Did You Know...

• that only 2% of dams in the U.S. are over 100 feet high, and more than 38,000 are under 25 feet?
• that 55% of dams in the U.S. are privately owned?
• that the most common primary purpose of dams is recreation?

These facts, as well as many others, are available from the National Inventory of Dams (NID), maintained and published by the Corps of Engineers. The NID is compiled from information provided by 16 Federal agencies and all states and Puerto Rico for dams they own or regulate. The NID includes all dams over 25 feet high, as well as lower dams with significant or high hazard potential. The Inventory has 42 fields of information, including height, length, type, primary purpose and owner, and can be accessed at www.tec.army.mil/nid.

The website features a detailed query function and an extensive map display. To query the NID for specific information on dams in the U.S., click on Introduction on the opening screen. Info Search on the left menu bar enables queries using any of the 42 fields. For display of dams on a map of the U.S., click on Map Display on the opening screen. Upon zooming in to state or larger scale, dams can be displayed by height or hazard classification, along with other features such as rivers, highways and county boundaries. Display at even larger scales, 1:1M or larger, shows detailed rivers and streams and water bodies.

Thanks to Anthony Niles, Corps of Engineers, for providing this Benefits of Dams.

(reprinted from the USSD Newsletter, March 2003, page 3)