Major Watersheds of Loudoun County, VA (2009) | |
Data format: SDE Feature Class File or table name: GISDBB.GISBROW.MAJSHEDS_POLY Coordinate system: Lambert Conformal Conic Theme keywords: inlandWaters, environment, water, watersheds |
|
Abstract:
This layer identifies the Major Watersheds of Loudoun County at the internal watershed basin level. The Major Watersheds identify the areas of Loudoun County that drain into a specified body of water. |
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.
This layer identifies the Major Watersheds of Loudoun County at the internal watershed basin level. The Major Watersheds identify the areas of Loudoun County that drain into a specified body of water.
Major watersheds are to be used in combination with other GIS data layers to keep track of developments & other changes at the watershed level. Developments & other similar changes affect the watersheds through increased runoff & it is imperative to be able to identify this.
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 (vertical datum, if applicable, NAVD88), US Survey foot units.
publication date
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. 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.
1 Harrison Street SE, 2nd floor
MS 60
Retention of attribute accuracy throughout the coverage to geodatabase feature class coversion process was ensured by a QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have, on a record by record basis, identical attribution when comparing all concatenated fields to all the user-defined attribution.
Topologically clean
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.
Retention of coordinate accuracy throughout the coverage to geodatabase feature class conversion process was ensured by a QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have the same record total, and on a record by record basis, area, perimeter, and length differential of less than +/- 0.5%.
This layer was created by tracing topographic lines to designate the watershed boundaries. The boundaries were then digitized digitally & generalized to create the watersheds layer.
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 coversion 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 HARN 83 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 This dataset was then converted to a feature class in a geodatabase in ArcSDE.
Major Watershed that each individual basin is located in
Loudoun County
Broad Run
Bull Run
Catoctin Creek
Clarks Run
Direct to Potomac River
Dutchman Creek
Goose Creek
Limestone Branch
Piney Run
Quarter Branch
Sugarland Run
Given acreage of watershed feature
Loudoun County
First sub-watershed of Major Watershed
Loudoun County
Second sub-watershed of Major Watershed
Loudoun County
Third sub-watershed of Major Watershed
Loudoun County
Fourth sub-watershed of Major Watershed
Loudoun County
Fifth sub-watershed of Major Watershed
Loudoun County
Sixth sub-watershed of Major Watershed
Loudoun County
Seventh sub-watershed of Major Watershed
Loudoun County
Unique code to identify Loudoun County Sub-Watershed
Loudoun County
Source that created or edited feature class
Loudoun County
Date feature class edited or created
Loudoun County
Not for public distribution. Internal User ID of editor creating or modifying a feature
Loudoun County
Internal feature number.
ESRI
Feature geometry.
ESRI
MA_SUB_CODE: Unique code to identify Loudoun County Sub-Watershed
Subcode Definition BR Broad Run BU Bull Run CA1 North Fork Catoctin Creek CA2 South Fork Catoctin Creek CA3 Lower Catoctin Creek CL Clarks Run DI Direct to Potomac River DU Dutchman Creek GO1 Upper Goose Creek GO2 North Fork Goose Creek GO3 Lower Goose Creek LI Limestone Branch PI Piney Run QU Quarter Branch SU Sugarland Run
MA_UPD_SOURCE: source by which feature was created or modified
Source Definition 0 Undetermined 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.
ESRI Personal 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 SE, 2nd Floor
MS 65