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Sunday, October 2, 2011 - Page updated at 08:30 p.m.
Condit Dam next to tumble in restoration plan
By Lynda V. Mapes
Seattle Times staff reporter
Contractors are scheduled to blow a hole in Condit Dam at the end of October, restoring the White Salmon River to its natural flow for the first time in nearly a century.
First Elwha and Glines Canyon, now Condit: the Northwest is a dam-busting epicenter, as three of the largest dams ever taken out in the U.S. tumble here.
"Internationally, people are looking at this and scratching their heads," said Gordon Grant, research hydrologist with the U.S. Forest Service research station in Corvallis, Ore. "... We have some explaining to do."
For the two dams on the Elwha River and the Condit, the explanations are, in part, similar. Both are because the structures, built in the early 1900s for private industry, lacked fish passage. When it came time to license and re-license the dams, they were more expensive to retrofit to meet modern environmental standards than their hydropower was worth.
The similarities end there. The Condit project is a fraction of the size of the undertaking on the Elwha. Removal will also be undertaken quite differently.
On the Elwha, removal of two dams will take about three years, because of the massive amount of sediment trapped behind the structures — about 24 million cubic yards.
But Oct. 26, contractors are scheduled to blow a hole in the bottom of Condit dam. The reservoir behind it is expected to drain in about six hours, returning the White Salmon River to its natural flow.
Much of the 2.4 million cubic yards of fine sediment behind the dam is expected to sluice out in the first flush. Winter rains will rinse out more, and high-pressure hoses will be turned on the sediment come spring, said Tom Gauntt, spokesman for PacifiCorp, which owns the dam.
Then, the 125-foot-high dam will be taken down like a wall, Gauntt said. By this time next year, it will be gone.
Not a moment too soon, said Tony Washines, an elder in the Yakama Indian Nation, a party to the settlement agreement under which the dam is coming out.
"It's long overdue," Washines said. "When we have a relatively small victory such as the Condit Dam, the elation and joy of our people is a heartfelt feeling, it is the satisfaction of seeing something return, that the land can have the opportunity to heal itself."
Opponents mourned the loss of recreation on Northwestern Lake upstream of the dam, and questioned taking out a carbon-free power source.
The White Salmon River, named for the salmon runs that once were abundant before the dam was built, today has no more spring chinook, coho, chum or steelhead. Tule fall chinook are listed as threatened under the federal Endangered Species Act. Bull trout have not been documented in the river since the 1990s.
With dam removal, it's expected that salmon in the Lower Columbia will recolonize the river, leading to restoration of the runs, said Bill Sharp, fisheries biologist for the Yakama.
Once the dam is breached at river mile 3.3 from its confluence with the Columbia, it will open main-stem and tributary habitats, including about 33 miles of new habitat for steelhead, 21 miles for coho, 13 miles for spring chinook and 8 miles for fall chinook.
No decision has been made about hatchery production. "There will be a period while we will wait and see if there is a need for supplementation," Sharp said.
Since its construction was completed in 1913, Condit Dam has diverted the river from its natural channel, and blocked downstream navigation and upstream fish passage. It was built by Northwestern Electric Company with the backing of private investors that owned the Crown Columbia Paper Company, to provide additional power to the mill in Camas, Clark County. Later, the dam also provided power to communities from Washougal, Clark County, to Portland.
In 1991, PacifiCorp filed for a new Condit license, and in 1996, the Federal Energy Regulatory Commission issued an environmental-impact statement calling for state-of-the-art fish passage and new in-river flow requirements.
The company estimated it would cost about $100 million to relicense the dam. Taking it out, at a cost of about $32 million, was the cheaper option, Gauntt said.
In 1999, PacifiCorp signed a settlement agreement to take out the dam, culminating two years of negotiations with state and federal agencies, American Whitewater, and 13 environmental groups.
For now, the dam is still generating electricity — enough to power about 7,000 average homes for a year. But a few days before blowing a hole in the dam, operators will shut the plant down for good.
Condit's power will be replaced from the company's other resources, including hydropower, wind and coal.
Lynda V. Mapes: 206-464-2736 or email@example.com
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