Mudslides

Understanding the Difference between Landslides and Mudslides

It is important for residents who live on steep hillsides and in canyons to be prepared for landslides and mudslides.  Areas that don’t have grass, trees, shrubs and plants, such as after a fire, are more likely to have landslides. This includes sliding, falling and flowing soil, rock, mud, brush and trees, especially during or after heavy rains. Slow-moving landslides can cause significant property damage, but they usually don’t cause injury or death.

Mudslides, however, are much more dangerous. According to the California Geological Survey, mudslides can easily exceed speeds of 10 miles per hour (mph) and often flow at rates of more than 20 mph. Because mudslides travel much faster than landslides, they can cause deaths, injuries and significant property damage.

Wherever you live, work, or play, take the following actions to help reduce your risk of death, injury and property losses from landslides, mudslides and other types of ground failure.

Mud and Debris Flow Safety Tips (LA County Fire Department)

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Staying safe: Before the landslide/mudslide

You can reduce the potential impacts of land movement by doing the following:

  • Assume that burn areas and canyon, hillside, mountain and other steep areas are more likely to have landslides and mudslides.
  • Limit the height of plants near buildings to 18 inches.
  • Use plants and bushes that are less likely to burn and keep them watered. This not only helps with landslides/mudslides, but is also helpful for fire safety.
  • Water landscape to promote early growth.
  • Get rid of litter and dead/dry vegetation.
  • Inspect slopes for increases in cracks, holes and other changes.
  • Build away from steep slopes, bottoms/mouths of steep ravines and drainage facilities.
  • Consult with a soil engineer or an engineering geologist to minimize the potential impacts of landslides.
  • Register with your community’s local emergency mass notification system. To be notified of County-wide disasters or emergencies impacting unincorporated communities, click here to sign up with Alert LA County.
  • Develop a family emergency plan that includes home evacuation routes, locations of utility shut-offs, and how family members will contact or reconnect with you if separated. Make sure that there is also an out-of-state contact too. Click here for more information on making plans for emergencies and disasters.
  • Make a disaster supply kit that includes enough food, water and medications that could last for at least 10 days. Click here for more information on keeping supplies for emergencies and disasters.
  • Have supplies to protect your home, including the following: hammer, nails, plywood, rain gauge, sand, sandbags and a shovel. Free sand and/or sandbags are also available at your local fire station. Click here for more information.

Staying safe: When it rains

Take Action

  • Take steps to protect your home by anticipating runoff and placing sandbags in areas as needed. Board up windows and doors as needed.
  • Prepare to evacuate, in case your local officials instruct you to do so.

Monitor

  • Monitor the amount of rain during intense storms. More than three to four inches of rain per day, or ½-inch per hour, have been known to trigger mudslides.
  • Look for geological changes near your home, such as cracked soil, bulging slopes, new holes on hillsides, or muddy waters.

Stay Informed

  • Listen to the radio or watch television for information and instructions from your local officials.

Los Angeles County residents, renters, and business owners, including persons with disabilities and others with access and functional needs, may call 211 LA County for emergency preparedness information, and other referral services. The toll-free 2-1-1 number is available 24 hours a day and seven days a week. 211 LA County services can also be accessed by visiting https://211la.org