WSDOT crews maneuvered the giant maw of a crane to pluck pieces from a logjam and drop them into the river to be carried downstream. It took about 14 hours to clear the jam.
Deftly maneuvering a crane armed with teeth reminiscent of a Tyrannosaurus rex, operators with the Washington State Department of Transportation (WSDOT) cleared a massive logjam on the Methow River under the south Gold Creek Bridge last week. It took 14 hours on Tuesday and Wednesday (May 16 and 17) to remove the blockage.
Trees, branches and other debris that have been propelled downstream by the powerful river flow can become wedged against a bridge or other structure instead of traveling with the current, North Central Region Supervisor Shelby Winkle told the Methow Valley News. The logjam was first discovered Tuesday morning.
That spot is susceptible to logjams because of the depth of the channel and the way water flows around the bend just upstream of the Gold Creek Bridge. Those factors tend to push debris north, where it can get hung up on the bridge supports, Winkle said.
The trees and other debris were caught between two of the bridge piers. If not relieved, the built-up pressure could threaten the integrity of the bridge, Winkle said. The force of the logs and water also scours the piers, he said.
The WSDOT crew brought in a specialized crane from their maintenance facility in Everett. The crane arm has a clamshell device that’s good for picking up logs and debris — kind of like a giant game of pick-up sticks — and then releasing them into the deep water channel, where they’re carried downstream, Winkle said.
The crane operators were able to target individual pieces of wood that they suspected were holding the majority of the pile in place. As wood is removed, the hydraulics of the water help to dislodge the jam, Winkle said.
“We target specific pieces that we think are holding up the majority of the pile and let the water do the rest of the work,” Winkle said.
Two days of work
The WSDOT crew — two crane operators, two ground-support personnel, and six support staff who handled traffic control and flagging — worked for eight hours on Tuesday and another six hours on Wednesday to clear the jam. Traffic was detoured via the Gold Creek Loop Road. The river was flowing freely as of about 2 p.m. Wednesday (May 17).
The Methow River near Pateros recorded its highest level this year on Wednesday morning (May 17) at 9.4 feet, when it was flowing at 15,700 cubic feet per second (cfs), or about 7.5 gallons per second. The day before, it hit 9.3 feet, according to forecaster Greg Koch with the National Weather Service (NWS) in Spokane. That’s just slightly below flood stage, which is 10 feet.
It’s not uncommon to see issues like this on the river. Logjams have occurred at the Gold Creek Bridge in the past, most recently in 2018. On May 10 of that year, the river crested at half a foot above flood stage — more than 21,000 cfs — the fourth-highest flow on record, Koch said.
Logs have also gotten caught on the Carlton Bridge in the past, although there have been no problems there this year, Winkle said.
The Methow River at Pateros has exceeded flood stage nine times since NWS records have been kept, starting in the 1960s. The highest in that period was in 1972, when the river hit 12.25 feet.
