Hydrograph 3 I I I I I I m I I I v I I L 2 1 I I I I Type II 24-hr JOYpar Rainfall-.5.55" - - - -Runoff Area=0.550 ac Runoffll Volllume=0.1208 of Runoff Depth>4.53" 'I Tc-6.0min CN=94 I I I I I 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 27 Hydrograph for Subcatchment 1 S: Pre -Developed Area of Current Work Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.35 0.06 0.02 5.25 0.37 0.07 0.02 5.50 0.40 0.08 0.03 5.75 0.42 0.09 0.03 6.00 0.44 0.10 0.03 6.25 0.47 0.12 0.03 6.50 0.50 0.13 0.03 6.75 0.52 0.15 0.04 7.00 0.55 0.17 0.04 7.25 0.58 0.19 0.04 7.50 0.61 0.21 0.04 7.75 0.64 0.23 0.04 8.00 0.67 0.25 0.05 8.25 0.70 0.27 0.05 8.50 0.73 0.30 0.06 8.75 0.77 0.32 0.07 9.00 0.82 0.36 0.07 9.25 0.86 0.39 0.08 9.50 0.90 0.43 0.08 9.75 0.95 0.46 0.09 10.00 1.00 0.51 0.10 10.25 1.06 0.56 0.11 10.50 1.13 0.61 0.13 10.75 1.21 0.68 0.15 11.00 1.30 0.76 0.18 11.25 1.42 0.87 0.24 11.50 1.57 1.00 0.31 11.75 2.15 1.54 1.41 12.00 3.68 3.01 3.80 12.25 3.92 3.25 0.51 12.50 4.08 3.40 0.33 12.75 4.19 3.51 0.24 13.00 4.28 3.60 0.20 13.25 4.36 3.68 0.17 13.50 4.43 3.75 0.15 13.75 4.50 3.81 0.13 14.00 4.55 3.87 0.12 14.25 4.60 3.91 0.11 14.50 4.65 3.96 0.10 14.75 4.69 4.01 0.10 15.00 4.74 4.05 0.09 15.25 4.78 4.09 0.09 15.50 4.82 4.13 0.08 15.75 4.85 4.16 0.08 16.00 4.88 4.19 0.07 16.25 4.92 4.22 0.07 16.50 4.95 4.25 0.07 16.75 4.98 4.28 0.06 17.00 5.00 4.31 0.06 17.25 5.03 4.34 0.06 17.50 5.06 4.37 0.06 17.75 5.09 4.39 0.06 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 5.11 4.42 0.06 18.25 5.14 4.44 0.05 18.50 5.16 4.47 0.05 18.75 5.18 4.49 0.05 19.00 5.20 4.51 0.05 19.25 5.23 4.53 0.05 19.50 5.25 4.55 0.04 19.75 5.27 4.57 0.04 20.00 5.28 4.59 0.04 Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 28 Summary for Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Runoff = 3.31 cfs @ 11.96 hrs, Volume= 0.174 af, Depth> 4.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10Year Rainfall=5.55" Area (ac) CN Description 0.430 98 Paved parking, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.430 98 Weighted Average 0.430 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Hydrograph ❑ Runoff 3.31 cfs Type II 24ohr 3 JOYpar Rainfall 5.55" Runoff Area=0.430 ac I I I I Runoff) Vollume-0.11741 of - - - - - - 2 Runoff Depth�4.86" 1 1 I I I Tc=6I'.0 m i n I I I I DN=98 1 I I I I I I 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 29 Hydrograph for Subcatchment 2S: Pre -Developed Area of Concrete Pad Previously Constructed Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.35 0.19 0.03 5.25 0.37 0.21 0.03 5.50 0.40 0.23 0.03 5.75 0.42 0.25 0.04 6.00 0.44 0.27 0.04 6.25 0.47 0.29 0.04 6.50 0.50 0.31 0.04 6.75 0.52 0.34 0.04 7.00 0.55 0.36 0.04 7.25 0.58 0.39 0.05 7.50 0.61 0.42 0.05 7.75 0.64 0.44 0.05 8.00 0.67 0.47 0.05 8.25 0.70 0.50 0.05 8.50 0.73 0.54 0.06 8.75 0.77 0.57 0.07 9.00 0.82 0.61 0.07 9.25 0.86 0.66 0.07 9.50 0.90 0.70 0.07 9.75 0.95 0.74 0.08 10.00 1.00 0.80 0.09 10.25 1.06 0.85 0.10 10.50 1.13 0.92 0.12 10.75 1.21 1.00 0.14 11.00 1.30 1.09 0.16 11.25 1.42 1.20 0.21 11.50 1.57 1.35 0.26 11.75 2.15 1.92 1.17 12.00 3.68 3.45 3.05 12.25 3.92 3.68 0.40 12.50 4.08 3.84 0.26 12.75 4.19 3.96 0.19 13.00 4.28 4.05 0.16 13.25 4.36 4.13 0.14 13.50 4.43 4.20 0.12 13.75 4.50 4.26 0.11 14.00 4.55 4.31 0.09 14.25 4.60 4.36 0.09 14.50 4.65 4.41 0.08 14.75 4.69 4.46 0.08 15.00 4.74 4.50 0.07 15.25 4.78 4.54 0.07 15.50 4.82 4.58 0.07 15.75 4.85 4.61 0.06 16.00 4.88 4.65 0.06 16.25 4.92 4.68 0.05 16.50 4.95 4.71 0.05 16.75 4.98 4.74 0.05 17.00 5.00 4.77 0.05 17.25 5.03 4.80 0.05 17.50 5.06 4.82 0.05 17.75 5.09 4.85 0.05 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 5.11 4.87 0.04 18.25 5.14 4.90 0.04 18.50 5.16 4.92 0.04 18.75 5.18 4.95 0.04 19.00 5.20 4.97 0.04 19.25 5.23 4.99 0.04 19.50 5.25 5.01 0.03 19.75 5.27 5.03 0.03 20.00 5.28 5.05 0.03 Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 30 Summary for Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Runoff = 3.31 cfs @ 11.96 hrs, Volume= 0.174 af, Depth> 4.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10Year Rainfall=5.55" Area (ac) CN Description 0.430 98 Paved parking, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.430 98 Weighted Average 0.430 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Hydrograph ❑ Runoff 3.31 cfs Type II 24ohr 3 JOYpar Rainfall 5.55" Runoff Area=0.430 ac I I I I Runoff) Vollume-0.11741 of - - - - - - 2 Runoff Depth�4.86" 1 1 I I I Tc=6I'.0 m i n I I I I DN=98 1 I I I I I I 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 31 Hydrograph for Subcatchment 4S: Post -Developed Area of Concrete Pad Previously Constructed Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.35 0.19 0.03 5.25 0.37 0.21 0.03 5.50 0.40 0.23 0.03 5.75 0.42 0.25 0.04 6.00 0.44 0.27 0.04 6.25 0.47 0.29 0.04 6.50 0.50 0.31 0.04 6.75 0.52 0.34 0.04 7.00 0.55 0.36 0.04 7.25 0.58 0.39 0.05 7.50 0.61 0.42 0.05 7.75 0.64 0.44 0.05 8.00 0.67 0.47 0.05 8.25 0.70 0.50 0.05 8.50 0.73 0.54 0.06 8.75 0.77 0.57 0.07 9.00 0.82 0.61 0.07 9.25 0.86 0.66 0.07 9.50 0.90 0.70 0.07 9.75 0.95 0.74 0.08 10.00 1.00 0.80 0.09 10.25 1.06 0.85 0.10 10.50 1.13 0.92 0.12 10.75 1.21 1.00 0.14 11.00 1.30 1.09 0.16 11.25 1.42 1.20 0.21 11.50 1.57 1.35 0.26 11.75 2.15 1.92 1.17 12.00 3.68 3.45 3.05 12.25 3.92 3.68 0.40 12.50 4.08 3.84 0.26 12.75 4.19 3.96 0.19 13.00 4.28 4.05 0.16 13.25 4.36 4.13 0.14 13.50 4.43 4.20 0.12 13.75 4.50 4.26 0.11 14.00 4.55 4.31 0.09 14.25 4.60 4.36 0.09 14.50 4.65 4.41 0.08 14.75 4.69 4.46 0.08 15.00 4.74 4.50 0.07 15.25 4.78 4.54 0.07 15.50 4.82 4.58 0.07 15.75 4.85 4.61 0.06 16.00 4.88 4.65 0.06 16.25 4.92 4.68 0.05 16.50 4.95 4.71 0.05 16.75 4.98 4.74 0.05 17.00 5.00 4.77 0.05 17.25 5.03 4.80 0.05 17.50 5.06 4.82 0.05 17.75 5.09 4.85 0.05 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 5.11 4.87 0.04 18.25 5.14 4.90 0.04 18.50 5.16 4.92 0.04 18.75 5.18 4.95 0.04 19.00 5.20 4.97 0.04 19.25 5.23 4.99 0.04 19.50 5.25 5.01 0.03 19.75 5.27 5.03 0.03 20.00 5.28 5.05 0.03 Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paqe 32 Summary for Subcatchment 5S: Post -Developed Area of Current Work Runoff = 3.94 cfs @ 11.96 hrs, Volume= 0.194 af, Depth> 4.24" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10Year Rainfall=5.55" Area (ac) CN Description 0.450 98 Paved parking, HSG B 0.100 61 >75% Grass cover, Good, HSG B 0.550 91 Weighted Average 0.100 18.18% Pervious Area 0.450 81.82% Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: Post -Developed Area of Current Work Hydrograph 3.94 cfs I 4 1 Type II 24-hr Wear Rainfall-5.55" 3 Runb#f-area-0-.550 ac 1 i Runoffs Volume-0.i1941 of Runoff Depth;4.Z4" LL2 I_ �_ I _II__--T'c-6'.Omin I I I I I I CN=91 I I I I I 1 I I I 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 33 Hydrograph for Subcatchment 5S: Post -Developed Area of Current Work Time Precip. Excess Runoff lours) (inches) (inches) (cfs) 5.00 0.35 0.02 0.01 5.25 0.37 0.03 0.01 5.50 0.40 0.03 0.02 5.75 0.42 0.04 0.02 6.00 0.44 0.05 0.02 6.25 0.47 0.06 0.02 6.50 0.50 0.07 0.02 6.75 0.52 0.08 0.03 7.00 0.55 0.09 0.03 7.25 0.58 0.11 0.03 7.50 0.61 0.12 0.03 7.75 0.64 0.13 0.03 8.00 0.67 0.15 0.04 8.25 0.70 0.17 0.04 8.50 0.73 0.19 0.05 8.75 0.77 0.21 0.05 9.00 0.82 0.24 0.06 9.25 0.86 0.27 0.06 9.50 0.90 0.29 0.06 9.75 0.95 0.33 0.07 10.00 1.00 0.36 0.08 10.25 1.06 0.40 0.10 10.50 1.13 0.45 0.11 10.75 1.21 0.51 0.13 11.00 1.30 0.58 0.16 11.25 1.42 0.68 0.21 11.50 1.57 0.80 0.28 11.75 2.15 1.29 1.31 12.00 3.68 2.71 3.67 12.25 3.92 2.94 0.50 12.50 4.08 3.09 0.32 12.75 4.19 3.20 0.23 13.00 4.28 3.29 0.19 13.25 4.36 3.37 0.17 13.50 4.43 3.43 0.15 13.75 4.50 3.49 0.13 14.00 4.55 3.55 0.12 14.25 4.60 3.60 0.11 14.50 4.65 3.64 0.10 14.75 4.69 3.69 0.10 15.00 4.74 3.73 0.09 15.25 4.78 3.77 0.09 15.50 4.82 3.80 0.08 15.75 4.85 3.84 0.08 16.00 4.88 3.87 0.07 16.25 4.92 3.90 0.07 16.50 4.95 3.93 0.07 16.75 4.98 3.96 0.06 17.00 5.00 3.99 0.06 17.25 5.03 4.01 0.06 17.50 5.06 4.04 0.06 17.75 5.09 4.07 0.06 Time Precip. Excess Runoff hours) (inches) (inches) (cfs) 18.00 5.11 4.09 0.05 18.25 5.14 4.11 0.05 18.50 5.16 4.14 0.05 18.75 5.18 4.16 0.05 19.00 5.20 4.18 0.05 19.25 5.23 4.20 0.05 19.50 5.25 4.22 0.04 19.75 5.27 4.24 0.04 20.00 5.28 4.26 0.04 Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 34 Summary for Link 3L: Pre -Developed Inflow Area = 0.980 ac, 93.88% Impervious, Inflow Depth > 4.68" for 10Year event Inflow = 7.41 cfs @ 11.96 hrs, Volume= 0.382 of Primary = 7.41 cfs @ 11.96 hrs, Volume= 0.382 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs N V 3 0 LL Link 3L: Pre -Developed Hydrograph 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Inflow ❑ Primary Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 35 Hydrograph for Link 3L: Pre -Developed Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 5.00 0.05 0.00 0.05 5.25 0.06 0.00 0.06 5.50 0.06 0.00 0.06 5.75 0.06 0.00 0.06 6.00 0.07 0.00 0.07 6.25 0.07 0.00 0.07 6.50 0.07 0.00 0.07 6.75 0.08 0.00 0.08 7.00 0.08 0.00 0.08 7.25 0.09 0.00 0.09 7.50 0.09 0.00 0.09 7.75 0.09 0.00 0.09 8.00 0.10 0.00 0.10 8.25 0.11 0.00 0.11 8.50 0.12 0.00 0.12 8.75 0.13 0.00 0.13 9.00 0.14 0.00 0.14 9.25 0.15 0.00 0.15 9.50 0.15 0.00 0.15 9.75 0.17 0.00 0.17 10.00 0.19 0.00 0.19 10.25 0.21 0.00 0.21 10.50 0.25 0.00 0.25 10.75 0.29 0.00 0.29 11.00 0.34 0.00 0.34 11.25 0.44 0.00 0.44 11.50 0.57 0.00 0.57 11.75 2.58 0.00 2.58 12.00 6.85 0.00 6.85 12.25 0.91 0.00 0.91 12.50 0.59 0.00 0.59 12.75 0.43 0.00 0.43 13.00 0.36 0.00 0.36 13.25 0.31 0.00 0.31 13.50 0.27 0.00 0.27 13.75 0.24 0.00 0.24 14.00 0.21 0.00 0.21 14.25 0.20 0.00 0.20 14.50 0.19 0.00 0.19 14.75 0.18 0.00 0.18 15.00 0.17 0.00 0.17 15.25 0.16 0.00 0.16 15.50 0.15 0.00 0.15 15.75 0.14 0.00 0.14 16.00 0.13 0.00 0.13 16.25 0.12 0.00 0.12 16.50 0.12 0.00 0.12 16.75 0.12 0.00 0.12 17.00 0.11 0.00 0.11 17.25 0.11 0.00 0.11 17.50 0.11 0.00 0.11 17.75 0.10 0.00 0.10 Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 18.00 0.10 0.00 0.10 18.25 0.10 0.00 0.10 18.50 0.09 0.00 0.09 18.75 0.09 0.00 0.09 19.00 0.09 0.00 0.09 19.25 0.08 0.00 0.08 19.50 0.08 0.00 0.08 19.75 0.08 0.00 0.08 20.00 0.07 0.00 0.07 Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 36 Summary for Link 6L: Post -Developed Inflow Area = 0.980 ac, 89.80% Impervious, Inflow Depth > 4.51" for Mear event Inflow = 7.25 cfs @ 11.96 hrs, Volume= 0.368 of Primary = 7.25 cfs @ 11.96 hrs, Volume= 0.368 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs N U 3 0 LL Link 6L: Post -Developed Hydrograph 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Inflow ❑ Primary Yancey Pre Post Type 1124-hr 10Year Rainfall=5.55" Prepared by Timmons Group Printed 8/21/2019 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 37 Hydrograph for Link 6L: Post -Developed Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 5.00 0.04 0.00 0.04 5.25 0.05 0.00 0.05 5.50 0.05 0.00 0.05 5.75 0.05 0.00 0.05 6.00 0.06 0.00 0.06 6.25 0.06 0.00 0.06 6.50 0.06 0.00 0.06 6.75 0.07 0.00 0.07 7.00 0.07 0.00 0.07 7.25 0.07 0.00 0.07 7.50 0.08 0.00 0.08 7.75 0.08 0.00 0.08 8.00 0.08 0.00 0.08 8.25 0.09 0.00 0.09 8.50 0.11 0.00 0.11 8.75 0.12 0.00 0.12 9.00 0.13 0.00 0.13 9.25 0.14 0.00 0.14 9.50 0.14 0.00 0.14 9.75 0.15 0.00 0.15 10.00 0.17 0.00 0.17 10.25 0.20 0.00 0.20 10.50 0.23 0.00 0.23 10.75 0.27 0.00 0.27 11.00 0.32 0.00 0.32 11.25 0.42 0.00 0.42 11.50 0.54 0.00 0.54 11.75 2.48 0.00 2.48 12.00 6.72 0.00 6.72 12.25 0.90 0.00 0.90 12.50 0.58 0.00 0.58 12.75 0.42 0.00 0.42 13.00 0.35 0.00 0.35 13.25 0.30 0.00 0.30 13.50 0.27 0.00 0.27 13.75 0.24 0.00 0.24 14.00 0.21 0.00 0.21 14.25 0.19 0.00 0.19 14.50 0.18 0.00 0.18 14.75 0.17 0.00 0.17 15.00 0.16 0.00 0.16 15.25 0.16 0.00 0.16 15.50 0.15 0.00 0.15 15.75 0.14 0.00 0.14 16.00 0.13 0.00 0.13 16.25 0.12 0.00 0.12 16.50 0.12 0.00 0.12 16.75 0.12 0.00 0.12 17.00 0.11 0.00 0.11 17.25 0.11 0.00 0.11 17.50 0.11 0.00 0.11 17.75 0.10 0.00 0.10 Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) 18.00 0.10 0.00 0.10 18.25 0.09 0.00 0.09 18.50 0.09 0.00 0.09 18.75 0.09 0.00 0.09 19.00 0.08 0.00 0.08 19.25 0.08 0.00 0.08 19.50 0.08 0.00 0.08 19.75 0.07 0.00 0.07 20.00 0.07 0.00 0.07 CLEAR ALL data input cells Project Name: Yancey Lumber Yard VSMP 6/25/2019 constant values Date: Linear Development Project? No calculation cells Site Information Post -Development Project (Treatment Volume and Loads) Enter Total Disturbed Area (acres) 0.98 Check: BMP Design Specifications List: 2013 Draft Stds & Specs t® Linear project? No 0 Land cover areas entered correctly? Total disturbed area entered? Pre-ReDevelopment Land Cover (acres) A Soils B Soils C Soils D Soils Totals Forest/Open Space (acres) -- undisturbed forest/open space 0.00 Managed Turf (acres) -- disturbed, graded for yards or other turf to be mowed/managed 0.06 0.06 Impervious Cover (acres) 0.92 0.92 0. 88 Post -Development Land Cover (acres) A soils B Soils C Soils D Soils Totals Forest/Open Space (acres) -- undisturbed, protected forest/open space or reforested land 0.00 Managed Turf (acres) -- disturbed, graded for 0.10 yards or other turf to be mowed/managed 0.10 Impervious Cover (acres) 0.88 0.88 Area Check OK. OK. K. 0.98 Constants Runoff Coefficients (Rv) Annual Rainfall (inches) 43 A Soils 8 Soils C Soils D Soils Target Rainfall Event (inches) 1.00 Forest/Open Space 0.02 0.03 0.04 0.05 Total Phosphorus (TP) EMC (mg/L) 0.26 Managed Turf 0.15 1 0.20 0.22 0.25 Total Nitrogen (TN) EMC (mg/L) 1.86 Impervious Cover 0.95 0.95 0.95 0.95 Target TP Load (lb/acre/yr) 0.41 Pj (unitless correction factor) 0.90 COVERLAND • • • POST DEVELOPMENT Land Cover Summary -Post Land Cover Summary -Pre Land Cover Summary -Post (Final) Land Cover Summary -Post Pre-ReDevelopment Listed Adjusted' Post ReDev. & New Impervious Post-ReDevelopment Post -Development New Impervious Forest/Open Space Cover (acres) 0.00 0.00 Forest/Open Space 0.00 Forest/Open Space 0.00 Cover (acres) Cover (acres) Weighted Rv(forest) 0.00 0.00 Weighted Rv(forest) 0.00 Weighted Rv(forest) 0.00 %Forest 0% 0% %Forest 0% %Forest 0% Managed Turf Cover (acres) 0.06 0.06 Managed Turf Cover 0.10 Managed Turf Cover 0.10 (acres) (acres) New Impervious Cover 0.00 Weighted Rv(turf) 0.20 0.20 Weighted Rv (turf) 0.20 Weighted Rv (turf) 0.20 %Managed Turf 6% 6% %Managed Turf 10% %Managed Turf 10% Impervious Cover (acres) 0.92 0.92 Impervious Cover 0.88 ReDev. Impervious 0.88 (acres) Cover (acres) (acres) Rv(impervious) 0.95 0.95 Rv(impervious) 0.95 Rv(impervious) 0.95 Rv(impervious) -- %Impervious 94% 94% %Impervious 90% %Impervious 90% Final Site Area (acres) 0.98 Total ReDev. Site Area 0.98 (acres)nxx- Final Post Dev Site Rv 0.87 ReDev Site Rv 0.87 Treatment Volume and Nutrient Load Final Post- Post-ReDevelopment Post -Development Total Site Area (acres) 0.98 0.98 Site Rv 0.90 0.90 Treatment Volume and Nutrient Load Pre-ReDevelopment Treatment Volume 0.0738 0.0738 Development 0.0713 Treatment Volume 0.0713 Treatment Volume -- (acre-ft) Treatment Volume (acre-ft) (acre-ft) (acre-ft) Final Post- Post-ReDevelopment Post -Development Pre-ReDevelopment Treatment Volume 3,216 3,216 Development 3,107 Treatment Volume 3,107 Treatment Volume (cubic -- (cubic feet) Treatment Volume (cubic fee[) feet) (cubic feet) Final Post- Post-ReDevelopment Post -Development TP Pre-ReDevelopment TP Load (lb/yr) 2.02 2.02 Development TP Load 1.95 Load (TP) 1.95 Load (lb/yr) (Ib/yr) (lb/yr)* Final Post -Development TP Post-ReDevelopment TP Pre-ReDevelopment TP Load per acre (Ib/acre/yr) 2.06 Load per acre 1.99 Load per acre 1.99 (lb/acre/yr) (Ib/acre/yr) Baseline TP Load (lb/yr) Max. Reduction Required (0.41 Ibs/acre/yr applied to pre -redevelopment area excluding pervious 0.40 (Below Pre- 10% land proposed for new impervious cover) ReDevelopment Load) Adjusted Land Cover Summary: I rY� Pre ReDevelopment land cover minus pervious land cover (forest/open space or TP Load Reduction Required for 0.13 TP Load Reduction Required for New 0 managed turf) acreage proposed for new impervious cover. Redeveloped Area Impervious Area (Ib/yr) (Ib/yr) Adjusted total acreage is consistent with Post-ReDevelopment acreage (minus acreage of new impervious cover). Column I shows load reduction requriement for new impervious cover (based on new development load limit 0.41 Ibs/acre/year). Post -Development Requirement fe TP Load Reduction Required (Ib/yr) 0.13