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HomeMy WebLinkAboutWPO202000032 Calculations 2021-06-03 (2)SHIMP ENGINEERING, P.C. Design Focused Engineering April 14, 2021 County of Albemarle Department of Community Development 401 McIntire Road Charlottesville, VA 22902 APPROVED by the Albemarle County Community Development Department Date 06/03/2021 File WJP0202000032 Regarding: 1300 Richmond Road — Flow Automotive Stormwater Management Plan Dear Reviewer, STIN M. SHIMP Lic. . 45183 (Al 14ItI ��r S%ONAL ti�� 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 4.62 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-B3a (energy balance equation). Flood protection is met per 9VAC25-870-66-C3c 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 and the energy balance equation is satisfied. Please note that runoff in POA 5 was analyzed using 9VAC25-870-66-B1a as it is released to an adequate manmade channel and does not cause erosion. An excerpt from the previously approved stormwater plan calculations for Pantops Comer WP0201800088 is included showing downstream channel adequacy. Please see below for a summary of energy balance calculations. The first table shows 1-yr, 24-hr storm event 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 areas which had lower post -development volumes than pre -development, the Q1 allowable was simply based on the pre -development Q1 per the energy balance equation statement 912 E. High St. Charlottesville, VA 229021434.227.5140 1 shimp-engineeong.com "Under no condition shall QDeve,oped be greater than QPre-Developed". 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 - Energy 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 1.33 0.060 0.056 Table 2. Values for DAs Outside LOD - Enen PREDEV POSTDEV PDA 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 ly Balance Equation Table 3. Summary of Results - Energy Balance Equation & Flood Protection Table 1 _ Table 2 Q1 Allowable=[(Q1Pre(LOD)`RvPre(LOD)`I.F.)/RvPost(LOD)]+ Q1Pre"RvPre/RvPost POA Q1 ALLOWABLE (cfs) Q1 PROPOSED (cfs) Q10 PRE (cfs) Q10 POST (cfs) 1 8.85 4.83 27.97 38.21* 2 1.41 0.49 7.29 3.74* 3 7.48 6.92 14.39 12.91 4 1.11 0.09 2.12 0.38 5 NA 1.22 2.67 2.41 *Discharges to Mapped Floodplain According to the VRRM spreadsheet included in this packet, the target phosphorus load reduction is 2.59 lb/yr. Nutrient credits will be purchased to satisfy this requirement in accordance with 9VAC25-870-65G. Stormwater Quality Calculations VRRM Redevelopment Spreadsheet 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 Excerpt from WPO201800088 SWM Calculations for POA 5 Stormwater Quality Calculations: VRRM Redevelopment Spreadsheet Nutrient Credit Letter of Availability Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report Pre -Development Stormwater Management Calculations Pre -Development Landuse Map Pre -Development HydroCAD Analysis 1S To Ex. Det. & OA 1 (In LOD) To PO 1 Direct (In LOD) To Ex. Det. POA (Outside L D) 5S To P A 1 Direcl (I utside LOD) 3L 6L a Runoff In LOD unoff Outside LOD 7L POA 1 Subcat Reach Aon Lin k PreDev POA 1 PreDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: To Ex. Det. & POA 1 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 Subcatchment 2S: To POA 1 Direct (in 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 Link 3L: Runoff In LOD Inflow=8.92 cfs 0.407 of Primary=8.92 cfs 0.407 of Subcatchment 4S: To Ex. Det. & POA 1 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 Subcatchment 5S: To POA 1 Direct 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 6L: Runoff Outside LOD Inflow=4.96 cfs 0.235 of Primary=4.96 cfs 0.235 of Link 7L: POA 1 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 8 PreDev POA 1 PreDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 1 S: To Ex. Det. & POA 1 (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 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 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, PreDev POA 1 PreDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 4 Summary for Link 3L: Runoff In LOD Inflow Area = 2.489 ac, 74.37% Impervious, Inflow Depth > 1.96" for 1 yr, 24 hr event Inflow = 8.92 cfs @ 11.95 hrs, Volume= 0.407 of Primary = 8.92 cfs @ 11.95 hrs, Volume= 0.407 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Subcatchment 4S: To Ex. Det. & POA 1 (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, 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 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 rut PreDev - POA 1 Prepared by Shimp Engineering, P.C. HvdroCADO 9.10 s/n 07054 © 2011 Hvdrol Tc Length PreDev POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Printed 4/15/2021 Software Solutions LLC Description 5.0 Direct Entry, Summary for Link 6L: Runoff Outside LOD Inflow Area = 1.266 ac, 84.44% Impervious, Inflow Depth > 2.23" for 1 yr, 24 hr event Inflow = 4.96 cfs @ 11.95 hrs, Volume= 0.235 of Primary = 4.96 cfs @ 11.95 hrs, Volume= 0.235 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 71-: POA 1 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 11 PreDev POA 1 PreDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 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 Subcatchment 1S: To Ex. Det. & POA 1 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 Subcatchment 2S: To POA 1 Direct (in 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 Link 3L: Runoff In LOD Inflow=18.34 cfs 0.871 of Primary=18.34 cfs 0.871 of Subcatchment 4S: To Ex. Det. & POA 1 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 Subcatchment 5S: To POA 1 Direct 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 6L: Runoff Outside LOD Inflow=9.63 cfs 0.472 of Primary=9.63 cfs 0.472 of Link 7L: POA 1 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 IN PreDev POA 1 PreDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 1 S: To Ex. Det. & POA 1 (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 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 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, 13 PreDev POA 1 PreDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 8 Summary for Link 3L: Runoff In LOD Inflow Area = 2.489 ac, 74.37% Impervious, Inflow Depth > 4.20" for 10 yr, 24 hr event Inflow = 18.34 cfs @ 11.95 hrs, Volume= 0.871 of Primary = 18.34 cfs @ 11.95 hrs, Volume= 0.871 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Subcatchment 4S: To Ex. Det. & POA 1 (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, 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 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 14 PreDev - POA 1 Prepared by Shimp Engineering, P.C. HvdroCADO 9.10 s/n 07054 © 2011 Hvdrol Tc Length PreDev POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Printed 4/15/2021 Software Solutions LLC Description 5.0 Direct Entry, Summary for Link 6L: Runoff Outside LOD Inflow Area = 1.266 ac, 84.44% Impervious, Inflow Depth > 4.47" for 10 yr, 24 hr event Inflow = 9.63 cfs @ 11.95 hrs, Volume= 0.472 of Primary = 9.63 cfs @ 11.95 hrs, Volume= 0.472 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 71-: POA 1 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 IN PreDev POA 1 PreDev - POA 1 Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 10 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 1S: To Ex. Det. & POA 1 Runoff Area=0.874 ac 89.02% Impervious Runoff Depth>7.92" Tc=5.0 min CN=96 Runoff=11.43 cfs 0.577 of Subcatchment 2S: To POA 1 Direct (in Runoff Area=1.615 ac 66.44% Impervious Runoff Depth>7.16" Tc=5.0 min CN=88 Runoff=20.12 cfs 0.964 of Link 3L: Runoff In LOD Inflow=31.54 cfs 1.541 of Primary=31.54 cfs 1.541 of Subcatchment 4S: To Ex. Det. & POA 1 Runoff Area=1.198 ac 88.98% Impervious Runoff Depth>7.85" Tc=5.0 min CN=95 Runoff=15.61 cfs 0.783 of Subcatchment 5S: To POA 1 Direct Runoff Area=0.068 ac 4.41% Impervious Runoff Depth>4.67" Tc=5.0 min CN=67 Runoff=0.61 cfs 0.026 of Link 6L: Runoff Outside LOD Inflow=16.22 cfs 0.810 of Primary=16.22 cfs 0.810 of Link 7L: POA 1 Inflow=47.76 cfs 2.351 of Primary=47.76 cfs 2.351 of Total Runoff Area = 3.755 ac Runoff Volume = 2.351 of Average Runoff Depth = 7.51" 22.24% Pervious = 0.835 ac 77.76% Impervious = 2.920 ac IM PreDev POA 1 PreDev - POA 1 Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 1 S: To Ex. Det. & POA 1 (In LOD) Runoff = 11.43 cfs @ 11.95 hrs, Volume= 0.577 af, Depth> 7.92" 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 0.003 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 POA 1 Direct (in LOD) Runoff = 20.12 cfs @ 11.95 hrs, Volume= 0.964 af, Depth> 7.16" 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 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, 17 PreDev POA 1 PreDev - POA 1 Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 12 Summary for Link 3L: Runoff In LOD Inflow Area = 2.489 ac, 74.37% Impervious, Inflow Depth > 7.43" for 100 yr, 24 hr event Inflow = 31.54 cfs @ 11.95 hrs, Volume= 1.541 of Primary = 31.54 cfs @ 11.95 hrs, Volume= 1.541 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Subcatchment 4S: To Ex. Det. & POA 1 (Outside LOD) Runoff = 15.61 cfs @ 11.95 hrs, Volume= 0.783 af, Depth> 7.85" 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 0.065 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, Summary for Subcatchment 5S: To POA 1 Direct (Outside LOD) Runoff = 0.61 cfs @ 11.96 hrs, Volume= 0.026 af, Depth> 4.67" 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 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 IM PreDev - POA 1 Prepared by Shimp Engineering, P.C. HvdroCADO 9.10 s/n 07054 © 2011 Hvdrol Tc Length PreDev POA 1 Type 11 24-hr 100 yr, 24 hr Rainfall=9. 10 " Printed 4/15/2021 Software Solutions LLC Description 5.0 Direct Entry, Summary for Link 6L: Runoff Outside LOD Inflow Area = 1.266 ac, 84.44% Impervious, Inflow Depth > 7.68" for 100 yr, 24 hr event Inflow = 16.22 cfs @ 11.95 hrs, Volume= 0.810 of Primary = 16.22 cfs @ 11.95 hrs, Volume= 0.81Oaf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 71-: POA 1 Inflow Area = 3.755 ac, 77.76% Impervious, Inflow Depth > 7.51" for 100 yr, 24 hr event Inflow = 47.76 cfs @ 11.95 hrs, Volume= 2.351 of Primary = 47.76 cfs @ 11.95 hrs, Volume= 2.351 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs iS 2S To POA 2 (IN OD) To P A 2 (Outside LOD) 3L POA 2 7S To POA 4 (IN SOD) 8L POA 4 Subcat Reach Aon Llnk 4S 5S To POA 3 (1 OD) To PO 3 (Outside LOD) 6L POA 3 9S To POA 5 (IN L D) 1OL POA 5 20 PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: 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 Subcatchment 2S: 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 Subcatchment 4S: 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 Subcatchment 5S: 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 Subcatchment 7S: 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 Subcatchment 9S: To POA 5 (IN LOD) Runoff Area=0.354 ac 65.54% Impervious Runoff Depth>2.05" Tc=5.0 min CN=92 Runoff=1.33 cfs 0.060 of Link 3L: POA 2 Inflow=0.88 cfs 0.056 of Primary=0.88 cfs 0.056 of Link 6L: POA 3 Inflow=7.47 cfs 0.354 of Primary=7.47 cfs 0.354 of Link 8L: POA 4 Inflow=1.11 cfs 0.052 of Primary=1.11 cfs 0.052 of Link 10L: POA 5 Inflow=1.33 cfs 0.060 of Primary=1.33 cfs 0.060 of Total Runoff Area = 5.315 ac Runoff Volume = 0.523 of Average Runoff Depth = 1.18" 59.12% Pervious = 3.142 ac 40.88% Impervious = 2.173 ac 21 PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 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 Description 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 Description 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 II 24-hr 1 yr, 24 hr Rainfall=3.03" 04 PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 4 Area (ac) CN Description 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 Description 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 II 24-hr 1 yr, 24 hr Rainfall=3.03" 23 PreDev PreDev Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD® 9.10 s/n 07054 02011 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 = 1.33 cfs @ 11.95 hrs, Volume= 0.060 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 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 0.122 80 >75% Grass cover, Good, HSG D 0.232 98 Impervious, HSG D 0.354 92 Weighted Average 0.122 34.46% Pervious Area 0.232 65.54% Impervious Area Tc Length Slope Velocity Capacity Description 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 24 PreDev PreDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Summary for Link 6L: 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 8L: 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 10L: POA 5 Inflow Area = 0.354 ac, 65.54% Impervious, Inflow Depth > 2.05" for 1 yr, 24 hr event Inflow = 1.33 cfs @ 11.95 hrs, Volume= 0.060 of Primary = 1.33 cfs @ 11.95 hrs, Volume= 0.060 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs W PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: 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 Subcatchment 2S: 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 Subcatchment 4S: 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 Subcatchment 5S: 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 Subcatchment 7S: 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 Subcatchment 9S: To POA 5 (IN LOD) Runoff Area=0.354 ac 65.54% Impervious Runoff Depth>4.33" Tc=5.0 min CN=92 Runoff=2.67 cfs 0.128 of Link 3L: POA 2 Inflow=7.29 cfs 0.312 of Primary=7.29 cfs 0.312 of Link 6L: POA 3 Inflow=14.39 cfs 0.706 of Primary=14.39 cfs 0.706 of Link 8L: POA 4 Inflow=2.12 cfs 0.104 of Primary=2.12 cfs 0.104 of Link 10L: POA 5 Inflow=2.67 cfs 0.128 of Primary=2.67 cfs 0.128 of Total Runoff Area = 5.315 ac Runoff Volume = 1.250 of Average Runoff Depth = 2.82" 59.12% Pervious = 3.142 ac 40.88% Impervious = 2.173 ac OU PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 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 Description 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 Description 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 II 24-hr 10 yr, 24 hr Rainfall=5.54" OrA PreDev PreDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 9 Area (ac) CN Description 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 Description 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 II 24-hr 10 yr, 24 hr Rainfall=5.54" ON PreDev PreDev Type 1124-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD® 9.10 s/n 07054 02011 HvdroCAD Software Solutions LLC Paoe 10 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 = 2.67 cfs @ 11.95 hrs, Volume= 0.128 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 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 0.122 80 >75% Grass cover, Good, HSG D 0.232 98 Impervious, HSG D 0.354 92 Weighted Average 0.122 34.46% Pervious Area 0.232 65.54% Impervious Area Tc Length Slope Velocity Capacity Description 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 29 PreDev PreDev Type 1124-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD@ 9.10 s/n 07054 02011 HvdroCAD Software Solutions LLC Paae 11 Summary for Link 6L: 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 outtlow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 8L: 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 10L: POA 5 Inflow Area = 0.354 ac, 65.54% Impervious, Inflow Depth > 4.33" for 10 yr, 24 hr event Inflow = 2.67 cfs @ 11.95 hrs, Volume= 0.128 of Primary = 2.67 cfs @ 11.95 hrs, Volume= 0.128 af, Atten= 0%, Lag= 0.0 min Primary outtlow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 30 PreDev PreDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: To POA 2 (IN LOD) Runoff Area=1.020 ac 0.00% Impervious Runoff Depth>3.60" Tc=5.0 min CN=58 Runoff=7.23 cfs 0.306 of Subcatchment 2S: To POA 2 (Outside LOD) Runoff Area=1.820 ac 0.00% Impervious Runoff Depth>3.60" Tc=5.0 min CN=58 Runoff=12.90 cfs 0.545 of Subcatchment 4S: To POA 3 (IN LOD) Runoff Area=0.316 ac 100.00% Impervious Runoff Depth>8.05" Tc=5.0 min CN=98 Runoff=4.15 cfs 0.212 of Subcatchment 5S: To POA 3 (Outside LOD) Runoff Area=1.534 ac 89.50% Impervious Runoff Depth>7.76" Tc=5.0 min CN=94 Runoff=19.90 cfs 0.992 of Subcatchment 7S: To POA 4 (IN LOD) Runoff Area=0.271 ac 92.99% Impervious Runoff Depth>7.85" Tc=5.0 min CN=95 Runoff=3.53 cfs 0.177 of Subcatchment 9S: To POA 5 (IN LOD) Runoff Area=0.354 ac 65.54% Impervious Runoff Depth>7.58" Tc=5.0 min CN=92 Runoff=4.54 cfs 0.224 of Link 3L: POA 2 Inflow=20.13 cfs 0.851 of Primary=20.13 cfs 0.851 of Link 6L: POA 3 Inflow=24.05 cfs 1.204 of Primary=24.05 cfs 1.204 of Link 8L: POA 4 Inflow=3.53 cfs 0.177 of Primary=3.53 cfs 0.177 of Link 10L: POA 5 Inflow=4.54 cfs 0.224 of Primary=4.54 cfs 0.224 of Total Runoff Area = 5.315 ac Runoff Volume = 2.456 of Average Runoff Depth = 5.54" 59.12% Pervious = 3.142 ac 40.88% Impervious = 2.173 ac 31 PreDev PreDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 13 Summary for Subcatchment 1S: To POA 2 (IN LOD) Runoff = 7.23 cfs @ 11.96 hrs, Volume= 0.306 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 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 Description 5.0 Direct Entry, Summary for Subcatchment 2S: To POA 2 (Outside LOD) Runoff = 12.90 cfs @ 11.96 hrs, Volume= 0.545 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 Description 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 = 4.15 cfs @ 11.95 hrs, Volume= 0.212 af, Depth> 8.05" 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" 00a PreDev PreDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 14 Area (ac) CN Description 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 Description 5.0 Direct Entry, Summary for Subcatchment 5S: To POA 3 (Outside LOD) Runoff = 19.90 cfs @ 11.95 hrs, Volume= 0.992 af, Depth> 7.76" 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 0.161 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 = 3.53 cfs @ 11.95 hrs, Volume= 0.177 af, Depth> 7.85" 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" 33 PreDev PreDev Type 11 24-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD® 9.10 s/n 07054 02011 HvdroCAD Software Solutions LLC Paoe 15 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 = 4.54 cfs @ 11.95 hrs, Volume= 0.224 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 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 0.122 80 >75% Grass cover, Good, HSG D 0.232 98 Impervious, HSG D 0.354 92 Weighted Average 0.122 34.46% Pervious Area 0.232 65.54% Impervious Area Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Summary for Link 3L: POA 2 Inflow Area = 2.840 ac, 0.00% Impervious, Inflow Depth > 3.60" for 100 yr, 24 hr event Inflow = 20.13 cfs @ 11.96 hrs, Volume= 0.851 of Primary = 20.13 cfs @ 11.96 hrs, Volume= 0.851 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 34 PreDev PreDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 16 Summary for Link 6L: POA 3 Inflow Area = 1.850 ac, 91.30% Impervious, Inflow Depth > 7.81" for 100 yr, 24 hr event Inflow = 24.05 cfs @ 11.95 hrs, Volume= 1.204 of Primary = 24.05 cfs @ 11.95 hrs, Volume= 1.204 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 8L: POA 4 Inflow Area = 0.271 ac, 92.99% Impervious, Inflow Depth > 7.85" for 100 yr, 24 hr event Inflow = 3.53 cfs @ 11.95 hrs, Volume= 0.177 of Primary = 3.53 cfs @ 11.95 hrs, Volume= 0.177 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 10L: POA 5 Inflow Area = 0.354 ac, 65.54% Impervious, Inflow Depth > 7.58" for 100 yr, 24 hr event Inflow = 4.54 cfs @ 11.95 hrs, Volume= 0.224 of Primary = 4.54 cfs @ 11.95 hrs, Volume= 0.224 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs W Post -Development Stormwater Management Calculations Post -Development Landuse Map Post -Development HydroCAD Analysis Excerpt from WPO201800088 SWIM Calculations for POA 5 cW iS 2S To Ex. Det. & P 1 To PO 1 Directly To (In LOD) In LOD) 3L Runoff In LOD 4S 5S Ex. Det. Al 1 To OA 1 Directly (Outside L D) Outside LOD) 6L R off Outsdie LOD 7P Detention Pond 8L POA 1 Subcat Reach Aon Llrlk 38 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: To Ex. Det. & POA 1 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 Subcatchment 2S: 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 Link 3L: Runoff In LOD Inflow=13.08 cfs 0.636 of Primary=13.08 cfs 0.636 of Subcatchment 4S: 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 Subcatchment 5S: 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 Link 6L: Runoff Outsdie LOD Inflow=5.20 cfs 0.272 of Primary=5.20 cfs 0.272 of Pond 7P: Detention Pond Peak Elev=343.74' Storage=12,356 cf Inflow=18.28 cfs 0.908 of Outflow=4.83 cfs 0.908 of Link 8L: POA 1 Inflow=4.83 cfs 0.908 of Primary=4.83 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 .x1 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 1 S: 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 2S: 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 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, Cro7 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 4 Summary for Link 3L: Runoff In LOD Inflow Area = 3.701 ac, 75.52% Impervious, Inflow Depth = 2.06" for 1 yr, 24 hr event Inflow = 13.08 cfs @ 11.95 hrs, Volume= 0.636 of Primary = 13.08 cfs @ 11.95 hrs, Volume= 0.636 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Subcatchment 4S: 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, Summary for Subcatchment 5S: 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 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 41 PostDev - POA 1 Prepared by Shimp Engineering, P.C. HvdroCADO 9.10 s/n 07054 © 2011 Hvdrol Tc Length PostDev POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Printed 4/15/2021 Software Solutions LLC Description 5.0 Direct Entry, Summary for Link 6L: Runoff Outsdie LOD Inflow Area = 1.930 ac, 56.17% Impervious, Inflow Depth = 1.69" for 1 yr, 24 hr event Inflow = 5.20 cfs @ 11.95 hrs, Volume= 0.272 of Primary = 5.20 cfs @ 11.95 hrs, Volume= 0.272 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Pond 7P: 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 = 4.83 cfs @ 12.10 hrs, Volume= 0.908 af, Atten= 74%, Lag= 9.0 min Primary = 4.83 cfs @ 12.10 hrs, Volume= 0.908 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 343.74' @ 12.11 hrs Surf.Area= 3,759 sf Storage= 12,356 cf Plug -Flow detention time= 27.1 min calculated for 0.907 of (100% of inflow) Center -of -Mass det. time= 27.2 min ( 821.9 - 794.7) Volume Invert Avail.Storage Storage Description #1 338.00' 22,569 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 338.00 800 0 0 340.00 1,634 2,434 2,434 342.00 2,690 4,324 6,758 344.00 3,921 6,611 13,369 346.00 5,279 9,200 22,569 Device Routina Invert Outlet Devices #1 Primary 338.00' 30.0" Round Culvert L= 64.3' Ke= 0.300 Inlet / Outlet Invert= 338.00' / 337.50' S= 0.0078'/' Cc= 0.900 n= 0.012 #2 Device 1 338.00' 8.0" Vert. 1-Yr Orifice C= 0.600 #3 Device 1 343.66' 48.0" Horiz. Top of Standpipe C= 0.600 Limited to weir flow at low heads #4 Primary 345.00' 7.0' long x 30.0' breadth Grassed Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 E,W PostDev POA 1 PostDev - POA 1 Type 11 24-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Primary OutFlow Max=4.69 cfs @ 12.10 hrs HW=343.73' (Free Discharge) 1-Culvert (Passes 4.69 cfs of 56.60 cfs potential flow) �2=1-Yr Orifice (Orifice Controls 3.90 cfs @ 11.19 fps) 3=Top of Standpipe (Weir Controls 0.78 cfs @ 0.87 fps) =Grassed Emergency Spillway ( Controls 0.00 cfs) Summary for Link 8L: POA 1 Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 1.93" for 1 yr, 24 hr event Inflow = 4.83 cfs @ 12.10 hrs, Volume= 0.908 of Primary = 4.83 cfs @ 12.10 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 43 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 2 yr, 24 hr Rainfall=3.66" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 7 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 1S: To Ex. Det. & POA 1 Runoff Area=0.571 ac 97.72% Impervious Runoff Depth=3.43" Tc=5.0 min CN=98 Runoff=2.99 cfs 0.163 of Subcatchment 2S: To POA 1 Directly (In Runoff Area=3.130 ac 71.47% Impervious Runoff Depth=2.51" Tc=5.0 min CN=89 Runoff=13.62 cfs 0.654 of Link 3L: Runoff In LOD Inflow=16.61 cfs 0.817 of Primary=16.61 cfs 0.817 of Subcatchment 4S: To Ex. Det. & POA 1 Runoff Area=1.238 ac 87.56% Impervious Runoff Depth=3.10" Tc=5.0 min CN=95 Runoff=6.23 cfs 0.319 of Subcatchment 5S: To POA 1 Directly Runoff Area=0.692 ac 0.00% Impervious Runoff Depth=0.52" Tc=5.0 min CN=58 Runoff=0.52 cfs 0.030 of Link 6L: Runoff Outsdie LOD Inflow=6.69 cfs 0.349 of Primary=6.69 cfs 0.349 of Pond 7P: Detention Pond Peak Elev=344.08' Storage=13,687 cf Inflow=23.30 cfs 1.166 of Outflow=15.19 cfs 1.166 of Link 8L: POA 1 Inflow=15.19 cfs 1.166 of Primary=15.19 cfs 1.166 of Total Runoff Area = 5.631 ac Runoff Volume = 1.166 of Average Runoff Depth = 2.48" 31.11% Pervious =1.752 ac 68.89% Impervious = 3.879 ac 44 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 2 yr, 24 hr Rainfall=3.66" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 1 S: To Ex. Det. & POA 1 (In LOD) Runoff = 2.99 cfs @ 11.95 hrs, Volume= 0.163 af, Depth= 3.43" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 2 yr, 24 hr Rainfall=3.66" 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 2S: To POA 1 Directly (In LOD) Runoff = 13.62 cfs @ 11.95 hrs, Volume= 0.654 af, Depth= 2.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 2 yr, 24 hr Rainfall=3.66" Area (ac) CN 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, 01 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 2 yr, 24 hr Rainfall=3.66" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 9 Summary for Link 3L: Runoff In LOD Inflow Area = 3.701 ac, 75.52% Impervious, Inflow Depth = 2.65" for 2 yr, 24 hr event Inflow = 16.61 cfs @ 11.95 hrs, Volume= 0.817 of Primary = 16.61 cfs @ 11.95 hrs, Volume= 0.817 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Subcatchment 4S: To Ex. Det. & POA 1 (Outside LOD) Runoff = 6.23 cfs @ 11.95 hrs, Volume= 0.319 af, Depth= 3.10" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 2 yr, 24 hr Rainfall=3.66" 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, Summary for Subcatchment 5S: To POA 1 Directly (Outside LOD) Runoff = 0.52 cfs @ 11.99 hrs, Volume= 0.030 af, Depth= 0.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 2 yr, 24 hr Rainfall=3.66" Area (ac) CN 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 CY7 PostDev - POA 1 Prepared by Shimp Engineering, P.C. HvdroCADO 9.10 s/n 07054 © 2011 Hvdrol Tc Length PostDev POA 1 Type 11 24-hr 2 yr, 24 hr Rainfall=3.66" Printed 4/15/2021 Software Solutions LLC Description 5.0 Direct Entry, Summary for Link 6L: Runoff Outsdie LOD Inflow Area = 1.930 ac, 56.17% Impervious, Inflow Depth = 2.17" for 2 yr, 24 hr event Inflow = 6.69 cfs @ 11.95 hrs, Volume= 0.349 of Primary = 6.69 cfs @ 11.95 hrs, Volume= 0.349 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Pond 7P: Detention Pond Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 2.48" for 2 yr, 24 hr event Inflow = 23.30 cfs @ 11.95 hrs, Volume= 1.166 of Outflow = 15.19 cfs @ 12.04 hrs, Volume= 1.166 af, Atten= 35%, Lag= 5.3 min Primary = 15.19 cfs @ 12.04 hrs, Volume= 1.166 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 344.08' @ 12.04 hrs Surf.Area= 3,976 sf Storage= 13,687 cf Plug -Flow detention time= 24.7 min calculated for 1.165 of (100% of inflow) Center -of -Mass det. time= 24.8 min ( 814.0 - 789.2) Volume Invert Avail.Storage Storage Description #1 338.00' 22,569 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 338.00 800 0 0 340.00 1,634 2,434 2,434 342.00 2,690 4,324 6,758 344.00 3,921 6,611 13,369 346.00 5,279 9,200 22,569 Device Routina Invert Outlet Devices #1 Primary 338.00' 30.0" Round Culvert L= 64.3' Ke= 0.300 Inlet / Outlet Invert= 338.00' / 337.50' S= 0.0078'/' Cc= 0.900 n= 0.012 #2 Device 1 338.00' 8.0" Vert. 1-Yr Orifice C= 0.600 #3 Device 1 343.66' 48.0" Horiz. Top of Standpipe C= 0.600 Limited to weir flow at low heads #4 Primary 345.00' 7.0' long x 30.0' breadth Grassed Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 CYI PostDev POA 1 PostDev - POA 1 Type 11 24-hr 2 yr, 24 hr Rainfall=3.66" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 11 Primary OutFlow Max=14.48 cfs @ 12.04 hrs HW=344.06' (Free Discharge) 1-Culvert (Passes 14.48 cfs of 59.06 cfs potential flow) �2=1-Yr Orifice (Orifice Controls 4.02 cfs @ 11.52 fps) 3=Top of Standpipe (Weir Controls 10.46 cfs @ 2.07 fps) =Grassed Emergency Spillway ( Controls 0.00 cfs) Summary for Link 8L: POA 1 Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 2.48" for 2 yr, 24 hr event Inflow = 15.19 cfs @ 12.04 hrs, Volume= 1.166 of Primary = 15.19 cfs @ 12.04 hrs, Volume= 1.166 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs 48 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 12 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 1S: To Ex. Det. & POA 1 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 Subcatchment 2S: 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 Link 3L: Runoff In LOD Inflow=27.14 cfs 1.371 of Primary=27.14 cfs 1.371 of Subcatchment 4S: 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 Subcatchment 5S: 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 Link 6L: Runoff Outsdie LOD Inflow=11.41 cfs 0.596 of Primary=11.41 cfs 0.596 of Pond 7P: Detention Pond Peak Elev=344.55' Storage=15,626 cf Inflow=38.55 cfs 1.968 of Outflow=38.21 cfs 1.968 of Link 8L: POA 1 Inflow=38.21 cfs 1.968 of Primary=38.21 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 Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 13 Summary for Subcatchment 1 S: 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 2S: 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 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, *1 PostDev POA 1 PostDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 14 Summary for Link 3L: Runoff In LOD Inflow Area = 3.701 ac, 75.52% Impervious, Inflow Depth = 4.45" for 10 yr, 24 hr event Inflow = 27.14 cfs @ 11.95 hrs, Volume= 1.371 of Primary = 27.14 cfs @ 11.95 hrs, Volume= 1.371 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Subcatchment 4S: 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, Summary for Subcatchment 5S: 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 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 51 PostDev - POA 1 Prepared by Shimp Engineering, P.C. HvdroCADO 9.10 s/n 07054 © 2011 Hvdrol Tc Length 5.0 PostDev POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Printed 4/15/2021 Software Solutions LLC Description Direct Entry, Summary for Link 6L: Runoff Outsdie LOD Inflow Area = 1.930 ac, 56.17% Impervious, Inflow Depth = 3.71" for 10 yr, 24 hr event Inflow = 11.41 cfs @ 11.95 hrs, Volume= 0.596 of Primary = 11.41 cfs @ 11.95 hrs, Volume= 0.596 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Pond 7P: 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 = 38.21 cfs @ 11.97 hrs, Volume= 1.968 af, Atten= 1%, Lag= 1.4 min Primary = 38.21 cfs @ 11.97 hrs, Volume= 1.968 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 344.55' @ 11.97 hrs Surf.Area= 4,294 sf Storage= 15,626 cf Plug -Flow detention time= 21.1 min calculated for 1.968 of (100% of inflow) Center -of -Mass det. time= 20.6 min ( 798.4 - 777.8) Volume Invert Avail.Storage Storage Description #1 338.00' 22,569 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 338.00 800 0 0 340.00 1,634 2,434 2,434 342.00 2,690 4,324 6,758 344.00 3,921 6,611 13,369 346.00 5,279 9,200 22,569 Device Routina Invert Outlet Devices #1 Primary 338.00' 30.0" Round Culvert L= 64.3' Ke= 0.300 Inlet / Outlet Invert= 338.00' / 337.50' S= 0.0078'/' Cc= 0.900 n= 0.012 #2 Device 1 338.00' 8.0" Vert. 1-Yr Orifice C= 0.600 #3 Device 1 343.66' 48.0" Horiz. Top of Standpipe C= 0.600 Limited to weir flow at low heads #4 Primary 345.00' 7.0' long x 30.0' breadth Grassed Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 M PostDev POA 1 PostDev - POA 1 Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 16 Primary OutFlow Max=35.59 cfs @ 11.97 hrs HW=344.50' (Free Discharge) 1-Culvert (Passes 35.59 cfs of 62.13 cfs potential flow) �2=1-Yr Orifice (Orifice Controls 4.17 cfs @ 11.95 fps) 3=Top of Standpipe (Weir Controls 31.41 cfs @ 2.99 fps) =Grassed Emergency Spillway ( Controls 0.00 cfs) Summary for Link 8L: POA 1 Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 4.19" for 10 yr, 24 hr event Inflow = 38.21 cfs @ 11.97 hrs, Volume= 1.968 of Primary = 38.21 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 53 PostDev POA 1 PostDev - POA 1 Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 17 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 1S: To Ex. Det. & POA 1 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 Subcatchment 2S: 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 Link 3L: Runoff In LOD Inflow=46.82 cfs 2.448 of Primary=46.82 cfs 2.448 of Subcatchment 4S: 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 Subcatchment 5S: 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 Link 6L: Runoff Outsdie LOD Inflow=21.01 cfs 1.103 of Primary=21.01 cfs 1.103 of Pond 7P: Detention Pond Peak Elev=344.96' Storage=17,428 cf Inflow=67.82 cfs 3.551 of Outflow=64.85 cfs 3.551 of Link 8L: POA 1 Inflow=64.85 cfs 3.551 of Primary=64.85 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 54 PostDev POA 1 PostDev - POA 1 Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 1 S: 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 2S: 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 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, M PostDev POA 1 PostDev - POA 1 Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 19 Summary for Link 3L: Runoff In LOD Inflow Area = 3.701 ac, 75.52% Impervious, Inflow Depth = 7.94" for 100 yr, 24 hr event Inflow = 46.82 cfs @ 11.95 hrs, Volume= 2.448 of Primary = 46.82 cfs @ 11.95 hrs, Volume= 2.448 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Subcatchment 4S: 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, Summary for Subcatchment 5S: 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 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 4-1 PostDev - POA 1 Prepared by Shimp Engineering, P.C. HvdroCADO 9.10 s/n 07054 © 2011 Hvdrol Tc Length 5.0 PostDev POA 1 Type 11 24-hr 100 yr, 24 hr Rainfall=9. 10 " Printed 4/15/2021 Software Solutions LLC Description Direct Entry, Summary for Link 6L: Runoff Outsdie LOD Inflow Area = 1.930 ac, 56.17% Impervious, Inflow Depth = 6.86" for 100 yr, 24 hr event Inflow = 21.01 cfs @ 11.95 hrs, Volume= 1.103 of Primary = 21.01 cfs @ 11.95 hrs, Volume= 1.103 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Summary for Pond 7P: 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 = 64.85 cfs @ 11.97 hrs, Volume= 3.551 af, Atten= 4%, Lag= 1.2 min Primary = 64.85 cfs @ 11.97 hrs, Volume= 3.551 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 344.96' @ 11.97 hrs Surf.Area= 4,570 sf Storage= 17,428 cf Plug -Flow detention time= 17.8 min calculated for 3.547 of (100% of inflow) Center -of -Mass det. time= 17.9 min ( 783.5 - 765.6) Volume Invert Avail.Storage Storage Description #1 338.00' 22,569 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 338.00 800 0 0 340.00 1,634 2,434 2,434 342.00 2,690 4,324 6,758 344.00 3,921 6,611 13,369 346.00 5,279 9,200 22,569 Device Routina Invert Outlet Devices #1 Primary 338.00' 30.0" Round Culvert L= 64.3' Ke= 0.300 Inlet / Outlet Invert= 338.00' / 337.50' S= 0.0078'/' Cc= 0.900 n= 0.012 #2 Device 1 338.00' 8.0" Vert. 1-Yr Orifice C= 0.600 #3 Device 1 343.66' 48.0" Horiz. Top of Standpipe C= 0.600 Limited to weir flow at low heads #4 Primary 345.00' 7.0' long x 30.0' breadth Grassed Emergency Spillway Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 PostDev POA 1 PostDev - POA 1 Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 21 Primary OutFlow Max=63.04 cfs @ 11.97 hrs HW=344.93' (Free Discharge) 1-Culvert (Passes 63.04 cfs of 64.99 cfs potential flow) �2=1-Yr Orifice (Orifice Controls 4.32 cfs @ 12.37 fps) 3=Top of Standpipe (Weir Controls 58.72 cfs @ 3.68 fps) =Grassed Emergency Spillway ( Controls 0.00 cfs) Summary for Link 8L: POA 1 Inflow Area = 5.631 ac, 68.89% Impervious, Inflow Depth = 7.57" for 100 yr, 24 hr event Inflow = 64.85 cfs @ 11.97 hrs, Volume= 3.551 of Primary = 64.85 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 58 iS 2S To POA 2 (IN OD) To P A 2 (Outside LOD) 3L POA 2 7S To POA 4 (IN 8L POA 4 Subcat Reach Aon Llnk 4S 5S To POA 3 (1 LOD) To P A 3 (Outside LOD) 6L POA 3 9S To POA 5 (IN L D) Ij 0L POA 5 59 PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: 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 Subcatchment 2S: 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 Subcatchment 4S: 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 5S: 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 Subcatchment 7S: 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 Subcatchment 9S: To POA 5 (IN LOD) Runoff Area=0.315 ac 71.43% Impervious Runoff Depth>2.14" Tc=5.0 min CN=93 Runoff=1.22 cfs 0.056 of Link 3L: POA 2 Inflow=0.49 cfs 0.030 of Primary=0.49 cfs 0.030 of Link 6L: POA 3 Inflow=6.92 cfs 0.338 of Primary=6.92 cfs 0.338 of Link 8L: POA 4 Inflow=0.09 cfs 0.004 of Primary=0.09 cfs 0.004 of Link 10L: POA 5 Inflow=1.22 cfs 0.056 of Primary=1.22 cfs 0.056 of Total Runoff Area = 3.465 ac Runoff Volume = 0.428 of Average Runoff Depth = 1.48" 48.86% Pervious = 1.693 ac 51.14% Impervious = 1.772 ac SIC PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 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 Description 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 Description 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 II 24-hr 1 yr, 24 hr Rainfall=3.03" 61 PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 4 Area (ac) CN Description 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 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 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 II 24-hr 1 yr, 24 hr Rainfall=3.03" :�a PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD® 9.10 s/n 07054 02011 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 = 1.22 cfs @ 11.95 hrs, Volume= 0.056 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 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 0.090 80 >75% Grass cover, Good, HSG D 0.225 98 Impervious, HSG D 0.315 93 Weighted Average 0.090 28.57% Pervious Area 0.225 71.43% Impervious Area Tc Length Slope Velocity Capacity Description 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 63 PostDev PostDev Type 1124-hr 1 yr, 24 hr Rainfall=3.03" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Summary for Link 6L: 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 8L: 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 10L: POA 5 Inflow Area = 0.315 ac, 71.43% Impervious, Inflow Depth > 2.14" for 1 yr, 24 hr event Inflow = 1.22 cfs @ 11.95 hrs, Volume= 0.056 of Primary = 1.22 cfs @ 11.95 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 64 PostDev PostDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: 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 Subcatchment 2S: 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 Subcatchment 4S: 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 Subcatchment 5S: 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 Subcatchment 7S: 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 Subcatchment 9S: To POA 5 (IN LOD) Runoff Area=0.315 ac 71.43% Impervious Runoff Depth>4.43" Tc=5.0 min CN=93 Runoff=2.41 cfs 0.116 of Link 3L: POA 2 Inflow=3.74 cfs 0.160 of Primary=3.74 cfs 0.160 of Link 6L: POA 3 Inflow=12.91 cfs 0.648 of Primary=12.91 cfs 0.648 of Link 8L: POA 4 Inflow=0.38 cfs 0.016 of Primary=0.38 cfs 0.016 of Link 10L: POA 5 Inflow=2.41 cfs 0.116 of Primary=2.41 cfs 0.116 of Total Runoff Area = 3.465 ac Runoff Volume = 0.940 of Average Runoff Depth = 3.26" 48.86% Pervious = 1.693 ac 51.14% Impervious = 1.772 ac a.7 PostDev PostDev Type 11 24-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 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 Description 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 Description 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 II 24-hr 10 yr, 24 hr Rainfall=5.54" :�y PostDev PostDev Type 1124-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD® 9.10 s/n 07054 02011 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 91.871/6 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/f0 (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 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 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 II 24-hr 10 yr, 24 hr Rainfall=5.54" 67 PostDev PostDev Type 1124-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD® 9.10 s/n 07054 02011 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 = 2.41 cfs @ 11.95 hrs, Volume= 0.116 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 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 0.090 80 >75% Grass cover, Good, HSG D 0.225 98 Impervious, HSG D 0.315 93 Weighted Average 0.090 28.57% Pervious Area 0.225 71.43% Impervious Area Tc Length Slope Velocity Capacity Description 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 68 PostDev PostDev Type 1124-hr 10 yr, 24 hr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD@ 9.10 s/n 07054 02011 HvdroCAD Software Solutions LLC Paae 11 Summary for Link 6L: 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 outtlow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 8L: 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 outtlow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Summary for Link 10L: POA 5 Inflow Area = 0.315 ac, 71.43% Impervious, Inflow Depth > 4.43" for 10 yr, 24 hr event Inflow = 2.41 cfs @ 11.95 hrs, Volume= 0.116 of Primary = 2.41 cfs @ 11.95 hrs, Volume= 0.116 af, Atten= 0%, Lag= 0.0 min Primary outtlow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 69 PostDev PostDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 1S: 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 Subcatchment 2S: 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 Subcatchment 4S: 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 Subcatchment 5S: 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 Subcatchment 7S: 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 Subcatchment 9S: To POA 5 (IN LOD) Runoff Area=0.315 ac 71.43% Impervious Runoff Depth>7.67" Tc=5.0 min CN=93 Runoff=4.07 cfs 0.201 of Link 3L: POA 2 Inflow=10.19 cfs 0.431 of Primary=10.19 cfs 0.431 of Link 6L: POA 3 Inflow=21.35 cfs 1.083 of Primary=21.35 cfs 1.083 of Link 8L: POA 4 Inflow=0.90 cfs 0.039 of Primary=0.90 cfs 0.039 of Link 10L: POA 5 Inflow=4.07 cfs 0.201 of Primary=4.07 cfs 0.201 of Total Runoff Area = 3.465 ac Runoff Volume = 1.755 of Average Runoff Depth = 6.08" 48.86% Pervious = 1.693 ac 51.14% Impervious = 1.772 ac rill PostDev PostDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 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 Description 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 Description 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 II 24-hr 100 yr, 24 hr Rainfall=9.10" 71 PostDev PostDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD® 9.10 s/n 07054 02011 HvdroCAD Software Solutions LLC Paoe 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 91.871/6 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/f0 (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 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 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 II 24-hr 100 yr, 24 hr Rainfall=9.10" FA PostDev PostDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HvdroCAD@ 9.10 s/n 07054 02011 HvdroCAD Software Solutions LLC Paae 15 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/f0 (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: To POA 5 (IN LOD) Runoff = 4.07 cfs @ 11.95 hrs, Volume= 0.201 af, Depth> 7.67" 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 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 0.090 80 >75% Grass cover, Good, HSG D 0.225 98 Impervious, HSG D 0.315 93 Weighted Average 0.090 28.57% Pervious Area 0.225 71.43% Impervious Area Tc Length Slope Velocity Capacity Description 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 73 PostDev PostDev Type 1124-hr 100 yr, 24 hr Rainfall=9. 10 " Prepared by Shimp Engineering, P.C. Printed 4/15/2021 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paqe 16 Summary for Link 6L: 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 8L: 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 10L: POA 5 Inflow Area = 0.315 ac, 71.43% Impervious, Inflow Depth > 7.67" for 100 yr, 24 hr event Inflow = 4.07 cfs @ 11.95 hrs, Volume= 0.201 of Primary = 4.07 cfs @ 11.95 hrs, Volume= 0.201 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 74 Rte 250 LD-229 Pantops Corner From To Design Catch. Runoff Increment Accum. Total Total Total Up Down Pipe Invert Pipe Pipe Velocity Flow time Structure Structure Storm Area Cost AC AC TOC Intensity Flow Invert Invert Length Slope Diameter Capacity Increment (ac) (min) (in/hr) (cfs) Elev. Elev. (ft) % (in) (cfs) (ft/s) (min) 1 2 3 4 5 6 7 8 1 9 10 11 1 12 1 13 14 15 16 17 18 Predev D1 8-22P 2-yr 1.45 0.62 0.90 0.90 5.00 5.17 4.68 389.50 377.60 263.0 4.52% 15 13.70 10.6 0.41 10-yr 5.00 6.81 6.16 11.4 0.38 Postdev D1 8-22P 2-yr 1.42 0.68 0.97 0.97 5.00 5.17 5.01 389.50 377.60 263.0 4.52% 15 13.70 10.8 0.41 10-yr 5.00 6.81 6.60 11.6 0.38 8-21 P 8-20P 2-yr 0.57 0.83 0.47 0.47 5.00 5.17 2.44 377.80 377.60 8.0 2.50 % 15 10.20 6.8 0.02 (Flow to inlet did not change) 10-yr 5.00 6.81 3.21 7.0 0.02 Predev 8-" 0.50 0.59 0.30 1.67 5.41 5.07 8.48 377.60 368.00 224.0 4.29% 18 21.76 11.9 10-qr 5.38 6.70 11.21 12.0 Postdev 8-20P 8-4P 2-yr 0.43 0.74 0.32 1.76 5.41 5.07 8.92 377.60 368.00 224.0 4.29% 18 21.80 11.4 0.33 10- r 5.38 6.70 1 11.80 1 12.9 0.29 4 Flow at 8-20P 2-yr 2-yr 0.44 10-yr 10-yr 0.59 Postdev Downstream Flows: 8-4P 7-22P 10-yr 0.67 0.82 0.55 2.31 5.67 6.62 15.33 367.10 361.00 291.0 2.10% 18 15.22 8.6 0.56 7-22P 7-18P 10-yr 1.14 0.84 0.96 3.28 6.23 6.47 21.21 357.37 348.87 200.0 4.25% 18 21.66 12.3 0.27 7-18P 7-3P 10-yr 1.00 0.85 0.85 4.13 6.50 6.40 26.44 348.39 342.50 147.0 4.01 % 18 18.16 10.3 0.24 7-313 7-1 P 10-yr 2.15 0.90 1.90 6.03 6.74 6.34 38.23 339.78 338.04 55.0 3.16 % 24 40.21 14.6 0.06 7-1P 6-16P 10-yr 0.32 0.85 0.28 6.30 6.80 6.33 39.88 335.40 330.40 95.0 5.26% 24 51.88 18.3 0.09 6-16P 6-17P 10-yr 0.53 0.85 0.46 6.77 6.89 6.31 42.68 330.30 312.10 79.0 23.04% 24 108.59 32.7 0.04 58 Rte 250 Inlets LD-347 Hydraulic Grade Line n = 0.013 Inlet Number 1 Outlet Water Surface Elev.' 2 Do 3 on 4 L. 5 S,% 6 Hf 7 Junction Loss Final H 19 Inlet Water Surface Elev. 20 Rim. Bev 21 Vo (8) Ho (9) O; (10) Vi (11) Q,V, (12) Hi (13) Angle (14) He (15) Ht (16) 1.3-H, (17) 0.51H, (18) 6-16P 313.70 2.00 42.68 79.00 3.560% 2.812 32.69 4.9781 39.88 18.30 729.9 1.820 15 0.988 7.786 10.598 324.30 338.65 7-1 P 332.00 2.00 39.88 95.00 3.109 % 2.954 18.30 2.2361 38.23 14.59 557.8 1.157 40 1.421 4.814 7.768 339.77 343.58 7-31P 339.77 2.00 38.23 55.00 2.8579/6 1.571 14.59 0.1983 26.44 10.28 271.8 0.574 5 0.098 0.871 2.442 342.21 345.50 7-18P 343.70 1.50 26.44 147.00 6.3379% 9.315 10.28 0.0985 21.21 12.25 259.8 0.816 5 0.140 1.054 0.5269 9.842 353.54 354.57 7-22P 353.54 L50 21.21 200.00 4.079% 8A58 12.25 0.1165 15.33 8.60 131.8 0.402 3 0.057 0.576 0.2879 8.446 361.99 364.37 8-4P 362.20 1.50 15.33 291.00 2.130 % 6.199 8.60 0.0459 11.80 12.90 152.2 0.904 1 0.103 1.054 0.5269 6.726 368.93 371.70 Postdev 8-20P 369.20 1.50 11.80 224.00 1.2629/6 2.828 11.40 0.0807 11.21 12.00 134.6 0.783 1 0.089 0.953 3.781 372.98 381.60 Postdev D1 378.60 1.25 6.60 263.00 1.0449% 2.745 11.60 1.2537 6.60 7.75 51.1 0.326 69 0.560 2.140 1.0698 3.814 382.41 393.60 Postdev D2 390.70 1.25 6.60 8.50 1.044 % 0.089 7.75 0.0373 6.60 7.75 51.1 0.009 - 0.037 0.084 0.1091 0.0546 0.143 390.84 393.09 `Outlet W SE is listed as the greater of either the calculated tailwater or the invert out. 60 Stormwater Quality Calculations VRRM Redevelopment Spreadsheet Nutrient Credit Letter of Availability Site Information lent Prol (Treatment Volume and Loads) Enter Total Disturbed Mae (acres) 4 ✓.62 Check: Inua. ign Spe[ifirloonslist. 201301a0asods&suers '0 LinorpmR No La., muer—as en1ere1 rorrerny2 ✓ Tomimeamma1eae.1—d? ✓ unaoner lacI .17 a a. I moo I ma II as ass T...tV.]....dNuIH..IL.Vd Treatment Volume and Nutrient Load TV Old ras 1. MI m and aedumon Reared lw/nl xss Nitrogen Loads (lassmaMlonal Pinnacles Only) .-.ramdoenn a. as IPo.5ZI-P..�a...�m,I sa.n eam 81 Site Results (Water Quality Compliance) Area Checks O.A.A O.A.B O.A.0 D.A.D D.A.E AREACHECK FOREST/WEN SPACE (a[) 0.00 O.N 0.00 1 0.00 0.00 OK. IMPERVIOUS COVER I IMPERVIOUS COVER TREATED Ia[ am 0.00 0.00�22. OWOK. MANAGED TURF AREA (ar) am 0.00 0.00 O.N OK.IMANAGEO TURF AREATRUM (az) 0.00 Om 0.00 0.00 OK. ARFA CHECK OK. OR. OK. OK. Site Treatment Volume (ft') 22,29D Runoff Reduction Volume and TP By Drainage Area O.A.AO.A.0 D.A.D DA.E TOTAL RUNOFF REDUCTION VOLUME ACHIEVED (N3) 0 0 0 0 0 0 TP LOAD AVAILABLE FOR REMOVAL Qb/yi O.m O.m O.m 0.m 0.m U.m TP LOAD REOUCTIONACHIEVED)Ib/yr) O.m O.m O.OD 0.m 0.m U.m TP LOAD REMAINING Alb/yr) 0.00 0.m am 0.00 0.00 0.m NITROGEN LOAD REDUCTION ACHIEVED (IblAl O.m O.m D.m O.m 0.00 D.m Total Phosphorus FINAL POST -DEVELOPMENT TP LOAD Qb/yp 2.66 TP LOAD REDUMON REQUIRED Pb/yFl 2.59 TP WAD REOUCTIONACHIEVED (1b/yr) D.m TP WAD REMAINING Qb/yQ: 7.66 REMAINING TP LOAD REDUCTION REQUIRED (Ib/yr): 2.59 Total Nitrogen (For Information Purposes) POST-DEVEmPMEm WAD (1b/1r)jj 5,139 NMtOGEN LOAD REDUCTION ACHIEVED IIb/yrl O.m REMAINING POST-OEVEW MENT NITROGEN LOAD IIb/yrl NIS 82 Virginia Runoff Reduction Method Worl sheet DEC, 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: 44027 Total Rainfall (in): 43 Total Disturbed Acreage: 4.62 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 19 Managed Turf (acres) 0.00 0.77 0.00 0.49 1.26 27 Impervious Cover (acres) 0.00 0.85 0.00 1.63 2.48 54 4.63 100 Post-ReDevelopment Land Cover (acres) A soils Bsoils CSoils DSolis 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 0.39 1.41 30 Impervious Cover (acres) 0.00 1.48 0.00 1.73 3.22 70 4.63 100 Site Tv and Land Cover Nutrient Loads Final Post -Development Post- pow Adjusted Pre- (Post-ReDevelopment ReDevelopment Development ReDevelopment & New Impervious) (New Impervious) Site Rv 0.73 0.68 0.95 0.67 Treatment Volume(fts) 12,190 9,638 2,552 9,482 TP Load (lb/yr) 7.66 6.06 1.60 5.96 Total TP Load Reduction Required (lb/yr) 2.59 1.29 1.30 Final Post -Development Load (Post-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load (lb/yr) 54.79 43.35 Pre ReDevelopment Final Post -Development Post-ReDevelopment TP TPLoadperacre TP Load per acre Load per acre (Ib/acre/yr) (lb/acre/yr) (lb/acre/yr) 1.53 1.66 1.56 83 Summary Print Virginia Runoff Reduction Method Nbrkeheet Site Compliance Summary Maximum% Reduction Required Belo 10% Pre-ReDevelopment Load Total Runoff Volume Reduction (it) 0 Total TP Load Reduction Achieved (lb/yr) 0.00 Total TN Load Reduction Achieved (lb/yr) 0.00 Remaining Post Development TP Load 7.66 (Ib/yr) Remaining TP Load Reduction (lb/yr) 2 69 Required Summary Prim Rivanna River Nutrient Bank 16, 2020 KENDRA PATRICK, EIT Project Engineer Shimp Engineering, P.C. 912 East High St. Charlottesville, VA 22902 KendraAShimp-Engineerinq.com With a copy to: Buddy Thomas ( bthomasCaD_flowauto.com Owner: Flow 1300 Richmond LLC Contact: Buddy Thomas ( bthomasCc)flowauto.com) Project: 1300 Richmond Road Project No.: 19.078 DEQ SWM No.: Location: 1300 Richmond Road Charlottesville, VA 22911 Coordinates: (38.03497,-78.45035) Legal Reference: TMP 78-6 & 78-7 Receiving Water: Meadow Creek HUC12: 020802040401 Estimated Credits Required: 2.59 lb Dear Kendra and Mr. Thomas, Certificate No. James-039 This letter is to confirm the availability to your project (referenced above ) of authorized Nutrient Credits sufficient to meet the your estimated requirements of 2.59 Nutrient Credits at our Rivanna River nutrient offset credit bank facility (the "Bank"). The Bank has been registered with the Virginia Department of Environmental Quality (DEQ). These Nutrient Credits are generated and managed under the terms of the Reduction Implementation Plan for the Bank dated November 2017, which was authorized by (DEQ) on September 5, 2018. The Bank has been authorized to provide Nutrient Credits for use in the James River watershed. These credits are transferable to those entities regulated under DEQ's Storm Water Management program in accordance with VA Code 62.1-44.15:27. If we can provide further assistance please feel free to contact our office. Hotel Street Capi 7,C, Bank Sponsor By Its M r Thomas I 540-68 -0171 Rivanna River Nutrient Offset Trading Bank, 31 Garrett Street, Warrenton, Virginia 20186 85 Independent Reports Excerpt from NRCS Soils Report NOAA Precipitation Report it r 12D i VA , _`� ��'�• T � 11 V n . " I i � Richn Intl MAPLEGEND Area of Interest (AOI) O Area of Interest (AOI) Solis O Soil Map Unit Polygons ,•.,I Soil Map Unit Lines Soil Map Unit Points Special Point Features V Blowout ® Borrow Pit Clay Spot Q Closed Depression Gravel Pit Gravelly Spot 0 Landfill A. Lava Flow Marsh or swamp Mine or Quarry O Miscellaneous Water O Perennial Water y Rock Outcrop + Saline Spot Sandy Spot Severely Eroded Spot o Sinkhole Slide or Slip $odic Spot Custom Soil Resource Report Spoil Area ® Stony Spot W Very Stony Spot Wet Spot 0 Other •� Special Line Features Water Features Streams and Canals Transportation 4_14 Rails ^/ Interstate Highways N US Routes Major Roads Local Roads Background . Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the 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 88 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 12D Catoctin silt loam, 15 to 25 percent slopes 2.5 18.4% 23B Yadkin clay loam, 2 to 7 percent slopes 3.2 24.0% 71 D Rabun Gay 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 Gass 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. 8 89 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, Description of Catoctin descriptions, and transects of the mapunit. 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 90 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 91 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, Description of Rabun descriptions, and transects of the mapunit. Setting Landform: Interfluves 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) high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Moderately high to 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 92 Custom Soil Resource Report 79B—Meadowville silt loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: 2v7kl 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 93 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: Interfluves 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 94 2/2/2020 Precipitation Frequency Data Server NOAA Atlas 14, Volume 2, Version 3 Location name: Charlottesville, Virginia, USA* Latitude: 36, Longitude:-78.4504° € Elevation: 410.47 ft'"' 'source: ESRI Maps « ° "source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonnin, D. Martin, B. Lin, T. Partybok, 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) Duration 1 2 5 10 25 50 1 100 00 200 500 1000 5-min (0.3118-0 392) (0.3779-048) (0.443-0.545) (0.497--0 613) (0.557-0687) (0.603-0.746) (0.645-0.602) (0.682-0854) (07 24-0 919) (07 58-0 974) 0.664 2 1.08 1.23 3 10.min (0.8-0.626) 50 (0.6069.745) 7 0 (09-0873) (0.7959980) (0.888-1310) (0.96 -1.19) (1.02127) (1.08-.35) (1.15-i 45) : 9 (1i 53) 7 1. 1. 1.74 15-min (0.635-0..783) (0.762-0937) (0. 978-1.10) (1.011224) (113-11..39) (1.22-3L51) (1.29-11..61) (1.36--11..71) (1.44-11..83)1 (1.50.193) 0.966 1.17 1.42 1.62 1.86 2.06 2.24 2A7 2.64 2.81 30.min (0.870-1.07) 1 (1.05-1.29) 1 (1.27-1.57) 1 (1.46-1.80) 1 (1.67-2.06) (1.83-2.27) (1.8-2.47) (2.12-2.8) (2.30-2.91) (2.43-3.12) 60.min �62) 2874) (1.091134) (1.3 (1-63-2.01) (1.M2.34) (2.22 (248.3.07) (27 3-3.40) (29 6-3.73) (3. 9-4818) (3.544.55) 3.07 3.911 6.47 2-hr (1.271.66) (1.54 260 (1.93 2950) (2.27�93) (2. 83.48) (3: 33894) 3.37-4.42) (3. 3-4591) (a. 0--85.60) (4696.20) 3-hr (1.39-1..82) (1.66-2.20) (2:92.76) (245-3.22) (2.9133.3) (3:9-4.34) (3.67-4.87) (4.05--5.43) (4.57-6.20) (4.996.86) 6-hr 276) (17 9 29) (2. 5 (2.66-3.43) (3. 2-4603) (37 3-4.84) (4: 5-5.53) (4.77-6.28) (5.32-�08) (6.09 822) (6.74-9.23) 2.53 3.05 3.80 4.51 5A8 6.36 7.30 8.33 9.85 11.2 12-hr (2.24-2.90) (2.69-3.50) (3.344.35) (3.95-5.15) (4.765.24) (547-7.22) (6.20-8.27) (6.99-9.43) (8.11-11.2) (9.0912.7) 24-hr (2. 2 3340) (3. 94612) (4. 9-6626) (4.94-6.20) (693-7.59) (6.95--8..79) (7.94-0.1) (g.M11-6) (10-5- 3.8) (11 8-15.7) 2-dey (320-3.99) (3. 9�84) (4. 3-6.15) (57 8-7.22) (6.99-8.77) (7. 8--0160.1) (9.04N.5) (102- 3.1) (11.8-15.4) (13.1-1 3) 88 14.6 6.4 3day 24 4 (3454.21) (4185.11) (5. -6.49) (6.22-761) (7.5294) (8.580.6) (9.72-2.1) (10.9-13.7) (126.2) (141- 8.2) 11.6 4-day (37 04.44) (4.475.37) (5685.82) (6.65�00) (895-9.71) (9.19-121.2) (10.4- 2.7) (1173-14A) (13.5- 6.9) (15.0. 9.1) 9 6.64 7-day (4.3165.11) (5. 9-6.16 (6A7-07670) (7.52 8 8) (999 0.8) (10.2- 2.3) (11.5-13.9) (12 845.7) (1476 8.3) 1 (162 0.4) 10 dey (4.91575) (58 9-6.90) (7.27 8a52) (8.37 9.84) (9.91--111.7) (111213.2) (12.4-14.8) (13.8 6.6) (15.6-19.0) (17.1---21.1) 2 17.7 921.3) 20 dey (663- .47) (7. 0-8.91) (9.41010.8) (107- 2.2) (12.3-14.2) (13.6- 5.7) (15.0-17.4) (16.3- 9.0) (181 (19.4 3.1) 30-day (8.06-9.11) (9.55-10.8) (11.3- 2.8) (12.6-14.3) (14.3-16.2) (15.6-17.7) (16.8- 9.2) (18.0-0.6) (19.5 22.6) (2027224.1) 45-day (101U 1.3) 1 (1t9-13.4) 1 (13.9- 5.6) 1 (15.44.3) 1 (173 9.5) 1 (187�-21.1) 1 (20.0.22.7) (21?324.2) (229426.2) (24.0.27.7) 60-dey 25 (11.9-13.2) (14.0-15.6 (16.1- 8.0) (17 9.8) (19222.1) (212P2- 3.7) (22.6-25.4) (239527.0) (25257 9.0) (267830.5) 1 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 95 hfps://hdsc.rws.noaa.govlhdsctpfds/pfds_Printpage.html?lat=38.0343&Ion=-78.4504&data=depth&units=english&series=pds 1/4