Washington Transportation Secretary Paula Hammond says Interstate 5 at Chehalis could be closed for four days.
She says the flooding is similar to the December 2007 flood that caused a four-day blockage on the main north-south route in Western Washington.
Transportation spokeswoman Alice Fiman says crews are still waiting to assess damage on the 20-mile closure.
Alice Fiman: “First we have to wait for the rivers to stop rising. Currently they’re still getting about a foot of water coming in. So once the river crests, we’ll start getting that water out of there and seeing what we’re working with. If there’s any damage to the highway and getting it reopened. One of our goals today is to get one route open and we’re really thinking that that is going to be I-90.”
Fiman says I-90 could open as early as Thursday night. The detour would route drivers onto Oregon’s I-84, then through Yakima and over Snoqualmie Pass. That would add more than 400 miles to the trip between Portland and Seattle.
Road closures have cut off access to several communities, including Montesano in Grays Harbor County. Fiman says crews are working to get needed supplies and freight to those areas.