June 7, 2011 - Washington dam removal in process

While state and federal governments pursue policies supporting the development of new renewable energy resources, existing hydroelectric dams are being removed.  Last year, I noted the plan to remove the Elwha and Glines Canyon Dams on the Elwha River on Washington's Olympic Peninsula.  That plan is moving forward; last week, after 99 years of producing renewable power, the dams' electricity-generating turbines have now been turned off.

The Elwha River restoration project will be the largest dam removal in U.S. history.  All told, the dam removal project is projected to cost $324.7 million.

The Elwha project is made more interesting by its factual context, including land conservation, fish impacts, and sedimentation.  Much of the river's 45-mile course runs through Olympic National Park, making power generation a use some feel is incongruous with the watershed's protected status.

The Elwha River was formerly home to impressive runs of anadromous fish, including salmon, which have been an important part of local native Americans' culture.  In 1910, the river produced approximately 390,000 wild salmon and sea-run trout, but that number dropped more than 99% to only about 3,000 wild native salmonids in 2005.  The dams are believed to have played a part in this decimation of that fish stock.

Thanks to the glacier-fed nature of the watershed, massive amounts of sediment have built up behind the dams -- perhaps as much as 24 million cubic yards, or enough sediment to cover almost 15,000 acres one foot deep.

Dam demolition and removal itself is scheduled to begin September 17, 2011.