Two mini vans - one red and one white - are caught in a landslide and have fallen off the road

Landslides & Debris Flow

Before a Landslide

During a Landslide

After a Landslide

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Landslides occur in all U.S. states and territories and can be caused by many factors including earthquakesstormsvolcanic eruptionsfire and human modifications of land. The most dangerous, life-threatening and deadliest landslides are the ones that occur quickly, often with little notice.

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A landslide occurs when masses of rock, mud or debris move down a slope. When a wildfire burns a slope, it increases the chance of landslides for several years.

How to protect yourself or your property depends on the type of landslide. Land-use zoning, professional inspections, and proper design can reduce many landslide problems, but evacuation often is the only way to protect lives from a debris flow or other fast-moving landslide.

Not all landslides are fast. Some slow-moving landslides move at a snail’s pace, stopping and starting, and not advancing more than three feet a year. While these landslides rarely cause loss of life, they can cause damage to land and property over time.

Before a Landslide

The following are things you can do to protect yourself, your family and your property from the effects of a landslide or debris flow:

An emergency supply kit that includes scissors, duct tape, plastic a flashlight and cleaning supplies.
  • Build an emergency kit.
  • Make a plan for your household, including your pets, so that you and your family know what to do and where to go in the event of a landslide.
  • Sign up for your community’s warning system. The Emergency Alert System (EAS) and National Oceanic and Atmospheric Administration (NOAA) Weather Radio also provide emergency alerts.
  • Leave if you have been told to evacuate or you feel it is unsafe to remain in your home. Text SHELTER + your ZIP code to 43362 (4FEMA) to find the nearest shelter in your area (example:  shelter 12345 ).
  • Consult a professional for advice on appropriate preventative measures for your home or business, such as flexible pipe fittings, which can resist breakage better.
  • Protect your property based on recommendations from a qualified geotechnical professional and/or local city/county guidance on protection from debris flow and flooding. You can't stop or change the path of a debris flow. However, you may be able to protect your property from floodwaters or mud by use of sandbags, retaining walls or k-rails (Jersey barriers).
  • In mud and debris flow areas, consider building channels or deflection walls to try to direct the flow around buildings. Be aware, however, that when a flow is big enough, it goes where it pleases. Also, you may be liable for damages if you divert a flow and it flows on a neighbor's property.
  • Talk to your insurance agent if you are at risk from a landslide. Debris flow may be covered by flood insurance policies from the National Flood Insurance Program (NFIP).

Recognize Warning Signs

Watch for debris flows and other fast-moving landslides that pose threats to life:

  • If you are near a wildfire burn area, sign up for emergency alerts and pay attention to weather forecasts for the burn area.
  • Listen and watch for rushing water, mud or unusual sounds.
  • Unusual sounds such as trees cracking or boulders knocking together, might indicate moving debris. A faint rumbling sound that increases in volume is noticeable as the landslide nears.
  • Huge boulders in the landscape can be signs of past debris flows.

Watch for slow-moving landslides, or earthflows, that pose threats to property:

  • Changes occur in your landscape such as patterns of storm-water drainage on slopes (especially the places where runoff water converges) land movement, small slides, flows, or progressively leaning trees.
  • Doors or windows stick or jam for the first time.
  • New cracks appear in plaster, tile, brick or foundations.
  • Outside walls, walkways or stairs begin pulling away from the building.
  • Slowly developing, widening cracks appear on the ground or on paved areas such as streets or driveways.
  • Underground utility lines break.
  • Bulging ground appears at the base of a slope.
  • Water breaks through the ground surface in new locations.
  • Fences, retaining walls, utility poles, or trees tilt or move.
  • The ground slopes downward in one direction and may begin shifting in that direction under your feet.

During a Landslide

A woman listing to the radio
  • Listen to local news stations on a battery-powered radio for warnings.
  • Always follow the instructions from local emergency managers. They provide the latest recommendations based on the threat in your community.
  • Stay alert and awake during a storm that could cause a landslide. Many deaths from landslides occur while people are sleeping.
  • Be aware that by the time you are sure a debris flow is coming, it will be too late to get away safely. Never cross a road with water or mud flowing. Never cross a bridge if you see a flow approaching because it can grow faster and larger too quickly for you to escape.
  • If you do get stuck in the path of a landslide move uphill as quickly as possible.
  • Avoid river valleys and low-lying areas during times of danger.
  • If you are near a stream or channel, be alert for any sudden increase or decrease in water flow or water that changes from clear to muddy. These can be signs that a landslide is coming.

After a Landslide

  • Stay away from the slide area. There may be danger coming from additional slides.
  • Listen to local radio or television stations for the latest emergency information.
  • Watch for flooding. Floods sometimes follow landslides and debris flows because they may both be started by the same conditions.
  • Check for injured and trapped persons near the slide, without entering the direct slide area. Direct rescuers to their locations.
  • Report broken utility lines and damaged roadways and railways to appropriate authorities. Reporting potential hazards will get the utilities turned off as quickly as possible, preventing further hazard and injury.
  • Allow trained professionals to check the building foundation, chimney, and surrounding land for damage.
  • Replant damaged ground as soon as possible since erosion caused by loss of ground cover can lead to flash flooding and additional landslides in the near future.
  • Seek advice from a geotechnical expert for evaluating landslide hazards or designing corrective techniques to reduce landslide risk. A professional can advise you of the best ways to prevent or reduce landslide risk, without creating further hazard.

Last Updated: 3/10/2024

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