National Hydrography Product Information Document
The National Hydrography Dataset (NHD) portrays the Nations surface water in a geospatial dataset designed for geographic information system (GIS). It is the geospatial framework for a water information system, designed to integrate all forms of water related data. This allows for advanced scientific analysis of water issues as well as general purpose mapping. The dataset consists of best available coverage for a 7.5 million mile river network and 6.5 million lakes. The dataset is free to access, continuously maintained, and ready for use. NGP will position itself to maintain and enrich the quality of NHD data through stewardship while expanding to provide new products and services that enhance our ability to serve science and our Communities Of Use (COU).