Highway 20 east of Rockport is down to one lane of traffic due to Skagit River flooding last week that washed away the ground beneath part of the road.
The state Department of Transportation is bringing crews to the area near milepost 101 this week to begin work on stabilizing the highway, spokeswoman Andrea Petrich said.
Work began Wednesday morning and is expected to continue 7:30 a.m. to 4 p.m. through Sunday as workers assess the situation and start planning repairs.
According to a news release, permanent repairs could take several weeks and those traveling through the area should plan for traffic delays.
The work could result in delays of up to 30 minutes, Petrich said.