Winter Storm Safety
Small mudslides and rockslides occur regularly in Malibu, especially during the rainy winter months. Since the Woolsey Fire, however, the threat of a large-scale mudslide has amplified in and around the burn areas. Denuded of vegetation that helps stabilize the earth, burned hillsides are now significantly more prone to mudslides (also called debris flows), both during and after heavy rains. The threat of mudslides will likely persist for the next three to five years, or until significant regrowth occurs.
Warning signs include:
- Leaning trees
- Water coming through the ground in new paces
- Slowly developing, widening cracks in the ground, streets, and driveways
- Tilting utility poles
- Decks or patios that start to lean away from a house
- Unusual sounds like trees cracking or boulders knocking together
- Doors or windows that stick or jam for the first time
- New cracks in tiles, bricks, or building foundations
Mudslides can strike with little or no warning and travel 55-100 miles per hour. They can travel several miles from their source, growing in size as they pick up trees, boulders, cars, and other materials.
The threat of mudslides does not abate completely once the skies clear after a rainstorm. Water can continue to seep deeper and deeper into the earth, saturating and shifting hillsides well below the surface. Water acts as a lubricant between soil particles, and the strength of saturated ground can be overcome by gravity. An entire hillside can begin flowing downhill if sufficiently soaked.
During intense rains, multiple agencies will coordinate to determine if evacuations are necessary. All mudslide- and rain-related evacuations are mandatory.
In the 2018-2019 rainy season, impacted residents were notified via the City's Disaster Notification System and the Los Angeles County Sheriff's Department. Evacuations were determined on a property-by-property basis, depending on conditions.
after the storm
If you are evacuated, wait until given the all-clear by Los Angeles County Sheriff's Department to return to your home.
If a mudslide occurs, you must stay away from the slide area because there may be danger of additional slides. Report broken utility lines and damaged roadways as soon as possible, and allow trained professionals to check the building foundation, chimney, and surrounding land for damage.