PORT ANGELES — Workers in two 16-foot motorboats began uncoupling a 10-acre flotilla of logs on Lake Mills on Friday and Saturday.
For about four hours, they nudged the logs toward a current that carried the debris through a gate in the Glines Canyon Dam.
There, a curling torrent of water hurled the logs 210 feet from the top of the edifice down to the comparatively passive Elwha River.
Federal Bureau of Reclamation workers are untangling several hundred logs that are putting pressure on a log boom that protects the dam’s spillway from debris and potential failure, said Kevin Yancy, Elwha Dam power plant supervisor.
If the boom broke, the debris could clog up the spillway, sending water over the top of the dam in an uncontrolled release of water that no one wants to see.
“We could have spillway failure with all that there and have a lot of water going downriver that we weren’t planning on dumping,” Yancy said.
“That’s a key concern with dam safety,” he said. “That’s why the log booms are in place there.”
During the project, which is expected to take several days, Lake Mills will remain open for recreation.
The schedule for breaking up the log jam will be dependent on water flow that must be fed by sufficient snowpack in the Olympics, Yancy said.
On Friday, 5,000 cubic feet a second roiled through the gate.
That equals 2.25 million gallons a minute, Yancy said.
Bureau of Reclamation workers clear the lake annually of woody debris.
But this year, the number of nuisance logs dramatically increased after a delta at the mouth of Lake Mills was cleared last fall.
The 37-acre delta, which gradually built up after Glines Canyon Dam was built on the Elwha River in 1927, was shaved of alder trees and a channel dug through it to release sediment as part of the $351 million Elwha River Restoration project.
The project includes tearing down the Glines Canyon Dam and its sister dam, the Elwha Dam, farther downriver beginning in September.
About 90 percent of the logs that are putting pressure on the boom are from the delta-clearing project, Yancy said Friday.
He stood on top of the wind- and rain-swept dam near the spillway while his boat-borne Bureau of Reclamation colleagues, dwarfed by the floating mass of wood, separated the logs.
Trees plucked from the delta still have their root wads intact, making the job this year even more difficult.
“They’re are all tied together like this,” Yancy said, knitting his rubber-gloved fingers together.
“To push that apart is quite a challenge,” he said.
For most of Friday morning, workers armed with a chain saw and 18-foot pike poles fought 20-knot winds, cutting through large logs and clearing a path to the main boom gate.
They finally opened it, allowing the debris to float toward its 20-story free fall.
Some of these logs will hang up on the river’s shoreline.
But many will float about nine miles downriver to Lake Aldwell, bumping up against the smaller, 108-foot Elwha Dam to be flung once again over a giant wall.
“In a week or so, we’re going to have to go to the lower dam and do the same thing,” Yancy said.
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Senior staff writer Paul Gottlieb can be reached at 360-417-3536 or at paul.gottlieb@peninsuladailynews.com.