UPDATE, 3/15/23 — In our most recent round of storms, slip-out activity has flared on Highway 101 in southern Humboldt near the Mendocino County line — and according to State Senator Mike McGuire, a permanent fix to the roadway is now forthcoming. He put it best: “The corridor is slumping into the river.”
Caltrans shared Wednesday evening that “one-way traffic at this location is anticipated for the foreseeable future” with delays of between 15 and 30 minutes expected. The agency said drainage challenges have been a historic problem given the highway’s proximity to the South Fork Eel River, among other concerns.
“This location near Milkyway Loop Road has experienced geological challenges dating back at least a decade, if not for the entirety of the roadway’s existence,” Caltrans wrote. “Crews first closed the northbound lane earlier this year on January 17 when it first started to sink. On March 9, the closed lane dramatically resumed sinking. No deformation of the live southbound traffic lane has been observed. Significant storms this winter are believed to be a factor as the North Coast continues to be prone to slow-moving geological challenges.”
According to Caltrans, multiple long-term solutions are being considered, following further analysis to decide on a final course of action. The agency noted that “long-term solution work will require longer periods of dry weather.” Per an update from McGuire, $20 million in state funding has been secured toward the effort.
Caltrans crews will be using specialized equipment to install approximately thirty soil nails of 40 feet in length to add more stabilizing support for the open lane. Crews are pleased with its stability, per the agency’s update.
COOKS VALLEY, CA, 3/14/23 — Caltrans is monitoring “slip-out activity” in southern Humboldt County near the Mendocino County line, the agency reported on Tuesday morning. The highway remained open as of 11:30 a.m.
“So long as the highway is open, it’s safe,” Caltrans said in a post to its District 1 Facebook page.
Crews are on-site responding to the potential slip-out — a phenomenon describing the collapse and sliding away of part of the road — near Cooks Valley, continuing the areas 24/7 monitoring. Construction and geotechnical staff are at work, as well as a specialized drilling subcontractor, the agency reported.
Caltrans plans “proactive stabilization efforts,” including the use of equipment such as soil nails. Soil nails are a construction technique used to stabilize slopes and help construct a retaining wall.
“While conditions are subject to change, the highway is currently open and we encourage travelers to check our social media and QuickMap for near real-time updates,” Caltrans spokesperson Myles Cochrane wrote in an email to The Mendocino Voice.
Cochrane said more information could be forthcoming this afternoon.
This article will be updated as the situation develops. Find more real-time weather updates at mendovoice.com.
Note: Kate Fishman covers the environment & natural resources for The Mendocino Voice in partnership with a Report For America. Her position is funded by the Community Foundation of Mendocino, Report for America, & our readers. You can support Fishman’s work with a tax-deductible donation here or by emailing [email protected]. Contact her at KFishman@mendovoice.com or at (707) 234-7735. The Voice maintains editorial control and independence.