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HomeMy WebLinkAboutWPO201600052 Calculations 2022-03-01SHIMP ENGINEERING, P.C. Design Focused Engineering TH � February 28, 2022 Emily Cox, PE— Engineering Reviewer U SHIMP Department of Community Development Lic. o. 4� 183 401 McIntire Road Charlottesville, VA 22902 `QsrL'NAL Regarding: Hunters Way VSMP Amendment 1 - WP0201600052 Dear Emily, Enclosed is the stormwater calculation packet for Hunters Way VSMP Amendment. This redevelopment will occupy a site that has an area of 1.46 acres. The disturbed area is 0.70 acres. The proposed stormwater design meets the runoff requirements set forth in 9VAC25-870-66, as well as the nutrient requirements set forth in 9VAC25-870-65. The current county approval is WPO 2016-00052. This site contains an existing stormwater management system that utilizes underground HDPE detention pipes to meet the energy balance equation and the flood protection criteria. A similar detention system will be added to continue to comply with the same requirements. After the redevelopment from this amendment, a slightly increased volume of runoff will go to the existing detention pipe and the remaining new runoff will be directed to a single barrel, 50 LF 60" PP detention pipe. All calculations utilize the approved conditions from the approved VSMP plan, the only changes are the increase in postdevelopment impervious area. Additionally, for final public health and safety concerns, runoff from the 100-year storm does not overtop this new detention system. To achieve nutrient treatment compliance, a total of 0.84 Ibs of phosphorous is required to be treated for this development per the VRRM redevelopment spreadsheet. This amount was calculated by inputting the total site area, and this includes the nutrient total from WPO 2016-00052. The sites water quality requirements will be addressed with the purchase of 0.26 Ibs of phosphorous nutrient credits. This purchase amount was calculated by subtracting the 0.58 Ibs of nutrient credits originally purchased for WPO 2016- 00052 in 2017 from the new total generated by the VRRM Redevelopment Spreadsheet for this amendment: 0.84 Ibs current amount - 0.58 Ibs previously purchased = 0.26 Ibs required. Site Runoff Quantity Totals Storm Events and Associated Peak Runoff Rates Pre-Dev Post-Dev POA 1 POA 1 1-Year 1.34 cfs 0.60 cfs 10-Year 5.30 cfs 2.96 cfs If you have any questions please do not hesitate to contact me at: Justinna.shimp-enoineering.com or by phone at434-299-9843. Contents: Pre -Development Calculations: Energy Balance Equation Pre-Dev Drainage Map PreDev HydroCAD Report Post-Dev Runoff Quantity Calculations: Post-Dev Drainage Map Post-Dev HydroCAD Report VDOT LD-204 Inlet Calcs VDOT LD-229 Culvert Capacity Post-Dev Runoff Quality Calculations: Post-Dev Land Cover Map VRRM Redev. Spreadsheet Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report Pre -Development Calculations: Energy Balance Equation Pre-Dev Drainage Map PreDev HydroCAD Report 2300 Hunters Way Energy Balance Equation 24 Hr 1 year Storm: Qdeveloped� I.F. (Qpre-developed RVPre-Developed) Rydeveloped Q0 developed� Qforested RVforested Rydeveloped Disturbed Area = 0.7 ac I.F. = 0.9 Qpre-developed = [Acfs RVPre-Developed = ac-ft QDeveloped Max = 0.60 cfs RVDeveloped = ac-ft Achieved Post-Dev Peak Runoff O1yr = 0.60 cfs. Site complies with 9VAC25-870-66-B(3)a 10-YEAR STORM: Opre=5.30 cfs Opost=2.96 cfs Site complies with 9VAC25-870-66-C(2)b HUNTER'S WAY l -x -7x -x �-x -x x �` / PRE -DEVELOPMENT v v v \ \ \ / DRAINAGE MAP i OOEN 1 / S ACE Z�l z' v / I _ g I MPERVIOUS I AREA v R O`co OQ� 1po ------ \ \ DRAINAGE TO POA ---- _ --- \� — ' 0.32 AC IMP \\ _ 0.79 AC TURF, 0.35 AC WOODS POINT OF ANALYSIS wm / \ *ALL SOILS ARE HSG B ._,�_ — I — — t exls�cExim I rxE 5oeo RUNOFF TO POA TOC MAX = 8 MIN 1—YEAR FLOW = 1.34 CFS, 0.075 AF 30 0 30 so 90 10—YEAR FLOW = 5.30 CFS SCALE: 1" = 30 1 Total Site Subcat Reach On Link 7As/nO7O54 nage Diagram for Hunters PreDev FHydpo Shimp Engineering, P.C., Printed 1/3/2019 02011 HydroCAD Software Solutions LLC Hunters PreDev Prepared by Shimp Engineering, P.C. Type 1124-hr 1-Year Rainfall=2.99" Summary for Subcatchment 1 S: Total Site Runoff = 1.34 cfs @ 12.01 hrs, Volume= 0.075 af, Depth> 0.62" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (ac) CN Printed 1/3/2019 0.319 98 Imp 0.345 55 Woods, Good, HSG B 0.796 61 >75% Grass cover, Good, HSG B 1.460 68 Weighted Average 1.141 78.15% Pervious Area 0.319 21.85% Impervious Area Tc Length EE Description Direct Entry, Hunters PreDev Prepared by Shimp Engineering, P.C. Type // 24-hr 10-Year Rainfall=5.47' Summary for Subcatchment 1 S: Total Site Runoff = 5.30 cfs @ 12.00 hrs, Volume= 0.270 af, Depth> 2.22" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.47" Area (ac) CN Printed 1/3/2019 0.319 98 Imp 0.345 55 Woods, Good, HSG B 0.796 61 >75% Grass cover, Good, HSG B 1.460 68 Weighted Average 1.141 78.15% Pervious Area 0.319 21.85% Impervious Area Tc Length EE Description Direct Entry, Post-Dev Runoff Quantity Calculations: Post-Dev Drainage Map Post-Dev HydroCAD Report VDOT LD-204 Inlet Calcs VDOT LD-229 Culvert Capacity HUNTER'S WAY / "'s� ^„�.... K. .... ... ...... .......... �....... .. .. _. .: .. '�IV.IJ /'\li IVI\I, V.VV fl, IIVII I J DETENTION 2 = 0.15 AC TOTAL (0.02 AC TURF, 0.13 AC IMP) - POINT OF ANALYSIS i I i i i i� 1� _ *ALL SOILS ARE HSG B --�"----�--� °91--T--� Ii RUNOFF TO POA i I f TOC MAX - 10 MIN 1-YEAR FLOW = 0.60 CFS, 0.151 AF 30 0 .30 60 90 10-YEAR FLOW -2.92 CFS, SCALE: �" = 3o MEETS ENERGY BALANCE EQUATION r PC LIMIT OF 0.60 CFS 1s s Total Site Subcat Reach On Link T rainage Diagram for Hunters PostDev Prepby Shimp Engineering, P.C., Printed 1/3/2019 FHyd'OCA10 s/n 07054 0 2011 HydroCAD Software Solutions LLC Hunters PostDev Prepared by Shimp Engineering, P.C. Type 1124-hr 1-Year Rainfall=2.99" Printed 1/3/2019 Summary for Subcatchment 1 S: Total Site Runoff = 2.97 cfs @ 12.00 hrs, Volume= 0.151 af, Depth> 1.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (ac) CN Description 0.740 98 impervious 0.720 61 >75% Grass cover, Good, HSG B 1.460 80 Weighted Average 0.720 49.32% Pervious Area 0.740 50.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Total Site 5S Inlet DA4 7P New 60" Det Pipe Detenttn Pipe 6S � 9L 4S Inlet DA (i) Ip1et DA 2 Unmanged Area Subcat Reach Aon Llnk Point of Analysis-MS4 ■ nlet DA Post-Dev Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" Prepared by {enter your company name here} Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Total Site Runoff Area=1.460 ac 50.68% Impervious Runoff Depth>1.24" Tc=8.0 min CN=80 Runoff=2.97 cfs 0.151 of Subcatchment 2S: Inlet DA 1 Runoff Area=6,770 sf 16.10% Impervious Runoff Depth>0.58" Tc=8.0 min CN=67 Runoff=0.13 cfs 0.007 of Subcatchment 3S: Inlet DA 2 Runoff Area=6,090 sf 100.00% Impervious Runoff Depth>2.76" Tc=5.0 min CN=98 Runoff=0.60 cfs 0.032 of Subcatchment 4S: Inlet DA 3 Runoff Area=20,880 sf 83.81 % Impervious Runoff Depth>2.15" Tc=5.0 min CN=92 Runoff=1.77 cfs 0.086 of Pond 5P: Detention Pipe Peak EIev=380.16' Storage=2,072 cf Inflow=2.46 cfs 0.125 of Outflow=0.32 cfs 0.125 of Subcatchment 5S: Inlet DA 4 Runoff Area=7,270 sf 89.41 % Impervious Runoff Depth>2.34" Tc=5.0 min CN=94 Runoff=0.65 cfs 0.033 of Subcatchment 6S: Unmanged Area Runoff Area=22,590 sf 3.67% Impervious Runoff Depth>0.39" Tc=15.0 min CN=62 Runoff=0.18 cfs 0.017 of Pond 7P: New 60" Det Pipe Peak EIev=372.21' Storage=0.011 of Inflow=0.65 cfs 0.033 of Outflow=0.11 cfs 0.033 of Link 9L: Point of Analysis-MS4 Inflow=0.60 cfs 0.174 of Primary=0.60 cfs 0.174 of Total Runoff Area = 2.920 ac Runoff Volume = 0.326 of Average Runoff Depth = 1.34" 49.49% Pervious = 1.445 ac 50.51% Impervious = 1.475 ac Post-Dev Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" Prepared by {enter your company name here) Printed 2/28/2022 HvdroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1S: Total Site Runoff = 2.97 cfs @ 12.00 hrs, Volume= 0.151 af, Depth> 1.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (ac) CN Description 0.740 98 impervious 0.720 61 >75% Grass cover, Good, HSG B 1.460 80 Weighted Average 0.720 49.32% Pervious Area 0.740 50.68% Impervious Area Tc Length Description 8.0 Direct Entry, Summary for Subcatchment 2S: Inlet DA 1 Runoff = 0.13 cfs @ 12.01 hrs, Volume= 0.007 af, Depth> 0.58" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (sf) CN Description 5,680 61 >75% Grass cover, Good, HSG B 1,090 98 Impervious 6,770 67 Weighted Average 5,680 83.90% Pervious Area 1,090 16.10% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 3S: Inlet DA 2 Runoff = 0.60 cfs @ 11.95 hrs, Volume= 0.032 af, Depth> 2.76" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (sf) CN 6,090 98 Impervious 6,090 100.00% Impervious Area Post-Dev Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" Prepared by (enter your company name here) Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 4 Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Summary for Subcatchment 4S: Inlet DA 3 Runoff = 1.77 cfs @ 11.95 hrs, Volume= 0.086 af, Depth> 2.15" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (sf) CN Description 3,380 61 >75% Grass cover, Good, HSG B 17,500 98 Impervious 20,880 92 Weighted Average 3,380 16.19% Pervious Area 17,500 83.81 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 5P: Detention Pipe Inflow Area = 0.775 ac, 73.15% Impervious, Inflow Depth > 1.94" for 1-Year event Inflow = 2.46 cfs @ 11.95 hrs, Volume= 0.125 of Outflow = 0.32 cfs @ 12.23 hrs, Volume= 0.125 af, Atten= 87%, Lag= 16.6 min Primary = 0.32 cfs @ 12.23 hrs, Volume= 0.125 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 380.16' @ 12.23 hrs Surf.Area= 1,416 sf Storage= 2,072 cf Plug -Flow detention time= 59.6 min calculated for 0.125 of (99% of inflow) Center -of -Mass det. time= 56.0 min ( 846.3 - 790.4 ) Volume Invert Avail.Storage Storage Description #1 378.20' 5,694 cf 60.0" D x 290.01 Pipe Storage Device Routing Invert Outlet Devices #1 Primary 378.20' 15.0" Round Culvert L= 58.0' Ke= 0.600 Inlet / Outlet Invert= 378.20' / 377.60' S= 0.0103 '/' Cc= 0.900 n= 0.013 #2 Device 1 378.20' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 380.40' 5.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 382.00' 18.0" Vert. Orifice/Grate C= 0.600 Post-Dev Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" Prepared by (enter your company name here) Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 5 Primary OutFlow Max=0.32 cfs @ 12.23 hrs HW=380.16' (Free Discharge) t1=Culvert (Passes 0.32 cfs of 6.40 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.32 cfs @ 6.52 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =Orifice/Grate ( Controls 0.00 cfs) Summary for Subcatchment 5S: Inlet DA 4 Runoff = 0.65 cfs @ 11.95 hrs, Volume= 0.033 af, Depth> 2.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (sf) CN Description 6,500 98 Impervious 770 61 >75% Grass cover, Good, HSG B 7,270 94 Weighted Average 770 10.59% Pervious Area 6,500 89.41 % Impervious Area Tc Length Description 5.0 Direct Entry, Summary for Subcatchment 6S: Unmanged Area Runoff = 0.18 cfs @ 12.11 hrs, Volume= 0.017 af, Depth> 0.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=2.99" Area (sf) CN Description 21,760 61 >75% Grass cover, Good, HSG B 830 98 Impervious 22,590 62 Weighted Average 21,760 96.33% Pervious Area 830 3.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Post-Dev Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" Prepared by {enter your company name here) Printed 2/28/2022 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paae 6 Summary for Pond 7P: New 60" Det Pipe Inflow Area = 0.167 ac, 89.41 % Impervious, Inflow Depth > 2.34" for 1-Year event Inflow = 0.65 cfs @ 11.95 hrs, Volume= 0.033 of Outflow = 0.11 cfs @ 12.14 hrs, Volume= 0.033 af, Atten= 83%, Lag= 11.4 min Primary = 0.11 cfs @ 12.14 hrs, Volume= 0.033 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 372.21' @ 12.14 hrs Surf.Area= 0.005 ac Storage= 0.011 of Plug -Flow detention time= 33.9 min calculated for 0.032 of (100% of inflow) Center -of -Mass det. time= 33.5 min ( 818.2 - 784.7) Volume Invert Avail.Storage Storage Description #1 369.50' 0.021 of 60.0" D x 47.0'L Pipe Storage S= 0.0033 '/' Device Routing Invert Outlet Devices #1 Primary 369.50' 15.0" Round Culvert L= 47.0' Ke= 0.600 Inlet / Outlet Invert= 369.50' / 369.00' S= 0.0106 '/' Cc= 0.900 n= 0.012 #2 Device 1 369.50' 2.5" Vert. Orifice/Grate C= 0.250 #3 Device 1 372.50' Weir Opening, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 1.00 1.50 1.90 1.99 Width (feet) 4.90 4.60 4.00 2.95 1.60 0.50 Primary OutFlow Max=0.11 cfs @ 12.14 hrs HW=372.21' (Free Discharge) t1=Culvert (Passes 0.11 cfs of 7.99 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.11 cfs @ 3.24 fps) t 3=Weir Opening ( Controls 0.00 cfs) Summary for Link 9L: Point of Analysis-MS4 Inflow Area = 1.460 ac, 50.33% Impervious, Inflow Depth > 1.43" for 1-Year event Inflow = 0.60 cfs @ 12.12 hrs, Volume= 0.174 of Primary = 0.60 cfs Co) 12.12 hrs, Volume= 0.174 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Post-Dev Hunters PostDev Type // 24-hr 10-Year Rainfall=5.47' Prepared by {enter your company name here} Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 7 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Total Site Runoff Area=1.460 ac 50.68% Impervious Runoff Depth>3.30" Tc=8.0 min CN=80 Runoff=7.80 cfs 0.402 of Subcatchment 2S: Inlet DA 1 Runoff Area=6,770 sf 16.10% Impervious Runoff Depth>2.13" Tc=8.0 min CN=67 Runoff=0.54 cfs 0.028 of Subcatchment 3S: Inlet DA 2 Runoff Area=6,090 sf 100.00% Impervious Runoff Depth>5.23" Tc=5.0 min CN=98 Runoff=1.10 cfs 0.061 of Subcatchment 4S: Inlet DA 3 Runoff Area=20,880 sf 83.81 % Impervious Runoff Depth>4.55" Tc=5.0 min CN=92 Runoff=3.57 cfs 0.182 of Pond 5P: Detention Pipe Peak Elev=381.82' Storage=4,421 cf Inflow=5.13 cfs 0.270 of Outflow=1.17 cfs 0.269 of Subcatchment 5S: Inlet DA 4 Runoff Area=7,270 sf 89.41 % Impervious Runoff Depth>4.77" Tc=5.0 min CN=94 Runoff=1.27 cfs 0.066 of Subcatchment 6S: Unmanged Area Runoff Area=22,590 sf 3.67% Impervious Runoff Depth>1.73" Tc=15.0 min CN=62 Runoff=1.11 cfs 0.075 of Pond 7P: New 60" Det Pipe Peak Elev=372.72' Storage=0.014 of Inflow=1.27 cfs 0.066 of Outflow=1.62 cfs 0.066 of Link 9L: Point of Analysis-MS4 Inflow=2.96 cfs 0.410 of Primary=2.96 cfs 0.410 of Total Runoff Area = 2.920 ac Runoff Volume = 0.813 of Average Runoff Depth = 3.34" 49.49% Pervious = 1.445 ac 50.51% Impervious = 1.475 ac Post-Dev Hunters PostDev Type 1124-hr 10-Year Rainfall=5.47" Prepared by {enter your company name here) Printed 2/28/2022 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Pace 8 Summary for Subcatchment 1 S: Total Site Runoff = 7.80 cfs @ 11.99 hrs, Volume= 0.402 af, Depth> 3.30" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.47" Area (ac) CN Description 0.740 98 impervious 0.720 61 >75% Grass cover, Good, HSG B 1.460 80 Weighted Average 0.720 49.32% Pervious Area 0.740 50.68% Impervious Area Tc Length Description 8.0 Direct Entry, Summary for Subcatchment 2S: Inlet DA 1 Runoff = 0.54 cfs @ 12.00 hrs, Volume= 0.028 af, Depth> 2.13" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.47" Area (sf) CN Description 5,680 61 >75% Grass cover, Good, HSG B 1,090 98 Impervious 6,770 67 Weighted Average 5,680 83.90% Pervious Area 1,090 16.10% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 3S: Inlet DA 2 Runoff = 1.10 cfs @ 11.95 hrs, Volume= 0.061 af, Depth> 5.23" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.47" Area (sf) CN 6,090 98 Impervious 6,090 100.00% Impervious Area Post-Dev Hunters PostDev Type // 24-hr 10-Year Rainfall=5.47' Prepared by (enter your company name here) Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 9 Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Summary for Subcatchment 4S: Inlet DA 3 Runoff = 3.57 cfs @ 11.95 hrs, Volume= 0.182 af, Depth> 4.55" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.47" Area (sf) CN Description 3,380 61 >75% Grass cover, Good, HSG B 17,500 98 Impervious 20,880 92 Weighted Average 3,380 16.19% Pervious Area 17,500 83.81 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 5P: Detention Pipe Inflow Area = 0.775 ac, 73.15% Impervious, Inflow Depth > 4.19" for 10-Year event Inflow = 5.13 cfs @ 11.95 hrs, Volume= 0.270 of Outflow = 1.17 cfs @ 12.12 hrs, Volume= 0.269 af, Atten= 77%, Lag= 9.9 min Primary = 1.17 cfs @ 12.12 hrs, Volume= 0.269 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 381.82' @ 12.12 hrs Surf.Area= 1,295 sf Storage= 4,421 cf Plug -Flow detention time= 63.4 min calculated for 0.269 of (100% of inflow) Center -of -Mass det. time= 60.4 min ( 835.3 - 774.9 ) Volume Invert Avail.Storage Storage Description #1 378.20' 5,694 cf 60.0" D x 290.01 Pipe Storage Device Routing Invert Outlet Devices #1 Primary 378.20' 15.0" Round Culvert L= 58.0' Ke= 0.600 Inlet / Outlet Invert= 378.20' / 377.60' S= 0.0103 '/' Cc= 0.900 n= 0.013 #2 Device 1 378.20' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 380.40' 5.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 382.00' 18.0" Vert. Orifice/Grate C= 0.600 Post-Dev Hunters PostDev Type // 24-hr 10-Year Rainfall=5.47' Prepared by (enter your company name here) Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 10 Primary OutFlow Max=1.16 cfs @ 12.12 hrs HW=381.81' (Free Discharge) t1=Culvert (Passes 1.16 cfs of 9.57 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.44 cfs @ 8.99 fps) 3=Orifice/Grate (Orifice Controls 0.72 cfs @ 5.28 fps) =Orifice/Grate ( Controls 0.00 cfs) Summary for Subcatchment 5S: Inlet DA 4 Runoff = 1.27 cfs @ 11.95 hrs, Volume= 0.066 af, Depth> 4.77" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.47" Area (sf) CN Description 6,500 98 Impervious 770 61 >75% Grass cover, Good, HSG B 7,270 94 Weighted Average 770 10.59% Pervious Area 6,500 89.41 % Impervious Area Tc Length Description 5.0 Direct Entry, Summary for Subcatchment 6S: Unmanged Area Runoff = 1.11 cfs @ 12.08 hrs, Volume= 0.075 af, Depth> 1.73" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.47" Area (sf) CN Description 21,760 61 >75% Grass cover, Good, HSG B 830 98 Impervious 22,590 62 Weighted Average 21,760 96.33% Pervious Area 830 3.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Post-Dev Hunters PostDev Type 1124-hr 10-Year Rainfall=5.47" Prepared by {enter your company name here) Printed 2/28/2022 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 11 Summary for Pond 7P: New 60" Det Pipe Inflow Area = 0.167 ac, 89.41 % Impervious, Inflow Depth > 4.77" for 10-Year event Inflow = 1.27 cfs @ 11.95 hrs, Volume= 0.066 of Outflow = 1.62 cfs @ 11.96 hrs, Volume= 0.066 af, Atten= 0%, Lag= 0.5 min Primary = 1.62 cfs @ 11.96 hrs, Volume= 0.066 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 372.72' @ 11.96 hrs Surf.Area= 0.005 ac Storage= 0.014 of Plug -Flow detention time= 29.7 min calculated for 0.066 of (100% of inflow) Center -of -Mass det. time= 29.2 min ( 795.3 - 766.1 ) Volume Invert Avail.Storage Storage Description #1 369.50' 0.021 of 60.0" D x 47.0'L Pipe Storage S= 0.0033 T Device Routing Invert Outlet Devices #1 Primary 369.50' 15.0" Round Culvert L= 47.0' Ke= 0.600 Inlet / Outlet Invert= 369.50' / 369.00' S= 0.0106 '/' Cc= 0.900 n= 0.012 #2 Device 1 369.50' 2.5" Vert. Orifice/Grate C= 0.250 #3 Device 1 372.50' Weir Opening, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 1.00 1.50 1.90 1.99 Width (feet) 4.90 4.60 4.00 2.95 1.60 0.50 Primary OutFlow Max=1.44 cfs @ 11.96 hrs HW=372.69' (Free Discharge) t1=Culvert (Passes 1.44 cfs of 8.87 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.12 cfs @ 3.52 fps) t 3=Weir Opening (Weir Controls 1.32 cfs @ 1.43 fps) Summary for Link 9L: Point of Analysis-MS4 Inflow Area = 1.460 ac, 50.33% Impervious, Inflow Depth > 3.37" for 10-Year event Inflow = 2.96 cfs @ 12.04 hrs, Volume= 0.410 of Primary = 2.96 cfs Co) 12.04 hrs, Volume= 0.41Oaf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Post-Dev Hunters PostDev Type // 24-hr 100-Year Rainfall=9.00" Prepared by {enter your company name here} Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 12 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Total Site Runoff Area=1.460 ac 50.68% Impervious Runoff Depth>6.56" Tc=8.0 min CN=80 Runoff=15.00 cfs 0.798 of Subcatchment 2S: Inlet DA 1 Runoff Area=6,770 sf 16.10% Impervious Runoff Depth>4.96" Tc=8.0 min CN=67 Runoff=1.26 cfs 0.064 of Subcatchment 3S: Inlet DA 2 Runoff Area=6,090 sf 100.00% Impervious Runoff Depth>8.75" Tc=5.0 min CN=98 Runoff=1.82 cfs 0.102 of Subcatchment 4S: Inlet DA 3 Runoff Area=20,880 sf 83.81 % Impervious Runoff Depth>8.03" Tc=5.0 min CN=92 Runoff=6.08 cfs 0.321 of Pond 5P: Detention Pipe Peak Elev=383.74' Storage=5,694 cf Inflow=9.01 cfs 0.487 of Outflow=10.18 cfs 0.485 of Subcatchment 5S: Inlet DA 4 Runoff Area=7,270 sf 89.41 % Impervious Runoff Depth>8.27" Tc=5.0 min CN=94 Runoff=2.14 cfs 0.115 of Subcatchment 6S: Unmanged Area Runoff Area=22,590 sf 3.67% Impervious Runoff Depth>4.33" Tc=15.0 min CN=62 Runoff=2.89 cfs 0.187 of Pond 7P: New 60" Det Pipe Peak Elev=372.76' Storage=0.014 of Inflow=2.14 cfs 0.115 of Outflow=2.20 cfs 0.115 of Link 9L: Point of Analysis-MS4 Inflow=14.37 cfs 0.787 of Primary=14.37 cfs 0.787 of Total Runoff Area = 2.920 ac Runoff Volume = 1.587 of Average Runoff Depth = 6.52" 49.49% Pervious = 1.445 ac 50.51% Impervious = 1.475 ac Post-Dev Hunters PostDev Type // 24-hr 100-Year Rainfall=9.00" Prepared by (enter your company name here) Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 13 Summary for Subcatchment 1 S: Total Site Runoff = 15.00 cfs @ 11.99 hrs, Volume= 0.798 af, Depth> 6.56" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.00" Area (ac) CN Description 0.740 98 impervious 0.720 61 >75% Grass cover, Good, HSG B 1.460 80 Weighted Average 0.720 49.32% Pervious Area 0.740 50.68% Impervious Area Tc Length Description 8.0 Direct Entry, Summary for Subcatchment 2S: Inlet DA 1 Runoff = 1.26 cfs @ 11.99 hrs, Volume= 0.064 af, Depth> 4.96" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.00" Area (sf) CN Description 5,680 61 >75% Grass cover, Good, HSG B 1,090 98 Impervious 6,770 67 Weighted Average 5,680 83.90% Pervious Area 1,090 16.10% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 3S: Inlet DA 2 Runoff = 1.82 cfs @ 11.95 hrs, Volume= 0.102 af, Depth> 8.75" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.00" Area (sf) CN 6,090 98 Impervious 6,090 100.00% Impervious Area Post-Dev Hunters PostDev Type // 24-hr 100-Year Rainfall=9.00" Prepared by (enter your company name here) Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 14 Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Summary for Subcatchment 4S: Inlet DA 3 Runoff = 6.08 cfs @ 11.95 hrs, Volume= 0.321 af, Depth> 8.03" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.00" Area (sf) CN Description 3,380 61 >75% Grass cover, Good, HSG B 17,500 98 Impervious 20,880 92 Weighted Average 3,380 16.19% Pervious Area 17,500 83.81 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 5P: Detention Pipe Inflow Area = 0.775 ac, 73.15% Impervious, Inflow Depth > 7.54" for 100-Year event Inflow = 9.01 cfs @ 11.95 hrs, Volume= 0.487 of Outflow = 10.18 cfs @ 12.00 hrs, Volume= 0.485 af, Atten= 0%, Lag= 2.7 min Primary = 10.18 cfs @ 12.00 hrs, Volume= 0.485 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 383.74' @ 12.00 hrs Surf.Area= 0 sf Storage= 5,694 cf Plug -Flow detention time= 54.2 min calculated for 0.484 of (99% of inflow) Center -of -Mass det. time= 51.2 min ( 814.8 - 763.6 ) Volume Invert Avail.Storage Storage Description #1 378.20' 5,694 cf 60.0" D x 290.01 Pipe Storage Device Routing Invert Outlet Devices #1 Primary 378.20' 15.0" Round Culvert L= 58.0' Ke= 0.600 Inlet / Outlet Invert= 378.20' / 377.60' S= 0.0103 '/' Cc= 0.900 n= 0.013 #2 Device 1 378.20' 3.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 380.40' 5.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 382.00' 18.0" Vert. Orifice/Grate C= 0.600 Post-Dev Hunters PostDev Type // 24-hr 100-Year Rainfall=9.00" Prepared by (enter your company name here) Printed 2/28/2022 HydroCAD09.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 15 Primary OutFlow Max=10.13 cfs @ 12.00 hrs HW=383.73' (Free Discharge) t1=Culvert (Passes 10.13 cfs of 12.27 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.55 cfs @ 11.19 fps) 3=Orifice/Grate (Orifice Controls 1.16 cfs @ 8.51 fps) =Orifice/Grate (Orifice Controls 8.42 cfs @ 4.76 fps) Summary for Subcatchment 5S: Inlet DA 4 Runoff = 2.14 cfs @ 11.95 hrs, Volume= 0.115 af, Depth> 8.27" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.00" Area (sf) CN Description 6,500 98 Impervious 770 61 >75% Grass cover, Good, HSG B 7,270 94 Weighted Average 770 10.59% Pervious Area 6,500 89.41 % Impervious Area Tc Length Description 5.0 Direct Entry, Summary for Subcatchment 6S: Unmanged Area Runoff = 2.89 cfs @ 12.07 hrs, Volume= 0.187 af, Depth> 4.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.00" Area (sf) CN Description 21,760 61 >75% Grass cover, Good, HSG B 830 98 Impervious 22,590 62 Weighted Average 21,760 96.33% Pervious Area 830 3.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.0 Direct Entry, Post-Dev Hunters PostDev Type 1124-hr 100-Year Rainfall=9.00" Prepared by {enter your company name here) Printed 2/28/2022 HvdroCAD® 9.10 s/n 07054 © 2011 HvdroCAD Software Solutions LLC Paae 16 Summary for Pond 7P: New 60" Det Pipe Inflow Area = 0.167 ac, 89.41 % Impervious, Inflow Depth > 8.27" for 100-Year event Inflow = 2.14 cfs @ 11.95 hrs, Volume= 0.115 of Outflow = 2.20 cfs @ 11.96 hrs, Volume= 0.115 af, Atten= 0%, Lag= 0.3 min Primary = 2.20 cfs @ 11.96 hrs, Volume= 0.115 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 372.76' @ 11.96 hrs Surf.Area= 0.005 ac Storage= 0.014 of Plug -Flow detention time= 26.3 min calculated for 0.115 of (100% of inflow) Center -of -Mass det. time= 25.7 min ( 779.2 - 753.5 ) Volume Invert Avail.Storage Storage Description #1 369.50' 0.021 of 60.0" D x 47.0'L Pipe Storage S= 0.0033 T Device Routing Invert Outlet Devices #1 Primary 369.50' 15.0" Round Culvert L= 47.0' Ke= 0.600 Inlet / Outlet Invert= 369.50' / 369.00' S= 0.0106 '/' Cc= 0.900 n= 0.012 #2 Device 1 369.50' 2.5" Vert. Orifice/Grate C= 0.250 #3 Device 1 372.50' Weir Opening, Cv= 2.62 (C= 3.28) Head (feet) 0.00 0.50 1.00 1.50 1.90 1.99 Width (feet) 4.90 4.60 4.00 2.95 1.60 0.50 Primary OutFlow Max=2.14 cfs @ 11.96 hrs HW=372.75' (Free Discharge) L1=Culvert (Passes 2.14 cfs of 8.98 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.12 cfs @ 3.56 fps) 3=Weir Opening (Weir Controls 2.02 cfs @ 1.65 fps) Summary for Link 9L: Point of Analysis-MS4 Inflow Area = 1.460 ac, 50.33% Impervious, Inflow Depth > 6.47" for 100-Year event Inflow = 14.37 cfs @ 12.00 hrs, Volume= 0.787 of Primary = 14.37 cfs @ 12.00 hrs, Volume= 0.787 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs LD-204 Stormwater Inlet Computations - 2300 Hunter's Way Inlets on Grade Only Sag Inlets Only Z U ii 8m' m r 0 m � o xhi ii [m] (7 m a `m U r `m a `° m y 15 m a n x a 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 (ft) (ac) (in/hr) (cfs) (cfs) (cfs) V) (T) (T) (ft) (ft) (cfs) (cfs) (ft) (ft) (ft) (ft) Inlets DI-3B 8 0.16 0.84 0.13 7.5 1.01 1.01 0.015 0.03 4.57 0.137 88.0% 0.887 0.121 8 0.16 0.84 0.13 4.0 0.54 0.54 0.015 0.03 3.61 0.108 100.0 % 0.538 0.000 Inlet DI-3B 8 0.13 0.90 0.12 7.5 0.88 0.88 0.015 0.03 4.34 0.130 91.7% 0.805 0.073 8 0.13 0.90 0.12 4.0 0.47 0.47 0.015 0.03 FO.O020 3.42 0.103 100.0 % 0.468 0.000 Inlet 3 DI-3C 10 0.42 0.82 0.34 7.5 2.58 2.78 0.015 0.03 0.20 0.5 0.39 6.64 9 10 0.42 0.82 0.34 4.0 1.38 1.38 0.015 0.03 0.15 0.5 0.30 4.16 9 Inlet 4 DI-7 4x4 0.21 0.81 0.17 7.5 1.28 1.35 0.015 0.03 0.13 0.5 0.26 7.60 12 4x4 0.21 0.81 0.17 40 068 0.68 0.015 0.03 0.09 0.5 1 0.18 5.55 12 '$t And S2 Bypass Flows included in Inlet CalculaVon LD-229 Storm Drain Design Computations Hunters Way From To Catch. Runoff Increment Accum. Total Total Total Up Down Pipe Invert Pipe Pipe Velocity Flowtime Structure Structure Area Coef 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 9 10 11 12 13 14 15 16 17 Inlet 3 Det.1 0.38 0.82 0.31 0.31 5.0 6.81 2.12 380.35 378.24 54.8 3.85% 15 13.7 8.1 0.11 Det. 1 Ex. 3' - - - - - - 1.09 378.22 377.04 61.1 1.93 % 15 9.7 5.2 0.19 Ex. 3 Ex. 2' - - - - - 1.09 374.60 370.46 50.8 8.16 % 15 20.0 8.7 0.10 Inlet Det.2 0.21 0.8 0.17 0.17 5.0 6.81 1.16 370.00 369.50 13.9 3.60% 15 13.3 6.7 0.03 Det.2 Ex. 2' - - - - - - 2.04 368.5 367.5 35.93 2.78% 15 11.7 7.2 0.08 Ex. 2 Ex. 1' - - - - - - 3.13 362.53 357.15 53.2 10.12% 15 22.3 12.80 0.07 'Note: flow computed from HydroCAD Post-Dev Runoff Quality Calculations: Post-Dev Land Cover Map VRRM Redev. Spreadsheet HUNTER'S WAY POST -DEVELOPMENT VRRM MAP t I I I I I I I I I I TURF p I I I . a4 •. E I I I i I v TURF IMP IMP IMP IMP al -- -----1 TURF I o � iOJ�O ly 1 0 A I I I I I I I I I I I I I I I I I I I I I I I I I I I I TURF / g TURF �� / POSTDEV SITE AREA 0.74 ACRES IMP, HSG B / 0.72 ACRES TURF, HSG B / PER VRRM SPREADSHEET V3, 0.84 LBS OF TP LOAD REDUCTION IS REQUIRED. 0.58 LBS HAS BEEN PURCHASED TO SATISFY WPO 2016-52. 0 30 60 OWNER SHALL PURCHASE 0.26 LBS OF PHOSPHOROUS CREDITS FROM AN SCALE: = 30 40PIAPPROVED NUTRIENT BANK. Project Name: I Nunterdway ' Date: 1/3/]A39 Linear Development Project? Na Information -Development Project (Treatment Volume and Loads) Enter Total Disturbed Area Dsa (oren/open spare a3s 0.3s Mare[ea Turflw®1-tllrturbea�gnaea br nmamdna,wnm as mna,ee/mana[ea aT9 0.T9 Imp•mMear�leee,l ... 0.3x aea forexa/oR _ refinenM lava D'm m. n.a.d nd lam®1 5 &Homey [reaea for n,ea n,dne,mnm ae mnv,m/mana[ea . 0.rz rmpmexl 1 1 0,74 1 1 O.14 daMmReax constantailues aro lice, ron Check: BMGO ri9n 5peclJlcatlo rs List: 2013 Ll2ft Stdc & Speo ❑nearprolect? Na Land Cover Is entered rorreetly? e/ Total disturbed area entered? e/ Lone[bwrsumme,y.we Lend meersummor Pert(rwq -_ ten¢epwrwmme ysan - tam eo..sumnwn•P«[ Pre.wRMMRM�m wyad --oar Pen ., so Ra R wa-aeDeeel=Im.m r.cDe=alro^emxe.imlw.iw n—Varoan xa- re, Isred a3s 0m Rmmuc R�e ome nl �.°iarve.lre am we[nMa FNfinenl 0.03 0m wegnrta F.{finenl O.te wdlnnm RdfrvMtl am %RMan za% 0x zFMan Mam[ea Ton Cove, aRa Ton Cave, Ma,.[eaname, IaeMl o.T9 0n apx on wa,Wai Rnoan am DID wei[bma Rv lmnl am wei[bmtl R. (adl 0.20 %Ma,r. 14% GS% sed Tart p9% aced Tart 6T'6 ImRrvimsfine, 4=real 0.32 0,32 Impel �nm1nre, o.Te ReDo.Ir,... am Nee Imp a, 0.az RHImRMo al Des 09s Rable aaaa) Des R.empervmml os9 it,(. Mwa1 ass %ImRmM¢ 22% 3]% %Im[ervlous sl% %Impervmu tMa TeYI ReRu. ace are, TeM1l silo area (aMM) I L.. .-I are am. lanea) lA6 xreel tll[ SMM 0.31 OA3 F-I Pear .1. R, 0.9R gMrYRM RA3 Treatment Volume and Nutrient Load Tmalment Volume and NuVierd Load - Daademem m,e Pre-ReDaaelnpmen Tre mvdVme anal ract-r=ampreena -peaenPmem la=re.xl 0.0394 o0313 rea an mvdume O.Om6 reat m mVolume C.3 3 Teatm tVdnme 0m3: lanaxl a r.ftl - la=mxl rvelopmem n..1—.Da 1,M PmFeDeaeRpmena mVdume t". 1,626 reament Vdume 3,026 amemeVolmee 1,6M re1...fad tVdune oura t'. 1=wsl=faal�e N., ------ Imbtf-" PeMeperelopmem Non) Final Po rt- P,aRaOevelopmena TP boa 1.08 1.02 Development TP Watl 1.93 Wad ce) 1.. PemmR D.91 (%/wl Ilb/wl (w1). �� .�;m. Wei lnM) .re.aeoe.n real ��an R�/a�eMlwaM`ace nN dsR ,3z naawnl naaw.0 R—ineiP NN 11bN,) May. RaA.oM uwuM '. Iolawacove,...tlmMp e.roeama = 'e -1 w wxoza or -. Mrawxm.vl� -- xmeml adl oevtl� IP WudReeunon TaMtatl a --.. --.. -.-- TP bad. on ce hF by NealbM B Vop Require¢ for a.30 Rejoiced Mr Xew 0.79 i^^°9ea dl °m^9e p°aad) RedevelopM Area I ¢Moos Area Ib/y,) Ilb/y,l mim TP load ReaduRlon Requlred (lb/yr) 1 0.84 Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0185&1... NOAA Atlas 14, Volume 2, Version 3 Location name: Charlottesville, Virginia, US* y/� �`' Latitude: 38.01Longitude:-78.4179° }, lkt�Elevation: 493 tt* source: Google Maps POINT PRECIPITATION FREQUENCY ESTIMATES GM Bounin, D. Martin, B. Lin, T Parzybok, Moira, and D. Riley NOAl1 National Weather Service, Silver Spring, Maryland PF tabular I PF graphics I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence Intervals (in inches)1 Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 0.352 0.418 0.489 0.551 0.620 0.674 0.725 0.772 OX27 0.874 5-min (0.317-0.391) (0.377-0.464) (0.440-0.541) (OA95-0.610) (0.555-0.684) (0.601-0.743) (0.642-0.798) (0.679-0.851) (0.721-0.914) (0.755-0.968) 0.562 0.668 0.783 0.881 0.988 7.07 1.15 1.22 1.31 1.38 10-min (0.506-0.624) (0.602-0.741) (0.705-0.867) (0.791-0.975) (0.884-1.091 (0.957-1.18) 1 (1.02-1.27) (1.08-1.35) (1.14-1.45) (1.19-1.52) 0.702 0.840 0.990 1.11 125 7.36 1A6 1.54 1.65 1.73 15-min (0.632-0.780) (0.757-0.932) (0.892-1.101 (1.00-1.23) (1.12-1.38) 1 (1.21-1.50) (1.29-1.60) (1.36-170) (1.44-1.82) (1.49-1.91) 0.962 1.16 1.41 1.61 1.85 2.05 2.23 2.90 2.62 F 2.80 30-min (0.867-1.07) 1 (1.05-1.29) 1 (1.27-1.56) 1 (1.45-1.79) 1 (1.66-2.05) (1.82-2.26) (1.98-2.46) 1 (2.12-2.65) 1 (2.28-2.90) 1 (2.42-3.10) 1.20 1.96 1.80 2.10 2A7 2.77 3.07 3.37 3.76 4.08 60-min (1.08-1.33) (1.31-1.61) (1.62-2.00) (1.89-2.33) (2.21-2.73) (2.47-3.06) (2.72-3.38) (2.97-3.71) 1 (3.28-4.16) (3.53-4.52) 1.44 7.75 2.78 257 3.06 3.47 3.89 4.33 F 4.93 5.43 2-hr (127-1.65) (1.54-1.99) (1.92-2.47) (2.26-2.90) (2.67-3.45) (3.02-3.92) (3.36-4.38) (3.71-4.87) (4.18-5.55) (4.57-6.14) 1.58 1.91 2.38 2.80 7 3.33 3.79 4.25 4.73 5.39 5.96 3-hr (1.39-1.81) (1.67-2.19) (2.08-2.73) (2.44-3.19) (2.90-3.80) (327-4.31) (3.65-4.83) (4.03-5.38) (4.54-6.14) (4.96-6.79) 2.00 2A1 2.99 3.53 4.24 4.87 5S2 622 7.27 8.09 6-hr (1.77-2.28) 1 (2.13-2.74) 1 (2.63-3.40) 1 (3.10-4.00) (3.70-4.80) 1 (4.21-5.49) (4.73-6.23) (528-7.02) (6.03-8.15) (6.67-9.14) 2.51 3.02 3.76 4.96 5.42 6.29 722 8.24 9.73 11.1 12-hr IF (222-2.88) 1 (2.67-3.46) 1 (3.31-4.30) (3.91-5.09) (4.71-6.17) 1 (5.41-7.14) (6.14-8.18) (6.91-9.32) (8.01-11.0) (8.98-12.6) 2.99 3.62 4.63 5.47 6.73 7.81 9.00 10.3 12.3 14.0 24-hr (2.68-3.36) 1 (3.25-4.07) 1 (4.14-5.20) (4.88-6.14) (5.96-7.52) (6.88-8.71) (7.86-10.0) (8.91-11.5) (10.4-13.6) (11.7-15.5) 3.52 4.27 5.43 6.39 7.78 a.95 10.2 11.6 13.6 15:3 2-day (3.17-3.94) 1 (3.84-4.78) 1 (4.88-6.07) 1 (5.72-7.13) (6.91-8.66) (7.89-9.94) (8.94-11.4) (10.1-12.9) (11.7-15.2) (13.0-17.1) F 5.78 6.79 8.26 9.50 10.8 12.3 14.4 16.2 F3-day]F-37577455 (3.40-4.16) (4.12-5.04) (5.23-6.41) (6.13-7.52) 1 (7.42-9.13) (8.47-10.5) (9.59-12.0) 1 (10.8-13.6) (12.5-16.0) (13.9-18.0) 3.98 4.82 6.12 7.19 8.74 70.0 11A 13.0 15.2 17.1 4-day](3.64-4.39) (4.41-5.31) (5.59-674) (6.55-7.90) (7.93-9.60) (9.06-11.0) (102-12.6) 1 (11.5-14.3) (13.3-16.7) (14.8-18.9) 4.62 5.57 6.96 8.11 9.76 11.1 12.6 14.2 16.5 18.4 7-day (425-5.05) 1 (5.11-6.08) 1 (6.38-7.61) 1 (7.41-8.86) (8.87-10.6) 1 (10.1-12.1) (11.3-13.8) 1 (12.6-15.5) (14.5-18.0) (16.0-20.2) 5.24 629 7.77 asir 10.7 12.1 13.5 15.1 17.3 19.1 10-da (4.84-5.68) 1 (5.81-6.82) (7.16-8A2) (8.25-9.72) (9.77-11.6) (11.0-13.1) (12.3-14.7) (13.6-16.4) (15.4-18.8) (16.9-20.9) 6.89 8.22 9.94 37713.7 74.6 1607717.5 19.6 2t.2 20-0ay (6.45-7.39) (7.70-8.81) (9.29-10.7) (10.5-12.1) (122-14.0) (13.5-15.6) (14.8-172) (16.1-18.8) (17.8-21.1) (19.2-22.8) 8.46 10.0 11.9 13.3 15.1 76S 17.8 19.1 20.9 222 30-day (7.95-9.01) (9.43-10.7) (112-12.6) (12.4-14.1) (14.1-16.0) (15.4-17.5) (16.6-19.0) (17.8-20.4) (19.3-22.8) (20.4-23.8) 10.6 12.5 t4.6 76.2 18.2 19.7 21.2 22S 24.4 25.7 45-dsy (9.97-11.2) 1 (11.8-13.2) 1 (13.8-15.5) 1 (15.2-17.1) 1 (17.1-19.3) 1 (18.5-20.9) 1 (19.8-22.4) 1 (21.0-23.9) 1 (22.6-25.9) 1 (23.8-27.4) 124 14.6 16.9 78.6 M 7 22.3 23.8 25.2 27.1 28.4 60aay (11.7-13.1) (13.8-15.4) (15.9-17.8) n5-19.6) (19.5-21.8) (21.0-23.5) (22.4-25.1) (23.7-26.7) (25.3-28.7) (26.4-30.2) 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 1 of 4 2/17/2016 11:17 AM Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0185&1... PDS-based depth -duration -frequency (DDF) curves Latitude: 38.01850. Longitude:-78.4179° 30 25 c 20 ....:- ..:.....:.....:.........:.....:.... .. a W v ._.:....:..._:.....:..... t..:........... ..... e15 .2 Z a 5 ........... ... .......;_;- .. ...............: 0 C C C C C T TT T T T T TT v vp v vp � v' r Duration 0 25 c c 20 5 0 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAA Atlas 14, Volume 2, Version 3 Created (GMT): Wed Feb 17 16:17:06 2016 Back to Too Maps & aerials Small scale terrain f -- Morganto - < _ o � aroFors, ,.� MARYLAND NEti thens Hanger srarion, w'J / ! Oa _ � �� ®'Belli I ashinaton DEL A LAW/ • / - OttE Average recurrence interval (years) — 1 2 5 10 — 25 50 100 200 500 1000 W E S T Nppbonal Foresr /Fieriisonbu g A The,George f Wsshm ronr i _rp*'' Viand Jers-- Ilksville ffeon aponally SO km 61 Duration 5+ ,n — 2-day — 10inin — 3-day 15-min — 4-aay - 30-min — 7-0ay — 60-min — 10-day 2-hr — 20-day — 3fir — 30-day — 6-ht — 45-day — 12-hr — 60-day — 24a1r 2 of 4 2/17/2016 11:17 AM Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0185&1... Large scale terrain YJIdwooA i j 1 '. �wlotteav U to / ♦r mO WOOLENMKl .v _ zz t ' ( Shadwell Keswick j� Monticello^i <t! 7 1 aa, zsz i�oi►. gle 2 km Map Report a map error Large scale map rws O n4j Wlldwood iarlottesville,- ,. 1 WOOLEN MILLS _ Shadwe" Keswick Monticello i sz rza � I �p �Rd zez Simeon Google 2km Map Report map error 3 of 4 2/17/2016 11:17 AM USDA United States Department of Agriculture MRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Albemarle County, Virginia June 20, 2016 3 1'PN 3U° N Custom Soil Resource Report 3 Soil Map 3 N N 726550 ]25W0 72%10 725W 726670 726700 725730 3 3 Map So L: 1:1,2M fprnW m Aporbak (83' x 11'� shed N Mebs 0 15 30 60 90 A `� 0 50 100 200 300 Map Ropcbm: Web Vouftr Cmeraoordinabe5: WGS84 Edge b[ : UTM Zone 17N WGS84 8 t a D° 053' N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AOI) #1 Spoil Area The soil surveys that comprise your AOI were mapped at 1:15,800. O Area of Interest (AOI) ® Stony Spot Solis very Stony Spot Warning: Soil Map may not be valid at this scale. 0 Soil Map Unit Polygons Wet Spot Enlargement of maps beyond the scale of mapping can cause N Soil Map Unit Lines Other misunderstanding of the detail of mapping and accuracy of soil line � Soil Map Unit Points p placement. The maps do not show the small areas of contrasting • Special Line Features soils that could have been shown of a more detailed scale. Special Point Features V Blowout Water Features Streams and Canals Please rely on the bar scale on each map sheet for map ® Borrow Pit measurements. Transportation Clay Spot ... Rails Source of Map: Natural Resources Conservation Service 0 Closed Depression Interstate Highways Web Soil Survey URL: hftp://websoilsuwey.nres.usda.gov Gravel Pit Coordinate System: Web Mercator (EPSG:3857) US Routes Gravelly Spot Major Roads Maps from the Web Soil Survey are based on the Web Mercator 0 Landfill Local Roads projection, which preserves direction and shape but distorts Lava Flow distance and area. A projection that preserves area, such as the A. Background Albers equal-area conic projection, should be used if more accurate Marsh or swamp . Aerial Photography calculations of distance or area are required. �. Mine or Quarry This product is generated from the USDA-NRCS certified data as of O Miscellaneous water the version date(s) listed below. O Perennial water Soil Survey Area: Albemarle County, Virginia y Rock Outcrop Survey Area Data: Version 10, Dec 11, 2013 + Saline Spot Soil map units are labeled (as space allows) for map scales 1:50,000 Sandy Spot or larger. Severely Eroded Spot Date(s) aerial images were photographed: May 9, 2011—Jun 4, 0 Sinkhole 2011 Slide or Slip The orthophoto or other base map on which the soil lines were Sotlic Spot compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting 0 Custom Soil Resource Report Map Unit Legend Albemarle County, Virginia (VA003) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 72C3 Rabun clay, 7 to 15 percent slopes, severely eroded 3.7 58.9% 72133 Rabun Gay, 15 to 25 percent slopes, severely eroded 2.5 0.1 39.5% 79B Starr silt loam, 2 to 7 percent slopes 1.6% Totals for Area of Interest 6.2 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments 10 Custom Soil Resource Report on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha - Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 11 Custom Soil Resource Report Albemarle County, Virginia 72C3—Rabun clay, 7 to 15 percent slopes, severely eroded Map Unit Setting National map unit symbol: kbdv 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: 80 percent Estimates are based on observations, Description of Rabun descriptions, and transects of the mapunit. Setting Landform: Interfluves Landform position (two-dimensional): Shoulder Landform position (three-dimensional): Side slope Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from greenstone Typical profile H1 - 0 to 4 inches: clay H2 - 4 to 48 inches: clay H3 - 48 to 79 inches: silty clay loam Properties and qualities Slope: 7 to 15 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) (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 high Available waterstorage in profile: Moderate (about 8.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B 72D3—Rabun clay, 15 to 25 percent slopes, severely eroded Map Unit Setting National map unit symbol: kbdw 12 Custom Soil Resource Report 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: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Rabun Setting Landform: I nterfluves Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down -slope shape: Linear Across -slope shape: Convex Parent material: Residuum weathered from greenstone Typical profile HI - 0 to 4 inches: clay H2 - 4 to 48 inches: clay H3 - 48 to 79 inches: silty clay loam Properties and qualities Slope: 15 to 25 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 8.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6e Hydrologic Soil Group: B 79B—Starr silt loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: kbf9 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 Starr and similar soils: 80 percent 13 Custom Soil Resource Report Estimates are based on observations, descriptions, and transects of the mapunit. Description of Starr 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 H1 - 0 to 18 inches: silt loam H2 - 18 to 53 inches: silty clay loam H3 - 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 14