OLYMPIA, Wash. -- Transportation crews are allowing trucks back on a stretch of Interstate 5 near Chehalis where the roadway has been closed due to flooding.

Road crews moved jersey barriers back into place and made other repairs Thursday as the floodwaters receded.

"I-5 is crucial to our economy and I'm pleased that our hard-working crews were able to get the freeway open to trucks today," said Secretary of Transportation Paula Hammond. "We're making every effort to get the freeway open to all traffic, but first we must get median barrier back in place to help keep drivers safe."

VIDEO: I-5 Opens To Truck Drivers

Both directions of I-5 have been closed near Centralia since Monday because of flooding, stopping traffic between Portland, Ore., and Seattle. Claudia Cornish, a state Department of Transportation spokeswoman, said this is the first complete freeway closure due to flooding in the area in 11 years.

According to the Department of Transportation, truck drivers will encounter mud and water over the roadway and other flood related damage.

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Washington State Patrol troopers will talk with each truck driver before they enter the section of road to explain the traffic revision and driving conditions.

No trucks will be allowed to exit or enter the freeway between mileposts 68 and 88 and no oversize loads allowed.

The freeway is not expected to reopen to passenger vehicles until sometime Friday when crews replace barriers and make other repairs.

When crews reopen the freeway to all vehicles, a 50 mph reduced speed limit will be in effect until crews complete permanent repairs.

Gov. Chris Gregoire said the storm and flooding that hit Western Washington this week were unprecedented in many ways. She said flooding hit record levels on the Chehalis, Skokomish and Elwha rivers. She compares the windblown trees she saw to her recollection of the damage from Mount St. Helens.

Gregoire is leading another tour of storm damage Saturday with Sens. Patty Murray and Maria Cantwell and Rep. Norm Dicks to enlist their help in congressional aid.

Gregoire is preparing a damage estimate for the Federal Emergency Management Agency. She said she had pledges of support from top officials. She said damages could be in the billions of dollars.

At least 300 people had been rescued by helicopter, and flights continued in what Gregoire described as the state's largest aerial search-and-rescue operation in a decade.

Health Department officials warned affected Washingtonians to boil water, throw out spoiled food and clean up after coming in contact with floodwaters, which are likely to be contaminated.

The Chehalis River was perhaps the single largest problem. It crested about 10 feet above flood stage near Centralia on Tuesday morning, leaving areas in Centralia, Chehalis and other parts of Lewis County underwater.

In nearby Grays Harbor County, where as many as 25,000 remained without electricity Wednesday night, officials were watching as that water worked its way downriver toward Aberdeen and the ocean.

Power was gradually returning to Grays Harbor County, including downtown Aberdeen, where about half of the city flood pumps were working.

At least three deaths were blamed on this week's storm and the damage that followed. In addition, two hikers were found dead after an avalanche in the snow- and rain-soaked Cascade Range.

In rural Winlock, police continued searching for an 81-year-old man who was presumed lost when a bank along a swollen creek near his house gave way.