CA Highway 1 Moved 400 Feet, Marks 1st Sea-Level Rise Caltrans Project

SONOMA COUNTY, CA — Caltrans Bay Area held a ribbon cutting Nov. 14 to celebrate the completion of the state Highway 1 Gleason Beach Roadway Realignment Project — the first project built by Caltrans with the primary purpose of addressing the effects of sea level rise

Caltrans began construction in August 2021 on the $77.3 million project that moved the highway 400 feet inland, away from rapidly eroding coastal bluffs that threatened to undermine the former highway.

The project involved building 4,000 feet of new highway, including an 810-foot, two-lane bridge with a separated pedestrian walkway and 12-foot shoulders to accommodate bicycle travel.

The new highway and bridge opened to traffic March 8, 2023, allowing Caltrans to abandon the old highway and concentrate on making significant environmental upgrades, including restoring Scotty Creek's natural connection to the ocean and repurposing the old highway as part of the California Coastal Rail Trail.

Parking spaces were also added to maintain and improve public access to the beach.

"The Gleason Beach Realignment Project has been a top priority for the State and County," said State Sen. Mike McGuire, "and it's been an all-hands-on-deck approach to get the job done. This specific segment of Highway 1 has been especially challenging, constantly being undermined by coastal erosion near Scotty Creek. That said, we needed to get the job done no matter what because Highway 1 is the spine of the coast. I'm grateful to Caltrans for taking on this project, and I truly appreciate the neighbors' patience with this process."

The new bridge spans Scotty Creek, allowing Caltrans to remove a large concrete culvert that once corralled the creek and directed it beneath the old highway. Without the culvert, Scotty Creek flows unimpeded to the ocean, allowing coho salmon and steelhead to swim upstream again to spawn. Likewise, a large wetland, once divided by the at-grade highway, will be able to flourish with the removal of the old road.

"The Gleason Beach Highway Realignment is the first project built by Caltrans with the primary purpose of addressing the effects of sea level rise," said Caltrans Bay Area Director Dina El Tawansy. "While the advancing ocean was the reason for this project, it would be foolish to imply that nature is our adversary. Indeed, this project used innovative designs to rectify past conflicts with nature, including removing impediments to Scotty Creek, reviving wetlands, and constructing a new bridge that accommodates pedestrian and bicycle travel."