Sonoma County Highway Eroded by Storm Raises Concerns About Fire Evacuation

Storm damage to a section of heavily trafficked Highway 116 in Sonoma County has some officials worried that long-term repairs could leave it hampered during an evacuation for an emergency such as a wildfire.

Soil under the road became soaked with rainwater on Monday and collapsed into the Russian River, which had risen over 20 feet, dragging down a section of the thoroughfare’s guardrail along with a few trees, just west of Monte Rio. With part of one lane eroded, it’s now down to one-way traffic control.

Repairs could take up to a year, according to Caltrans. Because the road is narrow, bordered by a steep mountain on one side and the river on the other, restoration crews are more limited than they would be in a more open area. And a “slip-out” or “wash-out,” when the slide happens under the road, is also more complicated.

“That’s often more difficult to repair than a slide, which is something that comes down on the road, and sometimes you can just use a frontloader and get rid of the debris that way, or build small walls to keep debris from coming down,” Caltrans spokesperson Jeff Weiss said.

Because the road is a major evacuation route, long-term repairs can be a concern looking ahead to the summer, when the risk for wildfires skyrockets. Multiple reports last year raised concerns with Sonoma County’s roadways and its readiness for a mass evacuation. Highway 116 is prone to gridlock, and critical roads are vulnerable to mudslides, a June report from the county’s Civil Grand Jury found.

As long as one lane remains open during repairs, Highway 116 could still be used in an evacuation, especially with everyone moving in one direction.

“Everybody would be evacuating from the coast; it would be very unlikely to be evacuating towards the coast,” Gold Ridge Fire Chief Shepley Schroth-Cary said. “It could hamper fire engines going towards the fire if we had a mass evacuation.”

If conditions worsen and the erosion spreads to the road’s second lane, evacuees would need to find an alternative route, potentially complicating transportation out of the area.

“Evacuations become very challenging if 116 is shut down,” Sonoma County Supervisor Lynda Hopkins said. “If folks are west of the shutdown scene, they would actually have to take Highway 1 all the way to 12, so actually going really past Bodega Bay and south along the coast.”

Repairs to the highway would entail building a temporary retaining wall to stabilize the road. The wall is made up of interlocking sheets of steel that can be lifted by cranes and are driven into the ground. This stops the initial sliding and prepares the road for a long-term fix. Once the area is stabilized, a permanent retaining wall will be constructed outside of the temporary one.

Caltrans immediately applied for emergency funding through the state to cover repairs. According to Weiss, “this meets the criteria for an emergency project.”

It is unclear how much the repairs might cost. Other projects in the past have cost upwards of $10 million, typically covered by emergency funds granted by the state.

The Monte Rio–Guerneville area has seen three landslide repair projects in the past year, including a restoration for a similar road erosion in December 2024, which took about a year to complete.

“The local folks are pretty accustomed to this happening. There’s other portions of 116 that are one-way traffic or one-lane traffic already from previous events,” Schroth-Cary said. “So this is just part of life along the river and in mountainous terrain.”