Experts worry California’s iconic Highway 1 will face ‘inevitable’ decline with climate change

The iconic 650-mile route faces a future of erosion, wildfires, and mudslides

Construction crews work on a section of Highway 1, which collapsed into the Pacific Ocean near Big Sur, California on January 31, 2021. Heavy rains caused debris flows of trees, boulders and mud that washed out a 150-foot section of the road. ((Photo by JOSH EDELSON / AFP) )

Experts are warning that California’s coast-hugging Highway 1, one of the most iconic drives in the world, could become structurally unsound as the climate crisis progresses, necessitating major changes to the state’s transit system.

In January, heavy rains pummelled the state’s central coast, whose hills had been stripped of vegetation the year before by record-breaking wildfires, sending a 40-foot wall of mud downhill that knocked out a 150-foot piece of road and affected 60 different sections of road. Repairs to the section are expected to be done this summer.

“You can keep putting these Band-Aids on it,” Gary Griggs, a University of California Santa Cruz professor told USA Today, but said it was “inevitable” at some point it will become too expensive, unfeasible, or insufficient to protect the magnificent route, which stretches through more than 650 miles of scenic coast line.

UCLA climate scientist Daniel Swaintold the paper that the highway, often built into sheer cliffs along the coast, "is not in a very geologically stable position even in the best of times". When the first stretches of the road opened in 1933, even then some sections were disabled because of landslides, and the road is rumoured to have never been fully operational for a calendar year. 

“It has always been a fragile environment fraught with concern and problems,” Lesley Ewing, a senior coastal engineer with the California Coastal Commission, told The Washington Post. “The roadway is crumbling because the ocean is just eating away at the cliffs.”

The climate crisis has made this arrangement even more precarious. In 2020, roughly 10,000 fire burned 4.2 million acres in California, more than 4 percent of the state’s landmass, and burn scars are dangerously vulnerable to sudden erosion and mudslides during heavy rains.

The January road collapse occurred near Big Sur, California’s Mud Creek, which sits below the where 2020’s Dolan fire burned the surrounding mountains.

The state has spent $200 million in emergency funds over the last 5-and-a-half years on the Big Sur coast alone, and $5 million cleaning up the Rat Creek slide. A 2017 slide took 14 months and $54 million to fix. Another in 1983 kept sections of road closed for 13 months.

State officials have considered a variety of ways to adapt the iconic road, which brings in millions of tourists a year and serves as a vital tourism hub for the region’s businesses. Proposed solutions include raising or widening the highway, planting protective vegetation on hillsides, expanding rail transportation, and building out more inland routes.

North of San Francisco, officials are re-routing a roughly ¾ mile stretch of road 400 feet away from deteriorating cliffs at a cost of $34 million, after 13 years of planning.