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New Hampshire Department of Environmental Services

Media Center

DATE: May 23, 2012
CONTACT: Rick Chormann, 603 271-1975

DES Partners with USGS to Improve Maps of NH’s River Systems

Concord, NH – The New Hampshire Geological Survey, a unit of the New Hampshire Department of Environmental Services, recently completed an agreement with the United States Geological Survey that recognizes NHGS as the official steward of the state’s Watershed Boundary Dataset. The dataset subdivides the landscape based on how water flows across the land surface, providing useful information for a variety of water resource management purposes. Because water is a shared resource, which knows no political boundaries, this dataset is an essential tool for managing and protecting the state’s precious water resources.

The Watershed Boundary Dataset, abbreviated WBD, is a standardized classification for the entire nation, which divides the landscape into a series of similarly sized areas based on land surface form or topography called hydrologic units. The WBD shows the highest areas from which water runs off to rivers and streams and their many branching tributaries, which together comprise the drainage network, or watershed. Smaller units fit together to create progressively larger units until they encompass the drainage network of major rivers, such as the Connecticut River. The boundary between neighboring units is called a watershed “divide,” because rain falling on opposite sides of this imaginary line will flow in different directions. More often than not, these boundaries cross political boundaries, highlighting the fact that water is a shared resource. Even though we live on different streets in different towns, we can still have the same “watershed address.”

As the steward of the state’s dataset, NHGS is responsible for ensuring that the boundaries are as accurate as possible, and that the most up-to-date version of the dataset is readily accessible to the public. The new stewardship agreement builds upon the commitment made by NHGS in 2009 when a similar agreement was completed for the National Hydrography Dataset, representing the drainage network itself. Combined stewardship of these two related datasets assures that they will both remain current and closely integrated with one another. GIS data for the two national datasets is available from, or from the National Map Viewer . The New Hampshire Geological Survey strives to provide the most complete and accurate information possible. If while using the WBD you find any errors, please feel free to report them to Neil Olson, NHGS, at

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NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
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