First construction season finished for Highway 1 realignment at Gleason Beach

The massive project is designed to combat the effects of climate change, rising seas and erosion that have undermined the highway.|

GLEASON BEACH — It will be a few years before motorists can travel the newly prescribed route of Highway 1 on the south Sonoma Coast — a three-quarter-mile stretch of road that has been under construction since late summer.

But steel and concrete pillars erected in recent months to support bridge decking that will be built next spring already delineate part of its path, as it swoops inland, curving up to 400 feet away from where the existing highway hugs the crumbling coast.

Caltrans and other state officials say the $30 million-plus realignment is a critical step in guarding the state’s scenic highway from rising seas and storm surge.

They says it’s the first of what will likely be many future adaptive projects in various areas of Highway 1 — though none perhaps as urgent.

The bluffs along some parts of Highway 1 between Jenner and Bodega Bay are losing up to 14 inches a year to scouring waves and seepage. Officials believe it is the fastest rate of coastal erosion anywhere in California.

Waves had been undermining the landscape for more than a decade when the problem came abruptly to the public’s attention in 1998, during a series of torrential storms that undercut the bluff and destabilized several homes on top, rendering some uninhabitable.

Over the years, the cliff kept disintegrating, despite substantial investments on sea walls and concrete bulwarks by several homeowners.

The erosion soon threatened the highway, eventually eating away at the asphalt edge. Caltrans has tried to reduce the risk to southbound motorists by shifting the lines and ultimately abandoning the failing westernmost lane, which started sagging and cracking as the ground below it became unstable. A second lane was added inland.

But the coast’s deterioration is only predicted to accelerate. The rising ocean and increased wave action are expected to carve away about 1.5 feet of land per year from the area by 2050 and 4.6 feet per year by 2100, according to the project environmental impact report.

Caltrans is moving the highway far inland to stay ahead of long-term erosion in an approach known as “managed retreat.”

Calling sea level rise “the biggest issue of the 21st century, Caltrans Acting Chief Engineer Nabeelah Abi-Rached said during a formal groundbreaking for the Gleason Beach project last month that it was just the first the agency would be mounting to address the problem.

“The rising seas that threaten Highway 1 here also threaten the highway on many locations along the coastline,” Abi-Rached said, “but we’re tackling it here first. I want to emphasize that this work is unprecedented.”

The extreme deterioration is complicated by the terrain. It starts at the north end atop the bluff, then dips toward the outlet of Scotty Creek and the surrounding flood plain before rising again on the south side of Scotty Beach. The task involves raising the highway above the salmon-bearing creek and the sensitive habitat adjacent, in addition to moving it inland.

The final project, in the planning and permitting stages since 2007, will include an 850-foot-long bridge that will be the largest human-made structure on the Sonoma Coast, larger than some coastal residents had hoped.

But the overall project is multifaceted in its approach and resulted from years of negotiation and accommodation that will result in certain offsets, as well. Among them are the daylighting of Scotty Creek, now confined by a box culvert, improving fish passage; cleanup of the concrete and constructions materials that have fallen to the base of the deteriorating cliff, where at least 12 homes have fallen or been removed since 1998; and improved public access to popular Scotty Beach.

Sonoma County is the birthplace of the enabling legislation for the California Coastal Commission, which granted the permit for the project to go forward. At the groundbreaking, the commission’s Executive Director, Jack Ainsworth, said the project “represents that bridge to a more resilient California.”

“This beautiful stretch of coast must be handled with care, and I think we’ve done that with this project,” he said.

Construction began unheralded Aug. 20 and wrapped for the season Saturday. It will be April 15 before work can begin again because of regulations surrounding wetlands, said Fabio La Serna, assistant resident engineer for Caltrans.

The parts of the project impinging on wetlands will continue seasonally until the entire realignment is completed in late 2023, or perhaps early 2024, La Serna said.

In the spring, construction crews will begin “a massive earthwork operation” to prepare for the new highway route, as well constructing the bridge decking, for which some support materials were being positioned last week, Fabio said.

The massive construction site was abuzz with activity, with huge cranes, a concrete pump with a large boom and other heavy equipment moving across a wide area. Wetland areas were covered with matting and 3-inch rock to help spread the weight, La Serna said.

Cattle grazed in a bright green pasture just across some wildlife fencing from the site, apparently immune to the noise and bustle.

At the mouth of Scotty Creek, across the highway from Scotty Beach, now owned by Sonoma County Regional Parks, three people stood watch, monitoring archaeological sites left from 11,000 years of Pomo and Coast Miwok residents in the area.

One of them, David Carrio, a tribal cultural monitor with the Federated Indians of Graton Rancheria, said they not only wanted to protect any ancestral remains that might surface during construction but also to guard artifacts buried over time on land that had provided food, medicine and an obvious place for fellowship and games in the past.

“This was our special place,” Carrio said. “A lot of people come to this beach and they fall in love with it. They say, ‘It’s our beach.’ It makes you proud.”

More on the project and a 3-D graphic can be found at

You can reach Staff Writer Mary Callahan at 707-521-5249 or On Twitter @MaryCallahanB.

Mary Callahan

Environment and Climate Change, The Press Democrat

I am in awe of the breathtaking nature here in Sonoma County and am so grateful to live in this spectacular region we call home. I am amazed, too, by the expertise in our community and by the commitment to protecting the land, its waterways, its wildlife and its residents. My goal is to improve understanding of the issues, to find hope and to help all of us navigate the future of our environment. 

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