Milestones in Elwha River dam removals: Fish still checked at Elwha Dam; most work focuses on Glines [**Gallery**]
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A tethered barge carrying an excavator with a jackhammer attachment chips away at the precipice as water flows over the Glines Canyon Dam. -- Photo by Keith Thorpe/Peninsula Daily News
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The east abutment of Glines Canyon Dam shows evidence of the progress demolition crews have made in removing the main dam structure. -- Photo by Keith Thorpe/Peninsula Daily News.
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Painted markings for pool elevation on the Glines Canyon intake tower mark the progress for the continually lowering level of Lake Mills. -- Photo by Keith Thorpe/Peninsula Daily News.
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The now-useless spillway gates of Glines Canyon Dam stand far above the current pool elevation of Lake Mills as workers remove the main portion of the dam far below. -- Photo by Keith Thorpe/Peninsula Daily News.
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The names Tom and Roy, possibly those of workers when Glines Canyon Dam was built, and the year 1927 are revealed on the intake tower when water levels fell below where they were painted. --Photo by Keith Thorpe/Peninsula Daily News.
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Rep. Norm Dicks stands in front of the Glines Canyon Dam — showing how the dam looked before its dismantling — in this photo taken in the mid-2000s. -- Photo by Keith Thorpe/Peninsula Daily News

By Paul Gottlieb
Peninsula Daily News

Who were Tom, Roy and Rob?

By Paul Gottlieb
Peninsula Daily News

OLYMPIC NATIONAL PARK — The steady dismantling of Glines Canyon Dam and the draining of Lake Mills has uncovered a landscape of mucky, gray sediment, neatly cut tree trunks — and at least one Kilroy-was-here jewel.

Previously underwater, the names “Tom,” “Roy” and possibly “Rob” are painted below what had been the waterline on the intake tower next to “1927,” when the dam was completed.

“They probably thought nobody will ever see this,” Barnard Construction project superintendent Aaron Jenkins said last week while it rained windblown, cold drops at the deconstruction site.

Workers are focusing efforts on Glines Canyon Dam after finishing demolition of the main structure of the smaller Elwha Dam downstream.

Dismantling the two dams began in September as part of the $325 million Elwha River restoration project.

With the snow-flecked Olympics as their backdrop, workers last week toiled on the upper dam by commandeering an excavator perched on a barge.

The excavator wielded a hydraulic hammer that hits with 4 tons of force in a relentless rhythm of hissing and pounding.

It has smashed a jagged, expanding hole in the dam.

As water cascaded down 14 stories, the barge appeared to float freely against the dam's wall on the other side, buffeted by water moving downstream as it sat on the diminishing lake.

It was steadied by cables anchored to the shoreline and into the abutments of the dam, and by steel I-beam “spuds” welded to the front of the barge that go down 23 feet, Jenkins said.

“It's not going anywhere,” Jenkins said of the barge.

“It probably is a little odd to look at.”

After May 1, the barge will be removed by a 500-ton crane parked in a graveled area where visitors to the dam once gathered.

At that point, because the dam widens closer to its base, workers will be able to work on their own on top of the dam.
OLYMPIC NATIONAL PARK — The tale of two dams has reached a milestone.

Last week, the Elwha River became a single, unhindered torrent rushing through a broad channel where the Elwha Dam once stood.

On the left side of the Elwha Dam site facing downstream, a man-made, dam-related channel was fully blocked by a berm Thursday and will be completely filled in by the end of July, project superintendent Aaron Jenkins said Friday.

As Barnard Construction workers start to wrap up work at the Elwha Dam site, they are focusing more attention on its imposing sister edifice 9 miles upstream, Glines Canyon Dam.

Workers began Friday to dismantle the upper dam's powerhouse, Jenkins said.

Workers began tearing down the Glines Canyon and Elwha dams the same week in mid-September.

Elwha Dam, completed in 1913, blocked the river just 5 miles from where the waterway pours into the Strait of Juan de Fuca at the Lower Elwha Klallam reservation.

Its demise after a century of damming the river opens the door for the return of several species of salmon, enabling them to swim upstream on their storied migration beginning — project managers hope — by the time the $325 million river restoration project is completed in September 2014.

Workers will continue excavating the entrance of the canyon, where a diversionary cofferdam still stands, for up to about five more weeks.

The river is finally coursing on its natural route, but fish won't swim fully upstream to Glines until the end of April when Lake Aldwell, created when Elwha Dam was completed, should be fully drained, Olympic National Park spokeswoman Barb Maynes said Saturday.

That can't happen until contractors remove about 30 feet left from a check dam that contractors built in the native channel to slow the flow of water to the channel that was blocked by a berm Thursday, she said.

The check dam must be removed gradually because the reservoir can be lowered only 11/2 to 2 feet a day to control the flow of sediment.

In about 10 days, work on removing the check dam will stop during a 14-day “hold” so the river can move back and forth across the reservoir, erode and build up more sediment, Maynes said Saturday.

“While the river is staying at the same level, it's just sort of meandering back and forth across the plane left behind,” she said.

“It's all centered around sediment transport and managing that, and where they get to certain levels of the reservoir.”

When the check dam is gone, “there will be no more reservoir,” Maynes said.

“[The river] will be restored to the type of flow it had before, and salmon will be able to return upstream like they did before.”

This slow, measured effort will open up 70 miles of river and tributaries and is intended to return the waterway to its former storied, salmon-rich glory.

Like Lake Aldwell, Lake Mills, created by Glines Canyon Dam, is being lowered no more than 11/2 to 2 feet a day.

It's where Barnard's approximately 30 workers and subcontractors will soon be turning their full attention.

At 210 feet tall, it was nearly twice the height of the 108-foot Elwha Dam and the tallest dam to be dismantled in U.S. history, but it's slowly being cut down.

Barnard wants to demolish Glines Canyon Dam, completed in 1927, by 2013, Jenkins said.

Workers have removed 70 feet, lowering Lake Mills by 60 feet; 10 feet of the dam was above water.

They expect to remove another 30 feet by May 1, cutting the dam down to about half its original size, Jenkins said.

That's when they must stop lowering the dam for a two-month “fish window” to protect salmon, Jenkins said.

Jenkins said there are 51/2 months of fish windows remaining this year: May 1-June 30, Aug. 1-mid-September and Nov. 1-Dec. 31.

That leaves 10 weeks of dam-removal work after June 30: July, the last half of September and October.

The fish windows are required to protect migrating fish from the 21 million to 28 million cubic yards of sediment piled mostly behind Glines Canyon Dam.

“There's a lot of fish windows here on out for the rest of the year,” Jenkins said, adding that it's caused the project to take longer than it otherwise might have.

Again, it's all about the movement of sediment.

About half of the sediment is coarse, which is good for salmon habitat, and half is fine, which is not so good, said Brian Winter, river restoration project manager for Olympic National Park.

The park is overseeing the project through the National Park Service because Glines Canyon Dam and almost all of the Elwha River lies within the park's boundaries, though Elwha Dam doesn't.

During May and June, the outmigration of smolt going downstream would be affected by the fine sediment, which compromises their ability to take oxygen out of water, Winter said last week.

“You want clean water and natural water conditions for them to go downstream,” Winter said last week, adding that each fish window has a specific protective purpose, depending on what fish species is in what stage of migration.

The 1980 explosion of Mount St. Helens provided a blueprint for establishing the fish windows that are slowing down the demolition of Glines Canyon Dam, Winter said.

The eruption triggered a flow of vast quantities of sediment into the Toutle River.

“Fish that would have normally returned to the Toutle River bypassed it because the sediment loads were so high,” Winter said.

During the fish windows, workers will continue dismantling Glines Canyon Dam's powerhouse, Jenkins said.

They also will work on removing the penstock, surge tower and gatehouse — until they can return the dam itself to the limelight Aug. 1.

________

Senior Staff Writer Paul Gottlieb can be reached at 360-417-3536 or at paul.gottlieb@peninsuladailynews.com.

Last modified: March 24. 2012 5:58PM
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