Description: The dataset contains locations and attributes of HUC-11 watersheds. The USGS presents a detailed explanation of HUCs at https://water.usgs.gov/GIS/huc.html. HUC-11 boundaries are compiled by each state. The export files of HUC-11 at the state level were provided by each respective state and are unmodified. HUC-11 boundaries for Delaware are not yet available. Also, a small portion of the Chesapeake Basin in NY State has not yet been completed.
Copyright Text: Department of Energy and Environment
Description: This layer depicts the conglomeration of the 4 layers used for TMDLs. It contains TMDL Subsheds, Direct Drain Overland (not piped), Direct Drain Sewersheds (piped), and Combined Sewer (CSS) Subsheds. This layer provided the granularity needed to facilitate further analysis. METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE.
Copyright Text: District Department of Energy and Environment
Description: This dataset is a digital hydrologic unit boundary layer for the District of Columbia only - to the watershed (10-digit) 6th level at 1:24,000 scale. It is a clipped version of the regional dataset using the DC Boundary. 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 (https://www.nrcs.usda.gov). 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, line source, and a metadata reference file.
Description: Wells are defined by 21 DCMR Chapter 18 as any test hole, shaft, or soil excavation created by any means including, but not limited to, drilling, coring, boring, washing, driving, digging, or jetting, for purposes including, but not limited to, locating, testing, diverting, artificially recharging, or withdrawing fluids, or for the purpose of underground injection. The Department of Energy & Environment's Regulatory Review Division reviews permit applications to install wells in private and public space through the Department of Licensing and Consumer Protection and the District Department of Transportation.
Copyright Text: Department of Energy and Environment
Description: This layer contains hydrography such as streams, rivers, and other linear hydrography features. Hidden hydrography, inferred drainage connectors, or culverts connect visible hydrography to form a continuous network. These connectors or hidden features maintain a predictable direction connecting the 2 points that conceal or infer the feature. Streams: Captured as single line if less than two meters wide. Both water edges plotted if wider than two meters. Docks and Piers: Visible outline delineated. Jetty: Visible outline delineated. Seawall: Single line plotted at the face of the seawall. Hidden Hydrography: Hidden hydrography is not obvious, even to someone standing under a bridge for example; it cannot be seen photogrammetrically and can be captured only from other sources. Segments of rivers, streams, and canals that flow under features such as bridges and roads are captured as continuous portions of the river, stream, or canal.
Copyright Text: Office of the Chief of Technology Officer
Description: Hydrography Centerline. The dataset contains lines representing planimetric Hydrography Centerline, created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO). These features were originally captured in 1999 and updated in 2005. The following planimetric layers were updated: - Building Polygons (BldgPly) - Bridge and Tunnel Polygons (BrgTunPly) - Metro Entrance Points (MetroEntPt) - Obscured Area Polygons (ObsAreaPly) - Railroad Lines (RailRdLn) - Road, Parking, and Driveway Polygons (RoadPly) - Sidewalk Polygons (SidewalkPly) - Under Construction Areas (UnderConstPly) - Wooded Areas (WoodPly) The following planimetric layers are new: - Horizontal and Vertical Control Points (GeoControlPt) - Hydrography Center Lines (HydroCenterLineLn).
Description: This dataset is a complete digital hydrologic unit boundary layer to the subwatershed (12-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. METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE.
Description: Water is a polygon feature class consisting of the following features and capture rules: Lakes, Reservoirs: Delineates the shoreline of all standing bodies of water designated as a lake or reservoir. Ponds: Delineates the outline of all standing bodies of water designated as ponds. Includes man-made ponds over 100 square feet. Rivers: Captures the banks of all flowing bodies of water two meters wide or wider, i.e., rivers. Pools: Captures the outline of the water portion of fountains and codes them as pools.
Copyright Text: Office of the Chief of Technology Officer
Description: 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.nrcs.usda.gov/). 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.
Description: This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey's National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the 'comments' field of the Wetlands_Project_Metadata feature class. Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.
Description: This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey's National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the 'comments' field of the Wetlands_Project_Metadata feature class. Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.