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HomeMy WebLinkAboutWPO201600052 Plan - VSMP WPO VSMP 2016-08-18 r PROJECT MANAGEM CIVIL ENGINEERINGENT LAND PLANNING ENGINEERING August 18, 2016 Engineering Review Albemarle County Community Development 401 Miclntire Road, North Wing Charlottesville, VA 22902 Regarding: 2300 Hunter's Way VSMP Plan This site is a currently developed lot that is being redeveloped to include an auto repair facility. The redevelopment involves less than an acre of disturbance and all new runoff will be routed to the existing storm sewer system. To meet storrmwater runoff quantity requirements, all runoff from impervious areas onsite will be routed to a three-run detention system under the parking lot. This will outlet to an existing stormwater manhole at flow rates that meet energy balance equation. To meet runoff quality requirements, 0.58 pounds of phosphorous nutrient credits will be purchased to offset the development nutrient loads. If you have any questions please do not hesitate to contact me at: JustinRshimp-engineerinq.com or by phone at 434-953-6116. Overall Drainage Area Summary: Pre-Dev Runoff Post-Dev Runoff 1-Year Storm 1.34 cfs 0.58 cfs „ 10-Year Storm 5.30 cfs 2.86 cfs ris r APPROVED by the Albemarle y Community Development Department 41. ®ae- ,.� _ __ ?,O_It�-cth- Contents: Stormwater Quantity Calculations: Energy Balance Equation Supporting HydroCAD Reports Stormwater Quality Calculations: VRRM Re-Development Spreadsheet Pre-Development Stormwater Management Calculations: Pre-Development Drainage Map Pre-Development HydroCAD Analysis Post-Development Stormwater Management Calculations: r. Post-Development Drainage Map Post-Development HydroCAD Analysis VDOT LD-204 Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report 011 WAN WM a w a 00 rr rr Stormwater Quantity Calculations: Energy Balance Equation Supporting HydroCAD Reports on or 11111 MO .r NO r rs 2300 Hunters Way Energy Balance Equation 24 Hr 1 year Storm: Qdevelopee I.F• *(Qpre-developed*RVPre-Developed)/RVdeveloped rr Qdeveloped5• (Qforested*RVforested)/RVdeveloped Drainage Area : r■ Qpre-developed RVpre-Developed = Qdeveloped = 0.70 cfs rr RVDeveloped — r is rtl ar ■r as sr rr rr r rr r• Hunters PreDev Type 1124-hr 1-Year Rainfall=2.99" .. Prepared by Shimp Engineering, P.C. Printed 8/18/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 1 s. Summary for Subcatchment 1S: Total Site Runoff = 1.34 cfs @ 12.01 hrs, Volume= 0.075 af, Depth> 0.62" sr 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" .r Area (ac) CN Description 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 Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, r See Pre-Dev Section of SWM Report For Land Conditions Map goo r MN r IMO i O il i SE N M lin INI i MIN all i all i r.. Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" .. Prepared by Shimp Engineering, P.C. Printed 8/18/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 1S: Total Site Runoff = 2.52 cfs @ 12.00 hrs, Volume= 0.129 af, Depth> 1.06" 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 * 0.616 98 impervious 0.844 61 >75% Grass cover, Good, HSG B r. 1.460 77 Weighted Average 0.844 57.81% Pervious Area 0.616 42.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, See Post-Dev Section of SWM Report For Land Conditions Map i aim UM MO Stormwater Quality Calculations: VRRM Re-Development Spreadsheet a. 1010 as 1011 MN 016 r.. sae Project Name: HUNTERS WAY CLEAR ALL data inputcelb 1 Date: 8/10/2016 (CtrlOShl)M5) constant values Linear Development Project? No calculation cella Site Information Post-Development Project(Treatment Volume and Loads) Enter Total Disturbed Area(acres) -211 0.83 V Check: BMP Design Specifications List:2013 Draft Stds&Specs Maximum reduction required: Linear project? No MI The site's net increase in impervious cover(acres)is:IIKEIMI Land cover areas entered correctly? ,/ Post-Development TP Load Reduction for Site(lb/yr):mil= Total disturbed area entered? ,/ Pre-ReDevelopment land Cover(acres) A Soils B Soils C Soils D Soils Totals forest/Open Space(acres)-undisturbed, MI protected forest/open space or reforested land 0.35 0.35 Managed Turf(acres)-disturbed,graded for yards or other turf to be mowed/managed 0.79 0.79 Impervious Cams(acres) 0.32 0.32 1.46 An Post-Development Land Cover(acres) A Soils 0 Soils C Soils 0 Soils Totals forest/Open Space(acres)-undisturbed, • protected forest/open space or reforested land 0.05 0.05 Managed Turf(arm)-disturbed,graded for yards or other turf to be mowed/managed 0.83 0.83 Impervious Cover(acres) 0.50 0.58 911111 Area Check OK. OK. OK. OK. 1.46 •Forest/Open Space areas must be protected in accordance with the Virginia Runoff Reduction Method Constants Runoff Coefficients(Rv) Annual Rainfall(inches) 43 A Soils B Soils CSoils D Soils Target Rainfall Event(inches) 1.00 forest/Open Space 0.02 0.03 0.04 0.05 In Total Phosphorus(TP)EMC(mg/L) 0.26 Managed Turf 0.15 0.20 0.22 0.25 Total Nitrogen(TNI EMC(mg/L) 1.86 Impervious Cover 0.95 0.95 0.95 0.95 Target TP Load(lb/acre/yr) 0.41 Pj(unitless correction factor) 0.90 LAND COVER SUMMARY--PRE-REDEVELOPMENT LAND COVER SUMMARY--POST DEVELOPMENT ,... Land Coversummary-Pre lar=SZMIZINIMLand Cover Summary-Post Land Cover Summary-post Pre-ReDevelopment Listed Adjusted' Post Re0ev.&New Impervious post-Reuevelopment post-Development New Impervious Forest/Open Space Cover lac es) 0,35 00gFtFor�es[/Open Space 005 Forest/Open Space � Ctover(acres) Cover(acres) 0.05 Weighted Ry(forest) 0.03 003 Weighted Rv(forest) 003 %Forest 24% 8% MEM ME= 96 Forest 4% Managed Turf Cover(acres) 0.79 0.79 Managed Turf Cover 0.83 Managed Turf 0.83 (acres) (acres) Weighted Rv(turf) 0.20 0.20 Weighted Ry(turf) 0.20 Weighted Rv(turf) 0.20 %Managed Turf 54% 66% %Managed Turf 69% Impervious Cover(acres) 0.32 0.32 Impervious Cover(acres) 0.58 Re.e,Impervious032 New Impervious Cover 026 NM Cover(acres) (acres) Rs(impervious) 095 0.951111=11111 11=2.11 Rs(Impervious) 0.95 Rs(impervious) 0.95 %Impervious 22% 27% =111. %Impervious 27% Total Slte Area(acres) 1.46 1.20 Final Site Area(acres) 1.46 Total 1150ev.Site Area L20 (acres) Site so 0.32 0.39 FInal Post ties Site Re 0.49 ReDev Site Rv 0.39 Treatment Volume and Nutrient Load Treatment Volume and Nutrient Load Pre-ReDevelopment Treatment Volume Final Post-Development post-ReDevelopment Post-Development (ave-XI 0.0394 0.0387 Treateat Treatment Volume 0.0599 Treatment Volume 0.0393 Treatment Volume 00206 (acreX) (acre-ft) (acre-ft) 40111 Final Post.Development Post•ReDevelopment Development ePse-ReOevelopmtm cat Volume (cubic feet) 1,715 1,687 iette 2,608 Treatment Volume 1,712 Treatment Volume(cubic 897 (cubic feet) (cubic feet) feet) Pre-ReDevelopment TP Load Final Post- PostReDevelopment a 1.08 1.06 Development TP Load 1.64 Load(TP) Los Post Development VP lb0.56 Iib/Yr) Load IIb/yr) (Ib/yr) (Ib/yr)• • Pre ReDevelopment TP Load per acre FnPost-Development TP P o men P (ft/acre/yr) 0.74 5.50 eo1.17 090 116/acre/vrl pbpvre/vrle 16 Bata cce ed Loadcsent 10.41 ms/acre/yr applied to preredevelopm area excluding pervious 0.49 I a eau ed w Pre- land waposed for new impervious coven ReOevemm ad) lspeL 10% 1Adjusted Land Cover Summary, new TP Load Reduction P Load Reduction Are Reoevelapm cat land cover minus pervious land rover dprest/open space or Required for 0.12 Requiredfo,New 0.46 paged tan/I oo gage proposed for impervious cover. Redeveloped Area Ills/yr) Impervious Area(Ib/yr) Adjusted total acreage n consistent with Post-ReDevelopment acreage(minus acreage of new impervious[over). Column I shows load reduction regurlement for new impervious cover(based on new development load limit,0.41 Ibs/acre/year). Post-Development Requirement for Site Area TP Load Reduction Required(lb/yr) 0.58 • • Virginia Runoff Reduction Method Worksheet 8r DEQ Virginia Runoff Reduction Method Re-Development Compliance Spreadsheet-Version 3.0 BMP Design Specications List: 2013 Draft Side&Specs - Site Summary Total Rainfall(In): 43 Total Disturbed Acreage: 0.83 Site Land Cover Summary Ili Pre-ReDevelopment Land Cover(acres) A soils 8 Soils C Soils D Soils Totals %of Total Forest/Open(acres) 0.00 0.35 0.00 0.00 0.35 24 Managed Turf(acres) 0.00 0.79 0.00 0.00 0.79 54 iiill impervious Cover(acres) 0.00 0.32 0.00 0.00 0.32 22 1.46 100 Post-ReDevelopment Land Cover(acres) A soils BSolls CSoils 05oi1s Totals %of Total iiiii Forest/Open(acres) 0.00 0.05 0.00 0.00 0.05 3 Managed Turf(acres) 0.00 0.83 0.00 0.00 0.83 57 Impervious Cover(xres) 0.00 0.58 0.00 0.00 0.58 40 •Forest/Open Space areas must be protected In accordance with the Virginia Runoff Reduction Method 1.46 100 Site Tv and Land Cover Nutrient Loads Mil Pre- Final Post-Development Post- Final Post-Development Post-ReDevelopment TP Post- Adjusted Pre- ReDevelopment (Post-ReDevelopment Development TP Load per acre Load per acre &New Impervious) ReDevelopment (New Impervious) ReDevelopment TP Load per acre (lb/acre/WI (Ib/acre/yr) (Ib/acre/yr) Site Rv 0.49 0.39 0.95 0.39 0.88 1.12 0.90 NI Treatment Volume(ft') 2,608 1,712 897 1,687 TP Load(Ib/yr) 1.64 1.08 0.56 1.06 Total TP Load Reduction Required(Ib/yr) 0.58 0.12 0.46 ibilli Final Post-Development Load Pre- (Post-ReDevelopment&New Impervious) :ReDevelopment TN Load(Ib/yr) 11.72 7.71 lilt Site Compliance Summary Maximum%Reduction Required Below Pre-ReOevelopment Load 10% NB Total Runoff Volume Reduction(ft) 0 Total TP Load Reduction Achieved(Ib/yr) 0.00 Total TN Load Reduction Achieved(ib/yr) 0.00 ON Remaining Post Development TP Load (Ib/yr) 1.64 Remaining TP Load Reduction(Ib/yr) Required 0.58 N BM r it IN ill itar tin Summary Prim aft Pre-Development Stormwater Management Calculations: Pre-Development Drainage Map Pre-Development HydroCAD Analysis tat era MB Oft OM M al N iii _ Ell .iMIIIM_. es N. iiiiii11111111111* 9P' . , , • I.:-•,:::::---:. ---1-1-.-----) -- ' 1k_ 1' /- ---(-17) I W I / I \\ / 00�/ / / - -- I 1 ---- — — — �\ \ 1 / f \ / / I \! ll € / � \ / -1 ;1 _ ,� \ / / -..._ \ I I 1 / :,'; / /\ 1 /I i 1 '' , F „............____ ,...................„..„,.....,, . , , i ,+ l / ,.) r3 J / ` D D if-----19 'o m i +- D s \ , % n ■ - \ 1 „ -- ---- ---- — 77.,,,,. -.----- -. 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Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 1S: 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" mai Area (sf) CN Description 13,890 98 Imp 15,045 55 Woods, Good, HSG B 34,691 61 >75%Grass cover, Good, HSG B 63,626 68 Weighted Average 49,736 78.17% Pervious Area 13,890 21.83% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, r. Hunters PreDev Type 1124-hr 10-Year Rainfall=5.47" Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 1S: 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" r Area (sf) CN Description 13,890 98 Imp 15,045 55 Woods, Good, HSG B +�. 34,691 61 >75%Grass cover, Good, HSG B 63,626 68 Weighted Average 49,736 78.17% Pervious Area 13,890 21.83% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, wit Post-Development Stormwater Management Calculations: Post-Development Drainage Map Post-Development HydroCAD Analysis VDOT LD-204 1a I \ ? 4 x .. _- I --'moi -_I —--—) ��I t OcI5c \. -,L__N / -- _-- _-- . . --t M - 36o i _ I_ Z> o_ / i I -7(.-----)-- 70 ( m D i - - / _ — �\ �_ -- � i /_ \ / Q I Ji I --- , , / / — -_0L5,---- ii i / \N'jN1 + + ' r • i 1 n 9a m: + +. + r-,- ■■ I II m i + ■ \M. +--- :, �" l - --S/ 1 v -1-- \ : 'II ' r-' ' -',,,,,PP-ck. + + ? -rte.1:1- - _ �" \i \ ill" - 08£'r I 7- - _ - �+ + -4- s_ _ _ ± + + + 01'09 _ ,-- _______rt_> ri-,-,-_______-_ _A, + t .._ ._41i , ) I \ ___// A\ ,.. 1 , .4 \I /-\ / /� _ _ - — - _ _ - 7 / os — — , / ' \ \ , . .- oo + - _ dr ._ VI ‘ \I I>\ ,c \0 '',,..+ di'''`.. ----'41, 2,.. . \ \a otf"\ \\ ', - _i__ / N \\\ \ / \ - \ " -ice cooalo / S'� '9 / \ ir Am DIT10 I OC D -< DDD �7 �'j' �r '"� \ x � � mnz F.: -0 D \ 09(41) - � z � � X � 0 � II II II m ; IL . . FJi� 9� ` \ O -1 -m __ D / It' N7/ \ • � rrn- CD II O � 000 � I /o / - \` \ t 0 0 0 -0 D D O -- -- O n � � Co O 777 � („1CA N. / ', \ ..-.\\ TIS II � D II DDDp J ��\ - \ � � /.. Ci) II Oz =C C) i/ \ � \ _ \ \ = / � O0 °o O0 \' � � � \ z rn c) rn -rlC.O n0 0 / / _ : * C) Fri� � O CCS O \ K < rn DO _, �7N W \ // ' fir C" -1i_AN T1D D , / Do OrnCO n n 'G� -vim \ o z � D _ - m z D � rn -< 0 Detenti n DA 2 <8S> Detention DA 1 etention DA 3 � 5P (10S) 0 BYPASS Detention Pipe Existing Houses 1,4 9L Point of Analysis-MS4 Subcat Reach on. Link Drainage Diagram for Hunters PostDev Prepared by Shimp Engineering, P.C., Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC rr Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 2S: Detention DA 1 Runoff = 0.14 cfs @ 12.00 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 1124-hr 1-Year Rainfall=2.99" 00, Area (sf) CN Description 5,680 61 >75%Grass cover, Good, HSG B 1,044 98 Impervious aft 6,724 67 Weighted Average 5,680 84.47% Pervious Area 1,044 15.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, sis Summary for Subcatchment 3S: BYPASS Runoff = 0.27 cfs @ 12.03 hrs, Volume= 0.020 af, Depth> 0.36" 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 29,227 61 >75%Grass cover, Good, HSG B 29,227 100.00% Pervious Area .M Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, am Summary for Subcatchment 7S: Detention DA 2 .. Runoff = 0.55 cfs @ 11.95 hrs, Volume= 0.030 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" as Area (sf) CN Description 5,644 98 Impervious 5,644 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" .. Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 8S: Detention DA 3 Runoff = 1.40 cfs @ 11.95 hrs, Volume= 0.069 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 1,747 61 >75% Grass cover, Good, HSG B 13,771 98 Impervious 15,518 94 Weighted Average 1,747 11.26% Pervious Area 13,771 88.74% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, am Summary for Subcatchment 10S: Existing Houses NIB Runoff = 0.44 cfs @ 11.96 hrs, Volume= 0.021 af, Depth> 1.81" 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 +�+ 4,480 98 Impervious 1,568 61 >75% Grass cover, Good, HSG B 6,048 88 Weighted Average 1,568 25.93% Pervious Area 4,480 74.07% 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= 0.779 ac, 73.49% Impervious, Inflow Depth > 1.96" for 1-Year event Inflow = 2.50 cfs @ 11.95 hrs, Volume= 0.128 af Outflow = 0.33 cfs @ 12.22 hrs, Volume= 0.127 af, Atten= 87%, Lag= 16.0 min Primary = 0.33 cfs @ 12.22 hrs, Volume= 0.127 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 380.23'@ 12.22 hrs Surf.Area= 1,375 sf Storage= 2,096 cf Plug-Flow detention time= 58.7 min calculated for 0.127 af (99%of inflow) Center-of-Mass det. time= 55.2 min ( 843.3 - 788.1 ) rr Hunters PostDev Type 1124-hr 1-Year Rainfall=2.99" • Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 4 Volume Invert Avail.Storage Storage Description #1 378.20' 5,498 cf 60.0" D x 280.0'L 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 Primary OutFlow Max=0.33 cfs @ 12.22 hrs HW=380.23' (Free Discharge) Culvert (Passes 0.33 cfs of 6.57 cfs potential flow) —2=Orifice/Grate (Orifice Controls 0.33 cfs @ 6.65 fps) OW —3=Orifice/Grate ( Controls 0.00 cfs) —4=Orifice/Grate ( Controls 0.00 cfs) Summary for Link 9L: Point of Analysis-MS4 Inflow Area = 1.450 ac, 39.48% Impervious, Inflow Depth > 1.22" for 1-Year event Inflow = 0.58 cfs @ 12.04 hrs, Volume= 0.147 of Primary = 0.58 cfs @ 12.04 hrs, Volume= 0.147 af, Atten= 0%, Lag=0.0 min Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Wit OW SW OW rr Hunters PostDev Type 1124-hr 10-Year Rainfall=5.47" Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 2S: Detention DA 1 Runoff = 0.56 cfs @ 11.99 hrs, Volume= 0.027 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 1,044 98 Impervious +� 6,724 67 Weighted Average 5,680 84.47% Pervious Area 1,044 15.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) r 7.0 Direct Entry, Summary for Subcatchment 3S: BYPASS Runoff = 1.78 cfs @ 12.00 hrs, Volume= 0.093 af, Depth> 1.66" 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 29,227 61 >75%Grass cover, Good, HSG B 29,227 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 7S: Detention DA 2 Runoff = 1.02 cfs @ 11.95 hrs, Volume= 0.056 af, Depth> 5.23" a. 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 5,644 98 Impervious +r 5,644 100.00% Impervious Area Tc Length Slope Velocity Capacity Description „s (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, .r Hunters PostDev Type II 24-hr 10-Year Rainfall=5.47" .. Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 8S: Detention DA 3 Runoff = 2.72 cfs @ 11.95 hrs, Volume= 0.142 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 1,747 61 >75%Grass cover, Good, HSG B 13,771 98 Impervious 15,518 94 Weighted Average 1,747 11.26% Pervious Area 13,771 88.74% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 10S: Existing Houses Runoff = 0.97 cfs @ 11.95 hrs, Volume= 0.048 af, Depth> 4.11" 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 O 4,480 98 Impervious 1,568 61 >75%Grass cover, Good, HSG B 6,048 88 Weighted Average 1,568 25.93% Pervious Area 4,480 74.07% 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= 0.779 ac, 73.49% Impervious, Inflow Depth > 4.21" for 10-Year event Inflow = 5.21 cfs @ 11.95 hrs, Volume= 0.273 of Outflow = 1.21 cfs @ 12.12 hrs, Volume= 0.272 af, Atten= 77%, Lag= 9.7 min Primary = 1.21 cfs @ 12.12 hrs, Volume= 0.272 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 381.96' @ 12.12 hrs Surf.Area= 1,211 sf Storage= 4,429 cf .. Plug-Flow detention time= 60.7 min calculated for 0.272 af (100%of inflow) Center-of-Mass det. time=57.8 min ( 831.0 - 773.2) Hunters PostDev Type 1124-hr 10-Year Rainfall=5.47" .. Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 7 Volume Invert Avail.Storage Storage Description #1 378.20' 5,498 cf 60.0" D x 280.0'L 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 rimary OutFlow Max=1.21 cfs @ 12.12 hrs HW=381.94' (Free Discharge) =Culvert (Passes 1.21 cfs of 9.78 cfs potential flow) —2=Orifice/Grate (Orifice Controls 0.45 cfs @ 9.16 fps) —3=Orifice/Grate (Orifice Controls 0.76 cfs @ 5.56 fps) —4=Orifice/Grate ( Controls 0.00 cfs) ' Summary for Link 9L: Point of Analysis-MS4 Inflow Area= 1.450 ac, 39.48% Impervious, Inflow Depth > 3.02" for 10-Year event Inflow = 2.86 cfs @ 12.02 hrs, Volume= 0.364 af Primary = 2.86 cfs @ 12.02 hrs, Volume= 0.364 af, Atten= 0%, Lag= 0.0 min ,,,, Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Hunters PostDev Type 1124-hr 50-Year Rainfall=7.81" ••• Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 2S: Detention DA 1 Runoff = 1.03 cfs @ 11.99 hrs, Volume= 0.051 af, Depth> 3.96" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 50-Year Rainfall=7.81" Area (sf) CN Description 5,680 61 >75% Grass cover, Good, HSG B 1,044 98 Impervious 6,724 67 Weighted Average 5,680 84.47% Pervious Area 1,044 15.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Summary for Subcatchment 3S: BYPASS Runoff = 3.62 cfs @ 12.00 hrs, Volume= 0.184 af, Depth> 3.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs in Type II 24-hr 50-Year Rainfall=7.81" Area (sf) CN Description +■ 29,227 61 >75%Grass cover, Good, HSG B 29,227 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, sie Summary for Subcatchment 7S: Detention DA 2 Runoff = 1.46 cfs @ 11.95 hrs, Volume= 0.082 af, Depth> 7.57" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 50-Year Rainfall=7.81" Area (sf) CN Description 5,644 98 Impervious 5,644 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Hunters PostDev Type II 24-hr 50-Year Rainfall=7.81" Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 8S: Detention DA 3 Runoff = 3.95 cfs @ 11.95 hrs, Volume= 0.210 af, Depth> 7.09" �. Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 50-Year Rainfall=7.81" Area (sf) CN Description 1,747 61 >75% Grass cover, Good, HSG B 13,771 98 Impervious +� 15,518 94 Weighted Average 1,747 11.26% Pervious Area 13,771 88.74% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 10S: Existing Houses Runoff = 1.46 cfs @ 11.95 hrs, Volume= 0.074 af, Depth> 6.38" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 50-Year Rainfall=7.81" Area (sf) CN Description 4,480 98 Impervious 1,568 61 >75% Grass cover, Good, HSG B 6,048 88 Weighted Average 1,568 25.93% Pervious Area 4,480 74.07% 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= 0.779 ac, 73.49% Impervious, Inflow Depth > 6.42" for 50-Year event Inflow = 7.83 cfs @ 11.95 hrs, Volume= 0.417 of Outflow = 6.45 cfs @ 12.02 hrs, Volume= 0.415 af, Atten= 18%, Lag= 3.7 min Primary = 6.45 cfs @ 12.02 hrs, Volume= 0.415 of r Routing by Stor-Ind method,Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev=383.11' @ 12.02 hrs Surf.Area= 382 sf Storage= 5,474 cf Plug-Flow detention time= 53.9 min calculated for 0.415 of (100%of inflow) Center-of-Mass det. time= 51.1 min ( 816.4- 765.3 ) Hunters PostDev Type 1124-hr 50-Year Rainfall=7.81" Prepared by Shimp Engineering, P.C. Printed 8/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 10 .. Volume Invert Avail.Storage Storage Description #1 378.20' 5,498 cf 60.0" D x 280.0'L 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 Primary OutFlow Max=5.89 cfs @ 12.02 hrs HW=383.01' (Free Discharge) 1=Culvert (Passes 5.89 cfs of 11.34 cfs potential flow) —2=Orifice/Grate (Orifice Controls 0.51 cfs @ 10.43 fps) am —3=Orifice/Grate (Orifice Controls 1.02 cfs @ 7.47 fps) —4=Orifice/Grate (Orifice Controls 4.36 cfs @ 3.43 fps) Summary for Link 9L: Point of Analysis-MS4 Inflow Area= 1.450 ac, 39.48% Impervious, Inflow Depth > 4.96" for 50-Year event Inflow = 10.02 cfs @ 12.01 hrs, Volume= 0.599 af Primary = 10.02 cfs @ 12.01 hrs, Volume= 0.599 af, Atten= 0%, Lag= 0.0 min NIS Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs .• r ami 41P!M auei N v co co — >, S P.Wpaid lwod i x (00 PD.. Nv nv� O d H!0 cMl 4 N C O U. LL N 1q6 ep- gino N e c o rr m M M 41daQ luiodpiW N o r dor ✓r O O passed(8 0 N i o 0 0 0 0 0 m 42 92 e 0C a� peldaelui 0 u"i °'g 0000 a) ou o e (1 O Aoueoiu3 °� •q • o c0°'o 0 O o • c▪ uno le 41dad r c.2 o' C 0000 peaid sO to:(OM V Jenne lelol M a M rr edols-X Jellno e co ins g yn edoIs-X aped�e o 0 0 o'( 000000a is* edoisJennre 2R �00088a. 0000002 W Y (0(0(o(o(0(0 C N sBuiuue N o o o o o o w000000 gQ �o lelol O r' i F,4 g a�aS N �0oocl d C Jenok.mo p o 40 r+ .. a §a0 CO2 a'.2 E luew4o1e0 O m to 0,v O -OCG(V r 0 * inoinino • /�l!sualul co� n�v is',Di�:v d o 66 6 VO CI CI is* ;Goo young In VS$rn ro ano O 0o0Go0 N N 00eeBUNluawgole0 v -m M^A A 0000 J $uiued0gin0M- 03w030300 C.)p� M ed(11alui N M a? o C iegwnN einlonilS r m 2 Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report sr as sis ass as sr s■ sr r ais irr Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. rr OM rr a a �„ 7 Custom Soil Resource Report Soil Map N 0. 0 726550 726580 726610 726640 726670 726700 726730 38°1'2"N .., " - ra � 38°1'Z N ! y¢ey # .y-A R a i Att.�C i 9 r, p. g.�}s 5 �} Y ( } IS N j f ^Ft '�i k.. V r &.A' i 1 ' Cr i3 \ ` te vp. **A : "`. . $ ♦g ,t' tt 1 y7 f. f f :yy S� o ow ✓r I N ,. A (ice f '�" l ° q t+�.:,r 44? ",,,,44 :41,0:; sr.: ' ' a'* t.4c� :a-1 �' Lje+ fka f1 N .'+ 4 p, Yr y f r t,..A.: -44 1 i Tana'i „tto, m{ ,�/Mo t ,.. itl1 -¢# 1R$ P ” r^ a ki'd�jJ" `. :',4' ga`^'�fir` . t„. "' Si • ' e r.}$b' +' 1 Oil i „),;° .'44‘ t '.., 1. *is"0r • ; , Stt :72D3''* l ��fi'r. jr,.....:,,,,, .to, , ,,,,,... T /may II i 3 ' k'y -k 1 ° s t3 4 i IL +f 8+ --.. ° z antitz 25O -- = N 4\-414'.. 'ZVI%,4,, lei, 4., . llt,..v 44„, y„jA a J ,ts 1 # y o ,' ± AA • & *y 9 irtor 4 y X19` # • /� 4el ♦ t a A94 3 "�J ,, '* * , lir`iitk: ,*' , 4 ' . (,,,f * * 11*i . ..:`it, loefr ,,, • • .440 L1 it *0 ir q r 1 1- iff $ ..f,. �; fit 4 T a,�i #� `/1,t` < ,t ft if,R ,,„„ I a I Ilk 38°0.53'N , Les«,3 liE '*. 13a•� - <�Fr�iiimk �F! J' i esir~rJ ,t 4 ry ,� 38°053N 8°053N 726550 726610 726640 726670 726700 726730 3 3 Map Scale:1:1,250 if punted on A portrait(8.5”x 11")sheet. N Meters P.w 0 15 30 60 90 ^ Feet 0 50 100 200 300 Map projection:Web Mercator Corner coordinates:WGS84 Edge tics:UTM Zone 17N WGS84 1 1 8 i a) w a c 0) 0 a v c co = C 02 0 3 O O c .�• • N�• m o as m - > co O. U $ 0) a) r N CO@ UU nCOU 0 .0 N o NcrnEm i) 0u) aa) 8E 2 cO E H 7 (u 8 cL a Z mo a co co w O U � a) n N N U f0 T N _a O co 15 0 CO CO °° Z TM c N co E 2 w — w I— a) y Eco E tu) uo) Zu)) -ooNZ -- 92 Z �N w 0 < E o a co c ° H O -- (a(p�20 ) U—u� w CO 070 > � o ii t No � Q @ U f6 a.Lam. @ L N N Q .O C °_N N (n C N N C O 0 0 Q t• Eoc ao f0i 33 � t0 � � om r Cj0 CO o caaou' y V. a) a) LV) O C N a) aTj c '0 N 3 a) O a O E >+ m U) a =m r ° Cl) a� Z a .� a) Cl) E o c co n a) CO En Z a O O O 0 0 N Ce 7 0 0 'O CO a a) CO O m N N o a) T `. E c >'-0 o aci CO — Cl) ° o a •••• o E ° N (13 E Om O T .fl y U Cl) u) 7 "O 0 .o 0 O a) _a a) -o 3 �.w E Q 0 as E co m` m -i coaN) Qoc � CO Q � a) N = aeric ._ N m E �• E � Y Ta) � s @ '^ a)• (1) isid m o` ova r T o -a C .N. 0_ 02 ) O N '- co a) N N m ._ O -p T7 a) .5 c F- o c CO Z « L �° ° N `° < O y o p CO aci CO v > N (n 3 3 C Tai C .com L C N N o) Eoa � � � o — m o0 `00 .o a .° ZQ a CO toP � N C m E .,, a) 7 cc -E `� U O aa)2 EI7 T m cn v �_ �' a O E co 7 N cn en f0 m > 4 O a.�YO a) V N > O O a) O a 0) O 0 CO c .N m a) m a) CO 2 0 — a) 0 7 a) E <a E I- W E a u°) d E v) 0 a--oo < 6 I- s U) CO N 0` O N II-- 0 .- o t 0 Q a) — d' a) 0 I 7 O (i) AIN CD 0) CKO N N N 7 m j. C CO - U) a U. U rn T. = m O T C "c 2 N U 0 O U N O. CO p J N y a) m0 m0 L Q N cn n m E �° o' a o c Z m d co _N m o_ $ a) a) t a y C `m u m ° Q u) U) > 5 0 co i co O cc E D 2 J Q a) t' m mi N O O Z IW ti`-,.'z Cl LL o. w : y 'a1 ( `" @■ .115 C7 3 m w J a N Q o _ 0 0 N N J C d Q Q O C O CO U) C d J d N _N ate) N CO «. d a. 3 ] O CO a 2 O. CO o ^ C 7 a) ... (n N a) Y O O LLl a n a a o ❑ 3 C7 c O. n in o Q o m m m m o v m d = LL a c p N °) N g 2 g o o` m — — LL O� T N > > U m a) a) U N Y C N t a) ° 'p 'p 'p O 0 m O m N N m C_ _N N O m m N C "O p < co co (/) .317D m U 0 U` 0 J J 2 2 2 n. 0 U) U) U) U) U) U) d a c m p Q h a rr Custom Soil Resource Report Map Unit Legend Albemarle County,Virginia(VA003) Map Unit Symbol Map Unit Name Acres in AOI Percent of AO1 72C3 Rabun clay,7 to 15 percent 3.7 58.9% slopes,severely eroded +r 72D3 Rabun clay, 15 to 25 percent 2.5 39.5% slopes,severely eroded 79B Starr silt loam,2 to 7 percent 0.1 1.6% slopes 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 ea 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 lin 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 .im 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 rr 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 rw 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. rr kis r. 11 r. Custom Soil Resource Report ON 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, descriptions, and transects of the mapunit. Description of Rabun 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 -Oto 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): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches 41111 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): 4e Hydrologic Soil Group: B 72D3—Rabun clay, 15 to 25 percent slopes, severely eroded su Map Unit Setting National map unit symbol: kbdw 12 as 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 MO 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: Interfluves Landform position (two-dimensional): Backslope ism 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 am 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 dwa 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 SIM rr ern rir IMO ON 14 rr am ea References American Association of State Highway and Transportation Officials(AASHTO).2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials(ASTM). 2005. Standard classification of soils for engineering purposes.ASTM Standard D2487-00. +. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. +■ Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. ,, Hurt,G.W.,and L.M.Vasilas,editors.Version 6.0,2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/soils/?cid=nres 142p2_054262 Soil Survey Staff. 1999. Soil taxonomy:A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nres.usda.gov/wps/portal/ .� nres/detail/national/soils/?cid=nres142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nrcs.usda.gov/wps/ portal/nres/detail/national/soils/?cid=nres142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nres142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. ,. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/land use/rangepasture/?cid=stelprd b 1043084 15 r Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/ n res/detail/soils/scientists/?cid=nres142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. so http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/? cid=nres142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land MN capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf NMI- ■ 16 N E NOAA Atlas 14,Volume 2,Version 3 Location name:Charlottesville0 ,Virginia,US* T mir/F Latitude:38.0185°,Longitude:-78.4179° ./ ,r Elevation:493 ft* *source:Google Maps 'ti, ,. ,, / POINT PRECIPITATION FREQUENCY ESTIMATES NM G.M Bonnin,D.Martin,B.Lin,T.Parzybok,MYekta,and D.Riley NOAA,National Weather Service,Silver Spring,Maryland PF tabular I PF_graphical I Maps_& aerials illl PF tabular PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches)1 AO Average recurrence interval(years) Duration 1 2 5 10 25 50 100 200 500 1000 5-min 0.352 0.418 0.489 0.551 0.620 0.674 0.725 0.772 0.827 0.874 rte (0.317-0.391),(0.377-0.464)i(0.440-0.541)L(0.495-0.610);(0.555-0.684)(0.601-0.743) (0.642-0.798),(0.679-0.851);(0.721-0.914)(0.755-0.968), 10-min 0.562 0.668 0.783 0.881 0.988 1.07 1.15 1.22 1.31 1.38 (0.506-0.624)(0.602-0.741) (0.705-0.867) (0.791-0.975) (0.884-1.09); (0.957-1.18) (1.02-1.27) (1.08-1.35) (1.14-1.45) (1.19-1.52) 0.702 0.840 ' 0.990 1.11 1.25 1.36 1.46 1.54 1.65 1.73 am 15-min (0.632-0.780) (0.757-0.932); (0.892-1.10) (1.00-1.23) (1.12-1.38) (1.21-1.50) (1.29-1.60) (1.36-1.70) (1.44-1.82) (1.49-1.91) 30-min 0.962 1.16 ' 1.41 1.61 1.85 2.05 2.23 2.40 2.62 2.80 (0.867-1.07) (1.05-1.29) (1.27-1.56) (1.45-1.79) (1.66-2.05) (1.82-2.26) (1.98-2.46) (2.12-2.65) (2.28-2.90) (2.42-3.10) or 60-min 1.20 1.46 1.80 2.10 2.47 2.77 3.07 3.37 3.76 4.08 (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) (3.28-4.16) (3.53-4.52) 2-hr 1.44 1.75 2.18 2.57 3.06 3.47 3.89 4.33 4.93 5.43 (1.27-1.65) (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) M 1.58 1.91 2.38 2.80 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) (3.27-4.31) (3.65-4.83) (4.03-5.38) (4.54-6.14) (4.96-6.79) 6-hr 2.00 2.41 2.99 3.53 4.24 4.87 5.52 6.22 7.21 8.09 r (1.77-2.28) (2.13-2.74) ! (2.63-3.40) (3.10-4.00) (3.70-4.80) (4.21-5.49) (4.73-6.23) (5.28-7.02) (6.03-8.15) (6.67-9.14) 12-hr 2.51 3.02 3.76 4.46 5.42 6.29 7.22 8.24 9.73 11.1 (2.22-2.88) (2.67-3.46) (3.31-4.30) (3.91-5.09) (4.71-6.17) (5.41-7.14) (6.14-8.18) (6.91-9.32) (8.01-11.0) (8.98-12.6) 24-hr 2.99 3.62 4.63 5.47 6.73 7.81 9.00 10.3 12.3 14.0 au (2.68-3.36) (3.254.07) (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) 2-day 3.52 4.27 5.43 6.39 7.78 8.95 10.2 11.6 13.6 15.3 (3.17-3.94) (3.84-4.78) (4.88-6.07) (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) 4.55 5.78 6.79 8.26 9.50 10.8 12.3 14.4 16.2 ,,, 3-day 3.75 (3.40-4.16) (4.12-5.04) (5.23-6.41) (6.13-7.52) (7.42-9.13) (8.47-10.5) (9.59-12.0) (10.8-13.6) (12.5-16.0) (13.9-18.0) 4-day 3.98 4.82 6.12 7.19 8.74 10.0 11.4 13.0 15.2 17.1 (3.644.39) (4.41-5.31) (5.59-6.74) (6.55-7.90) (7.93-9.60) (9.06-11.0) (10.2-12.6) (11.5-14.3) (13.3-16.7) (14.8-18.9) 7-day 4.62 5.57 6.96 8.11 9.76 11.1 12.6 14.2 16.5 18.4 (4.25-5.05) (5.11-6.08) (6.38-7.61) (7.41-8.86) (8.87-10.6) (10.1-12.1) (11.3-13.8) (12.6-15.5) (14.5-18.0) (16.0-20.2) 10-day 5.24 6.29 7.77 8.97 10.7 12.1 13.5 15.1 17.3 19.1 (4.84-5.68) (5.81-6.82) (7.16-8.42) (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) MI 20-day 6.89 8.22 9.94 11.3 13.1 14.6 16.0 17.5 19.6 21.2 (6.45-7.39) (7.70-8.81) 1 (9.29-10.7) (10.5-12.1) (12.2-14.0) (13.5-15.6) (14.8-17.2) (16.1-18.8) (17.8-21.1) (19.2-22.8) 30-day 8.46 10.0 ' 11.9 13.3 15.1 16.5 17.8 19.1 20.9 22.2 (7.95-9.01) (9.43-10.7) (11.2-12.6) (12.4-14.1) (14.1-16.0) (15.4-17.5) (16.6-19.0) (17.8-20.4) (19.3-22.3) (20.4-23.8) or 45-day 10.6 12.5 14.6 16.2 18.2 19.7 21.2 22.5 24.4 25.7 1 (9.97-11.2) (11.8-13.2) 1 (13.8-15.5) (15.2-17.1) (17.1-19.3) (18.5-20.9) (19.8-22.4) (21.0-23.9) (22.6-25.9) (23.8-27.4) 60-day 12.4 14.6 16.9 18.6 20.7 22.3 23.8 25.2 27.1 28.4 MNI (11.7-13.1) I (13.8-15.4) I (15.9-17.8) (17.5-19.6) (19.5-21.8) I (21.0-23.5) I (22.4-25.1) (23.7-26.7) I (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 MI 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 r. PF graphical OM PDS-based depth-duration-frequency (DDF) curves Latitude: 38.0185°, Longitude: -78.4179° No 30 r r r , r r Average recurrence .. 25 interval (years) c r 20 --- — t Q. we d 2 ; � 5 0 15 - • ,f — 10 • •ro ./ — 25 Y • • a. •10 x .... _ — 50 a, — 100 a • ' • 3-' — 200 5 - /F • - . — -.f-^-�`` --' - — 500 -- --'----' — 1000 • C c c c C .a i I a, >,>, >, ›. >, >, >,>, E E E E N tb r�. rav v v v v v v v,? V7 0 N f�4 N 0 O O un co '-4 '-4 r7 N M V,D Duration 30 , , r r r 25 / C 20 Duration a a, 5 mm — 2-day 0 15 — 10-mon — 3-fay ' 15 mtn — 4-day • ' -_-- 30-min — 7-day • '070 10 - — 60-min — 10-day a — 2-hr — 20-day -- --- _ — 3-hr — 30-day _'_ — 6-hr — 45-day _-- • �.__---_. —• — 12-hr — 60-day 0 t 1 1 t t t t 24-hr 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 Top Maps & aerials Small scale terrain Morgantovm 0r:j tiN Wayne Id l7 -, F�� E arronai!west � thens Ranger Station. O Baltimore Washington 1 ` I. DEtAWel Monongahela �/ E I National f crest r _ J r NArrisonbury *{ 10VIRGINIA .1', r, " ;+ a oder J' rhe,George , i,. 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