NHD Medium Resolution
In the late 1990s, the USGS and the US EPA collaborated to produce the National Hydrography Dataset Medium Resolution, at 1:100,000 scale for the conterminous U.S. In the early 2000s, the US EPA assumed the role of primary custodian for the NHD Medium Resolution to support their applications and those of other medium resolution users, while the USGS, U.S. Forest Service, and additional partners initiated the production of the NHD High Resolution at 1:24,000 scale or better. More background regarding the development history of NHD and related datasets may be found in the document Making the Digital Water Flow: The Evolution of Geospatial Surfacewater Frameworks.
Today, the US EPA manages the maintenance and distribution of NHD Medium Resolution as part of the NHDPlus Version 2 suite of products, which can be downloaded from the EPA NHDPlus website as described below.
The NHD Medium Resolution may be downloaded in regional datasets in either shapefile or File Geodatabase formats. The map below will automatically redirect you to the EPA NHDPlus website.
Additionally, the NHD Medium Resolution is available in modified format in a seamless national File GeoDatabase. The seamless geodatabase and accompanying User Guide is available for download on the NHDPlus National Data webpage.
List of areas by name
Documentation for medium resolution NHD is available in three documents:
NHD Concepts and Content
NHDPlusV2 User Guide
1:100,000-scale National Map Accuracy Standards
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