Skip to main content
U.S. flag

An official website of the United States government

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 designed to be used in general mapping and in the analysis of surface water systems. Using basic NHD features like flow network, linked information, and other characteristics, it is possible to study cause-and-effect relationships, such as determining how a source of poor water quality upstream might affect a fish population downstream.

Learn more: USGS Hydrography