The National Hydrography Dataset

This map displays surface water features from the National Hydrography Dataset (NHD), which was jointly developed by the U.S. Environmental Protection Agency (EPA) and the U.S. Geological Survey. Within the NHD, these surface water features are combined to form “reaches,” which provide the framework for linking water resources data to the NHD surface water drainage network. These linkages enable the analysis and display of the water resource data in upstream and downstream order. While initially based on 1:100,000 scale data, the NHD is designed to incorporate and encourage the development of higher resolution data required by many users.

Courtesy of the U.S. Environmental Protection Agency, Office of Water.