| Watersheds (WatershedPly) | |
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Data format: SDE Feature Class File or table name: DCGIS.WatershedPly Coordinate system: State Plane Coordinate System 1983 Theme keywords: Hydrology, Watershed, environment |
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Abstract:
This dataset is a complete digital hydrologic unit boundary layer to the watershed (10-digit) 6th level at 1:24,000 scale. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "FGDC Proposal, Version 1.0 - Federal Standards For Delineation of Hydrologic Unit Boundaries 3/01/02 ( http://www.ftw.nrcs.usda.gov/huc_data.html ). The hydrologic unit boundaries provide a uniquely identified and uniform method of subdividing large drainage areas.
Polygons are attributed with hydrologic unit codes, names, downstream hydrologic unit, flow modifications, and hydrologic unit type for 4th level (8-digit) sub-basin, 5th level (10-digit) watershed, 6th level (12-digit) subwatershed, and acres for subwatershed. An accompanying line shapefile is attributed with the highest hydrologic unit level for each hydrologic unit, linesource, and a metadata reference file.
All DC GIS data is stored and exported in Maryland State Plane coordinates NAD 83 meters.
METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE. |
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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.
This dataset is a complete digital hydrologic unit boundary layer to the watershed (10-digit) 6th level at 1:24,000 scale. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "FGDC Proposal, Version 1.0 - Federal Standards For Delineation of Hydrologic Unit Boundaries 3/01/02 ( http://www.ftw.nrcs.usda.gov/huc_data.html ). The hydrologic unit boundaries provide a uniquely identified and uniform method of subdividing large drainage areas. Polygons are attributed with hydrologic unit codes, names, downstream hydrologic unit, flow modifications, and hydrologic unit type for 4th level (8-digit) sub-basin, 5th level (10-digit) watershed, 6th level (12-digit) subwatershed, and acres for subwatershed. An accompanying line shapefile is attributed with the highest hydrologic unit level for each hydrologic unit, linesource, and a metadata reference file. All DC GIS data is stored and exported in Maryland State Plane coordinates NAD 83 meters. METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE.
This data is used for the planning and management of Washington, D.C. by local government agencies.
A text document that is provided with the data called Watershed Boundary Dataset (WBD) User Guide provides information on the methodology used to delineate the hydrologic units and provides definition for all the attributes. The smaller sized 6th level sub-watersheds (most within 10,000 to 40,000 acres) are useful for numerous application programs supported by a variety of local, State, and Federal Agencies. This data set is intended to be used as a tool for water-resource management and planning activities, particularly for site-specific and localized studies requiring a level of detail provided by large-scale map information. Until the entire nation is complete and HUC_8 codes are stable, the Geospatial Data Gateway will only be serving two WBD layers; HU12 linework and HU12 polygons (which consists of HUC_8, HUC_10, and HUC_12 codes, as well as HUC_10 and HUC_12 names). If you would like to derive HUC_2, HUC_4, HUC_6 codes and names or HUC_8 names, these values can be dissolved from WBD HU12 then joined to the USGS layer (HUC250K) for naming purposes. When ordering from the Gateway, the HUC250K USGS layer is listed as "8-Digit Hydrologic Units 1:250,000". For instructions about how to derive HU2, HU4, HU6, or HU8 codes or names, see the following document: ftp://ftp.ftw.nrcs.usda.gov/pub/wbd/hu_qa/wbdhu8.doc
publication date
Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.
441 4th St NW, Suite 930 South
United States Geologic Survey
Validated by source and/or responsible agency.
Validated by source and/or responsible agency.
Validated by source and/or responsible agency.
1:24000 source scale.
N/A
locations and attribution
Data was download from the USDA geospatial center. Then staff selected all watersheds that touch the DC boundary and exported the selection set to a new watershed layer.
441 4th St NW, Suite 930 South
Metadata imported.
Metadata imported.
Dataset copied.
Dataset copied.
Watershed Name
Internal feature number.
ESRI
Feature geometry.
ESRI
Feature geometry
ESRI
10 Digit (watershed) Hydrologic Unit Code
441 4th St NW, Suite 930 South
Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.
Most DC GIS datasets can be downloaded from "http://dcgis.dc.gov" on the data center page. Orders can also be made by contacting OCTO GIS at "dcgis@dc.gov", especially for datasets not available for download.
441 4th St NW, Suite 930 South