The National Hydrography Dataset Plus High Resolution (NHDPlus HR), a national geospatial dataset used to map and analyze rivers and watersheds across the 48 contiguous United States, is now supported by a newly published user’s guide aimed at improving accessibility and understanding of the data for the water science community.
Produced through collaboration between the U.S. Geological Survey, the U.S. EPA Office of Water, and the USGS National Geospatial Program, the guide was led by Rich Moore, research hydrologist at the USGS New England Water Science Center. Its publication reflects ongoing efforts to ensure that complex geospatial data can be efficiently applied by scientists, engineers, planners, and decision-makers.
NHDPlus HR brings together watershed boundaries, elevation data, and detailed stream and river networks into a unified, high-resolution framework covering the 48 contiguous states. This integrated structure allows users to examine how water flows across landscapes, linking upstream and downstream processes with greater precision. The dataset also includes precipitation, temperature, and average streamflow values for individual stream segments, supporting a broad range of technical analyses.
For water professionals, these capabilities translate into practical benefits. NHDPlus HR supports streamflow estimation, evaluation of aquatic habitat conditions, flood and drought assessments, and water quality studies. The data are also used to model water availability and to better understand risks associated with extreme hydrological events, informing both long-term planning and operational decisions.
The new user’s guide improves on the 2019 edition by offering more detailed explanations of dataset components and documenting USGS efforts to enhance data quality, including correcting disconnected stream networks. These refinements accompany the evolution of NHDPlus HR itself, which has expanded national mapped features from 2.7 million to nearly 24 million at a 1:24,000 scale or finer.
NHDPlus HR is also accessible through other USGS platforms, including the National Map Viewer, National Map Downloader, and StreamStats, reinforcing its value as a practical, science-based resource for the water sector.
