Flooded mineshaft to partially close WB I-90 near Issaquah in September

As if getting from home from eastern Washington isn’t congested enough, the state is about to close two of the three lanes of westbound Interstate 90 near Issaquah for the better part of two weeks.

This is going to be rough for westbound drivers, especially the truck drivers heading into Seattle. The Washington Department of Transportation (WSDOT) needs to replace the pavement about a mile east of High Point in Issaquah.

“We’re going to have the freeway reduced to one lane, 24 hours a day, from Sunday night through Thursday morning,” WSDOT’s Tom Pearce said.

The closure begins Sunday, Sept. 11, at 9 p.m. and lasts through Thursday morning Sept. 15, at 5 a.m. The following week the closures will be from 9 p.m. Sept. 18 to 5 a.m. Sept. 23.

“This section of I-90, especially this time of year, has a lot of traffic on the weekends,” Pearce said. “We want to keep the highway open over the weekends.”

Motorists, but especially semi-truck drivers, are encouraged to use the already congested Highway 18 corridor as an alternative. There just aren’t many other options to get around this, and with only one lane open the backups are expected to be significant.

So what’s happening here?

It goes back to our region’s mining history. Coal mining was a huge deal. Why do you think they call it Coal Creek Parkway? There was a mine that had to be closed and capped off in this area when I-90 was constructed. That mine has now filled with water, and it is spilling out under and over the freeway.

“Water is always going to find its way to where it wants to go,” Pearce said. “Part of this project is to guide that water. We’re going to put in new drainage, in addition to replacing the pavement so we can keep the water out from underneath the roadway.”

Even during our 90-degree weather, you can find water across the freeway there. The water is under-cutting the pavement and the concrete is cracking. The cracking has been made worse with the temperature extremes the road endures, expansion in the hot weather and ice filing gaps and cracking the concrete in cold weather.

Again, this is westbound I-90 only. It is during the week, not the weekends, but it still has the ability to cause long delays.

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