Caltrans TCB Closure Update 5-3-24

Caltrans TCB Road Closure 2

UPDATE 5/3: Topanga Canyon Landslide at Postmile 1.8 on SR-27

Caltrans’ Botanist team is surveying the Topanga Canyon slide area for Fountain Grass, a non-native invasive plant. It will even grow vigorously in the gaps between sections of concrete and bedrock of natural slopes. Its seeds are carried long distances in the wind. It is especially dangerous in fire hazard areas because it dries out early in the summer and becomes flammable. At the direction of California State Parks, Caltrans plans to remove fountain grass from the landslide area on State Route 27 in Topanga Canyon before clearance work begins. Once the landslide is cleared, native plant seeds would be spread on the bare hillside at night this fall when there is a better chance for growth. Clearance work, which involves removing and bagging the plants, is expected to occur next week.

More information about the plant is available at: https://www.cnps.org/life-with-plants/why-the-fountain-grass-must-go-3105

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.