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HomeMy WebLinkAboutWPO201600066 Calculations WPO VSMP 2016-12-12 ... al PROJECT MANAGEMENT Himp k CIVIL ENGINEERING II LAND PLANNING ENGINEERINGa December 12, 2016 ••• Bobby Jocz Albemarle County Community Development 401 Miclntire Road, North Wing r,,, Charlottesville, VA22902 Regarding: WPO 2016-00066 West Leigh VSMP Plan Dear Mr. Jocz, Enclosed is the stormwater management packet for the West Leigh VSMP Plan. The SWM water quality treatment was determined by the parcel land cover entered into the VRRM Development spreadsheet. Due +�. to the preservation of 0.90 acres of forested area on the site,water quality of the site runoff is not required to be improved. Site runoff will sheetflow to open space as per 9VAC25-870-66-3D. The onsite ditches will be grassed and protected with EC-2 Matting to prevent erosion within the channels. Each channel will manage under 2 cfs of runoff from the TR-55 design 10 year storm. This handbook contains the post-development land cover analysis, standard VDOT channel calculations for the ditches and culverts on site, and the necessary supporting calculations.Additionally, the velocities of runoff passing over level spreader 3, which outlets to steeper slopes and was deemed of critical consideration by the county,have been included. r.. If you have any questions please do not hesitate to contact me at: keane a shimp-engineering.com or by phone at 434-227-5140 ext. 3. Contents: Stormwater Quality Calculations: VRRM Development Spreadsheet VRRM Land Cover Map IR Post-Development Stormwater Management Calculations: Ditch Drainage Map •• VDOT LD-268 Ditch Sizing Chart Culvert Sizing Chart Level Spreader 3 Velocity Calculation Independent Reports: Excerpt from NRCS Soils Report .. NOAA Precipitation Report IMO NM Stormwater Quality Calculations: VRRM Development Spreadsheet VRRM Land Cover Map i MIN MN ION INE rr ON DEQ Virginia Runoff Reduction Method New Development Compliance Spreadsheet-Version 3.0 L 2011 BMP Standards and Specifications L 2013 Draft BMP Standards and Specifications Project Name: West Leigh Stream Crossingr ,v tt data input cells , «Date: 12/12/2016 constant values BMP Design Specifications List: 2013 Draft Stds&Specs calculation cells Site Information Post-Development Project(Treatment Volume and Loads) Land Cover (acres) A Soils B Soils C Soils D Soils J Totals Forest/Open Space(acres)--undisturbed, a ;protected forest/open space or reforested land 0.00 0.90 0.00 0.00 0.90 Managed Turf(acres)--disturbed,graded for yards or other turf to be mowed/managed 0.00 0.58 0.00 0.00 0.58 Impervious Cover(acres) 0.00 0.16 0.00 0.00 0.16 '." "Forest/Open Space areas must be protected in accordance with the Virginia Runoff Reduction Method 1 1.64 Constants Runoff Coefficients(Rv) Annual Rainfall(inches) 43 A Soils B Soils C Soils D Soils a '.Target Rainfall Event(inches) 1.00 Forest/Open Space 0.02 0.03 0.04 0.05 !Total Phosphorus(TP)EMC(mg/L) 0.26 Managed Turf 0.15 0.20 0.22 0.25 Total Nitrogen(TN)EMC(mg/L) 1.86 Impervious Cover 0.95 0.95 0.95 0.95 :Target TP Load(Ib/acre/yr) 0.41 ;Pi(unitless correction factor) 0.90 a Post-Development Requirement for Site Area TP Load Reduction Required(Ib/yr) 0.00 ** TP LOAD REDUCTION NOT REQUIRED a LAND COVER SUMMARY--POST DEVELOPMENT a Land Cover Summary Treatment Volume and Nutrient Loads Treatment Volume Forest/Open Space Cover(acres) 0.90 (acre-ft) 0.0246 a Weighted Rv(forest) 0.03 Treatment Volume(cubic feet) 1,071 %Forest 55% TP Load(lb/yr) 0.67 Managed Turf Cover(acres) 0.58 TN Load(Ib/yr) 4.81 (Informational Purposes Only) a Weighted Rv(turf) 0.20 %Managed Turf 35% Impervious Cover(acres) 0.16 a Rv(impervious) 0.95 L %Impervious 10% Site Area(acres) 1.64 Site Rv 0.18 I I I I I \ \ \ \ , x \ \ \ \. `` \ \ \ \ \ \ \\\\ /-___________________ \\ �\ \\ \ \\ \ \ \ \ \ \\ \ \ \ 1\ \\ \ \ \--77, \ \ \ \ \ \ \ \ V \ \ \ \ \ \ 1 \ \ \ \ \ \ _ \ \ \ 'N *. 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OM A • Link Drainage Diagram for West Leigh Ditches Prepared by Shimp Engineering, P.C., Printed 12/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC rr rr West Leigh Ditches Type 1124-hr 1-Year Rainfall=3.02" Prepared by Shimp Engineering, P.C. Printed 12/12/2016 .. HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 6S: DITCH 1 Runoff = 0.12 cfs @ 11.98 hrs, Volume= 0.006 af, Depth> 0.59" 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=3.02" Area (ac) CN Description 0.100 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B * 0.020 98 Imp 0.120 67 Weighted Average 0.100 83.33% Pervious Area 0.020 16.67% Impervious Area r Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: DITCH 2 Runoff = 0.18 cfs @ 11.98 hrs, Volume= 0.009 af, Depth> 0.59" 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=3.02" Area (ac) CN Description .. 0.140 61 >75% Grass cover, Good, HSG B 0.010 55 Woods, Good, HSG B * 0.030 98 Imp .. 0.180 67 Weighted Average 0.150 83.33% Pervious Area 0.030 16.67% Impervious Area " Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) w 5.0 Direct Entry, Summary for Subcatchment 8S: DITCH 3 Runoff = 0.15 cfs @ 12.00 hrs, Volume= 0.011 af, Depth> 0.28" 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=3.02" West Leigh Ditches Type 1124-hr 1-Year Rainfall=3.02" Prepared by Shimp Engineering, P.C. Printed 12/12/2016 +. HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 3 Area (ac) CN Description ,,, 0.110 61 >75% Grass cover, Good, HSG B 0.360 55 Woods, Good, HSG B * 0.020 98 Imp 0.490 58 Weighted Average 0.470 95.92% Pervious Area 0.020 4.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, km Summary for Subcatchment 9S: DITCH 4 +� Runoff = 0.10 cfs @ 11.98 hrs, Volume= 0.006 af, Depth> 0.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs r Type II 24-hr 1-Year Rainfall=3.02" Area (ac) CN Description 0.070 61 >75% Grass cover, Good, HSG B 0.040 55 Woods, Good, HSG B * 0.020 98 Imp 0.130 65 Weighted Average 0.110 84.62% Pervious Area 0.020 15.38% Impervious Area ., Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, NM West Leigh Ditches Type 1124-hr 10-Year Rainfall=5.52" Prepared by Shimp Engineering, P.C. Printed 12/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 6S: DITCH 1 Runoff = 0.47 cfs @ 11.96 hrs, Volume= 0.022 af, Depth> 2.17" 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=5.52" Area (ac) CN Description 0.100 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B * 0.020 98 Imp ma 0.120 67 Weighted Average 0.100 83.33% Pervious Area 0.020 16.67% Impervious Area ess Tc Length Slope Velocity Capacity .Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: DITCH 2 Of Runoff = 0.70 cfs @ 11.96 hrs, Volume= 0.033 af, Depth> 2.17" 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=5.52" Area (ac) CN Description �. 0.140 61 >75% Grass cover, Good, HSG B 0.010 55 Woods, Good, HSG B * 0.030 98 Imp .. 0.180 67 Weighted Average 0.150 83.33% Pervious Area 0.030 16.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 8S: DITCH 3 "' Runoff = 1.25 cfs @ 11.97 hrs, Volume= 0.060 af, Depth> 1.46" 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=5.52" West Leigh Ditches Type 1124-hr 10-Year Rainfall=5.52" Prepared by Shimp Engineering, P.C. Printed 12/12/2016 .. HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 5 Area (ac) CN Description ., 0.110 61 >75% Grass cover, Good, HSG B 0.360 55 Woods, Good, HSG B * 0.020 98 Imp 0.490 58 Weighted Average 0.470 95.92% Pervious Area 0.020 4.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 9S: DITCH 4 Runoff = 0.47 cfs @ 11.96 hrs, Volume= 0.022 af, Depth> 2.01" 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=5.52" Area (ac) CN Description 0.070 61 >75% Grass cover, Good, HSG B 0.040 55 Woods, Good, HSG B * 0.020 98 Imp 0.130 65 Weighted Average 0.110 84.62% Pervious Area 0.020 15.38% Impervious Area ,. Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, I H 0_ ul W T D 0 +) I I c 0 III N H N r-1 111 d- > > 0_ N Cr) Cr) N U W O o 0 0 a) Ln O O II . Ql N r-1 N J W lLC) 00 N c-i • N > r-1 c-i N N U W O N cr l0 N 0 0 O O O O O d O E i O - cel * Ili. O J w C W C > cn 0 § 1it 0 9 (I) 0 O cci X W LL 00 CO d- d- 0 — < 0 Y0 — < 0 O O r1 7 J W O O O O Q) 73 w '- = z IZ L.L N N d' 7t' O o o O O J LL O O O O -C -0 U) 0) N 1 CO CC C U) 11111 m cc) 0 TI 0 N co —TL N J co 0 m m � T• I III :E w o P o n o u-, N Q Gt I� N d' _O o C3 o O O O 1) as O E Ll Ln Lnt1•) � > O O O O Ca N N N al o N C — cnn 0 c 73 E o 1 0 o o c' if.; ui ul ui E U O H Zr) Q O N 00 c:)-, m c RS ,--1 ,_i r-1 p O < OO d O 76 LI _0 co I 0 U F- N Cr) d• U Q _O N > 1 _, t 1 1 ?;, i- lot; . 1 1 „ la, ,, 1 s ,!. ' j . i i ft :eV; ;4 w 2 I f;1gILi D s� ' r ~ �I i IIIIIIIIIIIiloInuIiuiuiiinhiouiuI T 1 - Millif !� � � � ' : 1-11 . t- ' —1_ I!!II!iIIIIIIIIIIIllflhIIflIOIIIIII 1 . „ r, .7, -toi ' .1 ! nanhalid......munismormon . • - i - .:7; rlIENEEMMIIIIIINIMr iNIMEMBEIMMEMEMNI Ti_ ' '1 vi;, ,, , lEUNIMMUMEMMUMMUMMII coommmEmmonor - - • S . sl �YIYII -4Q3 .:+:4 • (4:: ri 3 . ' ‘vi 4- '-y- 1 a 1IfIIIHhIflhIIIIIIifluiiiuipj' ( 8S DIT3 1 R SPREADER 3 I ' Reach 'on• 1111 Drainage Diagram for West Leigh Ditches Prepared by Shimp Engineering, P.C., Printed 12/12/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC I West Leigh Ditches Type 1124-hr 1-Year Rainfall=3.02" Prepared by Shimp Engineering, P.C. Printed 12/12/2016 r. HydroCAD®9.10 s/n 07054 © HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 8S: DITCH 3 Runoff = 0.15 cfs @ 12.00 hrs, Volume= 0.011 af, Depth> 0.28" 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=3.02" Area (ac) CN Description 0.110 61 >75% Grass cover, Good, HSG B 0.360 55 Woods, Good, HSG B * 0.020 98 Imp 0.490 58 Weighted Average 0.470 95.92% Pervious Area 0.020 4.08% Impervious Area r. Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Reach 11R: SPREADER 3 Inflow Area= 0.490 ac, 4.08% Impervious, Inflow Depth > 0.28" for 1-Year event Inflow = 0.15 cfs @ 12.00 hrs, Volume= 0.011 af Outflow = 0.15 cfs @ 12.01 hrs, Volume= 0.011 af, Atten= 2%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 0.33 fps, Min. Travel Time= 0.2 min Avg. Velocity = 0.11 fps, Avg. Travel Time= 0.7 min Peak Storage= 2 cf @ 12.00 hrs Average Depth at Peak Storage= 0.03' Bank-Full Depth= 0.20', Capacity at Bank-Full= 3.12 cfs 14.00' x 0.20' deep channel, n= 0.020 Length= 5.0' Slope= 0.0020'/' Inlet Invert= 0.01', Outlet Invert= 0.00' West Leigh Ditches Type 1124-hr 10-Year Rainfall=5.52" Prepared by Shimp Engineering, P.C. Printed 12/12/2016 .. HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 8S: DITCH 3 Runoff = 1.25 cfs @ 11.97 hrs, Volume= 0.060 af, Depth> 1.46" 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=5.52" Area (ac) CN Description 0.110 61 >75% Grass cover, Good, HSG B 0.360 55 Woods, Good, HSG B 0.020 98 Imp 0.490 58 Weighted Average 0.470 95.92% Pervious Area 0.020 4.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Reach 11R: SPREADER 3 Inflow Area= 0.490 ac, 4.08% Impervious, Inflow Depth > 1.46" for 10-Year event Inflow = 1.25 cfs @ 11.97 hrs, Volume= 0.060 af Outflow = 1.23 cfs @ 11.97 hrs, Volume= 0.060 af, Atten= 1%, Lag= 0.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 0.77 fps, Min. Travel Time= 0.1 min .. Avg. Velocity = 0.19 fps, Avg. Travel Time= 0.4 min Peak Storage=8 cf @ 11.97 hrs Average Depth at Peak Storage= 0.11' Bank-Full Depth= 0.20', Capacity at Bank-Full= 3.12 cfs 14.00' x 0.20' deep channel, n= 0.020 Length= 5.0' Slope= 0.0020 '/' Inlet Invert= 0.01', Outlet Invert= 0.00' West Leigh Ditches Type 1124-hr 50-Year Rainfall=7.81" Prepared by Shimp Engineering, P.C. Printed 12/12/2016 +.. HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 8S: DITCH 3 Runoff = 2.62 cfs @ 11.96 hrs, Volume= 0.121 af, Depth> 2.97" 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 (ac) CN Description 0.110 61 >75% Grass cover, Good, HSG B 0.360 55 Woods, Good, HSG B 0.020 98 Imp 0.490 58 Weighted Average 0.470 95.92% Pervious Area 0.020 4.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Reach 11R: SPREADER 3 Inflow Area= 0.490 ac, 4.08% Impervious, Inflow Depth > 2.97" for 50-Year event Inflow = 2.62 cfs @ 11.96 hrs, Volume= 0.121 af Outflow = 2.60 cfs @ 11.96 hrs, Volume= 0.121 af, Atten= 1%, Lag= 0.1 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Max. Velocity= 1.04 fps, Min. Travel Time= 0.1 min .., Avg. Velocity= 0.24 fps, Avg. Travel Time= 0.3 min Peak Storage= 13 cf @ 11.96 hrs Average Depth at Peak Storage= 0.18' Bank-Full Depth= 0.20', Capacity at Bank-Full= 3.12 cfs 14.00' x 0.20' deep channel, n= 0.020 Length= 5.0' Slope= 0.0020 '/' Inlet Invert= 0.01', Outlet Invert= 0.00' am r.. Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report aft WI NE +r USDA United States A product of the National Custom Soil Resource AWE. Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for \ RCS States Department of Agriculture and other Albemarle Federal agencies, State Natural agencies including the Resources Agricultural Experiment County, \Ii rg i n i a Conservation Stations, and local Service participants k i 1 1 1 f 1 Ii II 1 1 1 1 1 September 26, 2016 z z i N i, v a M 08L9TZb OSL9TZb OZL9TZ4 0699TZb 0999TZb 0£9971, 00991Zb ,... M„Zb,b£08L M„Zb,b£08L 8 ' r,,,. 8 .Ni N M n m M a �e�gh o v.! N r 8 ; N R. 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(n i5 N N ') I — — — O )) a) L C O > N N Q@ �i 3 0 N > > a m m a) v d Y c a `w L N ° 0 0 o c 0 o m o m m c > @ c u U c > a 0 u) u) u) •o m m 5) 0 () O J J 2 2 2- a CC U) u) v) Cl) in U) a) a c o N Q 0 Custom Soil Resource Report err Map Unit Legend NE Albemarle County,V1 1n1ia(VA003) Map Unit Symbol Map Unit Name Acres 1n AOi Percent of A01 ", IN 4C Ashe loam,7 to 15 percent 2.3 32.6% slopes 19B Cullen loam,2 to 7 percent 0.6 7.7% NO slopes 20C3 Cullen clay loam,7 to 15 percent 2.9 40.6% slopes,severely eroded rr 36B Hayesville loam,2 to 7 percent 1.1 14.6% slopes 37C3 Hayesville clay loam,7 to 15 0.3 4.4% percent slopes,severely so eroded Totals for Area of Interest 7.2 100.0% 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 .is 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 as 8 Custom Soil Resource Report 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 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 ais 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 r 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. 9 Custom Soil Resource Report Albemarle County, Virginia 4C—Ashe loam, 7 to 15 percent slopes Map Unit Setting National map unit symbol: kbc0 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 Ashe and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ashe Setting Landform: Mountain slopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Residuum weathered from granite and gneiss mi` Typical profile H1 -0 to 10 inches: loam H2- 10 to 19 inches: loam H3- 19 to 24 inches: sandy loam H4-24 to 79 inches: bedrock Properties and qualities Slope: 7 to 15 percent Depth to restrictive feature: 20 to 40 inches to lithic bedrock Natural drainage class: Somewhat excessively drained Runoff class: Low Capacity of the most limiting layer to transmit water(Ksat): Very low to high (0.00 to 5.95 in/hr) Depth to water table: More than 80 inches r. Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low(about 3.2 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4e dim Hydrologic Soil Group: B Hydric soil rating: No IWO 10 „• Custom Soil Resource Report 19B—Cullen loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: kb8b 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 Cullen and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Cullen Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down-slope shape: Convex ” Across-slope shape: Convex Parent material: Residuum weathered from acid and basic igneous rock Typical profile """ H1 - 0 to 8 inches: loam H2- 8 to 60 inches: clay H3- 60 to 67 inches: clay H4- 67 to 79 inches: bedrock Properties and qualities Slope: 2 to 7 percent rr Depth to restrictive feature: 60 to 120 inches to paralithic bedrock Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately high (0.00 to 0.20 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 7.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B w Hydric soil rating: No 11 — Custom Soil Resource Report r. 20C3—Cullen clay loam, 7 to 15 percent slopes, severely eroded Map Unit Setting National map unit symbol: kb8h 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 Cullen and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. If Description of Cullen Setting amLandform: Hilislopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Residuum weathered from acid and basic igneous rock Typical profile H1 - 0 to 8 inches: clay loam H2- 8 to 60 inches: clay H3- 60 to 67 inches: clay .. H4- 67 to 79 inches: bedrock Properties and qualities Slope: 7 to 15 percent as Depth to restrictive feature: 60 to 120 inches to paralithic bedrock Natural drainage class: Well drained Runoff class: Medium 40 Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately high (0.00 to 0.20 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None r Frequency of ponding: None Available water storage in profile: Moderate (about 7.4 inches) ,• Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Hydric soil rating: No 12 MN Custom Soil Resource Report NIS 36B—Hayesville loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: kb9q Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F r. Frost-free period: 195 to 231 days Farmland classification: All areas are prime farmland Map Unit Composition Hayesville and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hayesville Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Residuum weathered from granite and gneiss Typical profile H1 - 0 to 7 inches: loam H2- 7 to 58 inches: clay H3-58 to 67 inches: sandy clay loam .. H4- 67 to 83 inches: fine sandy 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 N,, 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: High (about 10.6 inches) Interpretive groups Ano Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B .r Hydric soil rating: No MS 13 „. Custom Soil Resource Report rr 37C3—Hayesville clay loam, 7 to 15 percent slopes, severely eroded ,,, Map Unit Setting National map unit symbol: kb9w 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 Hayesville and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. tem Description of Hayesville Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down-slope shape: Convex Across-slope shape: Convex Parent material: Residuum weathered from granite and gneiss Typical profile •” H1 - 0 to 7 inches: clay loam H2- 7 to 58 inches: clay H3-58 to 67 inches: sandy clay loam +�+ H4- 67 to 83 inches: fine sandy 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 r 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 r Frequency of ponding: None Available water storage in profile: High (about 10.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Hydric soil rating: No 1111 14 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 .e 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.nres.usda.gov/wps/portal/nres/ deta i l/n ati o n a l/soils/?cid=n res 142 p2_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/ arcs/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/soi ls/?cid=n res142p2_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.nres.usda.gov/wps/portal/nres/detail/soils/ ,,,,. home/?cid=nres142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nres.usda.gov/wps/portal/arcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 15 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. 1.1 National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=n res 142p2_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. http://www.n res.usda.gov/wps/portal/nres/detail/national/soils/? — cid=nres142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf ,r. r wr rr 16 r. NOAA Atlas 14,Volume 2,Version 3 Location name:Charlottesville,Virginia,USA* Latitude:38.0738°,Longitude:-78.5801° :"' vy Elevation:mitt** NE 'source:ESRI Maps y. '*source:USGS POINT PRECIPITATION FREQUENCY ESTIMATES 1.r G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley NOAA,National Weather Service,Silver Spring,Maryland PF tabular I PF graphical I Maps & aerials an PF tabular LPDS-based point precipitation frequency estimates with 90%confidence intervals(in inches)1 .. Duration_- -- Average recurrence interval(years) 1 iL 2 5 1 10 I 25 50 100 ( 200 500 1000 15-min 0347 1 0.415 0.488 0.548 0.618 0.673 I 0.723 0.772 I 0.831 0.878 .r (0.313-0385) (0375-0.460) (0.440-0.540)1(0493-0.606) (0.553-0.682)1(0.599-0.741) (0.641-0.797);(0.678-0351) (0.721-0.919) (0.755-0376), 10-min 0.555 I 0.663 0.782 ' 0.877 0.986 , 1 07 1.15 1.22 1.31 1.38 (0.500-0.615)„(0.599-0.735) (0.704-0.865) (0.789-0.970)' (0.882-1.09)i L0.954 1.18) (1.02:127) , (1.07:1.35)_ J1.14-1.45) (1.19 1.54) r 15-min I 0.693 ' 0.834 0.989 1.11 1.25 1.36 1.45 1.54 1 1.65 1.74 (0.625-0.769) (0.753-0.924) (0.891-1.09), (0.998-1.23) (1.12-1.38) 1 (1.21-1.50) ; (1.29-1.60) . (1:36-1.70) I (1.44-1.83) (1.49-1.93) 30-min ; 0.950 1 1.15 I 1.41 I 1.61 1.85 2.04 2.23 2.40 1 2.63 2.81 (0.857-1.05) (1.04-1.28) (1.27-1.55) I (1.45-1.78) (1.66-2.04) I (1.82-2.25) I (1.97-2.45) 1 (2.11-2.65) ; (2.29-2.91) (2.42-3.12) ; MEI I 1.19 145 1.80 2.09 2.46 2.77 3.06 3.37 3.77 410 160-min 1 (1.07-1.31) 1 (1.30-1.60) „(1.62-1.99) (1.88-2.31) (2.21-2.72) 1 (2.46-3.05) i (2.71-3.38)J (2,96-3.72) j (3.284.18) (3.53-4.56) l 2 (1. -hr 1.42 I 1.73 2.16 2.54 3.03 ;I 3.44 3.85 ' 4.29 4.90 5.41 111 (1.25-1.62) I (1.52-1.96)_ (1.91-2.46) (2.24-238) (2.65-3.42) 11.(2.99-338) I (3.344.35) (3.68 4.84) (4.16-5.54) (4.54-6.14)_ ro 3-hr I 1.55 1.89 i 237 I 2.77 3.31 I 3.76 I 4.22 1 4.71 ! 5.38 5.96 (1.37-1.78) I (1.66-2.16) ( (2.08-2.71) I (2.433.17) (2.883.77) 1 (3.254.27) , (3.634.80) 1 (4.013.36) I (4.533.13) (4.963.80) I 6-hr 2.00 I 2.41 3.00 I 3.53 4.24 4.87 5.52 , 6.23 I 724 8.13 I (1.77-2 25) (2_14-2.73) (2.653.39) (3.103.98) (3.71-4 78) I (4.223.46) (4.743.20) I (529-7.01) 1 (6.06-8.16) (6.70-9.18 ime2 12-hr 52 3.04 3.79 4.49 5.46 6.32 7.26 ! 8.29 9.82 11.2 I . (223-2.88) (2.693.47) (3.354.33) (3.943.11) (4.75-6 20) 1 (5.45-7.17) I (6.173.23) 1 (6.96 9.39) ; (8.08-11.2) (9.05-12.8) I 24-hr 3.02 I 3.66 4.67 I 5.52 6.77 1 7.85 9.04 10.4 I 12.3 14.0 sr I[(2.72-3.37) I (3.304.08) I (4.203.21) I (4.94 6.13) (6.03-7.51)_i (6.94-838) I (7.923.98) (837-11 4) 1 (10.5-13.6) (11.8J 5.4) I2-da3.56 4.31 i 5.48 I 6.44 7.83 9.00 10.3 11.6 I 13.6 15.3 I y (3.20-3.97) , (3.894.81) ( (4.93-6.10) I (5.77-7.16) (6.97-8.69) ; (7.95-9.97) ; (9.00-11.4) (10.1-12.9) I (11.7-15.2) (13.0-17.1) 13-da I 3.79 4.59 5.83 � 6.84 8.32 9.55 1 10.9 I 12.3 I 14.4 16.2 I Mu y i (3.444.20) ; (4.173.08) (5.29345)_ (6.19-7.56) (7.48-9 18) ; (8.53-10_5) (9.65-12.0) 1 (10.8:13.6) (12.5-15.9)_ J13.9:17.9)_; 4 day 4.02 4.87 6.17 I 7.25 8.80 I 10.1 11.5 13.0 15.2 17.1 I y__ ( (3.684.43) (4453.36) (5.64-6 80) I (6.61-7.96) (7 99-9 66) i (9.12-11.1) I (10.3-12 6) i (113-14.3) 1 (13A-16.7) (14.8-18.8) j rrr 7-day ( 4.67 5'62 7.02 8.17 9.82 11.2 1 12.6 I 14.2 16.5 18.3 ___ (4.28-5.09L J5.16-6._13)_ (643-7.67) j (7.473.91) (8.34-10.7) i (10.1:12.2) I (11.4-13.8)_012.7-15.5L (14.5-18.0) J16.030.1)_ I 10-day I 5.30 I 6.36 i 7.84 I 9.05 10.7 1 12.1 I 13.6 15.1 1 17.3 I 19.0 I (4.88-5 73) i (5.87-6.88) I (7.23-8.480 (8.32-9.78) ! (9.84-11 6) , (11.0-13.1) I (12.3-14.7)_1 J13.6-16.4) ! _(15.4-18.7)_1(16.8-20.7) no 20-da 6.96 I 8.30 j 10.0 11.4 13.2 14.6 16.1 I 17.6 I 19.6 21.2 ' (6.52-7.46) 1 (7.77-8.89) i (9.37-10.7) ; (10.6-12.2) (12.3-14.2) I (13.6-15.7) I (14.9-17.3) 1 (16.2-18.9) I (17.9-21.2) (19.2 23.0) I 130-da I 8.54 1 10.1 12.0 13.4 15.2 1 16.6 j 17.9 ' 193 I 21.0 22.3 (8 043.10)i (9.54-10.8) (11.3-12.7) I (12.6-14.2) (14.2-162) , (15 5-17.7) (16.7-19 1) 1 (17_9-20.6) I (194-22 5) (20.6_23.9) I 111111145-day 1 10.7 12.6 I 14.7 I 16.3 18.3 19.8 1 213 I 22 7 I 24.5 25.8 (10.1-11.3) (11.9-13.3) (13.9-15.6) I (15.4-17.3) (17.2-19.4) , (18.6-21.0) 1.(19.9-22.6) i (21.124.1) I (22.7-26.1) (23.8-275) I 60-day 12.5 1 14.7 17.0 18.7 20.8 , 22.4 23.9 25.3 .1_ 27.1 28.4 I ar [01.9_13 2) I� (14.0-15.5) L,(16.1-17.9)_ 1.(17.7-19.7) (19 7_21.9) (21.1-23.6)„Il(22.5-25 2) I (23_8 26.7) (25.4-28.7) l (26.530.1) 1 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; so 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 imi PF graphical .. PDS-based depth-duration-frequency(DDF) curves Latitude: 38.0738°. Longitude: -78_5801° — 30 1 1 1 I I I 1 I Average recurrence 25 intenal , , - (years) wi• 2 . . ::.-.... — 1 c20 ' .........,..... .... ..; . 4_, 2 o. a ' • • — 5 V ... c 15 ... _. . ...,. _ - — 10 o — 25 .2 • a. • , — 50 Nu 0 10 - - — 100 ci. • . ' — 200 . . ' , 5 , .. .., , ' — 1000 am _ , _ — 500 _,,---- „ --. : , . 0 C c c C C L. h... I- L. [.... >, >4>,,, >„ >4 >4 , , '2 F 7-- c- e- ..c -c -c ..c -c co a; to to to to to. 113- eV 6- C C rtl 141 1.6 rtij 4 =I dl t§i 4 R 3. -4 N ,., A 4 r-!.- 6 6 6 LA .6 ri N fel nt‘119 Duration 30 i 1 I I MI . , 25 • I ....F: • ' - Dtiration • I ca. dj ' , • • — SiTtin — 2-day -0 c 15 4., • . . . -. • — 10-min 15-min — 3-day — 4-day 2 , — 30-min — 7-day • I E . , . , . . • , • — 3-hr — 20-day — 30-day _ — 6-hr — 45-day I __ — ____ _, _____' -- 0 mr, -----i---- - ,i--” i -1 i r — 24-hr 1 2 5 10 25 50 100 200 500 1000 — 12-hr — 60-day Average recurrence interval (years) INOAA Atlas 14,Volume 2,Version 3 Created(GMT): Mon Oct 17 20:44:23 2016 Back to To I Maps & aerials ISmall scale terrain I I I 1 10/ 2)?m Large scale terrain • • Washington, D.C. H • 11A Rich 4., d • • Lyric hberg sbt. • 100km 60mi Large scale map A . Washington iiit r talon g 11,1 g HnrnSonbUrg N Jt10.1 ,Cf Stal NUM•MOM lichrndj_ -T- Lynchburg Blacksburg „Roanoke 100km 11 ml Nor 60 Large scale aerial