Both lanes of Highway 20 east of Loup Loup summit opened to traffic Tuesday (June 18), as crews were wrapping up emergency repairs prompted by a May 1 landslide.
The highway had been reduced to a single lane for the past seven weeks — except for eight days when the road was closed completely. Those traveling between the Methow Valley and Okanogan/Omak had to take a 70-mile detour during the full closure.
Hurst Construction of East Wenatchee was given a one-month emergency contract to start repair work, and they were able to finish the job. The cost of the repair should not exceed the $1.3 million estimate, according to Lauren Loebsack, communications manager for the North Central region of the Washington State Department of Transportation (WSDOT).
Highway 20 was undermined at milepost 222.4 on May 1 by a mudslide triggered by groundwater flowing 30 feet under the roadway, Loebsack said. The fill material used to repair the bank under the roadway contained porous rock that will allow groundwater to flow freely into Loup Loup Creek.
The repair project included building an access road to the bottom of the fill area, removing saturated soil, rebuilding the slope, and replacing damaged pavement and guardrail.
Previous slides
In April 2017, rainstorms triggered nine landslides over a 16-mile stretch of Highway 20, on either side of the Loup Loup summit. The highway was closed for three months during repairs. A mudslide east of the summit caused a brief closure in April 2018. The major slides of 2017 were attributed to the 2014 Carlton Complex Fire, which burned away vegetation and damaged the soil such that it was unable to absorb moisture.
WSDOT drives this stretch of Highway 20 daily, looking for risks, Loebsack said.
“WSDOT is acutely aware of the conditions caused by the fires over the past few years, so we are paying particular attention to keeping culverts under the roadway clear of debris. We monitor the snowpack and weather forecasts in an effort predict conditions that may potentially cause issues,” she said.
Lower valley delays
Those traveling through the lower Methow Valley can expect delays as crews reinforce the three bridges between Methow and Carlton.
Traffic is reduced to a single lane, controlled by a flagger, from 7 a.m. to 7 p.m. Monday through Friday. The work started on Monday (June 17).
Crews are starting at the southernmost of the three bridges in phase 3 of the rehabilitation project. Work is expected to continue through September.
