LONGVIEW — Washington State Department of Transportation contract crews Thursday continued clearing trees from the football field-sized landslide blocking State Route 4 west of Cathlamet, near Bjornsgard Road. But uncertainty about the slope’s stability slowed progress, and more hard rain could cause further delays, WSDOT officials said.
And it’s “still too soon to tell” when WSDOT can reopen at least one lane of the road, spokeswoman Tamara Greenwell said.
“We had hoped they would have been able to move more of the tree debris today, but with some of the uncertainty of the slope, that’s delaying things,” Greenwell said late Thursday afternoon.
The landslide showed “no signs of significant movement in the last couple days,” allowing crews contracted through Nutter Corp. to begin work to clear the debris, Greenwell said. Before that, heavy rains and spongy soil made the slide unsafe for work.
Forecasts for more heavy rain this weekend could complicate the cleanup because crews “aren’t really sure how it (the hillside) will behave,” Greenwell said.
The National Weather Service forecasts half-an-inch to three-quarters-of-an-inch of rain Friday night and up to one inch of rain Saturday in that area of the Lower Columbia River.
“That’s something we are tracking very closely,” Greenwell said
The weather service issued a flood watch Thursday that included Grays Harbor and Lewis counties. Forecasts predict the Grays River will crest at 12 feet Saturday, just under the minor flood stage. That’s but still about three feet short of previous crests during earlier storms this winter.
The slope above the highway gave way last week, sluicing nearly 1,350,000 cubic yards of debris, trees and rocks into the roadway. At about 300 feet long and 175 feet wide, the slide is about the size of a football field, WSDOT said.
“Crews are working with extreme caution and closely monitoring the hillside,” WDOT wrote in a news release late Wednesday afternoon. “While work to clear debris continues, we are developing a long-term fix to stabilize the hillside.”
“Our primary goal is to safely reopen at least one lane of the highway, but the timeline remains uncertain,” the release continues.
As long as conditions are safe to work, crews will continue cleanup efforts into the weekend, Greenwell said. Crews plan to put shipping containers between the slide and the hillside to help stabilize the slope.
WSDOT will “work, watch and move as quickly as possible” to open the highway, she said.
“The crews started removing some of the tree debris yesterday, which is giving us a better look at the landslide beneath it. Our geotechnical engineers are taking a look at that and reassessing,” Greenwell said.
During the closure, travelers can use Highway 30 as an alternate route by crossing the Lewis and Clark Bridge in Longview or the Astoria-Megler Bridge in Astoria, Ore.
In addition, the Wahkiakum County Ferry will run free of charge on a 24/7 schedule during the highway closure, according to the release.
