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National Hydrography Dataset (NHD)

General Information

The NHD is a comprehensive set of digital spatial data that represents the surface water of the United States using common features such as lakes, ponds, streams, rivers, canals, stream gages, and dams. More>>

Polygons are used to represent area features such as lakes, ponds, and rivers; lines are used to represent linear features such as streams and smaller rivers; and points are used to represent point features such as stream gages and dams. Lines also are used to show the water flow through area features such as the flow of water through a lake. The combination of lines is used to create a network of water and transported material flow to allow users of the data to trace movement in downstream and upstream directions. More detailed information about the NHD can be obtained from the United States Geological Survey (USGS) NHD website. The USGS serves as national steward for the NHD.

The NHD, in Oregon and Washington, is the result of over a decade of data development work. Partners within the two-state area initially collaborated on development of a high resolution dataset that was based on the "LLID" identifier. This dataset was maintained within the PNWHF infrastructure. In 2005, the PNWHF made a decision to migrate to the NHD format and this transition was completed by 2009. The precursor "LLID" dataset was the source for the NHD in Oregon and Washington. The NHD has now entered into a maintenance and stewardship phase.

Why NHD Stewardship?

Effective stewardship of the NHD ensures ongoing improvement of this set of high resolution hydrography features that adhere to agreed-upon national standards. It recognizes stewardship roles at the national level, and hierarchically, within each state. Communication and collaboration is encouraged. More>>

Stewardship identifies data quality deficiencies within the dataset and recognizes on-the-ground knowledge of the stewards and sub-stewards within each state. It ensures availability of the NHD dataset for maintenance and improvement, analysis, mapping and reporting activities. And lastly, it allows for the effective integration of these activities with similar activities for the WBD.

Have you identified the need for an edit to the NHD?

The PNWHF Partners are committed to improving the quality of the NHD through time. Each Partner is primarily responsible for data quality for the portion of the NHD on lands under their jurisdiction. Each partner also serves as a conduit for moving proposed updates through the PNWHF stewardship process. Any user of the NHD may submit proposed edits to the stewardship process. Please contact the individuals listed below if you identify a need for an improvement to the dataset.

Oregon State NHD Steward: Bob Harmon (Oregon Water Resources Department,

Washington State NHD Steward: Anita Stohr (Washington Department of Ecology, asto461@ECY.WA.GOV).

Availability and Download

The maintained (master) copy of the NHD is available from the national USGS repository. Downloads are currently available by 8-digit Hydrologic Unit (subbasin) and also by pre-staged extracts at the state or 4-digit Hydrologic Unit (SubRegion) spatial extent. Visit the above linked ftp locations for these pre-staged datasets.

Sharing Your Uses of the NHD

Has your organization used the NHD in innovative ways? Please send brief descriptions of such uses to Jay Stevens (BLM – or Tom Carlson (USGS – and they will be shared on this website.