Current State of Dam Removal in the Pacific Northwest

Over the past decade, there has been increased focus on the benefit of the continued use of old dams.  The growing movement for dam removal has focused on dams where the costs (including environmental, cultural, and safety impacts) outweigh the benefits of providing hydroelectricity, irrigation, and flood control.  Goals of dam removal can vary widely, but often include: removal of sediment build up behind the dams, allowing upstream and downstream fish migration, reinstating natural flows for fish and wildlife, returning water qualities to a more natural state, and eliminating safety risks of old dams.

Water flows through a spillway during a
dam removal in Washington.
Courtesy of the National Park Service

In the Pacific Northwest (Oregon, Washington, Idaho, and Northern California), there has been an increased focus on removal of old dams to allow salmon to return to their native spawning grounds.  These native spawning grounds are often far upstream of where the current dams permit the fish to travel.  Due to salmon-related concerns, among others, the Bureau of Reclamation and other dam operators have increasingly been deciding to decommission dams.

The first Northwest dam to be decommissioned and removed dates back to the 1970s, when the Washington Water Project (WWP) agreed to remove the Lewiston Dam at the mouth of the Clearwater River near its confluence with the Snake River in southeastern Idaho in 1973.  WWP agreed to remove the dam for several reasons: (1) the Clearwater had lost its salmon run in 1927, when the dam was constructed; and (2) the reservoir from the newly constructed Lower Granite Dam, down stream on the Snake River, interfered with the operation of the Lewiston Dam.

Following the removal of the Lewiston Dam, the Northwest didn't see further dam decommissioning and removal until the late 1990s.  In 1997, the Marie Dorian Dam, located on the Walla Walla River in northeastern Oregon, was removed after coordination between the Confederated Tribes of the Umatilla Indian Reservation and the U.S. Army Corps of Engineers.  The Marie Dorian Dam was removed primarily because it blocked salmon runs into the upper reaches of the Walla Walla River and its tributaries.

Marie Dorian Dam before removal
Courtesy of University of Montana

Walla Walla River after dam removal
Courtesy of University of Montana

Next, the Marmot Dam on Oregon's Sandy River was removed by its operator, Portland General Electric in 2007, after it became apparent that removal of the dam was a good economic decision because of the cost to install required fish ladders for salmon and maintain the old equipment.  The Sandy River now flows unimpeded from its headwaters on Mt. Hood to the Pacific Ocean.

In 2009, the Bureau of Reclamation removed the privately owned Savage Rapids Dam on the Rogue River in southwestern Oregon, also for salmon migration reasons.  The dam, previously used for irrigation, was removed after a Federal Court consent decree, in which the local irrigation district agreed to stop diverting water at Savage Dam if a pumping station for irrigation was constructed.  The pumping station went online in 2007.

Savage River Dam before removal.
Courtesy of the Bureau of Reclamation

Rogue River after the Savage Dam Removal
Courtesy of the Bureau of Reclamation

2011 and 2012 brought the removal of three large dams in Washington.  In 2011, Pacificorp, the operator of the Condit Dam on the White Salmon River in south-central Washington, began removing that dam.  The company expects there to be significant advantages for the spawning salmon and steelhead, cultural benefits to the tribes with the restoration of the fisheries, and recreational benefits in the form of increased opportunities for whitewater paddling.

Breaching of the Condit Dam in October 2011

Courtesy of National Geographic.

Additionally, the U.S. Department of Interior began removing the Elwha and Glines Canyon Dam on the Elwha River of Washington's Olympic Peninsula in September of 2011.  These two huge dams, previously used to generate hydroelectricity, had no fish ladders to allow for the passage of salmon and steelhead.  The removal of these two dams is the first step in a complete restoration of the Elwha River and its ecosystem.

Lake Mills, behind the Elwha Dam, slowly drains, revealing the build up of sediment.  

Courtesy of the National Park Service

Finally, in 2009, many parties, including operator Pacificorp, signed two agreements (Klamath Hydroelectric Settlement Agreement (KHSA) and the Klamath Basin Restoration Agreement (KBRA)),  that would begin the process of removing four dams on the Klamath River in northern California.  The Department of Interior has completed its draft environmental impact statement of the project, and awaits legislation from Congress to authorize a Secretarial Determination.  The Secretarial Determination will decide whether the removal of the four dams is beneficial to the public, and it will help restore the salmon and steelhead fisheries in the Klamath Basin.

Dam removal can have many benefits beyond allowing migratory fish to return to their native spawning grounds.  As the dams that have been removed demonstrate, removal often has cultural implications, particularly to the tribes surrounding the areas.  The Umatilla were instrumental in pushing for the removal of the Marie Dorian Dam; the Yakima tribes anticipate the return of the salmon runs which play an important part in their culture; the Elwha-Klallam tribe's creation site, which had been underwater for 100 years.

Ultimately, dam removal in the Northwest will likely continue, as the old infrastructure becomes expensive to fix, maintain, and modify to include fish ladders.  As these costs increase and the cultural, ecological, and social benefits accrue, the benefits will continue to outweigh the costs, leading to removal.