This map layer shows areal and linear water features of the United States, Puerto Rico, and the U.S. Virgin Islands. The original file was produced by joining the individual State hydrography layers from the 1:2,000,000- scale Digital Line Graph (DLG) data produced by the USGS. This map layer was formerly distributed as Hydrography Features of the United States. This is a revised version of the January 2003 map layer.

USA Detailed Water Bodies represents the major lakes, reservoirs, large rivers, lagoons, and estuaries in the United States. To download the data for this layer as a layer package for use in ArcGIS desktop applications, refer to USA Detailed Water Bodies.

Named Waterbody is a 1:24,000-scale, polygon and line feature-based layer that includes all named waterbodies depicted on the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps for the State of Connecticut. This layer only includes features located in Connecticut. Named Waterbody features include water, dams, flow connectors, aqueducts, canals, ditches, shorelines, and islands. The layer does not include the marsh areas, tidal flats, rocks, shoals, or channels typically shown on USGS 7.5 minute topographic quadrangle maps. However, the layer includes linear (flow) connector features that fill in gaps between river and stream features where water passes through marshes or underground through pipelines and tunnels. Note that connectors represent general pathways and do not represent the exact location or orientation of actual underground pipelines, tunnels, aqueducts, etc. The Named Waterbody layer is comprised of polygon and line features. Polygon features represent areas of water for rivers, streams, brooks, reservoirs, lakes, ponds, bays, coves, and harbors. Polygon features also depict related information such as dams and islands. Line features represent single-line rivers and streams, flow connectors, aqueducts, canals, and ditches. Line features also enclose all polygon features in the form of shorelines, dams, and closure lines separating adjacent water features. The Named Waterbody layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 so it does not depict conditions at any one particular point in time. Also, the layer does not reflect recent changes with the course of streams or location of shorelines impacted by natural events or changes in development since the time the USGS 7.5 minute topographic quadrangle maps were published. Attribute information is comprised of codes to identify waterbody features by type, cartographically represent (symbolize) waterbody features on a map, select waterbodies appropriate to display at different map scales, identify individual waterbodies on a map by name, and describe waterbody feature area and length. The names assigned to individual waterbodies are based on information published on the USGS 7.5 minute topographic quadrangle maps or other state and local maps. The Named Waterbody layer does not include bathymetric, stream gradient, water flow, water quality, or biological habitat information. Derived from the Hydrography layer, the Named Waterbody layer was originally published in 1999. The 2005 edition includes the same water features published in 1999, however some attribute information has been slightly modified and made easier to use. Also, the 2005 edition corrects previously undetected attribute coding errors and includes the flow connector features. Connecticut Named Waterbody Polygon includes the polygon features of a layer named Named Waterbody. Named Waterbody is a 1:24,000-scale, polygon and line feature-based layer that includes all named waterbodies depicted on the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps for the State of Connecticut. This layer only includes features located in Connecticut. Named Waterbody features include water, dams, flow connectors, aqueducts, canals, ditches, shorelines, and islands. The layer does not include the marsh areas, tidal flats, rocks, shoals, or channels typically shown on USGS 7.5 minute topographic quadrangle maps. However, the layer includes linear (flow) connector features that fill in gaps between river and stream features where water passes through marshes or underground through pipelines and tunnels. Note that connectors represent general pathways and do not represent the exact location or orientation of actual underground pipelines, tunnels, aqueducts, etc. The Named Waterbody layer is comprised of polygon and line features. Polygon features represent areas of water for rivers, streams, brooks, reservoirs, lakes, ponds, bays, coves, and harbors. Polygon features also depict related information such as dams and islands. Line features represent single-line rivers and streams, flow connectors, aqueducts, canals, and ditches. Line features also enclose all polygon features in the form of shorelines, dams, and closure lines separating adjacent water features. The Named Waterbody layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 so it does not depict conditions at any one particular point in time. Also, the layer does not reflect recent changes with the course of streams or location of shorelines impacted by natural events or changes in development since the time the USGS 7.5 minute topographic quadrangle maps were published. Attribute information is comprised of codes to identify waterbody features by type, cartographically represent (symbolize) waterbody features on a map, select waterbodies appropriate to display at different map scales, identify individual waterbodies on a map by name, and describe waterbody feature area and length. The names assigned to individual waterbodies are based on information published on the USGS 7.5 minute topographic quadrangle maps or other state and local maps. The Named Waterbody layer does not include bathymetric, stream gradient, water flow, water quality, or biological habitat information. Derived from the Hydrography layer, the Named Waterbody layer was originally published in 1999. The 2005 edition includes the same water features published in 1999, however some attribute information has been slightly modified and made easier to use. Also, the 2005 edition corrects previously undetected attribute coding errors and includes the flow connector features.

The National Hydrography Dataset (NHD) is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. NHD data was originally developed at 1:100,000-scale and exists at that scale for the whole country. This high-resolution NHD, generally developed at 1:24,000/1:12,000 scale, adds detail to the original 1:100,000-scale NHD. (Data for Alaska, Puerto Rico and the Virgin Islands was developed at high-resolution, not 1:100,000 scale.) Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. Reaches are also defined on waterbodies and the approximate shorelines of the Great Lakes, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee. For additional information on NHD, go to https://www.usgs.gov/national-hydrography.

Connecticut Hydrography Set:

Connecticut Hydrography Line includes the line features of a layer named Hydrography. Hydrography is a 1:24,000-scale, polygon and line feature-based layer that includes all hydrography features depicted on the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps for the State of Connecticut. This layer only includes features located in Connecticut. These hydrography features include waterbodies, inundation areas, marshes, dams, aqueducts, canals, ditches, shorelines, tidal flats, shoals, rocks, channels, and islands. Hydrography is comprised of polygon and line features. Polygon features represent areas of water for rivers, streams, brooks, reservoirs, lakes, ponds, bays, coves, and harbors. Polygon features also depict inundation areas, marshes, dams, aqueducts, canals, tidal flats, shoals, rocks, channels, and islands shown on the USGS 7.5 minute topographic quadrangle maps. Line features represent single-line rivers and streams, aqueducts, canals, and ditches. Line features also enclose all polygon features in the form of natural shorelines, manmade shorelines, dams, closure lines separating adjacent waterbodies, and the apparent limits for tidal flats, rocks, and areas of marsh. The layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 so it does not depict conditions at any one particular point in time. Also, the layer does not reflect recent changes with the course of streams or location of shorelines impacted by natural events or changes in development since the time the USGS 7.5 minute topographic quadrangle maps were published. Attribute information is comprised of codes to identify hydrography features by type, cartographically represent (symbolize) hydrography features on a map, select waterbodies appropriate to display at different map scales, identify individual waterbodies on a map by name, and describe feature area and length. The names assigned to individual waterbodies are based on information published on the USGS 7.5 minute topographic quadrangle maps or other state and local maps. The layer does not include bathymetric, stream gradient, water flow, water quality, or biological habitat information. This layer was originally published in 1994. The 2005 edition includes the same water features published in 1994, however some attribute information has been slightly modified and made easier to use. Also, the 2005 edition corrects previously undetected attribute coding errors.

Connecticut Hydrography Polygon includes the polygon features of a layer named Hydrography. Hydrography is a 1:24,000-scale, polygon and line feature-based layer that includes all hydrography features depicted on the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps for the State of Connecticut. This layer only includes features located in Connecticut. These hydrography features include waterbodies, inundation areas, marshes, dams, aqueducts, canals, ditches, shorelines, tidal flats, shoals, rocks, channels, and islands. Hydrography is comprised of polygon and line features. Polygon features represent areas of water for rivers, streams, brooks, reservoirs, lakes, ponds, bays, coves, and harbors. Polygon features also depict inundation areas, marshes, dams, aqueducts, canals, tidal flats, shoals, rocks, channels, and islands shown on the USGS 7.5 minute topographic quadrangle maps. Line features represent single-line rivers and streams, aqueducts, canals, and ditches. Line features also enclose all polygon features in the form of natural shorelines, manmade shorelines, dams, closure lines separating adjacent waterbodies, and the apparent limits for tidal flats, rocks, and areas of marsh. The layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 so it does not depict conditions at any one particular point in time. Also, the layer does not reflect recent changes with the course of streams or location of shorelines impacted by natural events or changes in development since the time the USGS 7.5 minute topographic quadrangle maps were published. Attribute information is comprised of codes to identify hydrography features by type, cartographically represent (symbolize) hydrography features on a map, select waterbodies appropriate to display at different map scales, identify individual waterbodies on a map by name, and describe feature area and length. The names assigned to individual waterbodies are based on information published on the USGS 7.5 minute topographic quadrangle maps or other state and local maps. The layer does not include bathymetric, stream gradient, water flow, water quality, or biological habitat information. This layer was originally published in 1994. The 2005 edition includes the same water features published in 1994, however some attribute information has been slightly modified and made easier to use. Also, the 2005 edition corrects previously undetected attribute coding errors.

The USGS National Hydrography Dataset (NHD) downloadable data collection from The National Map (TNM) is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. For additional information on NHD, go to https://www.usgs.gov/core-science-systems/ngp/national-hydrography.

DWR was the steward for NHD and Watershed Boundary Dataset (WBD) in California. We worked with other organizations to edit and improve NHD and WBD, using the business rules for California. California's NHD improvements were sent to USGS for incorporation into the national database. The most up-to-date products are accessible from the USGS website. Please note that the California portion of the National Hydrography Dataset is appropriate for use at the 1:24,000 scale.

For additional derivative products and resources, including the major features in geopackage format, please go to this page: https://data.cnra.ca.gov/dataset/nhd-major-features Archives of previous statewide extracts of the NHD going back to 2018 may be found at https://data.cnra.ca.gov/dataset/nhd-archive.

In September 2022, USGS officially notified DWR that the NHD would become static as USGS resources will be devoted to the transition to the new 3D Hydrography Program (3DHP). 3DHP will consist of LiDAR-derived hydrography at a higher resolution than NHD. Upon completion, 3DHP data will be easier to maintain, based on a modern data model and architecture, and better meet the requirements of users that were documented in the Hydrography Requirements and Benefits Study (2016). The initial releases of 3DHP include NHD data cross-walked into the 3DHP data model. It will take several years for the 3DHP to be built out for California. Please refer to the resources on this page for more information.

The FINAL,STATIC version of the National Hydrography Dataset for California was published for download by USGS on December 27, 2023. This dataset can no longer be edited by the state stewards. The next generation of national hydrography data is the USGS 3D Hydrography Program (3DHP).

Questions about the California stewardship of these datasets may be directed to nhd_stewardship@water.ca.gov.

The Hydrology Feature Dataset contains photogrammetrically compiled water drainage features and structures including rivers, streams, drainage canals, locks, dams, lakes, ponds, reservoirs and mooring cells. Rivers, Lakes, Ponds, Reservoirs, Hidden Lakes, Reservoirs or Ponds: If greater than 25 feet and less than 30 feet wide, is captured as a double line stream. If greater than 30 feet wide it is captured as a river. Lakes are large standing bodies of water greater than 5 acres in size. Ponds are large standing bodies of water greater than 1 acre and less than 5 acres in size. Polygons are created from Stream edges and River Edges. The Ohio River, Monongahela River and Allegheny River are coded as Major Rivers. All other River and Stream polygons are coded as River. If a stream is less than 25 feet wide it is placed as a single line and coded as a Stream. Both sides of the stream are digitized and coded as a Stream for Streams whose width is greater than 25 feet. River edges are digitized and coded as River.

A Drainage Canal is a manmade or channelized hydrographic feature. Drainage Canals are differentiated from streams in that drainage canals have had the sides and/or bottom stabilized to prevent erosion for the predominant length of the feature. Streams may have had some stabilization done, but are primarily in a natural state. Lakes are large standing bodies of water greater than five acres in size. Ponds are large standing bodies of water greater than one acre in size and less than five acres in size. Reservoirs are manmade embankments of water. Included in this definition are both covered and uncovered water tanks. Reservoirs that are greater than one acre in size are digitized. Hidden Streams, Hidden Rivers and Hidden Drainage Canal or Culverts are those areas of drainage where the water flows through a manmade facility such as a culvert. Hydrology Annotation is not being updated but will be preserved. If a drainage feature has been removed, as apparent on the aerial photography, the associated drainage name annotation will be removed. A Mooring Cell is a structure to which tows can tie off while awaiting lockage. They are normally constructed of concrete and steel and are anchored to the river bottom by means of gravity or sheet piling.

Mooring Cells do not currently exist in the Allegheny County dataset but will be added. Locks are devices that are used to control flow or access to a hydrologic feature. The edges of the Lock are captured. Dams are devices that are used to hold or delay the natural flow of water. The edges of the Dam are shown.

This dataset is harvested on a weekly basis from Allegheny County’s GIS data portal. The full metadata record for this dataset can also be found on Allegheny County's GIS portal. You can access the metadata record and other resources on the GIS portal by clicking on the “Explore” button (and choosing the "Go to resource" option) to the right of the "ArcGIS Open Dataset" text below.

Category: Environment

Department: Geographic Information Systems Group; Department of Administrative Services

Data Notes: Coordinate System: Pennsylvania State Plane South Zone 3702; U.S. Survey Foot

Development Notes: Original Lakes and Drainage datasets combined to create this layer. Data was updated as a result of a flyover in the spring of 2004. A database field has been defined for all map features named Update Year". This database field will define which dataset provided each map feature. Map features from the current map will be set to "2004". The earlier dataset map features the earlier dataset map features used to supplement the area near the county boundary will be set to "1993". All new or modified map data will have the value for "Update Year" set to "2004".

Data Dictionary: https://docs.google.com/spreadsheets/d/16BWrRkoPtq2ANRkrbG7CrfQk2dUsWRiaS2Ee1mTn7l0/edit?usp=sharing

The Watershed Boundary Dataset (WBD) from The National Map (TNM) defines the perimeter of drainage areas formed by the terrain and other landscape characteristics. The drainage areas are nested within each other so that a large drainage area, such as the Upper Mississippi River, is composed of multiple smaller drainage areas, such as the Wisconsin River. Each of these smaller areas can further be subdivided into smaller and smaller drainage areas. The WBD uses six different levels in this hierarchy, with the smallest averaging about 30,000 acres. The WBD is made up of polygons nested into six levels of data respectively defined by Regions, Subregions, Basins, Subbasins, Watersheds, and Subwatersheds. For additional information on the WBD, go to https://nhd.usgs.gov/wbd.html. The USGS National Hydrography Dataset (NHD) service is a companion dataset to the WBD. The NHD is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD is available nationwide in two seamless datasets, one based on 1:24,000-scale maps and referred to as high resolution NHD, and the other based on 1:100,000-scale maps and referred to as medium resolution NHD. Additional selected areas in the United States are available based on larger scales, such as 1:5,000-scale or greater, and referred to as local resolution NHD. For more information on the NHD, go to https://nhd.usgs.gov/index.html. Hydrography data from The National Map supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. Hydrography data is commonly combined with other data themes, such as boundaries, elevation, structures, and transportation, to produce general reference base maps. The National Map viewer allows free downloads of public domain WBD and NHD data in either Esri File or Personal Geodatabase, or Shapefile formats. The Watershed Boundary Dataset is being developed under the leadership of the Subcommittee on Spatial Water Data, which is part of the Advisory Committee on Water Information (ACWI) and the Federal Geographic Data Committee (FGDC). The USDA Natural Resources Conservation Service (NRCS), along with many other federal agencies and national associations, have representatives on the Subcommittee on Spatial Water Data. As watershed boundary geographic information systems (GIS) coverages are completed, statewide and national data layers will be made available via the Geospatial Data Gateway to everyone, including federal, state, local government agencies, researchers, private companies, utilities, environmental groups, and concerned citizens. The database will assist in planning and describing water use and related land use activities. Resources in this dataset:Resource Title: Watershed Boundary Dataset (WBD). File Name: Web Page, url: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/water/watersheds/dataset/?cid=nrcs143_021630 Web site for the Watershed Boundary Dataset (WBD), including links to:

Review Data Availability (Status Maps) Obtain Data by State, County, or Other Area Obtain Seamless National Data offsite link image
Geospatial Data Tools National Technical and State Coordinators Information about WBD dataset

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) provides a national network of flowlines, hydrolocations, and water bodies. Data for Alabama’s lakes, rivers, streams, and water features is derived from Elevation-Derived Hydrography (EDH) and supplemented by the National Hydrography Dataset (NHD) where necessary.

Water Bodies are used for water supply planning, the administration of related zoning restrictions, and to locate water supplies in rural areas for fighting fires.Supplemental_Information: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, NAVD88, US Survey foot units. OMAGI updates all base map data via a photogrammetric process, using aerial imagery that is flown yearly in phases. A different portion of the County is updated each year with the base map maintenance services contract, depending upon development patterns and update funding. See "Lineage" section for the list of extents for each Phase area, which are listed as “Data Sources”. The field “UPD_DATE” indicates the date a feature was last re-mapped, although it may have been reviewed for changes more recently.

This Dept. of State Office of the Geographer World Water Body Limits data set has both detailed and simplified versions posted here, along with a centroid point file. All are intended as non-authoritative reference guides for the placement of water body names on maps. This data set includes 158 water bodies worldwide: all tidal water bodies exceeding both 250 kilometers in length and, at some point, 100 kilometers in width, plus some notable smaller ones.….Numerous smaller water bodies are not included. In many locations, there are overlapping water body names (e.g. Golfo di Genova/ Ligurian Sea/ Mediterranean Sea) and the second field in this data set includes the more notable secondary/overlapping names. Also note that the shoreline of these water bodies is approximate and most small to medium sized islands are excluded. Names conform with the US Board on Geographic Names approved conventional and standard forms. While a member, the US has never and continues to generally not conform to various International Hydrographic Office water body limits documents and drafts since the 1940’s. Relatively recently, 13 IHO states voted to add a fifth ocean, the “Southern Ocean”, south of 60 degrees South latitude; many authorities continue to consider the world as having just four oceans.

The USGS National Hydrography Dataset (NHD) Downloadable Data Collection from The National Map (TNM) is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. For additional information on NHD, go to http://nhd.usgs.gov/.

This map is designed to be used as a basemap by marine GIS professionals and as a reference map by anyone interested in ocean data. The basemap includes a vector tile layer for marine water body names, undersea feature names, and derived bathymetric depth values in meters. Land features include administrative boundaries, cities, inland waters, roads, overlaid on land cover and shaded relief imagery, including ocean floor relief.The map was compiled from a variety of best available sources from several data providers, including General Bathymetric Chart of the Oceans GEBCO_08 Grid version 20100927 and IHO-IOC GEBCO Gazetteer of Undersea Feature Names August 2010 version (https://www.gebco.net), National Oceanic and Atmospheric Administration (NOAA) and National Geographic for the oceans; and DeLorme, HERE, and Esri for topographic content. The basemap was designed and developed by Esri.The Ocean Basemap currently provides coverage for the world down to a scale of ~1:577k; coverage down to ~1:72k in United States coastal areas and various other areas; and coverage down to ~1:9k in limited regional areas. This demonstrates how the Ocean Basemap can and will be extended with higher resolution bathymetric data. You can contribute your bathymetric data to this service and have it served by Esri for the benefit of the Ocean GIS community. For details, see the Community Maps Program.The Ocean Basemap includes two layers, a base layer and overlay vector reference layer, so that users can display their operational data between they layers as needed. For the latest and most detailed information, please visit the World Ocean Base map service description or World Ocean Reference tile layer.

This layer was developed by the Natural Resources Department of the Atlanta Regional Commission. The dataset contains polygonal hydrographic features including lakes, ponds, reservoirs, swamps, and marshes in the Metropolitan North Georgia Water Planning District.Original data were captured from the NHDWaterbody geospatial data layer included in the High Resolution National Hydrography Dataset Plus (NHDPlus HR). Features in the NHDWaterbody geospatial layer that intersected the Georgia State boundary were selected and spatially joined to Georgia county boundaries and the WBDHU8 geospatial data layer found in the U.S. Geological Survey's Watershed Boundary Dataset. Layers were spatially joined using the Largest Overlap matching method. The spatial join was removed upon calculating values for the COUNTY_FIPS, COUNTY_NAME, HUC8_ID, and HUC8_SUBBASIN attributes. The CLASS attribute was created to identify Lakes equal to or larger than 10 acres as Major and less than 0.5 acres as Minor. Data in the HYDRO_CAT and RESERVOIR_TYPE attributes were sourced from values encoded in the Feature Code (FCode) field of the NHDWaterbody geospatial data layer.Attributes:FEATURE = Type of hydrologic featureCLASS = Class used to identify major and minor waterbodiesGNIS_ID = A permanent, unique number assigned by the Geographic Names Information System (GNIS) to a geographic feature name for the sole purpose of uniquely identifying that name application as a record in any information system database, dataset, file, or documentGNIS_NAME = The Geographic Names Information System (GNIS) assigned proper name, specific term, or expression by which a particular geographic entity is known.HUC8_ID = 8-digit hydrologic unit code used to identify subbasins in the hydrologic unit systemHUC8_SUBBASIN = Subbasin name of the 8-digit hydrologic unit code in the hydrologic unit systemCOUNTY_FIPS = County Federal Information Processing System (FIPS) codeCOUNTY_NAME = County nameHYDRO_CAT = Hydrographic feature categoryRESERVOIR_TYPE = Type of reservoirACRES = Area of the feature in acresELEVATION = The vertical distance from a given datumGlobalID = A type of UUID (Universal Unique Identifier) in which values are automatically assigned by the geodatabase when a row is createdlast_edited_user = User to last edit featurelast_edited_date = Date feature was last editedShape = Feature geometryShape_Length = Length of the feature, which may differ from the field measured length due to differences in calculation. Units are map units.Shape_Area = Area of feature in map units squaredSource: U.S. Geological Survey, National Geospatial ProgramDate: 2023

Access National Hydrography ProductsThe National Hydrography Dataset (NHD) is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. NHD data was originally developed at 1:100,000-scale and exists at that scale for the whole country. This high-resolution NHD, generally developed at 1:24,000/1:12,000 scale, adds detail to the original 1:100,000-scale NHD. (Data for Alaska, Puerto Rico and the Virgin Islands was developed at high-resolution, not 1:100,000 scale.) Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. Reaches are also defined on waterbodies and the approximate shorelines of the Great Lakes, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee.The NHD is a national framework for assigning reach addresses to water-related entities, such as industrial discharges, drinking water supplies, fish habitat areas, wild and scenic rivers. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network, much like addresses on streets. Once linked to the NHD by their reach addresses, the upstream/downstream relationships of these water-related entities--and any associated information about them--can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS). GIS can also be used to combine NHD-based network analysis with other data layers, such as soils, land use and population, to help understand and display their respective effects upon one another. Furthermore, because the NHD provides a nationally consistent framework for addressing and analysis, water-related information linked to reach addresses by one organization (national, state, local) can be shared with other organizations and easily integrated into many different types of applications to the benefit of all.Statements of attribute accuracy are based on accuracy statements made for U.S. Geological Survey Digital Line Graph (DLG) data, which is estimated to be 98.5 percent. One or more of the following methods were used to test attribute accuracy: manual comparison of the source with hardcopy plots; symbolized display of the DLG on an interactive computer graphic system; selected attributes that could not be visually verified on plots or on screen were interactively queried and verified on screen. In addition, software validated feature types and characteristics against a master set of types and characteristics, checked that combinations of types and characteristics were valid, and that types and characteristics were valid for the delineation of the feature. Feature types, characteristics, and other attributes conform to the Standards for National Hydrography Dataset (USGS, 1999) as of the date they were loaded into the database. All names were validated against a current extract from the Geographic Names Information System (GNIS). The entry and identifier for the names match those in the GNIS. The association of each name to reaches has been interactively checked, however, operator error could in some cases apply a name to a wrong reach.Points, nodes, lines, and areas conform to topological rules. Lines intersect only at nodes, and all nodes anchor the ends of lines. Lines do not overshoot or undershoot other lines where they are supposed to meet. There are no duplicate lines. Lines bound areas and lines identify the areas to the left and right of the lines. Gaps and overlaps among areas do not exist. All areas close.The completeness of the data reflects the content of the sources, which most often are the published USGS topographic quadrangle and/or the USDA Forest Service Primary Base Series (PBS) map. The USGS topographic quadrangle is usually supplemented by Digital Orthophoto Quadrangles (DOQs). Features found on the ground may have been eliminated or generalized on the source map because of scale and legibility constraints. In general, streams longer than one mile (approximately 1.6 kilometers) were collected. Most streams that flow from a lake were collected regardless of their length. Only definite channels were collected so not all swamp/marsh features have stream/rivers delineated through them. Lake/ponds having an area greater than 6 acres were collected. Note, however, that these general rules were applied unevenly among maps during compilation. Reach codes are defined on all features of type stream/river, canal/ditch, artificial path, coastline, and connector. Waterbody reach codes are defined on all lake/pond and most reservoir features. Names were applied from the GNIS database. Detailed capture conditions are provided for every feature type in the Standards for National Hydrography Dataset available online through https://prd-wret.s3-us-west-2.amazonaws.com/assets/palladium/production/atoms/files/NHD%201999%20Draft%20Standards%20-%20Capture%20conditions.PDF.Statements of horizontal positional accuracy are based on accuracy statements made for U.S. Geological Survey topographic quadrangle maps. These maps were compiled to meet National Map Accuracy Standards. For horizontal accuracy, this standard is met if at least 90 percent of points tested are within 0.02 inch (at map scale) of the true position. Additional offsets to positions may have been introduced where feature density is high to improve the legibility of map symbols. In addition, the digitizing of maps is estimated to contain a horizontal positional error of less than or equal to 0.003 inch standard error (at map scale) in the two component directions relative to the source maps. Visual comparison between the map graphic (including digital scans of the graphic) and plots or digital displays of points, lines, and areas, is used as control to assess the positional accuracy of digital data. Digital map elements along the adjoining edges of data sets are aligned if they are within a 0.02 inch tolerance (at map scale). Features with like dimensionality (for example, features that all are delineated with lines), with or without like characteristics, that are within the tolerance are aligned by moving the features equally to a common point. Features outside the tolerance are not moved; instead, a feature of type connector is added to join the features.Statements of vertical positional accuracy for elevation of water surfaces are based on accuracy statements made for U.S. Geological Survey topographic quadrangle maps. These maps were compiled to meet National Map Accuracy Standards. For vertical accuracy, this standard is met if at least 90 percent of well-defined points tested are within one-half contour interval of the correct value. Elevations of water surface printed on the published map meet this standard; the contour intervals of the maps vary. These elevations were transcribed into the digital data; the accuracy of this transcription was checked by visual comparison between the data and the map.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map provides a national network of flowlines, hydrolocations, and water bodies. Includes catchments, drainage areas, and flow network derivatives as available. Data for Georgia’s lakes, rivers, streams, and water features is derived from Elevation-Derived Hydrography (EDH) and supplemented by the National Hydrography Dataset (NHD) where necessary.

USGS 3DHP provides a national network of flowlines, hydrolocations, and water bodies; catchments and drainage areas are added as available. Where Elevation-Derived Hydrography (EDH) has not been collected, data are supplemented by the National Hydrography Dataset (NHD).

A dissolved version of the AVec_DBC data using ArcView to ensure any summary SWB or watershed statistical data are not double counted. The VMAP_SUM_AD1 shapefile data layer is comprised of 64 derivative polygon surface water bodies by admin units features derived based on 1:1 000 000 data originally from VMap0. The layer provides nominal analytical/mapping at 1:1 000 000. Acronyms and Abbreviations: VMap0 - Vector Map for Level 0; SWB - Surface Water Body.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map provides a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated. Data for Idaho’s lakes, rivers, streams, and water features is derived from Elevation-Derived Hydrography (EDH) and supplemented by the National Hydrography Dataset (NHD) where necessary.

This is a statewide polygon layer in which each polygon has a unique Water Body Identification number (WBID). The assessment units are drainage basins, lakes, lake drainage areas, springs, rivers and streams, segments of rivers and streams, coastal, bay and estuarine waters in Florida. The polygons roughly delineate the drainage basins surrounding the water body assessment units. The WBIDs are used in the Basin Rotation Total Maximum Daily Load (TMDL) program as well as other applications. WBIDs are assigned a FDEP district as part of their attribution. There are multiple instances where a WBID may be assigned to an FDEP district, but physically fall within the boundary of a different district. This is because WBIDs are grouped together into basins called Planning Units and there are instances where a Planning Unit basin will fall across FDEP district boundaries. In these cases, for consistency's sake, all the WBIDs that are in the Planning Unit will be assigned to the same FDEP district. For information on which district the WBID physically falls in, please refer to the FDEP Regulatory Districts layer.