Lake Roosevelt’s environmental condition reflects a complex set of natural and human forces.
Present day conditions stem from 1942, which is when the lake was created to support development of the Bureau of Reclamation’s Columbia Basin Project. The waters rose by more than 400 feet, Grand Coulee Dam blocked the return of salmon from the Pacific, and the free flowing upper Columbia River became regulated. In addition, upstream mining, milling, smelting and pulp operations resulted in toxins, e.g.—lead, zinc and mercury, being embedded in Lake Roosevelt’s sediment.
The fishery pages explore both past and current conditions, including the extraordinary efforts of fishery managers to sustain and develop a fishery that is both culturally sensitive and available to 1.5 million annual visitors. The water quality pages explore issues related to sediment contamination, temperature and total dissolved gas. There are also several links to other web pages with information about Lake Roosevelt’s environment.