Sonoma Coast erosion forces Highway 1 lane closure, with a long-term fix years out

A stretch of southbound Highway 1 on the Sonoma Coast at risk of failure from coastal erosion for two decades has finally been abandoned - the cracked and sagging western-most lane shut down for good last week.

Abundant winter rainfall and regular wave action undercutting the deteriorating bluffs at Gleason Beach have finally made the affected lane too dangerous for traffic, triggering the emergency closure and switch to a single, shared lane all travelers, Caltrans said.

“I can describe it in one word: scary,” said Sonoma County planner Gary Helfrich, whose recent examination of the crumbling cliff and damaged highway turned up cracking along the double-yellow lines.

Short-term solutions are still being developed, but the hope at this point is to build a new, adjacent lane inland to carry northbound traffic and convert the existing northbound lane for use by those traveling south, Caltrans representatives said. Engineers also are contemplating trying to stabilize the coastal edge by embedding up to 60 50-foot steel beams vertically into what had been the southbound lane.

“We want to buy as much time as possible,” said Stefan Galvez-Abadia, chief of Caltrans’ Office of Environmental Analysis.

But that’s just an interim proposal.

Caltrans is still working to finalize a long-term fix that involves moving a three-quarter-mile stretch of the roadway inland 400 feet so the cliff’s accelerating retreat no longer poses a problem for coastal travel. The project includes construction of an 850-foot- long bridge that would span the Scotty Creek flood plain, raising the highway above sensitive creek habitat and tribal heritage sites that otherwise might be disturbed.

While Caltrans appeared poised to seek approval of its bypass plan from the California Coastal Commission a year ago, it now could be another full year before it is ready to do, though it also may be sooner, an agency spokeswoman said.

Among the outstanding issues are continued negotiations related to land and right-of-way acquisitions needed to construct what would be the largest man-made structure on the Sonoma Coast.

“I can tell you we are making progress,” Lindsey Hart, Caltrans’ chief spokeswoman.

But with all Caltrans projects, and particularly one in the coastal zone, the process is more complicated than most can imagine, she said.

“We’re still working with everybody involved to make sure that we do this right,” Hart said. “We are working to get that done within the next five years.”

The section of coastline known as Gleason Bleach, located on the rise above Scotty Creek, midway between Bodega Bay and Jenner, is retreating at an average rate of 14 inches a year, one of the fastest rates of coastal erosion in California.

The cliff side is littered with the debris of fallen homes, concrete armaments, pillars and other failed attempts to stabilize the bluffs and a number of homes that once afforded commanding ocean views - until the land gave way and structures began sliding into the sea about two decades ago.

The geology in that spot is a major factor, along with the constant wave action, storm runoff and drainage from the cliff top, Galvez-Abadia said.

“Certainly this year was really, really wet, and certainly there was some rapid erosion out there,” he said.

As the cliff edge cut closer to the highway, Caltrans took steps to shore up the road and clearly mark the edge as it laid plans for the permanent realignment. They were initially hoping to break ground in 2017 before pushing the project back to 2019.

Caltrans had said at least as early as 2014 that studies indicated an 87-foot section of the roadway abutting the bluff could be undermined within five years. That time has come.

Agency representatives in February had observed damage to the highway after this winter’s heavy storms, but then two weeks ago, observed that part of the southbound lane had dropped vertically and more cracks had appeared, requiring an emergency closure, Galvez-Abadia said.

“The roadway is moving,” he said.

Traffic lights have been installed so that one-way traffic control can be maintained along a 1,200-foot section of the highway for the foreseeable future. Motorists can expect five- to 10-minute delays. An average 4,900 motorists pass through the area each day.

The situation is likely to be exacerbated by another emergency lane closure Wednesday in Bodega Bay, where a section of Highway 1 just south of Bay Hill Road was reduced to one lane of traffic as a result of erosion and a failed culvert, officials said.

That will now require emergency repairs and an extended period of one-way traffic control between Bay Hill and Eastshore roads, as well as detours on some days on Bay Hill Road.

The bypass at Gleason Beach was one of 20 fixes initially considered for the area and was selected as the least environmentally damaging. The span is aimed to limit further harm to a creek with historic runs of coho salmon and steelhead trout, as well as surrounding wetlands and tribal sites.

The size of the structure and impacts on the viewshed have drawn criticism. Plans call for extensive habitat restoration, public access and park space.

“Visually, it’s kind of looking at the freeway, but everything is a tradeoff,” Helfrich said. “But those are not the issues that are holding up this project.”

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