Landslides a major risk for new home builders in Western Washington
Seattle’s skyline isn’t all that’s changed in recent years.
Landslides are also changing the local landscape.
“That big door, covered in cyclone fence--that was two-glass doors," said Richard Lord as he looked at what’s left of his Mukilteo home. He was inside with his dog when the hillside gave way, releasing a crushing wall of mud in 2011.
“You just have to be aware this could happen so you have to be aware of it," Lord said.
Years later, the mud is still sliding. In 2013, emergency officials in Snohomish County warned we could be entering a 10-year period of increased slide activity all the way from Everett to Seattle.
Property in that area is worth hundreds of millions of dollars.
“The solid purple is potential landslide hazards in unincorporated King County," said environmental scientist Greg Wessel as he pointed to a topical map on Vashon Island.
The deadly Oso landslide in 2014 pushed King and other counties to update their landslide mapping systems for the first time in more than 20 years. LIDAR is a sensing system that covers wide areas in great detail.
“It's more like jumping from the 1960s to the 2000s," Wessel said.
Wessel says engineers aren’t just looking at the next 10 years. To issue a permit to build a home, they have to look at the next 50 to 75 years.
“You don't want to deal with it at the hospital. You want to deal with it when you're designing your home," Wessel said.
Builders are responsible for mitigating the risk of a landslide.
Many walk away from the added cost of re-enforcing the foundation, adding pilings or retaining walls that can cost around $500,000.
“We hold those folks to a pretty high standard," Wessel said.
But with the Puget Sound population growing, Wessel expects more will try.
“People are trying to build on properties that 50 years ago, nobody would have attempted," Wessel said.
Lord won’t rebuild near the water. As a realtor, he has his own advice.
“You have to have flood insurance. That's the main thing and the other thing I would tell people is when disaster does hit, identify what position in life you are and just move on," Lord said.