| Limstone Overlay District (LOD) of Loudoun County, VA (2010) | |
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Data format: SDE Feature Class File or table name: GISDBB.GISBROW.LIMESTONE_OD_POLY Coordinate system: Lambert Conformal Conic Theme keywords: limestone, geology, conglomerate, zoning, overlay, environment, sinkholes, karst, bedrock, geoscientificInformation, environment, health, boundaries |
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Abstract:
The Limestone Overlay District (LOD) is a zoning overlay district adopted by the Loudoun County Board of Supervisors on 2/17/2010 and administered by the Loudoun County Department of Building and Development. The Department is responsible for all development approvals, review procedures, modifications and density calculations in the LOD as governed by Article VI, "Development Process and Administration", of the Revised 1993 Zoning Ordinance, and procedures in Chapter 8 of the Facilities Standards manual.
The LOD is generally comprised of the following geologic formations: Cf-Frederick Limestone, Ct-Tomstown Dolomite, JTRc-Catharpin Creek Formation, JTRcg-Catharpin Creek Formation Goose Creek Member, TRbl-Balls Bluff Siltstone Leesburg Member, and TRbs-Balls Bluff Siltstone Fluvial and Deltaic Sandstone Member.
The geographic area of the Limestone Overlay District (LOD) is generally east from the Catoctin Mountain Range to the Potomac River (excludes Lost Corner), and from just south of the Town of Leesburg north to Point of Rocks, MD (excludes the Town of Leesburg.) |
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Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
The Limestone Overlay District (LOD) is a zoning overlay district adopted by the Loudoun County Board of Supervisors on 2/17/2010 and administered by the Loudoun County Department of Building and Development. The Department is responsible for all development approvals, review procedures, modifications and density calculations in the LOD as governed by Article VI, "Development Process and Administration", of the Revised 1993 Zoning Ordinance, and procedures in Chapter 8 of the Facilities Standards manual. The LOD is generally comprised of the following geologic formations: Cf-Frederick Limestone, Ct-Tomstown Dolomite, JTRc-Catharpin Creek Formation, JTRcg-Catharpin Creek Formation Goose Creek Member, TRbl-Balls Bluff Siltstone Leesburg Member, and TRbs-Balls Bluff Siltstone Fluvial and Deltaic Sandstone Member. The geographic area of the Limestone Overlay District (LOD) is generally east from the Catoctin Mountain Range to the Potomac River (excludes Lost Corner), and from just south of the Town of Leesburg north to Point of Rocks, MD (excludes the Town of Leesburg.)
The land area delineated by the boundaries of the LOD is comprised of limestone and "Karst terrain" areas. The terrain is also characterized by the presence of certain natural features, such as sinkholes and rock outcrops. Thus, development on Karst terrain has a direct correlation to the potential for collapse and ground slippage and the susceptibility of groundwater and surface water pollution, and spring contamination, posing serious risks to public health, safety and welfare. The provisions of Section 4-1900 of the Revised 1993 Zoning Ordinance are intended to regulate land use and development in areas underlain by limestone and in areas with Karst features and terrain as shown on the official Limestone Overlay District Map of Loudoun County.
Data are stored in the corporate ArcSDE Geodatabase as a polygon feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN.
publication date
These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data. Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user.
1 Harrison Street SE, 2nd Floor
Mail stop 60
Limstone Overlay District is based on both field work by the County Soil Scientist and USGS's geology layer of Loudoun County.
Features may have been eliminated or generalized due to scale and intended use. To assist Loudoun County, Virginia in the maintenance of the data, please provide any information concerning discovered errors, omissions, or other discrepancies found in the data.
Cooperative agreement between USGS and Loudoun County Dept. of Natural Resources to map geology provided source data set for extraction of Limestone Conglomerate.
Extracted Limestone Conglomerate as a Zoning Overlay District
The Limestone data was originally created in 1991. The extent of the district was re-defined in 2002 for purposes of creating an overlay district as part of the Revised General Plan in 2003.
This data set was part of a batch process that converted legacy data from ArcInfo coverage in Librarian to a single-tiled ArcInfo coverage in preparation for a final conversion to ArcSDE Geodatabase Feature Classes. Data were extracted from Librarian using the EXTRACT TOPOLOGICAL command. Multi-tiled data sets were extracted into multiple coverages and then combined based on the feature type(s). Layers with both polygon and arc feature classes were processed with the Arc commands MAPJOIN and DISSOLVE. Arc feature classes alone were processed with the Arc commands, APPEND and DISSOLVE. Layers with both arc and point feature classes and point feature classes alone were processed with the Arc command, APPEND. When used, the arc command, DISSOLVE, was given with the <#all> option. All coverages were then reprojected to HARN83 using the following .prj file specifications: INPUT PROJECTION STATEPLANE UNITS FEET ZONE 5551 DATUM NAD27 NADCON PARAMETERS OUTPUT PROJECTION STATEPLANE UNITS FEET FIPSZONE 4501 DATUM HPGN NADCON PARAMETERS END The dataset was then converted to a feature class in a geodatabase in ArcSDE.
A 200' buffer was added to the western edge of the largest feature. The two smaller features, to the nothwest, received 200' buffers around the entire feature. Several donut holes were removed/filled in on the largest feature. Areas outside of County jurisdiction, such as the Town of Leesburg, were removed.
Internal feature number.
ESRI
Limestone Map Unit
USGS
Date feature class created or modified
Loudoun County
Source that created or edited feature class
Loudoun County
Not for public distribution. Internal User ID of editor creating or modifying a feature.
Loudoun County
Feature geometry.
ESRI
Area of feature in internal units
Loudoun County
Perimeter of feature in internal units
Loudoun County
LI_UPD_SOURCE: Source that created or edited feature class
Source Description 0 Unknown 1 Legacy 2 County 3 Contract
1 Harrison Street, S.E., 2nd Floor
MS 65
Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user. In no way will Loudoun County be liable to you or any third party for any direct, indirect, incidental, consequential, special, or exemplary damages or lost profits resulting from any use or misuse of these data.
ESRI Geodatabase Feature Class
ESRI Shapefile
AutoCad Digital Exchange File
Size limit: 4.5 GB. Visit our website at: http://www.loudoun.gov/omagi, click on "Loudoun County Mapping Documents & Order Forms." The "Forms" directory will lead you to custom & standard (countywide) data order forms. Hardcopy maps may also be available; please contact the Mapping Office Public Information Counter for more information regarding all data requests.
1 Harrison Street S.E., 2nd Floor
MS 65