PORT ANGELES — Like a double-edged sword, the Glines Canyon and Elwha dams have produced electricity for the North Olympic Peninsula for almost a century — while at the same time decimating the Elwha River’s once-iconic salmon run.
The sword will be withdrawn at 8 a.m. Wednesday.
That’s when three giant turbine generators at Elwha Dam and one at Glines Canyon Dam will be stopped for good.
“It really is the end of an era of hydroelectric generation on the Elwha River,” Elwha Dam plant supervisor Kevin Yancy said Friday.
“We are putting it to bed. It will never produce power again.”
The power cutoff will be followed by about 30 to 45 days of decommissioning the dams.
Federal Bureau of Reclamation workers will engage in such tasks as removing oil from power plant machinery, Yancy said.
The 19 megawatts produced annually by the dams pour into the Bonneville Power Administration grid.
It’s enough electricity to provide power to 11,000 to 12,000 homes, BPA spokesman Doug Johnson said.
But it’s minuscule compared with the 12,500 megawatts that coursed through BPA’s grid as of Thursday, he said.
“It’s tiny,” Johnson said. “It’s a very small amount compared to the overall generation.”
Wednesday’s shutdown will be a first step in returning the river to its wild state.
The river has been harnessed for power generation since 1913, when real estate baron Thomas Aldwell completed the first dam, the Elwha Dam, in 1913 without fish ladders.
Electricity generated by the river powered the developing cities of Port Angeles, Port Townsend and Poulsbo, as well as the Navy yard in Bremerton.
The second dam, Glines Canyon, went up — also without fish ladders — in 1927.
Barnard Construction Co. of Bozeman, Mont., will start tearing down the dams Sept. 17.
Bringing down the dams is part of a $327 million effort that began in 1992 with the passage of the federal Elwha Act, which directed the Department of the Interior to restore the river’s fisheries.
The project includes $26.9 million for Barnard Construction Co. to dismantle the dams by Sept. 17, 2014, and $91.4 million for industrial and municipal water treatment plants.
It’s a project of firsts — the largest tear-down of dams and second-largest ecosystem restoration project in the nation’s history.
“We let the contract for the first dam removal of this size,” Olympic National Park Superintendent Karen Gustin said Thursday.
“Turning off the power is definitely a first and probably does not happen that often in the dam management world,” she said.
“It’s definitely going to be an important day for the Bureau of Reclamation and a period of transition from generating power to shutting power off and moving to dam deconstruction and then river restoration.”
The dams are coming down to restore the fisheries.
The tear-down project will open up 70 miles of prime river habitat that empties into the Strait of Juan de Fuca that now is blocked by the Elwha Dam, the lower of the two dams, 4.9 miles from where fresh water meets salt water.
Wednesday’s power-generation shutoff will be followed by the lowering of the Lake Aldwell reservoir behind 108-foot-tall Elwha Dam beginning within the following week or so, Olympic National Park spokeswoman Barb Maynes said.
Workers will start draining Lake Mills behind 210-foot-tall Glines Canyon Dam beginning in late June or early July, she said.
Both lakes will be lowered 18 feet to the level of the dams’ spill-gate sills in preparation for destruction.
For the time being, the lakes will remain open for recreation, Maynes said, adding that a date has not been set for permanent closure to public use.
How the dams will be dismantled — whether by controlled blasting, by diamond-wire saw or a combination of methods — is still being discussed with Barnard Construction, Maynes said last week.
One issue has been settled: Concrete refuse from the dams will be deposited at county gravel pits on Harrick Road and Place Road, Clallam County Engineer Ross Tyler said last week.
That means truckers hauling the material won’t be rumbling through Port Angeles.
In addition, the county will get a percentage of that concrete for road projects, Tyler said.
“It makes wonderful road base material,” he said.
Four Barnard Construction employees, including project manager Brian Krohmer, have moved to the Port Angeles area for the three-year duration of the tear-down project, Krohmer said last week in an email.
“We do not anticipate any more Barnard personnel arriving on-site until August/September,” Krohmer said.
“We are utilizing local subcontractors when we need assistance with the preliminary work.”
As the dams are torn down, the two new water treatment plants will process Elwha River water made newly turbid by the controlled release of water carrying sediment behind the two dams, said Tim Randle, Bureau of Reclamation manager of the sedimentation and river hydraulic group.
A sediment study last summer raised estimates of the amount of sediment from 19 million cubic yards to between 21 million and 28 million cubic yards.
The increase in estimates should not have an impact on the project, Randle said.
Much, though not all, of that sediment will coat the Elwha River to provide habitat for five species of salmon that before the dams were built were estimated to number 400,000 spawning annually and have, since the dams locked down the river, dwindled to 3,000.
“We are predicting, according to computer models and lab experiments, that one-quarter to one-third of the sand and gravel will get out, and the rest will remain stable in the reservoir over the long term,” Randle said, adding that one-half to two-thirds of the silt will flow down the river while the remainder will stay in the reservoir.
What won’t happen is “this massive wave of sediment that’s coming all at once,” he said.
“It will be metered out over a period of time,” Randle said. “There is going to be a little more sediment going to Ediz Hook.”
Revegetation of the Elwha Valley will begin as the dams are drawn down, Maynes said.
Aldwell’s granddaughter, Noreen Frink, 72, of Seattle, expects to attend the Sept. 17 celebration to mark the beginning of the Elwha Dam’s demise.
Frink saw the Elwha Dam for the first time in October and toured it for the first time two weeks ago, she said last week.
“I think that what they are doing is proper,” she said of tearing down the dam her grandfather built.
“Hopefully, the fish will come up the stream, and that fish life will be restored.”
Lower Elwha Klallam Tribal Chairwoman Frances Charles recalled stories of disapproving tribal members standing along the Elwha River as the dams were being built in the early 1900s without fish ladders, knowing the tribe’s sustenance — salmon — would soon dwindle to a trickle.
Wednesday’s shutoff of power generation brings home the notion the dams are really coming down, Charles said.
“It makes it reality,” she said Thursday.
“When that day comes in September, it’s going to be overwhelming for our community members and our elders.”
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Senior Staff Writer Paul Gottlieb can be reached at 360-417-3536 or at paul.gottlieb@peninsuladailynews.com.