FAQs
For additional hydrography-related FAQs, please visit the Mapping, Remote Sensing, and Geospatial Data Questions page and choose "Hydrography" from the drop down.
How should I cite datasets and services from The National Map?
The USGS does not require a specific format when citing data obtained through The National Map . You should follow the citation guidelines provided by instructors or publication editors as appropriate. The following should help you find the information that you need: Citation for Datasets Author: U.S. Geological Survey Release date: the first four numbers of <pubdate> from dataset metadata for the...
What sources were used to produce the National Hydrography Dataset (NHD)?
The National Hydrography Dataset (NHD) is a combination of USGS hydrologic digital line graph (DLG) files and Environmental Protection Agency (EPA) reach files, version 3.0 (RF3). U.S. Forest Service Cartographic Feature Files (CFF) and USGS Tagged Vector Hydro (TVH) captured from 7.5-minute printed maps were also used. Some states also contributed their own stream layer data to the compilation of...
What is the positional accuracy of the National Hydrography Dataset (NHD)?
Original hydrographic data were compiled to meet National Map Accuracy standards . These standards have been maintained in the process of creating the NHD. At 1:100,000 scale, ninety percent of well-defined features are within 167 feet (0.02 inches at map scale) of their true geographic position. When higher resolution data are created and submitted, the positional accuracy may vary due to...
What is the National Hydrography Dataset (NHD)?
The National Hydrography Dataset (NHD) is a digital vector dataset used by Geographic Information Systems (GIS) to define the spatial locations of surface waters and is designed to provide comprehensive coverage of surface water data for the U.S. The NHD contains features such as lakes, ponds, streams, rivers, canals, dams, and stream gages in a relational database model system. These data are...
In what scale are the data in the National Hydrography Dataset (NHD)?
Scales for data in the National Hydrography Dataset: Conterminous United States, Hawaii, and the Virgin Islands, medium resolution - 1:100,000-scale Conterminous United States, Hawaii, and the Virgin Islands, high resolution - 1:24,000-scale Puerto Rico - 1:20,000-scale Alaska - 1:63,360-scale Users are encouraged to work with their state's principal steward to produce and submit data at higher...
What formats are available for hydrography data products in The National Map?
Depending on the product type, hydrography data are offered in Esri File Geodatabase 10.1, Shapefile or GeoPackage formats. National Hydrography Dataset (NHD) data is available as national extracts, state extracts, 4-digit sub-regions, 8-digit sub-basins, or in a specified extent from The National Map Downloader . A national extent of medium and high resolution NHD data in File Geodatabase format...
How do I download hydrography data products?
Download USGS hydrography data (datasets representing U.S. surface water for mapping and modeling applications) using The National Map Downloader or using download links that are listed at Access National Hydrography Products . Learn more: The National Map: Hydrography Training Videos National Hydrography Dataset User Guide For streamflow data, see: Where can I get real-time and historical...
Where can I find a list of URLs for The National Map services?
See The National Map Services for a complete list of map service URLs. That includes available REST, WMS, WMTS (cached base maps only), WFS, WCS, and other service links. Learn more: Training videos for The National Map Products and Services The National Map Applications