Dams
The river is the site for the largest dam removal project in history. The Elwha Ecosystem Restoration project is the second largest ecosystem restoration project the National Park Service has attempted, after the Everglades. The Elwha River Ecosystem and Fisheries Restoration Act of 1992 was signed by the first President Bush after Congress passed it in 1992. The project is projected to cost $350 million. The act authorized the Secretary of the Interior to acquire and remove two dams on the river and restore the ecosystem and native anadromous fisheries.
The 108-foot (33 m) tall Elwha Dam and the 210-foot (64 m) tall Glines Canyon Dam began dismanteling in stages starting in September 2011. Two downstream water treatment facilities were completed in early 2010 to protect the water supply for the city of Port Angeles and the fish hatcheries from silt and sediment that will wash downstream once the dams are removed. In order to protect fish stocks below the dams during removal, the dams will be taken out over a two-and-a-half to three-year process, to ensure there is no silt in the river while salmon are spawning downstream.
The Elwha Dam was completely dismantled in March, 2012, and the lake emptied in April 2012. Restoration of the area around the dam began, including tens of thousands of native plants started in local greenhouses.
Once dam removal is complete, salmon will naturally recolonize the 70 miles (110 km) of habitat in Olympic National Park. The area once under the reservoirs will be revegetated to prevent erosion and speed up ecological restoration of the area. Because almost all of the Elwha's watershed is in a National Park, the river should become relatively pristine, with few of the issues of agricultural runoff and water heating that affect other salmon river habitat in the Pacific Northwest. Model projections by the Park Service show that up to 392,000 fish will fill 70 miles of habitat, theoretically matching the "predam peak".
Read more about this topic: Elwha River