Landslide Safety All Over The Map In Washington | KUOW News and Information

Landslide Safety All Over The Map In Washington

Sep 30, 2014

The deadly Oso landslide in March sparked a debate over Snohomish County’s apparent failure to protect residents at the base of a known landslide zone.

But Washington state is dotted with landslide-prone slopes, and many counties and cities do less than Snohomish County to keep homes away from harm.

Most counties’ rules set buffers at 50 feet or less, although landslides often travel hundreds of feet. The Oso slide was an extreme case; it traveled more than 3,000 feet.

Joann Blalock lives near one of those hazardous slopes on Whidbey Island. Her home sits atop the Ledgewood Beach bluff, just south of the town of Coupeville, midway up the state’s longest island. The house itself sits 80 feet back from the bluff and its steep drop to Admiralty Inlet 200 feet below.

A 1,100-foot stretch of that bluff collapsed in March 2013. One home and a road in the Ledgewood Beach neighborhood were destroyed. Other homes had enough of their backyards disappear overnight that they had to be condemned.

"We chose after the slide to move back on the property about 20 feet," Blalock says. "I'm not afraid to live here, but I have a healthy respect for what nature can do."

Instead of tearing down her small house and putting up a larger one as planned, she’s building a new home just behind the old one.  

Her neighborhood sits several miles outside Coupeville, where that construction – done without any geotechnical study of the ground's stability – would be illegal. 

Coupeville's critical areas ordinance requires construction be set back at least 200 feet from a landslide hazard as tall as Ledgewood Beach's. Island County requires a 100-foot buffer.

Many Washington counties require smaller buffers or none at all.

Washington's Growth Management Act tries to steer development away from dangerous spots like coastal bluffs and landslides. But the law leaves it up to cities and counties to decide how.

A joint KUOW-EarthFix investigation found that local rules vary widely around the state, leaving some communities with much smaller margins of safety than others.

"Great views create blindness," says Ledgewood Beach resident Jan Wright.
Credit KUOW Photo/John Ryan

‘Great Views Create Blindness’

From beneath the Ledgewood Beach bluff, Jan Wright points up at a condemned house sitting at cliff's edge.

"Pretty dramatic," says Wright, the president of the Ledgewood Beach Property Owners Association.

“That backyard used to be 70 feet wide. It was a very nice backyard," she says. "It just fell in the middle of the night.”

That late-night landslide a year and a half ago gave Whidbey Island a new peninsula: a jumble of mud, rocks and trees sticking 300 feet west into Admiralty Inlet. Thirty-four houses had to be evacuated, some by boats landing on the beach; five were condemned.

The condemned houses can’t even be torn down: It would be too dangerous to bring in heavy machinery so close to the edge. The empty houses remain long-lasting scars on the Ledgewood Beach neighborhood.

The bluff, along with its majestic views of Admiralty Inlet, has always been a dominant feature of the neighborhood. A slide destroyed one house below the bluff in 1997. But, Wright says, until last year, few of her neighbors were concerned about landslides.

“The people who lived on the bluff where they did lose land, they were told by geologists they’d lose a few inches a year, maybe,” she said.

“They had 70 feet in their backyard; they felt safe. I think you could probably imagine that. But to lose 50 feet in a single night was pretty shocking.”

Wright says that night’s disaster didn’t really change how she or most of her neighbors feel about living near a crumbling bluff. Neither did this year's deadly Oso landslide – a deep-seated slide, similar geologically to the Ledgewood slide, only much larger.

"Great views create blindness," Wright says.

A condemned house on the edge of the Ledgewood Beach bluff on Whidbey Island.
Credit KUOW Photo/John Ryan
New construction on an eroding bluff on south Puget Sound's Harstine Island, in Mason County.
Credit KUOW Photo/John Ryan

‘Your House Might Fall In The Ocean’

Jim Simon, a Boeing retiree, says he was pretty naïve about landslides when he moved to Ledgewood Beach in 2005.

"Until this slide happened, it never occurred to me that this neighborhood would be at risk for a substantial slide,” he says.

"We were more concerned about airplane noise, moving to Whidbey Island," Simon says. "That's a much bigger concern than that your house might fall in the ocean."

Simon and Wright both live on Cedarcrest Avenue, a block inland from the street that lost houses overnight to erosion. They say they feel safe but wouldn’t want to live closer to the edge.

Since the 2013 slide, Simon has postponed plans to build a second home -- his retirement home -- on Cedarcrest. He says he’s less concerned about his street’s safety than about the reputation of a neighborhood with condemned houses and eroding backyards. 

“If neighborhood takes a 10 to 20 percent hit on property values, does it make sense to build?” Simon says.

He says he’s leaning toward building on his Cedarcrest lot. "When you look around the island, where else do you go?" Simon asks. "A lot of areas have the same problem."

Read The Fine Print

Unlike many counties, Island County makes anyone selling a property in a landslide hazard zone, or its 100-foot buffer, disclose the hazard in writing to the buyer. Jan Wright says that doesn’t deter many purchasers, given the paperwork buyers must sign.

"A lot of times people don’t read that carefully," she says.

While some homeowners and property rights advocates resent governments telling people what to do with their private property, Jim Simon says some restrictions are necessary.

“People are going to build as close to the edge to enjoy the view as they possibly can,” he says, “without regard to their own personal safety.”

“As soon as they slide, they’re going to complain to the government, ‘Why didn’t you warn me, and by the way, where’s my money for mitigating the fact that my house is damaged because you didn’t warn me?’”

Some homeowners in Ledgewood Beach and the adjacent Bonair neighborhood are preparing to sue Island County to get a slide-damaged road rebuilt and full access restored to their homes. People involved in the lawsuits declined to comment.

Jim Simon says he’d like to see a more cooperative approach. Groundwater lubricates the soil beneath deep-seated landslides. Simon is convinced that a combined effort to improve groundwater drainage would stabilize the bluff and the neighborhood’s property values. 

The Oso landslide dwarfs the dump trucks hauling its debris, nearly six months after the March 2014 slide.
Credit KUOW Photo/John Ryan

Risk Versus Reward

Natural disasters and measures to avoid them can be costly, especially for events as extreme and infrequent as the Oso slide.

Bob Gilbert, a University of Texas civil engineer, was part of a team of scientists to do a rapid assessment of the Oso slide this summer.

“If the risk, say, is once every 500 years, that’s many, many generations of people that wouldn’t be able to benefit from living in this area,” he says. “Do we really want to impose those kinds of restrictions?”

David Schonhard of Snohomish County Public Works at the Oso landslide, near the end of a six-month recovery and cleanup effort.
Credit KUOW Photo/John Ryan

Gilbert says how to manage such life-and-death risks is a difficult problem that each community should solve for itself.

“If one county, one municipality, one area has a different value system, then what the public policy is should reflect that value system,” he says.

Tim Trohimovich with the environmental group Futurewise in Seattle favors a statewide approach to landslide hazards. The planner and attorney says counties’ standard landslide buffers, which run 50 feet or less in most of the state, are too narrow.

“It’s not uncommon for a landslide to go hundreds of feet,” Trohimovich says.

Trohimovich says local governments generally lack the funding and the expertise to do a good job of identifying and managing landslide risks. And it’s not just property owners or locals who are affected when a local disaster strikes: The state and federal governments have spent millions in the wake of the Oso slide.

Many counties allow regulators to impose wider buffers based on site-specific studies. But restricting land use more than the legal minimum, or even delaying a building permit by requiring careful study of a geologic hazard, can be difficult, according to Trohimovich.

“If the ordinance doesn’t explicitly require it, there’s a lot of pressure on the planner to not require it,” he says.

State law doesn’t tell local governments how to regulate development, but it does make them revise their rules every decade.

Cities and counties around western Washington are scheduled to revise their approaches to landslides over the next two years. Governments in King, Pierce and Snohomish counties will be the first to examine new approaches to landslides and other critical areas in the coming year. 

John Ryan can be reached at jryan@kuow.org or 206-543-0637.