Living With Landslides

By Kristen Pope

On the evening of May 20, a massive landslide hurled millions of tons of mud, rocks, and debris down the hillside above California's Highway 1 near Mud Creek in the Big Sur area. Debris from the slide piled up to 40 feet deep on a one-third-of-a-mile stretch of the iconic coastal highway, creating 13 new acres of land, expanding California's shoreline, destroying the road, and causing a huge headache for area residents, planners, and the California Department of Transportation.

The remote and rugged mountainous region is a challenging place to build and maintain roads, and Highway 1, a vital link for local residents to surrounding schools, jobs, medical facilities, and other important services, is now closed indefinitely.

The state DOT, CalTrans, in partnership with other agencies, is working to get traffic flowing again, but they face a series of hurdles. Work cannot begin on the slide until it stops moving. Crews are constantly monitoring it using field mapping, radar monitoring, and drone surveys, among other techniques, to keep an eye on movement. Once the slide is stable, crews can move in to clear debris and rebuild the demolished the roadway.

In the meantime, transportation planners must decide whether to stabilize the road in place or relocate it altogether. Additional options to protect the road from future slides include retaining walls, rock sheds, or even a tunnel. CalTrans has no estimate on when the stretch of road will be reopened, but a similar event in 1983 near Julia Pfeiffer Burns State Park about 27 miles north of the Mud Creek slide closed the road for over a year.

A staggering 100 inches of rain fell on California this winter, resulting in a spring landslide that buried a quarter mile of scenic Highway 1 at Mud Creek, located around 70 miles south of Monterey. Photo by John Madonna, courtesy The New York Times.

A way of life

The Mud Creek slide hasn't been the only landslide to interfere with access to the Big Sur area this year. Another slide to the north, called Paul's Slide, also impeded access. That slide caused closures on and off since December. During that time, local residents and deliveries were allowed to pass that slide in an escorted convoy at designated times two or three times a day. The roadway was officially reopened in mid-July. To stabilize the slide, they excavated material from the slide's body and put it on the toe of the slide to buttress it.

"There are hundreds of slides along Highway 1, but many are dormant for years, and [then] some winter they wake up and wreak havoc," says CalTrans Public Information Officer Susana Cruz.

This winter, with over 100 inches of rain, was especially brutal for slides.

"Every winter, the county issues at least several emergency permits for landslides or washouts, slideouts, things like that along Highway 1," says Monterey County Resource Management Agency Associate Planner Joseph Sidor. "Typically, we issue two or three, maybe four, emergency permits to CalTrans or a county agency for a county road or for a private landowner in the Big Sur area. This past winter, between January and May, we issued over a dozen emergency permits not only in the Big Sur community, but also throughout the county for emergency landslides and slideout situations. About half were for CalTrans along Highway 1."

Planners, transportation officials, and residents have learned to live with the uncertainty of landslides and the potential for them to affect local transportation networks.

"The mantra across the Big Sur coast is 'living with landslides,'" Cruz says. "You don't really control them, you don't really get rid of them, you just kind of live with them. What we try to do ... first and foremost is keep the roadway open but, of course with the movement taking place, when it's not safe to open the roadway or there's too much material coming down, then obviously the road needs to stay closed."

About 30 miles away from the Mud Creek landslide, a February slide slammed into the Pfeiffer Canyon Bridge, moving the bridge several feet and fracturing one of its columns in multiple places. The bridge was torn down in March, and a new one is being fabricated. It is expected to be open by the end of September.

Mud Creek: Crews are constantly monitoring the slide to track its continued movement and determine when recovery work can safely begin. Here, a worker relocates radar equipment to Pyramid Rock, at the body of the slide, for more accurate monitoring. Photo courtesy Madonna Construction for CalTrans.

Normally, it would be a relatively short drive between Mud Creek and Pfeiffer Canyon Bridge, but the trip now requires an almost four-hour-long detour along winding mountain roads. However, the road systems were created with some degree of resiliency in mind and to provide alternate routes, even if they're not always the most convenient.

"The transportation network that millions of Americans depend on has a strength: It is a fungible network, which is to say, there's places for people to take a detour or another route," says Federal Highway Administration Public Affairs spokesman Doug Hecox. "We have a much more complicated multilevel network of roads, highways, and bypasses, and it gives drivers a lot more options."

In Big Sur, residents are also using an old-fashioned method of bypassing the downed bridge: walking. A hiking trail was constructed to circumvent the bridge, allowing residents to shuttle supplies, like groceries and toilet paper, to their homes on foot. The hike takes about 20 to 40 minutes each way, and many people park a car on either end if they can. Kids also use this route to catch the school bus. In July, tourists were also allowed to use the trail, which was previously restricted to locals and required a waiver and a "trail pass."

"The Big Sur community is unique in that they are a very resilient rural adaptive community," says Brandon Swanson, Monterey County Resource Management Agency planning services manager.

Paul's Slide: Following a landslide last December, this 35-mile stretch of Highway 1 was closed on and off for around seven months. CalTrans officially opened the road to the public in July, a month after this photo was taken. Photo courtesy California Department of Transportation.

Economic impacts

While locals are finding ways to make it work, the region's tourist-dependent economy is taking a big hit. Some predictions say the Big Sur region could lose $500 million in tourism revenue.

Farther north, another California community dependent on tourism found a solution to a particularly troublesome slide. But it wasn't simple — or inexpensive.

In San Mateo County, 15 miles south of San Francisco, a stretch of Highway 1 known as "Devil's Slide" has suffered from frequent landslides ever since it opened in 1937. One 1995 slide closed the road for 158 days, costing almost $3 million in repairs. Whenever the road closed, what would normally be a seven-mile drive turned into a winding 45-mile detour, which kept many tourists from the Half Moon Bay area.

After considering a wide variety of potential options and reroutes, in 1996, county residents opted to build a tunnel. This initiative allowed for construction of the 4,200-foot-long Tom Lantos Tunnels connecting Pacifica and Montara. The tunnels opened on March 25, 2013, and cost $439 million. The project was funded by federal emergency relief funds.

"People like it a lot," says CalTrans Public Information Branch Chief Bob Haus. "Now their economy isn't dependent on the weather, and they don't have to worry about it every time it rains if their economic lifeline is going to be closed."

The old stretch of Highway 1 is now a county park. Hikers, bikers, and horseback riders use the Devil's Slide Coastal Trail, a paved 1.3-mile, multiuse route that offers benches, observation scopes, interpretive signs, drinking fountains, restrooms, pet waste stations, and bike racks. It is part of the 1,200-mile-long California Coastal Trail, which is more than half complete. The project has received numerous awards from the California Chapter of the American Planning Association and others.

Pfeiffer Canyon Disaster: A California DOT engineer points to Pfeiffer Canyon Bridge columns destroyed by heavy rains. The bridge had to be demolished this spring. Photo by Haven Daley/Associated Press.

Finding New Routes: Unable to cross the canyon by car, residents of Big Sur were forced to find alternate routes — and transportation. With the help of a wagon, this family transferred its supplies across the damaged Pfeiffer Canyon Bridge on foot in February. Photo by David Royal/Monterey Herald, courtesy Associated Press.

Meanwhile, back on the Big Sur coast, planners are seeking their own solutions. Officials in the Big Sur area hold workshops where they meet with community members and property owners to discuss current and potential hazards. They try to be as proactive as possible and focus on preventative planning whenever possible, rather than simply waiting for people to come in for permits and addressing issues then.

"After all the forest fires we had last summer, our county department set up workshops down in the area to meet with affected property owners because there's always a greater risk of landslides and things like that after forest fires," Swanson says. The largest fire in 2016 was the Soberanes fire, which burned more than 132,000 acres and raged for nearly three months. One person was killed and 57 homes were destroyed.

The information fair-type events feature representatives from several agencies who all come together in one place in the community so residents don't have to travel far.

"Any kind of government planning is a complicated process," Swanson says. "We get down there and try and demystify it."

He notes the county partners with state agencies to assess areas with high erosion possibilities and to mitigate with options like K-rails, portable concrete barriers that act like a retaining wall, where appropriate. They also seek community input in identifying dangerous spots and areas to implement these potential improvements.

Rebuilding Bridges: This CalTrans rendering illustrates the new design for Pfeiffer Canyon Bridge. By using steel girders instead of columns, the structure will be less vulnerable to landslides. Rendering courtesy CalTrans.

Increased preparedness

It's not just coastal areas suffering from landslides. In September 2013, historic floods ravaged Colorado and eroded 1,000 years' worth of sediment from nearby foothills, according to scientists at the University of Colorado Boulder.

Those landslides killed three in addition to destroying buildings and roadways. In Boulder, a landslide unfurled huge rocks that ripped a building in half, and in Jamestown, a slide left a debris wall up to six feet thick in parts of town.

One of the deadliest landslides in U.S. history occurred near Oso, Washington, in March 2014. The slide killed 43 people and destroyed dozens of homes in the Steelhead Haven neighborhood in Snohomish County. It also dammed the river, causing flooding that led to further destruction.

Right after the slide, the county implemented a temporary building ban in the slide area and the nearby flood zone.

"As time went on, the river rechannelized and upstream flooding receded," says Snohomish County Department of Emergency Management Director Jason Biermann.

The slide led to numerous lawsuits as victims and their families alleged that nearby logging activities and a crib wall fence that retained soil contributed to the slide. The state of Washington settled for $50 million on the eve of the trial in 2016, and a timber company paid out $10 million, though other litigation is pending.

Planners and officials there are working to make sure such a tragedy never happens again. After the slide, Snohomish County Executive Dave Somers proposed a rule to not issue residential building permits for areas within a half-mile of landslide hazards. It was rejected, though, in favor of more moderate restrictions like requiring more geotechnical studies and wider setbacks.

After the slide, an expert commission analyzed the event and realized that the state needed better geologic hazard maps for risks such as landslides. The state allocated $36 million for this project through 2021.

Tom Lantos Tunnels: To better protect its highways, San Mateo County is going through mountains, not around them. These $439 million twin tunnels opened in March 2013 at Devil's Slide, a part of State Route 1 known for closures and rockslides. Photo by © Jeffrey G. Katz, Courtesy HNTB.

As of earlier this year, the state has collected LIDAR (light detection and ranging) data for almost a quarter of the state's land, covering over 17,000 square miles. With this technology, lasers on planes measure reflected light, providing imaging through trees to produce a more accurate model to help identify areas at risk of a variety of disasters, including landslides, and inform better decision making. The maps are now available online for public viewing, and plans are in the works to map even more of the state.

What to do with the Oso landslide area itself was another issue. In 2016, the Snohomish County Council agreed to purchase 100 land parcels where the slide occurred. However, according to the Seattle Times, only owners of 74 of those properties agreed to sell. Federal Emergency Management Agency funds assisted with the project, and one FEMA provision is that the land will remain undeveloped open space.

In addition to federal, state, and county actions, local residents are working to make sure they are prepared at the community level. "In terms of community resiliency, there have been a number of initiatives," Biermann says.

One is called the Christina Project, in honor of Christina Jefferds, a 45-year-old grandmother killed in the slide while caring for her infant granddaughter, who also perished. Jefferds had always expressed an interest in community emergency preparedness, so after she died, community members worked with the county's emergency management department to create an emergency preparedness program in her honor. The Christina Project is an adaptation of the "Map Your Neighborhood" program, a state emergency preparedness program.

This project works to help the community prepare for potential disasters — not just landslides, but also earthquakes, floods, volcanic eruptions, and wildfires. It designates certain roles and responsibilities within neighborhoods, drawing on each community member's strengths, such as medical skills. In the event of a disaster, people come together at rally points, look for people who are missing, and triage emergency assistance with the help of neighborhood captains.

"The idea is that in a disaster ... help may not be coming if it's regional because we're so rural," says Elaine Nerland, one of the project's coordinators.

Nerland's neighborhood is divided up by five bridges, and areas were designated with the assumption that bridges may be impassable after an event such as an earthquake, and each area should be prepared to be self-reliant.

"We have a slogan here called 'Oso strong.' The people here are a pretty resilient type of people," Nerland says. "Hopefully, we will never ever need these skills, but if we do, we know how to respond in a timely manner and in that golden hour or golden 48 hours of trying to help ourselves."

Kristen Pope is a freelance writer and editor in Jackson, Wyoming.

Resources

Washington LIDAR: lidarportal.dnr.wa.gov.