The Park Service, part of the Interior Department, acquired the dams in 2000 from Daishowa America. The federal government plans to remove the dams to restore salmon and trout runs in Olympic National Park.
The service seeks a 10-year construction permit to remove the structures. The Corps of Engineers is reviewing the application in accordance with the Rivers and Harbors Act and Clean Water Act. The U.S. Environmental Protection Agency is to comment to the Corps on aspects that could affect the aquatic environment pursuant to the Clean Water Act. The Washington Department of Ecology is to determine whether to certify the work and is reviewing the project for consistency with the Coastal Zone Management Act.
Congress passed the Elwha River Ecosystem and Fisheries Restoration Act in 1992, requiring the Secretary of Interior to restore the Elwha River ecosystem and native anadromous fisheries. Interior determined that dam removal is the only option that would accomplish full restoration. The proposed project also is to protect and restore treaty fishing rights for affected Indian tribes.
The Elwha River Act requires the Park Service to maintain the existing level of flood protection for developments along the Elwha River. Additionally, it requires the service to protect industrial and municipal water users from adverse water quality effects of dam removal.
The Park Service said restoration of natural sediment flow in the lower river would allow sediment to accumulate in areas that have eroded since the dams were built. That is expected to increase river elevations ranging from one to four feet in some areas, with an average increase of two feet.
Since the dams were built, about 18 million cubic yards of rock, gravel, sand, and sediment, have been trapped behind them.
Representatives of the National Park Service, city of Port Angeles, and Lower Elwha Klallam Tribe signed a memorandum of understanding in 2004 to advance the dam removal plan.