Dams power down in the largest US dam removal

May 28, 2011 - 10:43 AM

PORT ANGELES, Wash. (AP) — The Elwha River on Washington's Olympic Peninsula once teemed with legendary salmon runs before two towering concrete dams built nearly a century ago cut off fish access to upstream habitat, diminished their runs and altered the ecosystem.

On June 1, nearly two decades after Congress called for full restoration of the river and its fish runs, federal workers will turn off the generators at the 1913 dam powerhouse and set in motion the largest dam removal project in U.S. history.

Contractors will begin dismantling the dams this fall, a $324.7 million project that will take about three years and eventually will allow the 45-mile Elwha River to run free as it courses from the Olympic Mountains through old-growth forests into the Strait of Juan de Fuca.

"We're going to let this river be wild again," said Amy Kober, a spokeswoman for the advocacy group American Rivers. "The generators may be powering down, but the river is about to power up."

The 105-foot Elwha Dam also came on line in 1913, followed 14 years later by the 210-foot Glines Canyon Dam eight miles upstream. For years, they provided electricity to a local pulp and paper mill and the growing city of Port Angeles, Wash., about 80 miles west of Seattle. Electricity from the dams — enough to power about 1,700 homes — currently feeds the regional power grid.

A Washington state law required fish passage facilities, but none was built. So all five native species of Pacific salmon and other anadromous fish that mature in the ocean and return to rivers to spawn were confined to the lower five miles of the river. A hatchery was built but lasted only until 1922.

The fish are particularly important to members of the Lower Elwha Klallam Tribe, whose ancestors have occupied the Elwha Valley for generations and whose members recall stories of 100-pound Chinook salmon so plentiful you could walk across the river on their backs.

"We have never been happy that the salmon runs in the river were cut off," said Robert Elofson, Elwha River restoration director for the tribe, which along with environmental groups fought in the 1980s to tear down the dams. The tribe's land now includes about 1,000 acres on and near the Elwha River. "It's hard to have any pride when your main river of your tribe has been blocked and the salmon runs almost totally destroyed."

In 1910, the Elwha produced about 390,000 salmon and sea-run trout, including coho, pink, sockeye and chinook salmon and steelhead trout. The number of wild native sea-run fish dwindled to only about 3,000 in 2005.

Brenda Francis, a tribal spokeswoman and member, said her mother as a little girl recalled meetings where tribal members discussed taking down the dams. "The people never wanted the dams to go up in the first place," she said.

Because most of the river lies within the protected boundaries of Olympic National Park, scientists say the Elwha River restoration project also presents a unique opportunity to study how a river recovers once dam-free. Researchers will study how salmon return to the river, how their return will benefit wildlife such as bears and eagles, and how the estuary will be reshaped when sediment trapped behind the dams is released.

More than 24 million cubic yards of sediment are held behind the dams in Lake Mills and Lake Aldwell, enough to fill a football stadium two miles high, said David Reynolds, a spokesman for Olympic National Park. The National Park Service and the Lower Elwha Klallam Tribe are leading the river restoration project.

When the reservoirs are drain, 800 acres of barren land will be exposed. At the park's new greenhouse, park botanists and volunteers are busy transplanting and potting salal, gooseberry, ocean spray and other plants to fill the exposed land. Crews have been collecting seeds, cones and cuttings along the river since 2002.

The first 15,000 plants will be put in this fall. In all more than 400,000 plants will be used to restore a forested ecosystem, keep out exotic species and prevent erosion. "This is a great experiment for other dam removals," said Jill Zarzeczny, biological technician with the Elwha revegetation project.

On a recent day at the powerhouse, the dams were running at maximum generation, fed by glaciers and weather patterns that make it a rich water resource, said Kevin Yancy, the power plant's foreman. He works for the U.S. Bureau of Reclamation, which has operated the dams since the federal government bought them in 2000.

Starting in June, workers will take the electrical load off the generator, de-energize the lines coming into the plant, close the headgates and remove all hazardous energy so contractors can begin their work later this fall, Yancy said.

In the control room, original gauges, switches and other instrument are still in use, along with more modern equipment, to measure the reservoir water levels and amount of energy produced. A window in the room offers a view of the milky glacier-fed river below where Yancy said he will often see hundreds of fish jumping as they run up against the walls of the Elwha Dam.

"They want to go upstream," said Yancy. "Being a hydro guy none of us want to see power plants removed, but for this river and this story, it's time."

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On the Internet:

Elwha River Restoration: http://www.nps.gov/olym/naturescience/elwha-ecosystem-restoration.htm