Caltrans update #18 with photos

Date:Tuesday, January 24, 2023, at 2:30 p.m.
District:05 – Santa Barbara, San Luis Obispo, Monterey, San Benito, and Santa Cruz Counties
Contact:Kevin Drabinski or Alexa Bertola
Phone:(805) 549-3138 or (805) 549-3237

FOR IMMEDIATE RELEASE

UPDATE #18

HIGHWAY 1 REMAINS CLOSED AS REPAIRS CONTINUE

AT THREE MAJOR SLIDES 

MONTEREY / SAN LUIS OBISPO COUNTIES – Three major slides on Highway 1 on the Big Sur coast continue to keep the roadway closed. Repairs are underway at Paul’s Slide PM 22, the Mill Creek slide at PM 18, and at the Polar Star slide in northern San Luis Obispo County, one mile south of Ragged Point.

Paul’s Slide PM 22 / Major Activity Took Place Jan. 14, 2023

Paul’s Slide has once again accelerated in response to the recent heavy rainfall. The longstanding strategy of maintaining a catchment area protecting the highway with k-rail and a flexible rockfall fence is no longer feasible. The slide has advanced into the catchment area, over the protective k-rail and fence, and into the traveled way. Debris slides, flowing mud, and rockfall, now travel down slope directly onto the traveled way with nothing to stop them. Movement of the slide is unpredictable; the slope continues to adjust as the slide moves, causing material to flow and rocks to roll into the remaining lane.

The estimated time to reopen Highway 1 at Paul’s Slide with lane closures and traffic control in effect is three to four weeks.

Mill Creek Slide PM 18 / Major Activity Took Place Jan. 15, 2023

This slide flowed out and over the cut slope above northbound Highway 1 and onto both lanes of the roadway. Maintenance and contracted crews cut through the slide material along the highway, leaving a saturated soil mass that is actively pumping out water and mud onto the highway. Caltrans directed the contractor to stop digging into the slide and to wait until access from above the slide could be accomplished to remove it safely. The headscarp of the slide is approximately 100 feet above the highway and water is pumping from a spring into the displaced slide material between the headscarp and the highway below the slide. The saturated and oversteepened slope is on the edge of stability and is very likely to fail catastrophically, that is, in a rapid manner, in the near future.

The estimated time to reopen Highway 1 at Mill Creek is three to four weeks.

Polar Star / Major Activity Took Place Jan. 4, 2023

The slide at Polar Star brought rocky debris material down to the roadway which made it impossible to begin repairs working from the side of the slide at roadway level. Crews cut a path through the base of the accumulated rock debris in order to gain access for equipment, which is being used to remove the slide material, and which is helping advance the work of restoring safe highway access. The failure of the rocky material could occur at any time and has been failing slowly since the pathway was cut, constantly bringing rocks and soil down to the roadway from the oversteepened temporary cut. Unlike Paul’s Slide, there is no catchment area to offer a buffer between the slope and the roadway. As of Jan. 21, crews were able to begin work from above the slide, working down, and they continue to make progress on the slope cut and with slide removal. These repairs continue to bring material down which covers the entire roadbed.

Weather permitting, the estimated time to reopen Highway 1, for at least limited access at Polar Star, is now set at 4 weeks due to the progress made on the slide in recent days.

Passage is prohibited through Paul’s Slide, through Mill Creek, and through Polar Star, due to the dangerous conditions that exist at these slides.

Anyone attempting to pass through these slide areas are advised that they are not only putting themselves at grave risk, but they are also transferring that risk to public safety and first responder teams who would have to respond to any incidents.

Caltrans is committed to providing access to the roadway as soon as road conditions permit. Updates will be provided as soon as new information becomes available.

The closure of Highway 1 from the southern approach in San Luis Obispo County is located at the elephant seal vista area, four miles north of San Simeon. That location was selected as it provides an opportunity for large vehicles to turn around, an opportunity that is largely unavailable north of that location.

FIRIS OES-24 Mapping Airplane

I’ve only seen this used on Wildfires to map the size and location of wildfires, but found this of the Mill Creek Slide on twitterf

No new info re resupply as of 8 am, 1/24/23

No information was released yesterday about the possible helicopter resupply. Currently, Lisa Gehring is arranging for either Sand Dollar Beach parking lot, if downed trees can be cleared, or at Pacific Valley School across the street.

From NOAA’s NWS:

The official forecast, as a result, carries only
slight chance POPs for most of the area Sunday into Monday. It`s
also safe to say, temperatures will be below normal by Sunday and
into early next week. Still seeing signals for a wetter pattern
developing next week.