The art and science of landslide preparedness a decade after Oso

The rural residents and weekend visitors along Steelhead Drive had no time to react when a huge chunk of hillside broke loose above the North Fork Stillaguamish River ten years ago this week. The fast-moving wave of mud and debris shattered the Saturday morning peace near Oso, Washington, and buried a riverfront neighborhood under 30 feet or more of mud.

The 43 people who died there on March 22, 2014, will be remembered during the dedication of a permanent memorial at the slide site this Friday. A massive scar on the nearby hillside serves as a reminder of the need for vigilance around steep slopes.

In the aftermath of the Oso landslide, state and federal agencies stepped up efforts to prevent a repeat of such heavy casualties. Since 2015, the Washington State Department of Natural Resources received more than $13 million in phases from the Legislature – and another $5 million from the feds – to collect and analyze remote sensing imagery.

“Oftentimes, landslides happen where they have occurred before,” DNR landslide hazards geologist Mitch Allen said. “If they’ve happened in the past, it’s likely they’re going to happen there in the future – especially if development or whatever land use is going on impacts those landslides.”

https://washingtonstatestandard.com/2024/03/18/the-art-and-science-of-landslide-preparedness-a-decade-after-oso/