Travelers on eastbound Interstate 90 and Newport Way Northwest in Issaquah should prepare for weekday lane closures starting Wednesday, Oct. 11.
Washington State Department of Transportation (WSDOT) maintenance crews will perform emergency repair work on a culvert that caused a sinkhole on I-90 in July. It is crucial that the emergency work takes place prior to winter weather in order to prevent further sinkholes from developing.
Travelers should prepare for lane closures from 9 a.m.-2:30 p.m. Mondays through Thursdays. The work is scheduled to start Oct. 11, and should be completed by Nov. 8.
Crews will close the left eastbound I-90 lane just past exit 13 to Lakemont Boulevard Southeast. Those who travel on Newport Way Northwest should expect intermittent flagging near Southeast 54th Street during the working hours.
WSDOT is coordinating closure details for the $75,000 project with the City of Issaquah.
History of culvert
The culvert is located underneath the eastbound lanes of I-90 and Southeast Newport Way and was installed over 48 years ago. The pipe, which is 42 inches in diameter and approximately 330 feet long, has deteriorated over time. Crews need to make repairs in order to prevent additional sinkholes.
Repairing the culvert
WSDOT crews will repair the culvert by inserting a liner into it to provide a safe and secure way for water to flow under I-90. This emergency repair work will extend the life of the culvert until it is funded for replacement.