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HomeMy WebLinkAboutWPO202000032 Calculations 2020-06-08SHIMP ENGINEERING, P.C. Design Focused Engineering June 2, 2020 County of Albemarle Department of Community Development 401 McIntire Road Charlottesville, VA 22902 Regarding: 1300 Richmond Road — Flow Automotive Stormwater Management Plan Dear Reviewer, The purpose of this project is to make improvements to a site with existing automobile services and sales. The two existing buildings will be expanded upon, and one new sales building will be constructed. The total area of disturbance is 4.39 acres. Runoff from the site is analyzed at five points, labeled POA1 thru POA5. Please see VSMP plan sheets C12 and C13 for the locations of these drainage areas and points of analysis. The drainage areas to points of analysis 1 thru 3 are separated into disturbed and undisturbed area, since the improvement factor is only applied to the disturbed portions. Points of analysis 4 and 5 include only disturbed area, since the disturbances create no change to the drainage patterns outside the limits of disturbance in those areas. Drainage areas to POA 1 are further separated into drainage to the existing detention system on site and drainage straight to POA 1. All end up at POA 1, but this separation was used to ensure that the existing detention system will continue to function as designed. The post -development drainage area acreage and curve number to the existing detention system are less than in pre -development conditions. Runoff to POA 1 is held in a detention pond and released at a peak flow rate that complies with channel protection requirements set forth in 9VAC25-870-66-B3 (energy balance equation). Flood protection is met as runoff is outlet into a mapped floodplain. Runoff to all other points of analysis complies with channel protection requirements and flood protection requirements as the post -development 10 yr, 24 hr storm is released at a peak flow rate less than in pre -development conditions. Please see below for a summary of energy balance calculations. The first table shows 1 yr, 24 hr storm peak flow rates and runoff volume for drainage areas within the disturbed area. The improvement factor of 0.8 is applied to these values in the energy balance equation. The second table shows all values for drainage areas outside of the limits of disturbance, no improvement factor was applied to these values. The third table shows the final results, along with 10 yr, 24 hr storm peak flow rates of both pre and post development conditions. For further detail on these drainage areas and calculations, please see the HydroCAD reports included in this document. Table 1. Values for DAs Within LOD - Energ Balance Equation PREDEV POSTDEV POA Q1 RV RV 1 8.92 0.407 0.636 2 0.32 0.02 0.006 3 1.37 0.068 0.024 4 1.11 0.052 0.004 5 0.67 0.031 0.023 912 E. High Sr. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com Table 2. Values for DAs Outside LOD — Energy Balance Equation PREDEV POSTDEV POA Q1 RV RV 1 4.96 0.235 0.272 2 0.56 0.036 0.023 3 6.11 0.285 0.315 4 N/A N/A N/A 5 N/A N/A N/A Table 3. Summary of Results — Energy Balance Equation & Flood Protection Table 1 Table 2 Q1 Allowable = (Q1 Pre(LOD)*RvPre(LOD)*I.F.)/RvPost(LOD)I+[(Q1 Pre*RvPre)/RvPost] POA Q1 ALLOWABLE (cfs) Q1 PROPOSED (cfs) Q10 PRE (cfs) Q10 POST (cfs) 1 8.85 7.73 27.97 37.75* 2 1.73 0.49 7.29 3.74* 3 8.63 6.92 14.39 12.91 4 11.54 0.09 2.12 0.38 5 0.72 0.51 1.32 1.03 *Discharges to Mapped Floodplain According to the VRRM spreadsheet included in this packet, the target phosphorus load reduction is 2.49 lb/yr. Nutrient credits will be purchased to satisfy this requirement. Contents: Pre -Development Stormwater Management Calculations: Pre -Development Landuse Map Pre -Development HydroCAD Analysis Post -Development Stormwater Management Calculations: Post -Development Landuse Map Post -Development HydroCAD Analysis Stormwater Quality Calculations: VRRM Redevelopment Spreadsheet Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report Pre -Development Stormwater Management Calculations Pre -Development Landuse Map Pre -Development HydroCAD Analysis L HC I , `.\ 7 9 B HSG B I HD SGB ? I HSG B - -f j 1 I I I I I I it � 8 8 it HSG D Ic 71 D I I� HSG B Im / I I 78-5A I CORNER, LC / I 358-684, / S PLAT ED: HC / 1 / / 23B HSG B / I I � I I PRE -DEVELOPMENT LANDUSE MAP I 41 1 1300 RICHMOND ROAD OPEN SPACE TURF IMPERVIOUS I T.M. 78-9 TCO PARTNERS, LLC D.B. 13 D.B. 3657-569 569 THRU 578 PLAT \ D.B. 3339-701, 704 THRU 707 PLAT ZONED: HC J HSG B HSG D _0 �� 0 , 0.89 AC �Y/17 Y/\-Z I 2.32 AC To Ex. Det. & POA1 LOD) To P A 1 Direct (IN LOD) POA 1 (WITHIN LOD) Subcat Reach on Link To POA 1 Direct (Outside LOD) PreDev - POA 1 PreDev - POA 1 Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 2 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: To Ex. Det. & POA1 (IN Runoff Area=0.874 ac 89.02% Impervious Runoff Depth>2.42" Tc=5.0 min CN=96 Runoff=3.65 cfs 0.176 of Subcatchment2S: To Ex. Det. & POA1 Runoff Area=1.198 ac 88.98% Impervious Runoff Depth>2.32" Tc=5.0 min CN=95 Runoff=4.89 cfs 0.232 of Subcatchment4S: To POA 1 Direct (IN LOD)Runoff Area=1.615 ac 66.44% Impervious Runoff Depth>1.71" Tc=5.0 min CN=88 Runoff=5.27 cfs 0.231 of Subcatchment5S: To POA 1 Direct (Outside Runoff Area=0.068 ac 4.41 % Impervious Runoff Depth>0.53" Tc=5.0 min CN=67 Runoff=0.07 cfs 0.003 of Link 3L: POA 1 (WITHIN LOD) Inflow=13.88 cfs 0.642 of Primary=13.88 cfs 0.642 of Total Runoff Area = 3.755 ac Runoff Volume = 0.642 of Average Runoff Depth = 2.05" 22.24% Pervious = 0.835 ac 77.76% Impervious = 2.920 ac PreDev - POA 1 PreDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1S: To Ex. Det. & POA1 (IN LOD) Runoff = 3.65 cfs @ 11.95 hrs, Volume= 0.176 af, Depth> 2.42" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.003 61 >75% Grass cover, Good, HSG B 0.079 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.093 80 >75% Grass cover, Good, HSG D 0.699 98 Impervious, HSG D 0.874 96 Weighted Average 0.096 10.98% Pervious Area 0.778 89.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: To Ex. Det. & POA1 (Outside LOD) Runoff = 4.89 cfs @ 11.95 hrs, Volume= 0.232 af, Depth> 2.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.065 61 >75% Grass cover, Good, HSG B 0.688 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.067 80 >75% Grass cover, Good, HSG D 0.378 98 Impervious, HSG D 1.198 95 Weighted Average 0.132 11.02% Pervious Area 1.066 88.98% Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, PreDev - POA 1 PreDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 4 Summary for Subcatchment 4S: To POA 1 Direct (IN LOD) Runoff = 5.27 cfs @ 11.96 hrs, Volume= 0.231 af, Depth> 1.71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.062 58 Woods/grass comb., Good, HSG B 0.295 61 >75% Grass cover, Good, HSG B 0.691 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.185 80 >75% Grass cover, Good, HSG D 0.382 98 Impervious, HSG D 1.615 88 Weighted Average 0.542 33.56% Pervious Area 1.073 66.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 1 Direct (Outside LOD) Runoff = 0.07 cfs @ 11.98 hrs, Volume= 0.003 af, Depth> 0.53" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.042 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.023 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.003 98 Impervious, HSG D 0.068 67 Weighted Average 0.065 95.59% Pervious Area 0.003 4.41 % Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, PreDev - POA 1 PreDev - POA 1 Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 5 Summary for Link 3L: POA 1 (WITHIN LOD) Inflow Area = 3.755 ac, 77.76% Impervious, Inflow Depth > 2.05" for 1 yr, 24 hr event Inflow = 13.88 cfs @ 11.95 hrs, Volume= 0.642 of Primary = 13.88 cfs @ 11.95 hrs, Volume= 0.642 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PreDev - POA 1 PreDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: To Ex. Det. & POA1 (IN Runoff Area=0.874 ac 89.02% Impervious Runoff Depth>4.70" Tc=5.0 min CN=96 Runoff=6.89 cfs 0.343 of Subcatchment2S: To Ex. Det. & POA1 Runoff Area=1.198 ac 88.98% Impervious Runoff Depth>4.61" Tc=5.0 min CN=95 Runoff=9.36 cfs 0.461 of Subcatchment4S: To POA 1 Direct (IN LOD)Runoff Area=1.615 ac 66.44% Impervious Runoff Depth>3.92" Tc=5.0 min CN=88 Runoff=11.45 cfs 0.528 of Subcatchment5S: To POA 1 Direct (Outside Runoff Area=0.068 ac 4.41 % Impervious Runoff Depth>1.99" Tc=5.0 min CN=67 Runoff=0.27 cfs 0.011 of Link 3L: POA 1 (WITHIN LOD) Inflow=27.97 cfs 1.343 of Primary=27.97 cfs 1.343 of Total Runoff Area = 3.755 ac Runoff Volume = 1.343 of Average Runoff Depth = 4.29" 22.24% Pervious = 0.835 ac 77.76% Impervious = 2.920 ac PreDev - POA 1 PreDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 7 Summary for Subcatchment 1S: To Ex. Det. & POA1 (IN LOD) Runoff = 6.89 cfs @ 11.95 hrs, Volume= 0.343 af, Depth> 4.70" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.003 61 >75% Grass cover, Good, HSG B 0.079 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.093 80 >75% Grass cover, Good, HSG D 0.699 98 Impervious, HSG D 0.874 96 Weighted Average 0.096 10.98% Pervious Area 0.778 89.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: To Ex. Det. & POA1 (Outside LOD) Runoff = 9.36 cfs @ 11.95 hrs, Volume= 0.461 af, Depth> 4.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.065 61 >75% Grass cover, Good, HSG B 0.688 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.067 80 >75% Grass cover, Good, HSG D 0.378 98 Impervious, HSG D 1.198 95 Weighted Average 0.132 11.02% Pervious Area 1.066 88.98% Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, PreDev - POA 1 PreDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 8 Summary for Subcatchment 4S: To POA 1 Direct (IN LOD) Runoff = 11.45 cfs @ 11.95 hrs, Volume= 0.528 af, Depth> 3.92" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.062 58 Woods/grass comb., Good, HSG B 0.295 61 >75% Grass cover, Good, HSG B 0.691 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.185 80 >75% Grass cover, Good, HSG D 0.382 98 Impervious, HSG D 1.615 88 Weighted Average 0.542 33.56% Pervious Area 1.073 66.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 1 Direct (Outside LOD) Runoff = 0.27 cfs @ 11.96 hrs, Volume= 0.011 af, Depth> 1.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.042 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.023 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.003 98 Impervious, HSG D 0.068 67 Weighted Average 0.065 95.59% Pervious Area 0.003 4.41 % Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, PreDev - POA 1 PreDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 9 Summary for Link 3L: POA 1 (WITHIN LOD) Inflow Area = 3.755 ac, 77.76% Impervious, Inflow Depth > 4.29" for 10 yr, 24 hr event Inflow = 27.97 cfs @ 11.95 hrs, Volume= 1.343 of Primary = 27.97 cfs @ 11.95 hrs, Volume= 1.343 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 1S 2S To POA 2 (IN OD) To P A 2 (Outside LOD) 3L 7S To POA 4 (IN OD) S POA 4 Subcat Reach on Link 4S 5S To POA 3 (IN OD) To PO 3 (Outside LOD) 4L POA 3 9S To POA 5 (IN L D) 12L ram. PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paoe 2 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To POA 2 (IN LOD) Runoff Area=1.020 ac 0.00% Impervious Runoff Depth>0.24" Tc=5.0 min CN=58 Runoff=0.32 cfs 0.020 of Subcatchment2S: To POA 2 (Outside LOD) Runoff Area=1.820 ac 0.00% Impervious Runoff Depth>0.24" Tc=5.0 min CN=58 Runoff=0.56 cfs 0.036 of Subcatchment4S: To POA 3 (IN LOD) Runoff Area=0.316 ac 100.00% Impervious Runoff Depth>2.59" Tc=5.0 min CN=98 Runoff=1.37 cfs 0.068 of Subcatchment5S: To POA 3 (Outside LOD) Runoff Area=1.534 ac 89.50% Impervious Runoff Depth>2.23" Tc=5.0 min CN=94 Runoff=6.11 cfs 0.285 of Subcatchment7S: To POA 4 (IN LOD) Runoff Area=0.271 ac 92.99% Impervious Runoff Depth>2.32" Tc=5.0 min CN=95 Runoff=1.11 cfs 0.052 of Subcatchment9S: To POA 5 (IN LOD) Runoff Area=0.173 ac 71.10% Impervious Runoff Depth>2.14" Tc=5.0 min CN=93 Runoff=0.67 cfs 0.031 of Link 3L: POA 2 Inflow=0.88 cfs 0.056 of Primary=0.88 cfs 0.056 of Link 4L: POA 3 Inflow=7.47 cfs 0.354 of Primary=7.47 cfs 0.354 of Link 11 L: POA 4 Inflow=1.11 cfs 0.052 of Primary=1.11 cfs 0.052 of Link 12L: POA 5 Inflow=0.67 cfs 0.031 of Primary=0.67 cfs 0.031 of Total Runoff Area = 5.134 ac Runoff Volume = 0.493 of Average Runoff Depth = 1.15" 59.80% Pervious = 3.070 ac 40.20% Impervious = 2.064 ac PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1S: To POA 2 (IN LOD) Runoff = 0.32 cfs @ 12.00 hrs, Volume= 0.020 af, Depth> 0.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 1.020 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 1.020 58 Weighted Average 1.020 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: To POA 2 (Outside LOD) Runoff = 0.56 cfs @ 12.00 hrs, Volume= 0.036 af, Depth> 0.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN D 1.820 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 1.820 58 Weighted Average 1.820 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 4S: To POA 3 (IN LOD) Runoff = 1.37 cfs @ 11.95 hrs, Volume= 0.068 af, Depth> 2.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 4 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.102 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.214 98 Impervious, HSG D 0.316 98 Weighted Average 0.316 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 3 (Outside LOD) Runoff = 6.11 cfs @ 11.95 hrs, Volume= 0.285 af, Depth> 2.23" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.161 61 >75% Grass cover, Good, HSG B 0.702 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.671 98 Impervious, HSG D 1.534 94 Weighted Average 0.161 10.50% Pervious Area 1.373 89.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To POA 4 (IN LOD) Runoff = 1.11 cfs @ 11.95 hrs, Volume= 0.052 af, Depth> 2.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 5 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.019 61 >75% Grass cover, Good, HSG B 0.252 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.271 95 Weighted Average 0.019 7.01 % Pervious Area 0.252 92.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 5 (IN LOD) Runoff = 0.67 cfs @ 11.95 hrs, Volume= 0.031 af, Depth> 2.14" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.050 80 >75% Grass cover, Good, HSG D 0.123 98 Impervious, HSG D 0.173 93 Weighted Average 0.050 28.90% Pervious Area 0.123 71.10% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 3L: POA 2 Inflow Area = 2.840 ac, 0.00% Impervious, Inflow Depth > 0.24" for 1 yr, 24 hr event Inflow = 0.88 cfs @ 12.00 hrs, Volume= 0.056 of Primary = 0.88 cfs @ 12.00 hrs, Volume= 0.056 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 6 Summary for Link 4L: POA 3 Inflow Area = 1.850 ac, 91.30% Impervious, Inflow Depth > 2.29" for 1 yr, 24 hr event Inflow = 7.47 cfs @ 11.95 hrs, Volume= 0.354 of Primary = 7.47 cfs @ 11.95 hrs, Volume= 0.354 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 11 L: POA 4 Inflow Area = 0.271 ac, 92.99% Impervious, Inflow Depth > 2.32" for 1 yr, 24 hr event Inflow = 1.11 cfs @ 11.95 hrs, Volume= 0.052 of Primary = 1.11 cfs @ 11.95 hrs, Volume= 0.052 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 12L: POA 5 Inflow Area = 0.173 ac, 71.10% Impervious, Inflow Depth > 2.14" for 1 yr, 24 hr event Inflow = 0.67 cfs @ 11.95 hrs, Volume= 0.031 of Primary = 0.67 cfs @ 11.95 hrs, Volume= 0.031 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paoe 7 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To POA 2 (IN LOD) Runoff Area=1.020 ac 0.00% Impervious Runoff Depth>1.32" Tc=5.0 min CN=58 Runoff=2.62 cfs 0.112 of Subcatchment2S: To POA 2 (Outside LOD) Runoff Area=1.820 ac 0.00% Impervious Runoff Depth>1.32" Tc=5.0 min CN=58 Runoff=4.67 cfs 0.200 of Subcatchment4S: To POA 3 (IN LOD) Runoff Area=0.316 ac 100.00% Impervious Runoff Depth>4.86" Tc=5.0 min CN=98 Runoff=2.52 cfs 0.128 of Subcatchment5S: To POA 3 (Outside LOD) Runoff Area=1.534 ac 89.50% Impervious Runoff Depth>4.52" Tc=5.0 min CN=94 Runoff=11.87 cfs 0.578 of Subcatchment7S: To POA 4 (IN LOD) Runoff Area=0.271 ac 92.99% Impervious Runoff Depth>4.61" Tc=5.0 min CN=95 Runoff=2.12 cfs 0.104 of Subcatchment9S: To POA 5 (IN LOD) Runoff Area=0.173 ac 71.10% Impervious Runoff Depth>4.43" Tc=5.0 min CN=93 Runoff=1.32 cfs 0.064 of Link 3L: POA 2 Inflow=7.29 cfs 0.312 of Primary=7.29 cfs 0.312 of Link 4L: POA 3 Inflow=14.39 cfs 0.706 of Primary=14.39 cfs 0.706 of Link 11 L: POA 4 Inflow=2.12 cfs 0.104 of Primary=2.12 cfs 0.104 of Link 12L: POA 5 Inflow=1.32 cfs 0.064 of Primary=1.32 cfs 0.064 of Total Runoff Area = 5.134 ac Runoff Volume = 1.186 of Average Runoff Depth = 2.77" 59.80% Pervious = 3.070 ac 40.20% Impervious = 2.064 ac PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 8 Summary for Subcatchment 1S: To POA 2 (IN LOD) Runoff = 2.62 cfs @ 11.97 hrs, Volume= 0.112 af, Depth> 1.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 1.020 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 1.020 58 Weighted Average 1.020 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: To POA 2 (Outside LOD) Runoff = 4.67 cfs @ 11.97 hrs, Volume= 0.200 af, Depth> 1.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN D 1.820 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 1.820 58 Weighted Average 1.820 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 4S: To POA 3 (IN LOD) Runoff = 2.52 cfs @ 11.95 hrs, Volume= 0.128 af, Depth> 4.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 9 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.102 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.214 98 Impervious, HSG D 0.316 98 Weighted Average 0.316 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 3 (Outside LOD) Runoff = 11.87 cfs @ 11.95 hrs, Volume= 0.578 af, Depth> 4.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.161 61 >75% Grass cover, Good, HSG B 0.702 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.671 98 Impervious, HSG D 1.534 94 Weighted Average 0.161 10.50% Pervious Area 1.373 89.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To POA 4 (IN LOD) Runoff = 2.12 cfs @ 11.95 hrs, Volume= 0.104 af, Depth> 4.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 10 Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.019 61 >75% Grass cover, Good, HSG B 0.252 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.271 95 Weighted Average 0.019 7.01 % Pervious Area 0.252 92.99% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 5 (IN LOD) Runoff = 1.32 cfs @ 11.95 hrs, Volume= 0.064 af, Depth> 4.43" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.050 80 >75% Grass cover, Good, HSG D 0.123 98 Impervious, HSG D 0.173 93 Weighted Average 0.050 28.90% Pervious Area 0.123 71.10% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 3L: POA 2 Inflow Area = 2.840 ac, 0.00% Impervious, Inflow Depth > 1.32" for 10 yr, 24 hr event Inflow = 7.29 cfs @ 11.97 hrs, Volume= 0.312 of Primary = 7.29 cfs @ 11.97 hrs, Volume= 0.312 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 11 Summary for Link 4L: POA 3 Inflow Area = 1.850 ac, 91.30% Impervious, Inflow Depth > 4.58" for 10 yr, 24 hr event Inflow = 14.39 cfs @ 11.95 hrs, Volume= 0.706 of Primary = 14.39 cfs @ 11.95 hrs, Volume= 0.706 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 11 L: POA 4 Inflow Area = 0.271 ac, 92.99% Impervious, Inflow Depth > 4.61" for 10 yr, 24 hr event Inflow = 2.12 cfs @ 11.95 hrs, Volume= 0.104 of Primary = 2.12 cfs @ 11.95 hrs, Volume= 0.104 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 12L: POA 5 Inflow Area = 0.173 ac, 71.10% Impervious, Inflow Depth > 4.43" for 10 yr, 24 hr event Inflow = 1.32 cfs @ 11.95 hrs, Volume= 0.064 of Primary = 1.32 cfs @ 11.95 hrs, Volume= 0.064 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Post -Development Stormwater Management Calculations Post -Development Landuse Map Post -Development HydroCAD Analysis POST -DEVELOPMENT LANDUSE MAP 1300 RIC;HMOND ROAD T.M. 78-9 TCO PARTNERS, LLC D.B. 4710-713 D.B. 3657-569 THRU 578 PLAT D.B. 3339-701, 704 THRU 707 PLAT ZONED: HC 78-5A CORNER, LC 358-684, S PLAT ED: HC jrl, 1S 7S (8S ' ( 9S o Ex. Det. & P A 1 (IN To Ex. 4et. & POA 1 POA 1 Directl LOD) (O tside LOD) LOD y To POA 1 Directly (Outside LOD) 4P Detenti n Pond 6L POA 1 Subcat Reach on Link PostDev POA 1 PostDev - POA 1 Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 2 Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To Ex. Det. & POA 1 (IN Runoff Area=0.571 ac 97.72% Impervious Runoff Depth=2.80" Tc=5.0 min CN=98 Runoff=2.47 cfs 0.133 of Subcatchment7S: To Ex. Det. & POA 1 Runoff Area=1.238 ac 87.56% Impervious Runoff Depth=2.48" Tc=5.0 min CN=95 Runoff=5.06 cfs 0.256 of Subcatchment8S: To POA 1 Directly (IN Runoff Area=3.130 ac 71.47% Impervious Runoff Depth=1.93" Tc=5.0 min CN=89 Runoff=10.61 cfs 0.503 of Subcatchment9S: To POA 1 Directly Runoff Area=0.692 ac 0.00% Impervious Runoff Depth=0.28" Tc=5.0 min CN=58 Runoff=0.21 cfs 0.016 of Pond 4P: Detention Pond Peak Elev=344.68' Storage=7,794 cf Inflow=18.28 cfs 0.908 of Outflow=7.73 cfs 0.908 of Link 6L: POA 1 Inflow=7.73 cfs 0.908 of Primary=7.73 cfs 0.908 of Total Runoff Area = 5.631 ac Runoff Volume = 0.908 of Average Runoff Depth = 1.93" 31.11% Pervious = 1.752 ac 68.89% Impervious = 3.879 ac PostDev POA 1 PostDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here} Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1S: To Ex. Det. & POA 1 (IN LOD) Runoff = 2.47 cfs @ 11.95 hrs, Volume= 0.133 af, Depth= 2.80" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.002 61 >75% Grass cover, Good, HSG B 0.058 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.011 80 >75% Grass cover, Good, HSG D 0.500 98 Impervious, HSG D 0.571 98 Weighted Average 0.013 2.28% Pervious Area 0.558 97.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To Ex. Det. & POA 1 (Outside LOD) Runoff = 5.06 cfs @ 11.95 hrs, Volume= 0.256 af, Depth= 2.48" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.066 61 >75% Grass cover, Good, HSG B 0.684 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.088 80 >75% Grass cover, Good, HSG D 0.400 98 Impervious, HSG D 1.238 95 Weighted Average 0.154 12.44% Pervious Area 1.084 87.56% Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, PostDev POA 1 PostDev - POA 1 Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 4 Summary for Subcatchment 8S: To POA 1 Directly (IN LOD) Runoff = 10.61 cfs @ 11.95 hrs, Volume= 0.503 af, Depth= 1.93" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.673 61 >75% Grass cover, Good, HSG B 1.335 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.220 80 >75% Grass cover, Good, HSG D 0.902 98 Impervious, HSG D 3.130 89 Weighted Average 0.893 28.53% Pervious Area 2.237 71.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 1 Directly (Outside LOD) Runoff = 0.21 cfs @ 12.00 hrs, Volume= 0.016 af, Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.645 58 Woods/grass comb., Good, HSG B 0.047 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.692 58 Weighted Average 0.692 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: Detention Pond Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 1.93" for 1 yr, 24 hr event Inflow = 18.28 cfs @ 11.95 hrs, Volume= 0.908 of Outflow = 7.73 cfs @ 12.06 hrs, Volume= 0.908 af, Atten= 58%, Lag= 6.6 min Primary = 7.73 cfs @ 12.06 hrs, Volume= 0.908 of PostDev POA 1 PostDev - POA 1 Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 5 Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 344.68' @ 12.06 hrs Surf.Area= 3,429 sf Storage= 7,794 cf Plug -Flow detention time= 7.6 min calculated for 0.907 of (100% of inflow) Center -of -Mass det. time= 7.6 min ( 802.3 - 794.7 ) Volume Invert Avail.Storage Storage Description #1 340.00' 13,114 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 340.00 254 0 0 342.00 1,304 1,558 1,558 344.00 2,811 4,115 5,673 346.00 4,630 7,441 13,114 Device Routing Invert Outlet Devices #1 Primary 340.00' 24.0" Round Culvert L= 73.1' Ke= 0.600 Inlet / Outlet Invert= 340.00' / 338.70' S= 0.0178 '/' Cc= 0.900 n= 0.012 #2 Device 1 340.00' 12.0" Vert. Orifice/Grate C= 0.600 #3 Primary 344.70' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=7.70 cfs @ 12.06 hrs HW=344.65' (Free Discharge) 1=Culvert (Passes 7.70 cfs of 27.09 cfs potential flow) L2=Orifice/Grate (Orifice Controls 7.70 cfs @ 9.81 fps) 3=0 rifice/Grate ( Controls 0.00 cfs) Summary for Link 6L: POA 1 Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 1.93" for 1 yr, 24 hr event Inflow = 7.73 cfs @ 12.06 hrs, Volume= 0.908 of Primary = 7.73 cfs @ 12.06 hrs, Volume= 0.908 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs PostDev POA 1 PostDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 6 Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To Ex. Det. & POA 1 (IN Runoff Area=0.571 ac 97.72% Impervious Runoff Depth=5.30" Tc=5.0 min CN=98 Runoff=4.56 cfs 0.252 of Subcatchment7S: To Ex. Det. & POA 1 Runoff Area=1.238 ac 87.56% Impervious Runoff Depth=4.95" Tc=5.0 min CN=95 Runoff=9.67 cfs 0.511 of Subcatchment8S: To POA 1 Directly (IN Runoff Area=3.130 ac 71.47% Impervious Runoff Depth=4.29" Tc=5.0 min CN=89 Runoff=22.58 cfs 1.119 of Subcatchment9S: To POA 1 Directly Runoff Area=0.692 ac 0.00% Impervious Runoff Depth=1.48" Tc=5.0 min CN=58 Runoff=1.78 cfs 0.085 of Pond 4P: Detention Pond Peak Elev=345.50' Storage=10,931 cf Inflow=38.55 cfs 1.968 of Outflow=37.75 cfs 1.968 of Link 6L: POA 1 Inflow=37.75 cfs 1.968 of Primary=37.75 cfs 1.968 of Total Runoff Area = 5.631 ac Runoff Volume = 1.968 of Average Runoff Depth = 4.19" 31.11% Pervious = 1.752 ac 68.89% Impervious = 3.879 ac PostDev POA 1 PostDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 7 Summary for Subcatchment 1S: To Ex. Det. & POA 1 (IN LOD) Runoff = 4.56 cfs @ 11.95 hrs, Volume= 0.252 af, Depth= 5.30" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.002 61 >75% Grass cover, Good, HSG B 0.058 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.011 80 >75% Grass cover, Good, HSG D 0.500 98 Impervious, HSG D 0.571 98 Weighted Average 0.013 2.28% Pervious Area 0.558 97.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To Ex. Det. & POA 1 (Outside LOD) Runoff = 9.67 cfs @ 11.95 hrs, Volume= 0.511 af, Depth= 4.95" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.066 61 >75% Grass cover, Good, HSG B 0.684 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.088 80 >75% Grass cover, Good, HSG D 0.400 98 Impervious, HSG D 1.238 95 Weighted Average 0.154 12.44% Pervious Area 1.084 87.56% Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, PostDev POA 1 PostDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 8 Summary for Subcatchment 8S: To POA 1 Directly (IN LOD) Runoff = 22.58 cfs @ 11.95 hrs, Volume= 1.119 af, Depth= 4.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.673 61 >75% Grass cover, Good, HSG B 1.335 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.220 80 >75% Grass cover, Good, HSG D 0.902 98 Impervious, HSG D 3.130 89 Weighted Average 0.893 28.53% Pervious Area 2.237 71.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 1 Directly (Outside LOD) Runoff = 1.78 cfs @ 11.97 hrs, Volume= 0.085 af, Depth= 1.48" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.645 58 Woods/grass comb., Good, HSG B 0.047 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.692 58 Weighted Average 0.692 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: Detention Pond Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 4.19" for 10 yr, 24 hr event Inflow = 38.55 cfs @ 11.95 hrs, Volume= 1.968 of Outflow = 37.75 cfs @ 11.97 hrs, Volume= 1.968 af, Atten= 2%, Lag= 1.4 min Primary = 37.75 cfs @ 11.97 hrs, Volume= 1.968 of PostDev POA 1 PostDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 9 Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 345.50' @ 11.97 hrs Surf.Area= 4,179 sf Storage= 10,931 cf Plug -Flow detention time= 6.6 min calculated for 1.968 of (100% of inflow) Center -of -Mass det. time= 6.4 min ( 784.2 - 777.8 ) Volume Invert Avail.Storage Storage Description #1 340.00' 13,114 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 340.00 254 0 0 342.00 1,304 1,558 1,558 344.00 2,811 4,115 5,673 346.00 4,630 7,441 13,114 Device Routing Invert Outlet Devices #1 Primary 340.00' 24.0" Round Culvert L= 73.1' Ke= 0.600 Inlet / Outlet Invert= 340.00' / 338.70' S= 0.0178 '/' Cc= 0.900 n= 0.012 #2 Device 1 340.00' 12.0" Vert. Orifice/Grate C= 0.600 #3 Primary 344.70' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=35.58 cfs @ 11.97 hrs HW=345.46' (Free Discharge) 1=Culvert (Passes 8.42 cfs of 29.94 cfs potential flow) L2=Orifice/Grate (Orifice Controls 8.42 cfs @ 10.72 fps) 3=Orifice/Grate (Weir Controls 27.16 cfs @ 2.85 fps) Summary for Link 6L: POA 1 Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 4.19" for 10 yr, 24 hr event Inflow = 37.75 cfs @ 11.97 hrs, Volume= 1.968 of Primary = 37.75 cfs @ 11.97 hrs, Volume= 1.968 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs PostDev POA 1 PostDev - POA 1 Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 10 Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To Ex. Det. & POA 1 (IN Runoff Area=0.571 ac 97.72% Impervious Runoff Depth=8.86" Tc=5.0 min CN=98 Runoff=7.50 cfs 0.422 of Subcatchment7S: To Ex. Det. & POA 1 Runoff Area=1.238 ac 87.56% Impervious Runoff Depth=8.50" Tc=5.0 min CN=95 Runoff=16.13 cfs 0.877 of Subcatchment8S: To POA 1 Directly (IN Runoff Area=3.130 ac 71.47% Impervious Runoff Depth=7.77" Tc=5.0 min CN=89 Runoff=39.32 cfs 2.026 of Subcatchment9S: To POA 1 Directly Runoff Area=0.692 ac 0.00% Impervious Runoff Depth=3.93" Tc=5.0 min CN=58 Runoff=4.90 cfs 0.227 of Pond 4P: Detention Pond Peak Elev=345.93' Storage=12,793 cf Inflow=67.82 cfs 3.551 of Outflow=64.81 cfs 3.551 of Link 6L: POA 1 Inflow=64.81 cfs 3.551 of Primary=64.81 cfs 3.551 of Total Runoff Area = 5.631 ac Runoff Volume = 3.551 of Average Runoff Depth = 7.57" 31.11% Pervious = 1.752 ac 68.89% Impervious = 3.879 ac PostDev POA 1 PostDev - POA 1 Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 11 Summary for Subcatchment 1S: To Ex. Det. & POA 1 (IN LOD) Runoff = 7.50 cfs @ 11.95 hrs, Volume= 0.422 af, Depth= 8.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.002 61 >75% Grass cover, Good, HSG B 0.058 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.011 80 >75% Grass cover, Good, HSG D 0.500 98 Impervious, HSG D 0.571 98 Weighted Average 0.013 2.28% Pervious Area 0.558 97.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To Ex. Det. & POA 1 (Outside LOD) Runoff = 16.13 cfs @ 11.95 hrs, Volume= 0.877 af, Depth= 8.50" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.066 61 >75% Grass cover, Good, HSG B 0.684 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.088 80 >75% Grass cover, Good, HSG D 0.400 98 Impervious, HSG D 1.238 95 Weighted Average 0.154 12.44% Pervious Area 1.084 87.56% Impervious Area Tc Length Slope Velocity Capacity Description min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, PostDev POA 1 PostDev - POA 1 Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 12 Summary for Subcatchment 8S: To POA 1 Directly (IN LOD) Runoff = 39.32 cfs @ 11.95 hrs, Volume= 2.026 af, Depth= 7.77" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.673 61 >75% Grass cover, Good, HSG B 1.335 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.220 80 >75% Grass cover, Good, HSG D 0.902 98 Impervious, HSG D 3.130 89 Weighted Average 0.893 28.53% Pervious Area 2.237 71.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 1 Directly (Outside LOD) Runoff = 4.90 cfs @ 11.96 hrs, Volume= 0.227 af, Depth= 3.93" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN Description 0.645 58 Woods/grass comb., Good, HSG B 0.047 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.692 58 Weighted Average 0.692 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: Detention Pond Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 7.57" for 100 yr, 24 hr event Inflow = 67.82 cfs @ 11.95 hrs, Volume= 3.551 of Outflow = 64.81 cfs @ 11.97 hrs, Volume= 3.551 af, Atten= 4%, Lag= 1.2 min Primary = 64.81 cfs @ 11.97 hrs, Volume= 3.551 of PostDev POA 1 PostDev - POA 1 Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 6/1/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 13 Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 345.93' @ 11.97 hrs Surf.Area= 4,566 sf Storage= 12,793 cf Plug -Flow detention time= 5.6 min calculated for 3.547 of (100% of inflow) Center -of -Mass det. time= 5.6 min ( 771.2 - 765.6 ) Volume Invert Avail.Storage Storage Description #1 340.00' 13,114 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 340.00 254 0 0 342.00 1,304 1,558 1,558 344.00 2,811 4,115 5,673 346.00 4,630 7,441 13,114 Device Routing Invert Outlet Devices #1 Primary 340.00' 24.0" Round Culvert L= 73.1' Ke= 0.600 Inlet / Outlet Invert= 340.00' / 338.70' S= 0.0178 '/' Cc= 0.900 n= 0.012 #2 Device 1 340.00' 12.0" Vert. Orifice/Grate C= 0.600 #3 Primary 344.70' 48.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=62.97 cfs @ 11.97 hrs HW=345.90' (Free Discharge) 1=Culvert (Passes 8.79 cfs of 31.40 cfs potential flow) L2=Orifice/Grate (Orifice Controls 8.79 cfs @ 11.19 fps) 3=Orifice/Grate (Weir Controls 54.18 cfs @ 3.59 fps) Summary for Link 6L: POA 1 Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 7.57" for 100 yr, 24 hr event Inflow = 64.81 cfs @ 11.97 hrs, Volume= 3.551 of Primary = 64.81 cfs @ 11.97 hrs, Volume= 3.551 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs 1S 2S To POA 2 (IN OD) To P A 2 (Outside LOD) 3L 7S To POA 4 (IN OD) S POA 4 Subcat Reach on Link 4S 5S To POA 3 (IN OD) To PO 3 (Outside LOD) 4L POA 3 9S To POA 5 (IN L D) 12L ram. PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paoe 2 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To POA 2 (IN LOD) Runoff Area=0.236 ac 0.00% Impervious Runoff Depth>0.32" Tc=5.0 min CN=61 Runoff=0.12 cfs 0.006 of Subcatchment2S: To POA 2 (Outside LOD) Runoff Area=1.180 ac 0.00% Impervious Runoff Depth>0.24" Tc=5.0 min CN=58 Runoff=0.37 cfs 0.023 of Subcatchment4S: To POA 3 (IN LOD) Runoff Area=0.123 ac 91.87% Impervious Runoff Depth>2.32" Tc=5.0 min CN=95 Runoff=0.50 cfs 0.024 of Subcatchment SS: To POA 3 (Outside LOD) Runoff Area=1.506 ac 94.49% Impervious Runoff Depth>2.51" Tc=5.0 min CN=97 Runoff=6.41 cfs 0.315 of Subcatchment7S: To POA 4 (IN LOD) Runoff Area=0.105 ac 10.48% Impervious Runoff Depth>0.45" Tc=5.0 min CN=65 Runoff=0.09 cfs 0.004 of Subcatchment9S: To POA 5 (IN LOD) Runoff Area=0.136 ac 66.91 % Impervious Runoff Depth>2.05" Tc=5.0 min CN=92 Runoff=0.51 cfs 0.023 of Link 3L: POA 2 Inflow=0.49 cfs 0.030 of Primary=0.49 cfs 0.030 of Link 4L: POA 3 Inflow=6.92 cfs 0.338 of Primary=6.92 cfs 0.338 of Link 11 L: POA 4 Inflow=0.09 cfs 0.004 of Primary=0.09 cfs 0.004 of Link 12L: POA 5 Inflow=0.51 cfs 0.023 of Primary=0.51 cfs 0.023 of Total Runoff Area = 3.286 ac Runoff Volume = 0.395 of Average Runoff Depth = 1.44" 50.15% Pervious = 1.648 ac 49.85% Impervious = 1.638 ac PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1S: To POA 2 (IN LOD) Runoff = 0.12 cfs @ 11.99 hrs, Volume= 0.006 af, Depth> 0.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.236 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.236 61 Weighted Average 0.236 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: To POA 2 (Outside LOD) Runoff = 0.37 cfs @ 12.00 hrs, Volume= 0.023 af, Depth> 0.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN D 1.180 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 1.180 58 Weighted Average 1.180 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 4S: To POA 3 (IN LOD) Runoff = 0.50 cfs @ 11.95 hrs, Volume= 0.024 af, Depth> 2.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 4 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.008 61 >75% Grass cover, Good, HSG B 0.060 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.002 80 >75% Grass cover, Good, HSG D 0.053 98 Impervious, HSG D 0.123 95 Weighted Average 0.010 8.13% Pervious Area 0.113 91.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 3 (Outside LOD) Runoff = 6.41 cfs @ 11.95 hrs, Volume= 0.315 af, Depth> 2.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.747 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.083 80 >75% Grass cover, Good, HSG D 0.676 98 Impervious, HSG D 1.506 97 Weighted Average 0.083 5.51 % Pervious Area 1.423 94.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To POA 4 (IN LOD) Runoff = 0.09 cfs @ 11.98 hrs, Volume= 0.004 af, Depth> 0.45" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 5 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.094 61 >75% Grass cover, Good, HSG B 0.011 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.105 65 Weighted Average 0.094 89.52% Pervious Area 0.011 10.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 5 (IN LOD) Runoff = 0.51 cfs @ 11.95 hrs, Volume= 0.023 af, Depth> 2.05" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.03" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.045 80 >75% Grass cover, Good, HSG D 0.091 98 Impervious, HSG D 0.136 92 Weighted Average 0.045 33.09% Pervious Area 0.091 66.91 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 3L: POA 2 Inflow Area = 1.416 ac, 0.00% Impervious, Inflow Depth > 0.25" for 1 yr, 24 hr event Inflow = 0.49 cfs @ 12.00 hrs, Volume= 0.030 of Primary = 0.49 cfs @ 12.00 hrs, Volume= 0.030 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 6 Summary for Link 4L: POA 3 Inflow Area = 1.629 ac, 94.29% Impervious, Inflow Depth > 2.49" for 1 yr, 24 hr event Inflow = 6.92 cfs @ 11.95 hrs, Volume= 0.338 of Primary = 6.92 cfs @ 11.95 hrs, Volume= 0.338 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 11 L: POA 4 Inflow Area = 0.105 ac, 10.48% Impervious, Inflow Depth > 0.45" for 1 yr, 24 hr event Inflow = 0.09 cfs @ 11.98 hrs, Volume= 0.004 of Primary = 0.09 cfs @ 11.98 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 12L: POA 5 Inflow Area = 0.136 ac, 66.91 % Impervious, Inflow Depth > 2.05" for 1 yr, 24 hr event Inflow = 0.51 cfs @ 11.95 hrs, Volume= 0.023 of Primary = 0.51 cfs @ 11.95 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PostDev PostDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paoe 7 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To POA 2 (IN LOD) Runoff Area=0.236 ac 0.00% Impervious Runoff Depth>1.53" Tc=5.0 min CN=61 Runoff=0.71 cfs 0.030 of Subcatchment2S: To POA 2 (Outside LOD) Runoff Area=1.180 ac 0.00% Impervious Runoff Depth>1.32" Tc=5.0 min CN=58 Runoff=3.03 cfs 0.130 of Subcatchment4S: To POA 3 (IN LOD) Runoff Area=0.123 ac 91.87% Impervious Runoff Depth>4.61" Tc=5.0 min CN=95 Runoff=0.96 cfs 0.047 of Subcatchment5S: To POA 3 (Outside LOD) Runoff Area=1.506 ac 94.49% Impervious Runoff Depth>4.78" Tc=5.0 min CN=97 Runoff=11.95 cfs 0.600 of Subcatchment7S: To POA 4 (IN LOD) Runoff Area=0.105 ac 10.48% Impervious Runoff Depth>1.84" Tc=5.0 min CN=65 Runoff=0.38 cfs 0.016 of Subcatchment9S: To POA 5 (IN LOD) Runoff Area=0.136 ac 66.91 % Impervious Runoff Depth>4.33" Tc=5.0 min CN=92 Runoff=1.03 cfs 0.049 of Link 3L: POA 2 Inflow=3.74 cfs 0.160 of Primary=3.74 cfs 0.160 of Link 4L: POA 3 Inflow=12.91 cfs 0.648 of Primary=12.91 cfs 0.648 of Link 11 L: POA 4 Inflow=0.38 cfs 0.016 of Primary=0.38 cfs 0.016 of Link 12L: POA 5 Inflow=1.03 cfs 0.049 of Primary=1.03 cfs 0.049 of Total Runoff Area = 3.286 ac Runoff Volume = 0.873 of Average Runoff Depth = 3.19" 50.15% Pervious = 1.648 ac 49.85% Impervious = 1.638 ac PostDev PostDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 8 Summary for Subcatchment 1S: To POA 2 (IN LOD) Runoff = 0.71 cfs @ 11.97 hrs, Volume= 0.030 af, Depth> 1.53" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.236 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.236 61 Weighted Average 0.236 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: To POA 2 (Outside LOD) Runoff = 3.03 cfs @ 11.97 hrs, Volume= 0.130 af, Depth> 1.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN D 1.180 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 1.180 58 Weighted Average 1.180 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 4S: To POA 3 (IN LOD) Runoff = 0.96 cfs @ 11.95 hrs, Volume= 0.047 af, Depth> 4.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" PostDev PostDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 9 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.008 61 >75% Grass cover, Good, HSG B 0.060 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.002 80 >75% Grass cover, Good, HSG D 0.053 98 Impervious, HSG D 0.123 95 Weighted Average 0.010 8.13% Pervious Area 0.113 91.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 3 (Outside LOD) Runoff = 11.95 cfs @ 11.95 hrs, Volume= 0.600 af, Depth> 4.78" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.747 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.083 80 >75% Grass cover, Good, HSG D 0.676 98 Impervious, HSG D 1.506 97 Weighted Average 0.083 5.51 % Pervious Area 1.423 94.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To POA 4 (IN LOD) Runoff = 0.38 cfs @ 11.96 hrs, Volume= 0.016 af, Depth> 1.84" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" PostDev PostDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 10 Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.094 61 >75% Grass cover, Good, HSG B 0.011 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.105 65 Weighted Average 0.094 89.52% Pervious Area 0.011 10.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 5 (IN LOD) Runoff = 1.03 cfs @ 11.95 hrs, Volume= 0.049 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.54" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.045 80 >75% Grass cover, Good, HSG D 0.091 98 Impervious, HSG D 0.136 92 Weighted Average 0.045 33.09% Pervious Area 0.091 66.91 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 3L: POA 2 Inflow Area = 1.416 ac, 0.00% Impervious, Inflow Depth > 1.36" for 10 yr, 24 hr event Inflow = 3.74 cfs @ 11.97 hrs, Volume= 0.160 of Primary = 3.74 cfs @ 11.97 hrs, Volume= 0.160 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PostDev PostDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 11 Summary for Link 4L: POA 3 Inflow Area = 1.629 ac, 94.29% Impervious, Inflow Depth > 4.77" for 10 yr, 24 hr event Inflow = 12.91 cfs @ 11.95 hrs, Volume= 0.648 of Primary = 12.91 cfs @ 11.95 hrs, Volume= 0.648 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 11 L: POA 4 Inflow Area = 0.105 ac, 10.48% Impervious, Inflow Depth > 1.84" for 10 yr, 24 hr event Inflow = 0.38 cfs @ 11.96 hrs, Volume= 0.016 of Primary = 0.38 cfs @ 11.96 hrs, Volume= 0.016 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 12L: POA 5 Inflow Area = 0.136 ac, 66.91 % Impervious, Inflow Depth > 4.33" for 10 yr, 24 hr event Inflow = 1.03 cfs @ 11.95 hrs, Volume= 0.049 of Primary = 1.03 cfs @ 11.95 hrs, Volume= 0.049 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PostDev PostDev Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paoe 12 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: To POA 2 (IN LOD) Runoff Area=0.236 ac 0.00% Impervious Runoff Depth>3.95" Tc=5.0 min CN=61 Runoff=1.83 cfs 0.078 of Subcatchment2S: To POA 2 (Outside LOD) Runoff Area=1.180 ac 0.00% Impervious Runoff Depth>3.60" Tc=5.0 min CN=58 Runoff=8.36 cfs 0.354 of Subcatchment4S: To POA 3 (IN LOD) Runoff Area=0.123 ac 91.87% Impervious Runoff Depth>7.85" Tc=5.0 min CN=95 Runoff=1.60 cfs 0.080 of Subcatchment5S: To POA 3 (Outside LOD) Runoff Area=1.506 ac 94.49% Impervious Runoff Depth>7.99" Tc=5.0 min CN=97 Runoff=19.75 cfs 1.003 of Subcatchment7S: To POA 4 (IN LOD) Runoff Area=0.105 ac 10.48% Impervious Runoff Depth>4.43" Tc=5.0 min CN=65 Runoff=0.90 cfs 0.039 of Subcatchment9S: To POA 5 (IN LOD) Runoff Area=0.136 ac 66.91 % Impervious Runoff Depth>7.58" Tc=5.0 min CN=92 Runoff=1.75 cfs 0.086 of Link 3L: POA 2 Inflow=10.19 cfs 0.431 of Primary=10.19 cfs 0.431 of Link 4L: POA 3 Inflow=21.35 cfs 1.083 of Primary=21.35 cfs 1.083 of Link 11 L: POA 4 Inflow=0.90 cfs 0.039 of Primary=0.90 cfs 0.039 of Link 12L: POA 5 Inflow=1.75 cfs 0.086 of Primary=1.75 cfs 0.086 of Total Runoff Area = 3.286 ac Runoff Volume = 1.639 of Average Runoff Depth = 5.99" 50.15% Pervious = 1.648 ac 49.85% Impervious = 1.638 ac PostDev PostDev Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 13 Summary for Subcatchment 1S: To POA 2 (IN LOD) Runoff = 1.83 cfs @ 11.96 hrs, Volume= 0.078 af, Depth> 3.95" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.236 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.236 61 Weighted Average 0.236 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 2S: To POA 2 (Outside LOD) Runoff = 8.36 cfs @ 11.96 hrs, Volume= 0.354 af, Depth> 3.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN D 1.180 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 1.180 58 Weighted Average 1.180 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 4S: To POA 3 (IN LOD) Runoff = 1.60 cfs @ 11.95 hrs, Volume= 0.080 af, Depth> 7.85" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" PostDev PostDev Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 14 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.008 61 >75% Grass cover, Good, HSG B 0.060 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.002 80 >75% Grass cover, Good, HSG D 0.053 98 Impervious, HSG D 0.123 95 Weighted Average 0.010 8.13% Pervious Area 0.113 91.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 3 (Outside LOD) Runoff = 19.75 cfs @ 11.95 hrs, Volume= 1.003 af, Depth> 7.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.747 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.083 80 >75% Grass cover, Good, HSG D 0.676 98 Impervious, HSG D 1.506 97 Weighted Average 0.083 5.51 % Pervious Area 1.423 94.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: To POA 4 (IN LOD) Runoff = 0.90 cfs @ 11.96 hrs, Volume= 0.039 af, Depth> 4.43" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" PostDev PostDev Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 15 Area (ac) CN DescriDtion 0.000 58 Woods/grass comb., Good, HSG B 0.094 61 >75% Grass cover, Good, HSG B 0.011 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.000 80 >75% Grass cover, Good, HSG D 0.000 98 Impervious, HSG D 0.105 65 Weighted Average 0.094 89.52% Pervious Area 0.011 10.48% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 5 (IN LOD) Runoff = 1.75 cfs @ 11.95 hrs, Volume= 0.086 af, Depth> 7.58" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.10" Area (ac) CN Description 0.000 58 Woods/grass comb., Good, HSG B 0.000 61 >75% Grass cover, Good, HSG B 0.000 98 Impervious, HSG B 0.000 79 Woods/grass comb., Good, HSG D 0.045 80 >75% Grass cover, Good, HSG D 0.091 98 Impervious, HSG D 0.136 92 Weighted Average 0.045 33.09% Pervious Area 0.091 66.91 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 3L: POA 2 Inflow Area = 1.416 ac, 0.00% Impervious, Inflow Depth > 3.66" for 100 yr, 24 hr event Inflow = 10.19 cfs @ 11.96 hrs, Volume= 0.431 of Primary = 10.19 cfs @ 11.96 hrs, Volume= 0.431 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs PostDev PostDev Type 11 24-hr 100 yr, 24 hr Rainfall=9.10" Prepared by {enter your company name here) Printed 5/29/2020 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 16 Summary for Link 4L: POA 3 Inflow Area = 1.629 ac, 94.29% Impervious, Inflow Depth > 7.98" for 100 yr, 24 hr event Inflow = 21.35 cfs @ 11.95 hrs, Volume= 1.083 of Primary = 21.35 cfs @ 11.95 hrs, Volume= 1.083 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 11 L: POA 4 Inflow Area = 0.105 ac, 10.48% Impervious, Inflow Depth > 4.43" for 100 yr, 24 hr event Inflow = 0.90 cfs @ 11.96 hrs, Volume= 0.039 of Primary = 0.90 cfs @ 11.96 hrs, Volume= 0.039 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 12L: POA 5 Inflow Area = 0.136 ac, 66.91 % Impervious, Inflow Depth > 7.58" for 100 yr, 24 hr event Inflow = 1.75 cfs @ 11.95 hrs, Volume= 0.086 of Primary = 1.75 cfs @ 11.95 hrs, Volume= 0.086 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Stormwater Quality Calculations VRRM Redevelopment Spreadsheet 1300 Richmond Road Site Information n�ai rez�icz Post -Development Project (Treatment Volume and Loads) -__■__, EnterTotal Disturbed Area (acres) �— _--� B14P Design Specifications Ust. 2013 Draft Stcls & Specs Maximum reduction required: 209't The site's net increase in impery s cover (acres) is. 0.724 Post -Development TP Load Reduction for5ite /Ib/yr/: 2.49 —_, Pre-ReDevelopment Land Cover (acres) Post -Development Land Cover (acres) Runoff Coefficients IRV) LAND COVER SUMMARY --PRE-REDEVELOPMENT -- LAND COVER SUMMARY --POST DEVELOPMENT - L-dC—,S,- Treatment Volume and Nutrient Load Post -Development Requirement Requirement for Site Area Site Results (Water Quality Compliance) Area Checks D.A. A D.A. B D.A. C D.A. D D.A. E AREA CHECK FOREST/OPEN SPACE (ac) 0.00 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER (ac) 0.00 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER TREATED(ac) 0.00 0.00 0.00 0.00 0.00 OK. MANAGED TURF AREA (ac) 0.00 0.00 0.00 0.00 0.00 OK. MANAGED TURF AREA TREATED (ac) 0.00 0.00 0.00 0.00 0.00 OK. AREA CHECK OK. OK. OK. OK. OK. Site Treatment Volume (fe) 11,545 Runoff Reduction Volume and TP By Drainage Area D.A. D D.A. E TOTAL RUNOFF REDUCTION VOLUME ACHIEVED (fe) 0 0 0 0 0 0 TP LOAD AVAILABLE FOR REMOVAL (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 TP LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 TP LOAD REMAINING (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 Total Phosphorus FINAL POST -DEVELOPMENT TP LOAD(Ib/yr)P1.25P TP LOAD REDUCTION REQUIRED (Ib/yr)TP LOAD REDUCTION ACHIEVED (Ib/yr)TP LOAD REMAINING (Ib/yr): REMAINING TP LOAD REDUCTION REQUIRED (Ib/yr): 2.49 Total Nitrogen (For Information Purposes) POST -DEVELOPMENT LOAD (Ib/yr) 51.89 NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 REMAINING POST -DEVELOPMENT NITROGEN LOAD (Ib/yr) 51.89 Virginia Runoff Reduction Method Worksheet DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2013 Draft Stds & Specs Site Summary Project Title: 1300 Richmond Road Date: 43979 Total Rainfall (in): 43 Total Disturbed Acreage: 4.40 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) A soils B Soils C Soils D Soils Totals % of Total Forest/Open (acres) 0.00 0.89 0.00 0.00 0.89 20 Managed Turf (acres) 0.00 0.77 0.00 0.41 1.18 27 Impervious Cover (acres) 0.00 0.85 0.00 1.48 2.32 53 4.40 100 Post -Re Development Land Cover (acres) A soils B Soils C Soils D Soils Totals % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 1.02 0.00 0.33 1.35 31 Impervious Cover (acres) 0.00 1.48 0.00 1.56 3.05 69 4.40 100 Site Tv and Land Cover Nutrient Loads Final Post -Development Post- Post- Adjusted Pre- (Post-ReDevelopment KeDevelopment Development velopment & New Impervious) (New Impervious) Site Rv 0.72 0.68 0.95 0.67 Treatment Volume (ft) 11,545 9,049 2,497 8,893 TP Load (lb/yr) 7.25 5.69 1.57 5.59 iTotal TP Load Reduction Required (lb/yr) 1 2.49 1 1.22 11.27 Final Post -Development Load Pre- st-ReDevelopment & New Impervious) ReDevelopment ITN Load (lb/yr) 51.89 40.64 Pre- Final Post -Development Post-ReDevelopmentTP ReDevelopment TP Load per acre Load per acre TP Load per acre (lb/acre/yr) (lb/acre/yr) (lb/acre/yr) 1.52 1.65 1.55 Summary Print Virginia Runoff Reduction Method Worksheet Site Compliance Summary Maximum %Reduction Required Below 2091. Pre-ReDevelopment Load Total Runoff Volume Reduction (ft) 0 Total TP Load Reduction Achieved (Ib/yr) 0.00 Total TN Load Reduction Achieved (lb/yr) 0.00 Remaining Post Development TP Load (lb/yr) 7.25 Remaining TP Load Reduction (lb/yr) Required 2.49 Summary Print Independent Reports Excerpt from NRCS Soils Report NOAA Precipitation Report Custom Soil Resource Report 3 Soil Map F N Ik 7235M 7236M 7236W M700 M740 38' 2' 12" N 0 N N a 0 N a 0 a dN N 7 38° 1' 59" N 723580 723620 723660 723700 723740 3 Map Scale: 1:1,910 W printed on A portrait (8.5" x 11") sheet Meters N 0 25 50 100 150 Feet 0 50 100 200 300 Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 6 3 io N 7237W 723M 38° 2' 12" N e e v o_ 7 N V N N V Q 38° 1' 59" N 723820 723860 3 G N Ik MAP LEGEND Area of Interest (AOI) 0 Area of Interest (AOI) Soils 0 Soil Map Unit Polygons im 0 Soil Map Unit Lines ■ Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit .4 Gravelly Spot 0 Landfill Lava Flow Marsh or swamp + Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip oa Sodic Spot Custom Soil Resource Report MAP INFORMATION A Spoil Area The soil surveys that comprise your AOI were mapped at 1:15,800. Stony Spot Very Stony Spot Warning: Soil Map may not be valid at this scale. Wet Spot Enlargement of maps beyond the scale of mapping can cause Other misunderstanding of the detail of mapping and accuracy of soil .- Special Line Features line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed Water Features scale. - Streams and Canals Transportation Please rely on the bar scale on each map sheet for map �}} Rails measurements. Interstate Highways Source of Map: Natural Resources Conservation Service US Routes Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Major Roads Local Roads Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts Background distance and area. A projection that preserves area, such as the Aerial Photography Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Albemarle County, Virginia Survey Area Data: Version 13, Sep 17, 2019 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: May 20, 2019—Aug 1, 2019 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 7 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 12D 23B Catoctin silt loam, 15 to 25 percent slopes 2.5 3.2 18.4% 24.0% Yadkin clay loam, 2 to 7 percent slopes 71 D Rabun clay loam, 15 to 25 percent slopes 2.6 19.4% 79B Meadowville silt loam, 2 to 7 percent slopes 0.7 5.4% 88 Udorthents, loamy, 2 to 25 percent slopes 4.4 32.8% Totals for Area of Interest 13.3 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. 0 Custom Soil Resource Report Albemarle County, Virginia 12D—Catoctin silt loam, 15 to 25 percent slopes Map Unit Setting National map unit symbol: 2yfhj Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Not prime farmland Map Unit Composition Catoctin and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Catoctin Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from greenstone Typical profile A - 0 to 5 inches: silt loam Bw - 5 to 18 inches: very channery silt loam C - 18 to 28 inches: extremely channery silt loam R - 28 to 79 inches: bedrock Properties and qualities Slope: 15 to 25 percent Depth to restrictive feature: 20 to 40 inches to lithic bedrock Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Hydric soil rating: No 10 Custom Soil Resource Report 2313—Yadkin clay loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: 2v7hx Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: All areas are prime farmland Map Unit Composition Yadkin and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Yadkin Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from greenstone Typical profile Ap - 0 to 4 inches: clay loam BA - 4 to 10 inches: clay loam Bt - 10 to 63 inches: clay C - 63 to 88 inches: clay loam Properties and qualities Slope: 2 to 7 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 8.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Hydric soil rating: No 11 Custom Soil Resource Report 71 D—Rabun clay loam, 15 to 25 percent slopes Map Unit Setting National map unit symbol: 2xxyk Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Not prime farmland Map Unit Composition Rabun and similar soils: 75 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Rabun Setting Landform: I nterfluves Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down -slope shape: Linear Across -slope shape: Convex Parent material: Residuum weathered from greenstone Typical profile A - 0 to 6 inches: clay loam Bt - 6 to 48 inches: clay C - 48 to 79 inches: silty clay loam Properties and qualities Slope: 15 to 25 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 8.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6e Hydrologic Soil Group: B Hydric soil rating: No 12 Custom Soil Resource Report 79B—Meadowville silt loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: 2v7k1 Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: All areas are prime farmland Map Unit Composition Meadowville, occasionally flooded, and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Meadowville, Occasionally Flooded Setting Landform: Drainageways Landform position (two-dimensional): Footslope Landform position (three-dimensional): Head slope Down -slope shape: Concave Across -slope shape: Convex Parent material: Colluvium derived from igneous rock Typical profile A - 0 to 18 inches: silt loam Bt - 18 to 53 inches: silty clay loam 2C - 53 to 79 inches: gravelly clay loam Properties and qualities Slope: 2 to 7 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: Occasional Frequency of ponding: None Available water storage in profile: High (about 9.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B Hydric soil rating: No 13 Custom Soil Resource Report 88—Udorthents, loamy, 2 to 25 percent slopes Map Unit Setting National map unit symbol: 2xxz3 Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Not prime farmland Map Unit Composition Udorthents and similar soils: 85 percent Minor components: 5 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Udorthents Setting Landform: I nterfluves Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from granite and gneiss Properties and qualities Slope: 2 to 25 percent Depth to restrictive feature: More than 80 inches Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Minor Components Hatboro, occasionally flooded Percent of map unit: 5 percent Landform: Flood plains Down -slope shape: Linear Across -slope shape: Linear Hydric soil rating: Yes 14 2/2/2020 Precipitation Frequency Data Server NOAA Atlas 14, Volume 2, Version 3 Location name: Charlottesville, Virginia, USA* Latitude: 38.0343°, Longitude:-78.4504° Elevation: 410.47 ft** source: ESRI Maps m y� ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonnin, D. Martin, B. Lin, I Parzybok, M.Yekta, and D. Riley NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.353 0.420 0.492 0.553 0.623 0.677 IF 0.728 IF 0.775 IF 0.832 IF 0.878 (0.318-0.392) (0.379-0.466) (0.443-0.545) (0.497-0.613) (0.557-0.687) (0.603-0.746) (0.645-0.802) (0.682-0.854) (0.724-0.919) (0.758-0.974) 10-min 0.564 0.672 0.788 0.885 0.993 1.08 1.16 1.23 1.32 1.38 (0.508-0.626) (0.606-0.745) (0.709-0.873) (0.795-0.980) (0.888-1.10) (0.961-1.19) 1 (1.02-1.27) 1 (1.08-1.35) 1 (1.15-1.45) 1 (1.19-1.53) 15-min 0.705 0.844 0.996 1.12 1.26 F 1.46 1.55 1.66 1.74 (0.635-0.783) (0.762-0.937) (0.897-1.10) 1 (1.01-1.24) 1 (1.13-1.39) 1 (1.29-1.61) 11 (1.36-1.71) 1 (1.44-1.83) (1.50-1.93) 30-min 0.966 1.17 1.42 1.62 1.86 2.06 2.24 2.41 2.64 2.81 (0.870-1.07) (1.05-1.29) 1 (1.27-1.57) 1 (1.46-1.80) 1 (1.67-2.06) 1 (1.83-2.27) (1.98-2.47) 1 (2.12-2.66) 1 (2.30-2.91) 1 (2.43-3.12) 60-min 1.21 1.46 1.82 2.11 2.48 2.79 3.08 3.39 3.78 4.11 (1.09-1.34) (1.32-1.62) (1.63-2.01) 1 (1.90-2.34) 1 (2.22-2.74) 11 (2.48-3.07) (2.73-3.40) (2.98-3.73) 1 (3.29-4.18) (3.54-4.55) 2-hr 1.45 1.76 2.19 2.58 3.07 3.48 3.91 4.35 4.96 5.47 (1.27-1.66) (1.54-2.00) (1.93-2.50) (2.27-2.93) (2.68-3.48) (3.03-3.94) (3.37-4.42) (3.73-4.91) 1 (4.20-5.60) (4.59-6.20) 3-hr 1.59 1.92 2.40 2.81 3.35 3.81 4.28 4.76 5.43 6.00 (1 .39-1.82) (1.68-2.20) (2.10-2.76) (2.45-3.22) (2.91-3.83) (3.29-4.34) (3.67-4.87) (4.05-5.43) (4.57-6.20) 1 (4.99-6.86) 6-hr 2.02 2.43 3.02 3.56 4.28 4.91 5.57 6.28 7.28 8.17 (1.79-2.29) 1 (2.15-2.76) 1 (2.66-3.43) 1 (3.12-4.03) 11 (3.73-4.84) 1 (4.25-5.53) 1 (5.32-7.08) 1 (6.09-8.22) 1 (6.74-9.23) 12-hr 2.53 3.05 3.80 4.51 5.48 6.36 7.30 8.33 9.85 F 11.2 (2.24-2.90) (2.69-3.50) (3.34-4.35) (3.95-5.15) (4.76-6.24) (5.47-7.22) (6.20-8.27) (6.99-9.43) (8.11-11.2) 1 (9.09-12.7) 24-hr 3.03 3.66 4.68 5.54 6.81 7.90 9.10 10.4 12.4 14.1 (2.72-3.40) (3.29-4.12) (4.19-5.26) (4.94-6.20) (6.03-7.59) (6.95-8.79) (7.94-10.1) (9.00-11.6) (10.5-13.8) 1 (11.8-15.7) 2-day 3.57 4.33 5.51 6.48 7.88 9.06 10.3 11.7 13.8 15.5 (3.20-3.99) (3.89-4.84) (4.93-6.15) (5.78-7.22) 1 (6.99-8.77) (7.98-10.1) 1 (9.04-11.5) (10.2-13.1) (11.8-15.4) 1 (13.1-17.3) 3-day 3.80 4.61 5.86 6.88 8.37 9-.62-T 11.0 12.4 14.6 F 16.4 (3.45-4.21) (4.18-5.11) (5.30-6.49) (6.22-7.61) (7.52-9.24) 1 (8.58-10.6) (9.72-12.1) (10.9-13.7) (12.7-16.2) 1 (14.1-18.2) 4-day 4.03 4.89 6.21 7.29 8.86 10.2 11.6 13.1 15.4 17.3 (3.70-4.44) (4.47-5.37) (5.68-6.82) (6.65-8.00) 1 (8.05-9.71) (9.19-11.2) (10.4-12.7) (11.7-14.4) (13.5-16.9) 1 (15.0-19.1) 7-day 4.69 5.64 7.06 8.22 9.89 11.3 12.8 14.4 16.7 18.6 (4.31-5.11) 1 (5.19-6.16) 1 (6.47-7.70) 1 (7.52-8.96) 1 (9.00-10.8) (10.2-12.3) 1 (11.5-13.9) 1 (12.8-15.7) 1 (14.7-18.3) 11 (16.2-20.4) 10-day 5.31 6.38 7.88 9.10 10.8 12.2 13.7 15.3 17.5 19.4 (4.91-5.75) 1 (5.89-6.90) 1 (7.27-8.52) 1 (8.37-9.84) 1 (9.91-11.7) (11.1-13.2) (12.4-14.8) 1 (13.8-16.6) 1 (15.6-19.0) 1 (17.1-21.1) 20-day 6.98 8.32 10.1 11.4 13.3 14.7 16.2 17.7 19.8 21.4 (6.53-7.47) (7.80-8.91) (9.41-10.8) (10.7-12.2) (12.3-14.2) (13.6-15.7) (15.0-17.4) (16.3-19.0) (18.1-21.3) 1 (19.4-23.1) F��d:a:y]F 8.56 10.1 12.0 13.4 15.3 16.7 18.0 19.4 21.1 22.5 (8.06-9.11) (9.55-10.8) (11.3-12.8) (12.6-14.3) (14.3-16.2) (15.6-17.7) (16.8-19.2) (18.0-20.6) (19.5-22.6) (20.7-24.1) [457day 10.7 12.6 14.8 16.4 18.4 19.9 21.4 22.8 24.6 26.0 (10.1-11.3) (11.9-13.4) (13.9-15.6) (15.4-17.3) (17.3-19.5) (18.7-21.1) (20.0-22.7) (21.3-24.2) (22.9-26.2) 1 (24.0-27.7) 60-day 12.5 14.8 17.0 18.7 20.9 22.5 24.0 25.5 27.3 28.7 (11.9-13.2) (14.0-15.6) (16.1-18.0) (17.7-19.8) (19.7-22.1) (21.2-23.7) (22.6-25.4) (23.9-27.0) (25.5-29.0) (26.7-30.5) Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical https:Hhdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.htmI?lat=38.0343&Ion=-78.4504&data=depth&units=engIish&series=pds 1/4