Remember meForgot password?
    Log in with Twitter

article imageElwha River restoration project set to begin in Washington

By Lynn Herrmann     Sep 1, 2011 in Environment
Port Angeles - A major river restoration project is set to begin in the US Pacific Northwest this month, as two large dams will be removed, enabling the river to flow freely for the first time in 100 years and helping bring back its astounding salmon runs.
Washington’s Elwha River, a short-but-steep 45-mile river flows from the heart of Olympic National Park to the Strait of Juan de Fuca. Before dams were built on the river in 1913 and 1927, it was home to a legendary salmon run, including six species of Pacific salmon and steelhead.
Soon, the river will be on the road to recovery, as the Elwha Dam (1913) and the Glines Canyon Dam (1927) begin being dismantled. Glines Canyon Dam, at 210 feet, will be the tallest dam ever removed in the US.
Building of the dams on the Elwha dealt a devastating blow to the salmon, as well as to the Lower Elwha Klallam Tribe, dependent on the salmon runs since time immemorial. Without marine nutrients once brought upriver by the salmon, the wildlife and ecosystem dependent on such a natural act suffered.
Dam removal diagram.
Dam removal diagram.
Additionally, through normal currents and flooding events, the river will be able to transport silt, gravel and sediment, naturally replenishing lower river and beach habitats.
American Rivers notes that in 2011, called “the year of the river” by the leading conservation group, a milestone of 1000 dams will be reached.
Dismantling the Elwha Dam, at river mile 4.9, and the Glines Canyon Dam, at river mile 13, will open up more than 70 miles of pristine and protected habitat in the Elwha and its tributaries.
The dismantling process will be done in stages over several years. A diversion channel will be built at Elwha Dam where water from Lake Aldwell will drain into. This initial stage will lower the lake by 50 feet. At that time, construction crews will conduct controlled blasting in dismantling the dam, also removing rock fill used to repair a large hole at the base of the dam in 1913.
Glines Canyon Dam is twice as high as Elwha Dam, and its removal will be more complex. Dismantled in 7.5 foot increments, the dam will undergo cuttings with diamond wire saws, isolating large pieces of concrete. The 22-ton blocks of concrete will then be winched by crane to trucks located on cliffs next to the dam.
Glines Canyon Dam  Washington.
Glines Canyon Dam, Washington.
The Dan Driscoll/flickr
Most of the water behind Glines Canyon Dam will release through an existing outlet pipe, with successive notches made in the existing concrete to follow. After water left behind the dam reaches reservoir bed, controlled blasting will remove the remainder of the dam.
American Rivers notes about 40 percent of the sand and silt accumulated behind this dam will be carried downstream, washed into the ocean within 3-5 years.
Before the dams were built, the free-flowing Elwha supported runs of Pacific salmon, coho, pink, chum and sockeye. It also carried spring, summer and fall Chinook. Combined, these legendary runs neared 400,000 fish, with individual Chinook in excess of 100 pounds. Other fish using the Elwha included sea-run cutthroat trout, winter and summer runs of steelhead, and native char.
The dams were built between 1910 and 1927 to provide hydroelectric power to a mill in Port Angeles, a town located along the north Olympic Peninsula. Neither dam had fish passage facilities, eliminating historic spawning habitat.
Opposed to the dams since they were built, the Lower Elwha Klallam Tribe has been a staunch advocate of their removal. The Tribe was the first on record in calling for restoration of the river.
Eventually, the environmental community got involved. Relicensing efforts by the owner and operator of the dams where challenged and in 1992, the Elwha River Ecosystems and Fisheries Restoration Act was passed by Congress.
The dams produced only a modest amount of power, and thanks to alternative energy supplies from the Northwest power grid, they are no longer needed. The two dams and related facilities were purchased for $29.5 million by the federal government in 2000 from the Fort James Corporation. According to the Seattle Times, the US Bureau of Reclamation stopped power generation at both dams on June 1.
A multi-day, multi-venue event, Celebrate Elwha! will be held in Port Angeles and the Elwha River Valley September 15-18, marking the beginning of the dam removal process. The event will include a two-day science symposium, educational activities, and numerous music acts and art displays in downtown Port Angeles
More about elwha river, Restoration, elwha dam, glines canyon, legendary
More news from
Latest News
Top News