National Inventory of Dams

The NID is a congressional authorized database, which documents dams in the United States and its territories. The database contains information about the dam's location, size, purpose, type, last inspection, regulatory facts, and other technical data. The NID is updated approximately every two years by collecting dam information from the 50 states, Puerto Rico and 18 federal agencies.

Fact Sheet (pdf, 134 KB)
National Inventory of Dams Website