Multiple cars of a freight train were pushed off the tracks due to a mudslide in Everett on Dec. 17, 2012. (Jennifer Buchanan / Herald file)

Multiple cars of a freight train were pushed off the tracks due to a mudslide in Everett on Dec. 17, 2012. (Jennifer Buchanan / Herald file)

Puget Sound rail services avoid landslides with science

New forecasting tools can anticipate blockages and avoid tragedy on the Seattle-Everett rail line.

MUKILTEO — It started as a dribble of mud trickling down the side of a cliff. In seconds, a wall of brush and dirt hurtled into a freight train passing below. Seven cars were knocked off the tracks, piling up like toppled Jenga tiles.

The slide in winter of 2012 was just a shallow mudslide near Everett. But it puts into perspective the dangers of the railway between Seattle and Everett, a corridor hugged on one side by Puget Sound and on the other by steep bluffs of unstable, clay-rich glacial deposits.

Here, it’s not a matter of if, but when the earth will crumble. Every winter, dozens — and sometimes hundreds — of landslides occur in the Pacific Northwest.

“It’s no secret we get day after day of heavy rainfall that saturates the cliffs, and we are caught at the bottom with shovels,” said Gus Melonas, a spokesman for BNSF Railway, the company that owns the right-of-way along the tracks.

For years, scientists with the U.S. Geological Survey have been developing new ways to reliably forecast landslides, to prevent economic losses and save lives. But just as meteorologists don’t always get the weather right, geologists sometimes have trouble figuring out what’s going on underground.

“Anything that involves forecasting and prognostication is part art, part science,” said Martin Young, director of transportation and maintenance for Sound Transit.

Disaster in the ’90s

USGS scientist Rex Baum was called to Washington after the winter of 1996, when hundreds of landslides wreaked havoc throughout the state.

The winter was an outlier. Up to two feet of snow fell in the northern lowlands here at the end of December. Then, in the last few days of the year, it started raining. The snow melted rapidly, triggering a series of landslides that caused the deaths of at least four people and millions of dollars in property damage.

One of the largest slides happened a few weeks later, after water settled deep into the ground. Along the coastal bluffs in Woodway, a hillside tumbled onto the railroad, spreading a pile of dirt and debris across 500 feet of tracks and 50 feet into Possession Sound. It dumped five rail cars into the water, while engineers plowed their locomotives through mud to safety.

A couple of hours earlier, an Amtrak train had passed through carrying 650 passengers.

It was Baum’s job to figure out how to keep people and property out of harm’s way.

To do that, he and other USGS scientists developed models to gauge rainfall over days, to show how much water the ground had soaked up and how much more it might absorb.

It’s been useful, Baum said, but it’s an indirect way of estimating when landslides will happen, since it doesn’t reveal how water is acting underground. And it doesn’t account for how melting snow can build into a torrent with heavy rain, a factor in the ’96 slides.

The forecast model could create false alarms and false negatives.

Multiple cars of a freight train were pushed off the tracks due to a mudslide in Everett on Dec. 17, 2012. (Jennifer Buchanan / Herald file)

Multiple cars of a freight train were pushed off the tracks due to a mudslide in Everett on Dec. 17, 2012. (Jennifer Buchanan / Herald file)

A new model

One way to deliver more reliable results was to measure the moisture in the soil directly, Baum concluded in an academic paper in 2008.

But it wasn’t until 2015 that USGS scientist Ben Mirus installed monitors along the Mukilteo bluffs to find out what was going on under the surface.

With monitors, Mirus could see how fast groundwater moved and how much the dirt could hold. Though he was working with a small sample size, the initial results were promising. The new system was a better predictor than rainfall models, he said.

That’s not to say that ground moisture should be the only tool to predict landslides. It works best when combined with rainfall analysis, he said.

Ideally, Baum said they would set up more monitoring stations on diverse slopes in the same area: wet and dry, steep and flat, shrubby and bare.

Even then, Baum said, “we’re dealing with natural (phenomena) and natural systems, so there’s a lot of uncertainty that you’re dealing with because there are so many unknowns.”

Ed Harp / USGS, retired                                 A January 1997 landslide in Woodway.

Ed Harp / USGS, retired A January 1997 landslide in Woodway.

Mother Nature

It was a wake-up call, Young said, when Sound Transit canceled over 200 trains because of landslides in the winter of 2012, the most of any year. The agency needed to be better prepared so passengers weren’t inconvenienced.

In 2016, Sound Transit started using data from Mirus’ work, as well as the earlier rainfall measurements. If a landslide looks likely, transit leaders will get together and decide whether they need to cancel service ahead of time and set up alternative bus routes.

They don’t choose to stop trains ahead of time very often. About three meetings have been called in the past two years. Leaders canceled service just once, for a Sunday Seahawks game.

“Then sure enough, there was a slide later that day,” Young said.

The pre-emptive cancellation was a first for Sound Transit. Before, standard policy was to cancel service for 48 hours after a landslide occurred.

Young said the agency can’t stop service for every threat of a landslide, as they aren’t always serious. But as the forecasting models become more accurate, he said passengers may see more cancellations.

Forecasting isn’t the only way to protect against slides. The state has poured resources into landslide mitigation efforts, including detailed lidar maps. Some of the new emphasis was spurred by the deadly 2014 slide near Oso.

In the past few years, BNSF has used millions of dollars in state money to build hundreds of feet of catchment walls along the Mukilteo bluffs. The walls collect debris before it lands on the tracks. All that’s required is a rail crane to stop by and scoop up excess dirt from behind the wall, said Melonas, the BNSF spokesman.

Sound Transit only canceled 53 trains last winter, a huge drop from 2012, that’s largely credited to new walls.

“We fought back Mother Nature with technology,” Melonas said. “We know we’re not going to win the battle every day, but we’ve seen significant improvements.”

Zachariah Bryan: 425-339-3431; zbryan@heraldnet.com. Twitter: @zachariahtb.

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Local News

Customers enter and exit the Costco on Dec. 2, 2022, in Lake Stevens. (Olivia Vanni / The Herald)
Costco stores could be impacted by looming truck driver strike threat

Truck drivers who deliver groceries and produce to Costco warehouses… Continue reading

Two Washington State ferries pass along the route between Mukilteo and Clinton as scuba divers swim near the shore Sunday, Oct. 22, 2023, in Mukilteo, Washington. (Ryan Berry / The Herald)
Ferry system increases ridership by a half million in 2024

Edmonds-Kingston route remains second-busiest route in the system.

Alina Langbehn, 6, center, and Vera A., 6, right, sit on a swing together at Drew Nielsen Neighborhood Park after school on Tuesday, Jan. 28, 2025 in Everett, Washington. (Olivia Vanni / The Herald)
Everett council votes to renovate Drew Nielsen Park

Construction on the $345,000 upgrade could start as early as this fall.

Northshore School District bus driver Stewart O’Leary pictured next to his buses shattered drivers side windshield on Friday, Feb. 14, 2025 in Bothell, Washington. (Olivia Vanni / The Herald)
‘Put me in, coach’: Bus driver back at work after struck by metal bar

Stewart O’Leary, a Northshore employee, has received national attention for his composure during a frightening bus trip.

Lynnwood councilor Joshua Binda speaks during a Lynnwood City Council meeting on Wednesday, Nov. 20, 2024. (Olivia Vanni / The Herald)
Does the Lynnwood Council VP live in Lynnwood? It’s hard to say.

Josh Binda’s residency has been called into question following an eviction and FEC filings listing an Everett address. He insists he lives in Lynnwood.

Robin Cain with 50 of her marathon medals hanging on a display board she made with her father on Thursday, Jan. 2, 2025 in Lake Stevens, Washington. (Olivia Vanni / The Herald)
Running a marathon is hard. She ran one in every state.

Robin Cain, of Lake Stevens, is one of only a few thousand people to ever achieve the feat.

People line up to grab food at the Everett Recovery Cafe on Wednesday, Dec. 4, 2024 in Everett, Washington. (Olivia Vanni / The Herald)
Coffee, meals and compassion are free at the Everett Recovery Cafe

The free, membership-based day center offers free coffee and meals and more importantly, camaraderie and recovery support.

The Everett Wastewater Treatment Plant along the Snohomish River on Thursday, June 16, 2022 in Everett, Washington. (Olivia Vanni / The Herald)
Everett water, sewer rates could jump 43% by 2028

The rate hikes would pay for improvements to the city’s sewer infrastructure.

The bond funded new track and field at Northshore Middle School on Thursday, Oct. 24, 2024 in Bothell, Washington. (Courtesy of Northshore School District)
Northshore School District bond improvements underway

The $425 million bond is funding new track and field complexes, playgrounds and phase one of two school replacements.

An American Robin picks a berry from a holly tree on Thursday, Feb. 13, 2025 in Edmonds, Washington. (Olivia Vanni / The Herald)
Calling all birders for the annual Great Backyard Bird Count

The Audubon Society will hold its 28th annual Great Backyard… Continue reading

A view of one of the potential locations of the new Aquasox stadium on Monday, Feb. 26, 2024 in Everett, Washington. The site sits between Hewitt Avenue, Broadway, Pacific Avenue and the railroad. (Olivia Vanni / The Herald)
Initial prep work for AquaSox stadium to start, with $200k price tag

The temporary agreement allows some surveying and design work as the city negotiates contracts with designers and builders.

Aaron Kennedy / The Herald
The Joann Fabric and Crafts store at 7601 Evergreen Way, Everett, is one of three stores in Snohomish County that will close as part of the retailer’s larger plan to shutter more than half of its stores nationwide.
Joann store closure plan includes Everett, Arlington, Lynnwood locations

The retail giant filed a motion in court to close approximately 500 stores in the U.S.

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.