Caltrans TCB Closure Update 4-30-24

Boulder on Topanga Canyon Blvd

UPDATE 4/30: Topanga Canyon Landslide at Postmile 1.8 on SR-27

  • Caltrans has met with Los Angeles County Public Works Department and is starting three joint task forces: Geology report review, material haul route planning, and emergency traffic management groups. These efforts include working with the Los Angeles County Fire Department on the emergency evacuation concerns.
  • The geology report group had the kick-off meeting last Friday, and the geologists from Los Angeles County Public Works and California Geological Survey have participated in a joint field review with Caltrans staff on April 29.
  • All permit questions and concerns have been sent to CalOES (California Governor’s Office of Emergency Services) for assistance where needed.
  • Caltrans is also looking into drone lighting to plan for excavation work at night.
  • A geotechnical report is expected to be completed next week. Information from the mapping operations will be used to refine the quantities and calculations into the model for our report. The landslide is not as deep-seated as initially thought, meaning there may be less material that has to be removed from the top down. Activity will pick up quickly once the report is complete.
  • The geotechnical report will determine what equipment will be needed to clear the landslide, possibly a spider excavator, excavator, bulldozers or loaders.
  • The landslide has not moved in some time and is not expected to move further if the warm, dry weather continues.
  • The contractor, Flo Engineering, has built a 5-foot-tall berm with a silt fence to protect Topanga Creek and a trail to the top of hill runs zig zag along the side of the landslide. Both elements were completed last week.
  • In the meantime, Caltrans is clearing large boulders that are susceptible to falling on roadway (see attached photo). The SR-27 full closure remains in effect from Grand View Drive to PCH / Route 1.
  • We are focused on seeing if we can clear this landslide prior to September.


  • After an assessment on Tuesday (4/30) during morning commute time, Caltrans will adjust the signal timing to provide a longer green light for Tuna Canyon Road motorists turning to southbound lanes on Pacific Coast Highway (Route 1). This is expected to be completed by Wednesday (5/1) morning. The timing is staggered with 30-second green on Tuna Canyon Road and 150 second green on PCH (Route 1) from 7 a.m. to 9 a.m. The green time on Tuna Canyon decreases through the course of the day and into the evening. Tuna Canyon is a one-way county road so motorists cannot access northbound during evening commute period. Motorists should allot for extra time when traveling on Tuna Canyon. Thank you.

See OneTopanga to read the full Caltrans updates and to see the presentation at the last Topanga Town Council meeting.

Hear Megan Jamerson of KCRW radio: Landslide Closure Leaves Topanga Canyon in Distress.

Read how the Town Council is working behind the scenes to address critical concerns like school transportation, business funding, and much more.

Read the chat questions and comments from TTC’s Caltrans April meeting. Know that the TTC will be pushing out the responses as they are received from officials.

Sign up to receive the Zoom link for the next TTC meeting on May 15th. If you already receive the newsletters directly from the TTC, then no need to respond.

To get updated emergency information, TCEP’s Emergency Status Page or @TCEP90290

Road questions can be sent to, Caltrans’ designated email communication system. For more links, visit’s Caltrans road closure update page.

See video of Caltrans loaders working on TCB.



Caltrans TCB Road Closure 3

Caltrans TCB Road Closure 2

Caltrans TCB Road Closure 1

Caltrans Worker TCB Landslide


Fernwood Pothole repair

Fernwood sinkhole

Tuna Sinkhole temp repair

Tuna sinkhole