Chokepoints: Arlington fish passage to cause year-long I-5 delays

A year of construction is going to cause significant delays getting in and out of Arlington as the state tackles more culverts under Interstate 5 (I-5).

The overnight lane closures on both north and southbound I-5 were set to begin last night. The Washington Department of Transportation (WSDOT) is removing the culverts under I-5 and Old Highway 99 just south of State Route 532.

To make room for the work, WSDOT’s Madison Sehlke said contractors will be closing a lane in each direction of the freeway over the next eight weeks to build new bypasses.

“They will be two-lane bypass roads in each direction, so one north and one south,” she said. “They are standard lanes, 12 feet with standard shoulders as well. Once traffic is on the bypass road, there will be a speed reduction to 60 miles per hour.”

The temporary freeway lanes will be to the west of the current main line.

“We’re expecting that the bypass will take eight weeks to complete so that does put us at the end of April or beginning of May,” Sehlke said. “Right in time for our Skagit Valley Tulip Festival.”

The public should expect delays on I-5 for the festival and really any travel for the rest of the year. The freeway is going to remain in this configuration for months.

“This is a two-year project,” Sehlke said. “We’re hoping to have traffic shifted back (on I-5) by the end of December.”

But this is expected to have significant impacts.

“We’re encouraging people to avoid peak times if possible when traveling through the area, but if they are traveling through those peak times expect delays and to factor in extra travel time,” Sehlke said.

When traffic shifts back to the main line of I-5, WSDOT will then close Old Highway 99 for six months. That’s expected in early 2026.

More from MyNorthwest: Fixing the Gorst corner conundrum in Kitsap County

Travel delays and disruptions

So what are we getting in exchange for the travel delays and disruptions?

Replacing the small box culverts that block Secret Creek with giant arches under the freeway will open up about five miles of fish habitat. More than 2,000 feet of the creek is being restored, but WSDOT’s Sehlke said it’s not just about fish.

“Yes, it’s for fish passages, but I like to emphasize that this is a wildlife connectivity corridor, which also benefits the local wildlife in the area,” Sehlke said.

The arch culverts are 68 feet wide, which will create undercrossings for the deer, coyote, bobcat and beaver in the area.

Workers will have to dig down about 80 feet to restore the natural habitat.

Total price tag: $57.5 million.

More from MyNorthwest: Washington bridges suffer while lawmakers underfund maintenance and preservation

Follow @https://twitter.com/newsguysully