National Weather Service issues extensive landslide warning

Issaquah staff reported Dec. 9 the site had remained stable through recent heavy rains. Dewatering wells and other erosion controls were installed shortly after the landslide and continue to be monitored.

By Daniel Nash • December 11, 2015 3:23 pm
Parcel 9 in Issaquah's Talus community shortly after crews worked to contain the November landslide. The movement caused the road to buckle at the location of the stop sign in the photo above.
Parcel 9 in Issaquah's Talus community shortly after crews worked to contain the November landslide. The movement caused the road to buckle at the location of the stop sign in the photo above.

The National Weather Service has issued an extensive landslide warning for Western Washington.

Continued rainfall on top of days of heavy rain and elevated precipitation in November has increased soil moisture to high levels, making the ground less stable, the report read.

The warning was issued to a large swath of the western state, primarily hitting the corridor stretching from Whatcom to Lewis County. The report specifically named the Bellevue metro area as one of the affected areas.

Water saturation in the soil was cited by geotechnical engineers as a major cause of the November landslide on Parcel 9 in Issaquah’s Talus community on Cougar Mountain.

However, Issaquah staff reported Dec. 9 the site had remained stable through recent heavy rains. Dewatering wells and other erosion controls were installed shortly after the landslide and continue to be monitored.

Gov. Jay Inslee declared a state of emergency Wednesday in the wake of severe storms.

State transportation officials had closed down nine routes throughout the state due to damage, flooding or debris resulting from storms that occurred between Nov. 30 and Dec. 8.

Friday afternoon, the U.S. Department of Transportation authorized $1 million in Quick Release Emergency Relief funding to the Washington State Department of Transportation for emergency repairs to highways damaged by landslides and flooding. WSDOT had requested $3 million.