Caltrans Says Tramonto Slide Repairs Must Start at Top

The Tramonto Landslide was documented in 1958 in local papers. Streets collapsed and homes slid off the hill. 
Los Angeles Examiner Negatives Collection, 1950-1961.

Caltrans Public Information Officer Marc Bishoff in an April 30 statement regarding the Tramonto slide said that Caltrans cannot fix the northbound lane of Pacific Coast Highway until Los Angeles takes care of the origin of the slide, which is on City property.

“The lane closure on State Route 1 (Pacific Coast Highway) near Porto Marina Way in Pacific Palisades is due to a slide referred to as the ‘Tarmonto Slide.’ This slide area has been an issue for many years and was recently triggered again by winter storms.

“This slide originated outside of state/Caltrans right of way, although it continues to encroach onto our right of way,” Bishoff said. “A joint [2010] study was done by the City of Los Angeles, the property owner, and Caltrans documenting the history of the slide and how to make repairs.

“Our Construction, Maintenance, and Geotechnical divisions have determined that the unstable nature of the slide requires that repairs start from the top of the slide, which is outside of our jurisdiction and right of way,” Bishoff said. “Once the slope has been stabilized from the top, we can continue with repairs at the bottom of the slide.”

Bishoff added that “Caltrans is in the process of requesting an emergency Director’s Order to potentially realign striping around the slide to provide a second northbound lane, if feasible, on PCH. We do not have an estimate on when the work would occur.”

Caltrans cannot fix the bottom of the slide to reopen one northbound lane on PCH until the top of the slide is repaired.

Councilmember Traci Park’s office was sent this statement and asked for a comment. If one is received, an update will be posted.

A May 7 Planning and Land Use Management (PLUM) is scheduled regarding the construction of four large homes, with basements, on the Tramonto slide. Los Angeles Senior City Planner Juliet Oh, was asked if the City had evidence that building on a slide stabilized a slope. Oh had not responded by posting time. If she does this story will be  updated.


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One Response to Caltrans Says Tramonto Slide Repairs Must Start at Top

  1. Bart Young says:

    On behalf of the Castellammare Home Owners, I commend Mr. Bishop, Mr. Medina and the others at Caltrans for holding the City of Los Angeles accountable for mitigating the Tramonto Landslide. The city never delivered on its promise years ago to repair the slide after spending hundreds of thousands on research and a comprehensive plan to do so. Instead, they abandoned our streets and then approved a development of gigantic homes at the top of slide without requiring the proper hydrology and engineering to stabilize the entire slide and prevent a catastrophic that could wipe out PCH like we saw at La Conchita in 1995 and 2005.

    LADBS claims they frequently allow home development active landslides throughout the city. I am still asking to see examples and specific locations. Unless there is some supernatural breakthrough technology, it is commonly believed by geologists throughout the world that building homes in the middle of an active landslide is a recipe for disaster. Here is why:

    Building structures on a landslide is not a proven method of preventing further slides. In fact, it can exacerbate the risk of a landslide for the following reasons:
    1. Excavation or other ground-disturbing activities, which can weaken the ground and trigger a landslide. Even if the houses are built using specialized construction techniques, such as piling or deep foundations, the risk of a landslide cannot be eliminated.
    2. Building houses on the top of a landslide slope can increase the weight on the ground, which can further destabilize the soil or rock and increase the risk of a landslide. Additionally, building structures on unstable ground can also weaken the soil or rock and reduce its ability to resist the forces of gravity.
    As an HOA it has been extremely difficult to find experts to testify against the city and big developers. Doing so can be a career killer. CMHO has clearly been the underdog in this battle.
    We are overjoyed and extremely grateful that Caltrans has made clear the heart of the problem and is requiring the City of LA to do what is right for the safety and long-term use of Pacific Coast Highway.
    Clearly, no developer would purchase this landslide if they knew they could never develop it.
    So, who gave them the confidence they could buy it and build whatever they want without adhering to the URS study conducted in 2010 or even an Environmental Impact Report?
    Stay tuned. We are about to find out.

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