HomeMy WebLinkAboutWPO201500001 Calculations 2015-04-02 PROJECT MAGEM
sHimpt CIVIL EANNGINEERINENTG
LAND PLANNING
ENGINEERING
April 2, 2015
Mr. Max Greene
Engineer Technician
County of Albemarle
Department of Community Development
Regarding: Northside Drive Stockpile
Stormwater Quality and Quantity Plan
Dear Mr. Greene,
Enclosed are the calculations proving compliance relating to storm water quantity and quality requirements.
Water quality standards, (9VAC25-870-96), are met by the purchase of nutrient credits. The VDEQ Runoff
Reduction Method Spreadsheet indicates that the required phosphorus removal on the site is .28 lb/yr.
In order to meet Minimum Water Quantity Standards, channel protection and flood protection needs to be
addressed (9VAC25-870-66) in accordance with the following energy balance equation for natural storm
water conveyance systems:
QUeveloped I.F. QPre-developed RVPre-Developed) RV), eloped
We found the RVpre of the site by determining the longest time of concentration of the limits of disturbance
and entering it into HydroCAD along with the pre development site conditions (wood/grass combo). The
hydrograph determined that Qpre=.24 cfs and RVpre=.037 ac-ft.
RVpost wasfound using the HydroCAD model for post-development conditions to be RVpost=.054 ac-ft.
The next goal was to find the Qpsst for the site: QDeveloped= 0.8 * (QPre_developod* RVPre-Developed)/RVDeveloped,
we determined the required Qpsst= .13 cfs. The SWM plan exceeds that requirement as shown in the table
below.
Summary Table for project outflows:
Pre-Development Post-Development
1-Yr Flow .24 cfs .08 cfs
'T
O l
U JUST'i •, • y
ic. o. 5183
() w;
ONAL
Contents:
Pre-Development Stormwater Management Calculations:
Pre-Development Drainage Map
Pre-Development Time of Concentration Calculations
Pre-Development HydroCAD Analysis
Stormwater Quality Calculations:
VDEQ RRM Spreadsheet
Post-Development Stormwater Management Calculations:
Post-Development Drainage Map
Post-Development Time of Concentration Calculations
Post-Development HydroCAD Analysis
Culvert Calculations
Independent Reports:
Excerpt from NRCS Soils Report
NOAA Precipitation Report
Pre-Development Stormwater Management Calculations
Pre-Development Drainage Map
Pre-Development Time of Concentration Calculations
Pre-Development HydroCAD Analysis
/ /' // / / !
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Pre Development:
Overland Flow Pre Development:
L = 200' Shallow F ow
Slope = 7.5% L = 155.5'
C = .25 (Woods/Grass Combo, HSG B) Slope = 7.1%
Tc = 15.1 min Woods/Grass, HSG B
Velocity = 1.35 ft/s
Tc = L/60V
Tc = 1.9min
1S
SITE DRAI AGE AREA
2 L
POINT OF ANALYSIS
Subcat) Reach '0n• Link Drainage Diagram for HALL-PRE
Prepared by Shimp Engineering P.C., Printed 4/1/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC
HALL-PRE Type 1124-hr 1 YEAR STORM Rainfall=2.97"
Prepared by Shimp Engineering P.C. Printed 4/1/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC Page 2
Summary for Subcatchment 1S: SITE DRAINAGE AREA
Runoff = 0.24 cfs @ 12.17 hrs, Volume= 0.037 af, Depth> 0.26"
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 STORM Rainfall=2.97"
Area(ac) CN Description
1.700 58 Woods/grass comb., Good, HSG B
1.700 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.1 Direct Entry, Overland
1.9 Direct Entry, Shallow
17.0 0 Total
Summary for Link 2L: POINT OF ANALYSIS
Inflow Area= 1.700 ac, 0.00% Impervious, Inflow Depth > 0.26" for 1 YEAR STORM event
Inflow = 0.24 cfs @ 12.17 hrs, Volume= 0.037 of
Primary = 0.24 cfs @ 12.17 hrs, Volume= 0.037 af, Atten= 0%, Lag=0.0 min
Primary outflow= Inflow, Time Span=0.00-24.00 hrs, dt=0.05 hrs
HALL-PRE Type 1124-hr 10 YEAR STORM Rainfall=5.42"
Prepared by Shimp Engineering P.C. Printed 4/1/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC Page 3
Summary for Subcatchment 1S: SITE DRAINAGE AREA
Runoff = 2.63 cfs @ 12.11 hrs, Volume= 0.198 af, Depth> 1.40"
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 STORM Rainfall=5.42"
Area(ac) CN Description
1.700 58 Woods/grass comb., Good, HSG B
1.700 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.1 Direct Entry, Overland
1.9 Direct Entry,Shallow
17.0 0 Total
Summary for Link 2L: POINT OF ANALYSIS
Inflow Area= 1.700 ac, 0.00% Impervious, Inflow Depth > 1.40" for 10 YEAR STORM event
Inflow = 2.63 cfs @ 12.11 hrs, Volume= 0.198 of
Primary = 2.63 cfs @ 12.11 hrs, Volume= 0.198 af, Atten=0%, Lag=0.0 min
Primary outflow= Inflow, Time Span=0.00-24.00 hrs, dt=0.05 hrs
Post-Development Stormwater Management Calculations
Post-Development Drainage Map
Post-Development Time of Concentration Calculations
Post-Development HydroCAD Analysis
Culvert Calculations
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\ \ \\ \` _( I I ; , /' , / ToC Summary
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Detention Pond Prof i e
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510.0, S1.Q.G
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SCALE: 1 " = 10'
BMMT
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Post Development: Post Development:
P Post Development:
• Overland Flow Shallow Flow Channel Flow
L = 200' L = 135.2 L = 98.1
Slope = 7.5% Slope = 2.3%
Slope = 6.8%
C = .35 (Grass, HSG B) Grass, HSG B H = 2.3
Tc = 13.2 min Velocity = 1.75 ft/s Tc = 1.3 min
Tc = L/60V
Tc = 1.3min
DS
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Post Development (Bypass): Post Development (Bypass):
Overland Flow Channel Flow
L = 116.6' L = 558.7'
Slope = 6.0% Slope = 4.6%
C = .25 (Brush, HSG B) H = 26'
Tc = 11.8min Tc = 3.2min
41,
DRAINAG AREA
/ \,
/3S
i
/2 :' BYPASS DRAINAGE
DETENTION OND
4L
1
POINT OF ANALYSIS
Cubca\ Reach 'On• Itil Drainage Diagram for HALL-POST
Prepared by Shimp Engineering P.C., Printed 4/2/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC
HALL-POST Type 1124-hr 1 YEAR STORM Rainfall=2.97"
Prepared by Shimp Engineering P.C. Printed 4/2/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC Page 2
Summary for Subcatchment 1 S: DRAINAGE AREA
Runoff = 0.5333 cfs @ 12.13 hrs, Volume= 0.054 af, Depth> 0.38"
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 STORM Rainfall=2.97"
Area(ac) CN Description
1.590 61 >75%Grass cover, Good, HSG B
0.110 98 Unconnected pavement, HSG B
1.700 63 Weighted Average, UI Adjusted CN = 62
1.590 93.53% Pervious Area
0.110 6.47% Impervious Area
0.110 100.00% Unconnected
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.2 200 0.25 Direct Entry,overland
1.3 132 1.69 Direct Entry,shallow
1.3 98 1.26 Direct Entry,channel
15.8 430 Total
Summary for Pond 2P: DETENTION POND
Inflow Area= 1.700 ac, 6.47% Impervious, Inflow Depth > 0.38" for 1 YEAR STORM event
Inflow = 0.5333 cfs @ 12.13 hrs, Volume= 0.054 af
Outflow = 0.0781 cfs @ 13.49 hrs, Volume= 0.051 af, Atten=85%, Lag=81.7 min
Primary = 0.0781 cfs @ 13.49 hrs, Volume= 0.051 af
Routing by Stor-Ind method, Time Span=0.00-24.00 hrs, dt= 0.05 hrs
Peak Elev=500.14' @ 13.49 hrs Surf.Area= 1,134 sf Storage=686 cf
Plug-Flow detention time= 119.0 min calculated for 0.051 af (94%of inflow)
Center-of-Mass det. time=89.1 min ( 1,012.2- 923.1 )
Volume Invert Avail.Storage Storage Description
#1 499.50' 6,636 cf Custom Stage Data(Prismatic) Listed below(Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
499.50 1,024 0 0
501.50 1,369 2,393 2,393
504.00 2,025 4,243 6,636
Device Routing Invert Outlet Devices
#1 Primary 499.00' 15.0" Round Culvert L=30.0' Ke=0.100
Inlet/Outlet Invert=499.00'/498.50' S=0.0167'I' Cc= 0.900
n=0.013
#2 Device 1 499.50' 2.0"Vert. 1 YEAR ORIFICE C=0.600
#3 Device 1 501.50' 24.0" Horiz. RISER C= 0.600 Limited to weir flow at low heads
Primary OutFlow Max=0.0781 cfs @ 13.49 hrs HW=500.14' (Free Discharge)
L =Culvert (Passes 0.0781 cfs of 4.9083 cfs potential flow)
2=1 YEAR ORIFICE (Orifice Controls 0.0781 cfs @ 3.58 fps)
3=RISER (Controls 0.0000 cfs)
HALL-POST Type 1124-hr 1 YEAR STORM Rainfall=2.97"
Prepared by Shimp Engineering P.C. Printed 4/2/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC Page 3
Summary for Subcatchment 3S: BYPASS DRAINAGE
Runoff = 0.6700 cfs @ 12.11 hrs, Volume= 0.062 af, Depth> 0.42"
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 STORM Rainfall=2.97"
Area(ac) CN Description
1.570 58 Woods/grass comb., Good, HSG B
0.200 98 Paved parking, HSG B
1.770 63 Weighted Average
1.570 88.70% Pervious Area
0.200 11.30% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
11.8 Direct Entry, Overland
3.2 Direct Entry, Channel
15.0 0 Total
Summary for Link 4L: POINT OF ANALYSIS
Inflow Area= 1.700 ac, 6.47% Impervious, Inflow Depth > 0.36" for 1 YEAR STORM event
Inflow = 0.0781 cfs @ 13.49 hrs, Volume= 0.051 af
Primary = 0.0781 cfs @ 13.49 hrs, Volume= 0.051 af, Atten= 0%, Lag= 0.0 min
Primary outflow= Inflow, Time Span=0.00-24.00 hrs, dt=0.05 hrs
HALL-POST Type 1124-hr 10 YEAR STORM Rainfall=5.42"
Prepared by Shimp Engineering P.C. Printed 4/2/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 1S: DRAINAGE AREA
Runoff = 3.4589 cfs @ 12.09 hrs, Volume= 0.240 af, Depth> 1.70"
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 STORM Rainfall=5.42"
Area(ac) CN Description
1.590 61 >75%Grass cover, Good, HSG B
0.110 98 Unconnected pavement, HSG B
1.700 63 Weighted Average, UI Adjusted CN =62
1.590 93.53% Pervious Area
0.110 6.47% Impervious Area
0.110 100.00% Unconnected
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.2 200 0.25 Direct Entry, overland
1.3 132 1.69 Direct Entry, shallow
1.3 98 1.26 Direct Entry, channel
15.8 430 Total
Summary for Pond 2P: DETENTION POND
Inflow Area= 1.700 ac, 6.47% Impervious, Inflow Depth> 1.70" for 10 YEAR STORM event
Inflow = 3.4589 cfs @ 12.09 hrs, Volume= 0.240 of
Outflow = 2.7190 cfs @ 12.21 hrs, Volume= 0.212 af, Atten=21%, Lag= 7.2 min
Primary = 2.7190 cfs @ 12.21 hrs, Volume= 0.212 af
Routing by Stor-Ind method, Time Span=0.00-24.00 hrs, dt=0.05 hrs
Peak Elev=501.75' @ 12.21 hrs Surf.Area= 1,435 sf Storage=2,745 cf
Plug-Flow detention time= 141.7 min calculated for 0.211 of (88%of inflow)
Center-of-Mass det. time=84.7 min (951.5 -866.8)
Volume Invert Avail.Storage Storage Description
#1 499.50' 6,636 cf Custom Stage Data(Prismatic) Listed below(Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
499.50 1,024 0 0
501.50 1,369 2,393 2,393
504.00 2,025 4,243 6,636
Device Routing Invert Outlet Devices
#1 Primary 499.00' 15.0" Round Culvert L=30.0' Ke=0.100
Inlet/Outlet Invert=499.00'/498.50' S= 0.0167'/' Cc= 0.900
n=0.013
#2 Device 1 499.50' 2.0"Vert. 1 YEAR ORIFICE C= 0.600
#3 Device 1 501.50' 24.0" Horiz. RISER C=0.600 Limited to weir flow at low heads
Primary OutFlow Max=2.5178 cfs @ 12.21 hrs HW=501.74' (Free Discharge)
t--LCulvert (Passes 2.5178 cfs of 10.3470 cfs potential flow)
2=1 YEAR ORIFICE (Orifice Controls 0.1541 cfs @ 7.07 fps)
3=RISER (Weir Controls 2.3637 cfs @ 1.59 fps)
HALL-POST Type 1124-hr 10 YEAR STORM Rainfall=5.42"
Prepared by Shimp Engineering P.C. Printed 4/2/2015
HydroCAD?9.10 s/n 07054 ?2011 HydroCAD Software Solutions LLC Page 5
Summary for Subcatchment 3S: BYPASS DRAINAGE
Runoff = 3.8932 cfs @ 12.08 hrs, Volume= 0.262 af, Depth> 1.77"
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 STORM Rainfall=5.42"
Area(ac) CN Description
1.570 58 Woods/grass comb., Good, HSG B
0.200 98 Paved parking, HSG B
1.770 63 Weighted Average
1.570 88.70% Pervious Area
0.200 11.30% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
11.8 Direct Entry, Overland
3.2 Direct Entry, Channel
15.0 0 Total
Summary for Link 4L: POINT OF ANALYSIS
Inflow Area= 1.700 ac, 6.47% Impervious, Inflow Depth > 1.50" for 10 YEAR STORM event
Inflow = 2.7190 cfs @ 12.21 hrs, Volume= 0.212 af
Primary = 2.7190 cfs @ 12.21 hrs, Volume= 0.212 af, Atten=0%, Lag= 0.0 min
Primary outflow= Inflow, Time Span= 0.00-24.00 hrs, dt=0.05 hrs
Chapter 3-Culverts
Appendix BC-I Inlet Control,Circular Conant
�,,, CHART 1O
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—. HEADWATER DEPTH FOR
.. •�,�.•• CONCRETE PIPE CULVERTS
......�..i.e..... E.rc+ww WITH INLET CONTROL
Source: HOS.5
I W} 41307 0.a4uee Menu.!
Culvert Calculation :
Q10= 2. 96 cfs
HW= . 98 ft
Hall Stonecrushing Yard
Culvert Flow Calculations
lio 4.4
C-factors
Impervious 0.9
Woods 0.3
Brush 0.25
Total A Impervious Woods Brush CA C Qio
Culvert 1 I 56886 5305 0 51581 17670 10.31 I 1.78 I
Flow 1.78 cfs Flow 9.883 cfs
Depth 0.359 ft Depth 1.25 ft
Area of Flow 0.292 sq ft Area of Flow 1.227 sq ft
Wetted Perimeter 1.414 ft Wetted Perimeter 3.927 ft
Hydraulic Radius 0.206 ft Hydraulic Radius 0.313 ft
Average Velocity 6.104 fps Average Velocity 8.053 fps
Top Width(T) 1.131 ft Top Width(T) 0 ft
Storm water Quality Calculations
VDEQ RRM Spreadsheet
Virginia Runoff Reduction Method New Development Worksheet-v2.8-June 2014
To be used w/2011 BMP Standards and Specifications
Site Data
Project Name: Northside Dr.Stockpile
Date:
Ilk data input cells
calculation cells
constant values
1.Post-Development Project&Land Cover Information
Constants
Annual Rainfall(inches)
Target Rainfall Event(inches) 1.00
Phosphorus EMC(mg/L) 0.26 Nitrogen EMC(mg/L) 1.88
Target Phosphorus Target Load(Ib/acre/yr) 0.41
P1 0.90
Land Cover (acres)
A soils B Soils C Soils D Soils Totals
Forest/Open Space(acres)-undisturbed, up
protected forest/open space or reforested land 0.00 0.00 0.00 0.00 .. 0.00
Managed Turf(acres)--disturbed,graded for
yards or other turf to be mowed/managed 0.00 1.86 0.00 0,00 1.86
Impervious Cover(acres) i 0.00 0.11 0.00 0.11
Total 1.97
Rv Coefficients
A soils B Soils C Soils D Soils
Forest/Open Space 0.02 0.03 0.04 0.05
Managed Turf 0.15 0.20 0.22 0.25
Impervious Cover 0.95 0.95 0.95 0.95
Land Cover Summary
Forest/Open Space Cover(acres) 0.00 _
Weighted Rv(forest) 0.00
%Forest 0%
Managed Turf Cover(acres) 1.86
Weighted Rv(turf) 0.20
%Managed Turf 94%
Impervious Cover(acres) 0.11
Rv(impervious) 0.95
%Impervious 6%
Total Site Area(acres) 1.97
Site Rv 0.24
Post-Development Treatment Volume(acre-ft) 0.04
Post-Development Treatment Volume(cubic
feet) 1,730
Post Development Load(TP)(Ib/yr) 1.091 Post Development Load(TN)(Ib/yr), 7.77
Total Load(TP)Reduction Required(Ib/yr) 0.28
Virginia Runoff Reduction Method Worksheet
Virginia Runoff Reduction Method New Development Worksheet-v2.8-June 2014
Site Data Summary
Total Rainfall=43 inches
Site Land Cover Summary
A Soils B Soils C Soils D Soils Total r %of Total
Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00
Turf(acres) 0.00 1.86 0.00 0.00 1.86 94.42
Impervious(acres) 0.00 0.11 0.00 0.00 0.11 5.58
1.97 100.00
Site Rv 0.24
Post Development Treatment Volume(ft3) 1730
Post Development TP Load(Ib/yr) 1.09
Post Development TN Load(Ib/yr) 7.77
Total TP Load Reduction Required(lb/yr) 0.28
Total Runoff Volume Reduction(ft3) 0
Total TP Load Reduction Achieved(lb/yr) 0
Total TN Load Reduction Achieved(Ib/yr) 0.00
Adjusted Post Development TP Load(Ib/yr) 1.09
Remaining Phosphorous Load Reduction(Lb/yr)Required 0.28
Drainage Area Summary
D.A.A D.A.B D.A.C D.A.D D.A.E Total
Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00
Turf(acres) 1.86 0.00 0.00 0.00 0.00 1.86
Impervious(acres) 0.11 0.00 0.00 0.00 0.00 0.11
1.97
Drainage Area Compliance Summary
D.A.A D.A.B D.A.C D.A.D D.A.E Total
TP Load Red.(lb/yr) 0.00 0.00 0.00_ 0.00 0.00 0.00
TN Load Red.(lb/yr) 0.00 0.00 0.00 0.00 0.00 0.00
Summary Print
Virginia Runoff Reduction Method Worksheet
Drainage Area A Summary
Land Cover Summary
A Soils B Soils C Soils D Soils Total %of Total
Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00
Turf(acres) 0.00 1.86 0.00 0.00 1.86 94.42
Impervious(acres) 0.00 0.11 0.00 0.00 0.11 5.58
1.97
BMP Selections
Practice Credit Area(acres) Downstream
Practice
Total Impervious Cover Treated(acres) 0.00
Total Turf Area Treated(acres) 0.00
Total TP Load Reduction Achieved in D.A.A(lb/yr) 0.00
Total TN Load Reduction Achieved in D.A.A(Ib/yr) 0.00
Summary Print
Virginia Runoff Reduction Method Worksheet
Channel and Flood Protection
Weighted CN 1-year 2-year storm 10-year
storm Adjusted CN storm
Adjusted Adjusted
CN CN
Target Rainfall Event(in) 2.97 0.00 5.42
D.A.A CN 63 63 100 63
D.A.B CN 0 #N/A 100 #N/A
D.A.C CN 0 #N/A 100 #N/A
D.A.D CN 0 #N/A 100 #N/A
D.A.E CN 0 #N/A 100 #N/A
Summary Print
Independent Reports
Excerpt from NRCS Soils Report
NOAA Precipitation Report
USDA United States A product of the National Custom Soil Resource
Department of Cooperative Soil Survey;
Agriculture a joint effort of the United Report for
RCS States Department of
Agriculture and other Al b e m a r l e
Federal agencies, State
Natural agencies including the
Resources Agricultural Experiment County, \fi rg i n i a
Conservation Stations, and local
Service participants
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Meters
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/V 0 150 300 600 900
///��� Map pmje�on:Well Mercator Comer coordinates:WGS84 FrlgP tl6:UTM Zone 17N WGS84
8
Custom Soil Resource Report
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) li Spoil Area The soil surveys that comprise your AOI were mapped at 1:15,800.
n Area of Interest(AOI) Q Stony Spot
Soils Very Stony Spot Warning:Soil Map may not be valid at this scale.
I I Soil Map Unit Polygons
Wet Spot Enlargement of maps beyond the scale of mapping can cause
Soil Map Unit Lines misunderstandingof the detail of mapping and accuracyof soil line
Other PP 9
Soil Map Unit Points placement.The maps do not show the small areas of contrasting
.• Special Line Features soils that could have been shown at 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
r Rails Source of Map: Natural Resources Conservation Service
tj Closed Depression ow, Interstate Highways Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
• Gravel Pit US Routes Coordinate System: Web Mercator(EPSG:3857)
Gravelly Spot Major Roads Maps from the Web Soil Survey are based on the Web Mercator
O Landfill Local Roads projection,which preserves direction and shape but distorts
distance and area.A projection that preserves area,such as the
A. Lava Flow 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
® Miscellaneous Water the version date(s)listed below.
O Perennial Water
Soil Survey Area: Albemarle County,Virginia
v Rock Outcrop Survey Area Data: Version 10,Dec 11,2013
4. 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,
• Sinkhole 2011
, Slide or Slip
The orthophoto or other base map on which the soil lines were
Sodic Spot compiled and digitized probably differs from the background
imagery displayed on these maps.As a result,some minor shifting
of map unit boundaries may be evident.
9
Custom Soil Resource Report
Map Unit Legend
Albemarle County,Virginia(VA003)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
2D Albemarle fine sandy loam,15 to 3.1 11.0%
25 percent slopes
21B Culpeper fine sandy loam,2 to 7 1.7 6.1%
percent slopes
27B Elioak loam,2 to 7 percent 0.9 3.0%
slopes
27C Elioak loam,7 to 15 percent 1.8 6.4%
slopes
34D Glenelg loam, 15 to 25 percent 2.0 7.0%
slopes
47C Louisburg sandy loam,7 to 15 2.3 8.1%
percent slopes
88 Udorthents,loamy 15.9 56.2%
W Water 0.6 2.2%
'Totals for Area of Interest 28.3 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the soils
or miscellaneous areas in the survey area. The map unit descriptions, along with the
maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas.A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils.On the landscape,
however,the soils are natural phenomena,and they have the characteristic variability
of all natural phenomena. Thus, the range of some observed properties may extend
beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic
class rarely, if ever, can be mapped without including areas of other taxonomic
classes. Consequently, every map unit is made up of the soils or miscellaneous areas
for which it is named and some minor components that belong to taxonomic classes
other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management.These are called contrasting,or dissimilar,components.They generally
are in small areas and could not be mapped separately because of the scale used.
Some small areas of strongly contrasting soils or miscellaneous areas are identified
by a special symbol on the maps. If included in the database for a given area, the
10
3/24/2015 Precipitation Frequency Data Server
NOAA Atlas 14,Volume 2,Version 3 or,
d' Location name:Charlottesville,Virginia, US*
. •h Latitude:38.1466°, Longitude:-78.4279°
11Id
\ t" Elevation:466 ft*
'+mnd *source:Google Maps
POINT PRECIPITATION FREQUENCY ESTIMATES
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
PF tabular
PDS-based point precipitation frequency estimates with 90%confidence intervals (in inches)1
Duration Average recurrence interval(years)
1 2 5 10 25 50 100 200 500 1000
5-min 0.348 0.416 0A89 0.550 0.621 0.676 0.728 0.778 0.839 0.889
(0.314-0.386) (0.376-0.461) (0.441-0.540) (0.495-0.608) (0.556-0.684) (0.602-0.744) (0.645-0.802) (0.684-0.857) (0.730-0.928) (0.786-0.986)
10-min 0.556 0.665 0.783 0.879 0.989 1.08 1.16 1.23 1.33 1.40
(0.502-0.616) (0.601-0.737) (0.706-0.865) (0.791-0.972) (0.886-1.09) (0.959-1.19) (1.02-1.27) (1.08-1.36) (1.15-1.47) (1.21-1.55)
15-min 0.695 0.836 0.990 1.11 1.25 1.36 1.46 1.56 1.67 1.76
(0.628-0.770) (0.755-0.926) (0.893-1.09) L(1.00-1.23) (1.12-1.38) (1.21-1.50) (1.29-1.61) (1.37-1.71) (1.45-1.85) (1.51-1.95)
30-min 0.953 1.16 1.41 1.61 1.86 2.05 2.24 2.42 2.66 2.85
(0.861-1.05) (1.04-1.28) (1.27-1.55) (1.45-1.78) (1.66-2.05) (1.83-2.26) (1.98-2.47) (2.13-2.67) (2.31-2.94) (2.45-3.16)
60-min 1.19 1.45 1.80 2.10 2A7 2.78 3.08 3A0 3.81 4.16
(1.07-1.32) (1.31-1.60) (1.63-1.99) (1.89-2.32) (2.21-2.73) (2.48-3.06) (2.73-3.40) (2.99-3.74) (3.32-4.22) (3.58-4.61)
2-hr 1A3 1.74 2.17 2.56 3.06 3.46 3.89 4.35 4.98 5.52
(1.27-1.61) (1.54-1.96) (1.93-2.45) (2.26-2.88) (2.68-3.42) (3.03-3.89) (3.39-4.37) (3.75-4.88) (4.25-5.60) (4.65-6.22)
3-hr 1.56 1.90 2.37 2.78 3.33 3.79 4.26 4.76 5A6 6.07
(1.38-1.78) (1.67-2.16) (2.09-2.71) (2.44-3.17) (2.90-3.78) (3.28-4.29) (3.67-4.83) (4.07-5.40) t (4.61-6.21) (5.06-6.91)
6-hr 1.99 2A0 2.98 3.51 4.22 4.85 5.51 6.22 7.25 8.15
(1.76-2.25) (2.13-2.73) (2.63-3.38) (3.08-3.98) (3.69-4.79) (4.20-5.48) (4.72-6.22) (5.28-7.04) (6.06-8.21) (6.72-9.25)
12-hr 2A9 3.00 3.74 4A3 6.39 6.25 7.18 8.21 9.74 11.1
(2.20-2.85) (2.65-3.43) (3.30-4.27) (3.89-5.05) (4.69-6.13) (5.38-7.09) (6.11.8.15) (6.90-9.31) (8.02-11.1) (9.01-12.7)
24-hr 2.97 3.59 4.59 5.42 6.66 7.71 8.88 10.2 12.1 13.7
(2.66-3.34) (3.22-4.05) (4.10-5.16) (4.83-6.09) (5.90-7.46) (6.79-8.62) (7.74-9.91) (8.77-11.3) (10.3-13.5) (11.5-15.3)
3.50 4.24 5.38 6.33 7.69 8.84 10.1 11 A 13.4 15.0
2-day (3.15-3.91) (3.82-4.73) (4.84-8.01) (5.67-7.05) (6.85-8.55) (7.81-9.81) (8.84-11.2) (9.95-12.7) (11.5-15.0) (12.8-16.8)
3.72 4.51 5.73 6.73 8.18 9.39 10.7 12.1 14.2 15.9
3-day (3.38-4.13) (4.09-5.00) (5.19-6.35) (6.08-7.45) (7.35-9.04) (8.38-10.4) (9.48-11.8) (10.7-13.4) (12.3-15.7) (13.7-17.7)
3.95 4.78 6.07 7.13 8.66 9.95 it 11.3 l 12.8 15.0 16.8
4-day (3.61-4.36)- (4.37-5.27) (5.53-6.69) (6.49-7.84) (7. 4-9.52) (8.95-10.9) (10.1-12.5) (11.4-14.1) (13.2-16.5) (14.6-18.6)
7-day 4.59 5.53 6.91 8.04 9.67 11.0 12.5 14A 16.3 18.1
(4.20-5.04) (5.06-6.06) (6.31-7.58) (7.33-8.82) (8.77-10.6) (9.95-12.1) (11.2-13.7) (12.5-15.4) (14.3-17.9) (15.7-20.0)
10-clay 5.21 6.25 7.72 8.91 10.6 12A 13A 14.9 17.1 18.8
(4.79-5.67) (5.75-6.80) (7.09-8.38) (8.17-9.87) (9.66-11.5) (10.9-13.0) (12.1-14.5) (13.4-16.2) (15.2-18.6) (18.6-20.6)
--
20-day 6.85 8.17 9.87 11.2 13.0 14.4 15.9 17A 194 20.9
(6.40-7.37) (7.83-8.78) (9.20-10.6) (10.4-12.0) (12.1-14.0) (13.3-15.5) (14.6-17.1) (15.9-18.7) (17.6-20.9) (18.9.22.7)
30�Jay 8A0 9.96 11.8 13.2 15.0 16.4 17.7 19.0 20.7 22.0
(7.89-8.98) (9.36-10.6) (11.1-12.6) (12.3-14.0) (14.0-16.0) (15.2-17.4) (16.4-18.9) (17.6-20.3) (19.1-22.2) (20.2-23.7)
10.5 12.4 14.5 16.1 18.1 19.5 21.0 22A 24.1 25A
45-day (9.89-11.2) (11.7-13.2) (13.8-15.4) (15.1-17.0) (17.0-19.1) (18.3-20.7) (19.6-22.3) (20.8-23.8) (22.4-25.7) (23.5-27.2)
60-clay 12.3 14.5 16.7 18A 20.5 22.1 23.6 25.0 26.8 28.1
(11.7-13.0) (13.7-15.3) (15.8-17.7) (17.4-19.4) (19.3-21.7) (20.8-23.3) (22.1-24.9) (23.4-26.4) (25.0-28.4) (26.1-29.8)
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. _
sack to Too
PF graphical
http://hdsc.nws.Hoag.gov/hdsc/pfds/pfds_printpage.html?tat=38.1466&lon=-78.4279&data=depth&units=english&series=pds 1/4
3/24/2015 Precipitation Frequency Data Server
PDS-based depth-duration-frequency(DDF) curves
Latitude: 38.1466°, Longitude: -78.4279°
30 1 I I 1 I I 1 1 I 1
•
25 t a ,
c •
- 20 Average recurrence
interval
-0 (years)
c 15
a • 2
5 -. . . • • — 25
r� • - _ . . — 50
0 �.� — 200
c c c c c
E E E L t a. a.a. 5, >, a. a.a.
— 500E E N � lb a 'O
u1O 1A $ N rl1 sl' r O — 1000
Duration
30 I 1 1 1 1
•
25 --
c
r- 20 -•
iv
-o
15
. 0— 1
0 ''''' T —r---_._--t r- . _ I r _t.___. --1
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval(years)
NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Tue Mar 24 17:07:40 2015
Duration
— 5-min — 2-day
— 10-nun 3-day
16•mrn — 4-day
— 30 mtn — 7-day
— 60-nrn — 10-day
— 2-hr — 20-day
— 3-hr — 30-day
— 6-hr — 45-day
— 12-hr — 60-day
— 24-hr
http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.1466&Ion=-78.42798data=depth&units=english&series=pds 2/4
3/24/2015 Precipitation Frequency Data Server
•
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3/24/2015 Precipitation Frequency Data Server
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US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
Office of Hvdroloaic Development
1325 East West Highway
Silver Spring,MD 20910
Questions?:HDSC.QuestionsCa)noaa,00v
Disclaimer
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