Landslides and Mudflows

Landslides and mudflows usually strike without warning. The force of rocks, soil, or other debris moving down a slope can devastate anything in its path.

Before a landslide

  • Get a ground assessment of your property.
  • Your county geologist or county planning department may have specific information on areas vulnerable to landslides. Consult a professional geotechnical expert for advice on corrective measures you can take.


  • Mudflow is covered by flood insurance policies from the National Flood Insurance Program. Flood insurance can be purchased through a local insurance agency.

Minimize home hazards

  • Plant ground cover on slopes to stabilize the land, and build retaining walls.
  • Build channels or deflection walls to direct the flow around buildings.
  • Remember: If you build walls to divert debris flow and the flow lands on a neighbor's property, you may be liable for damages.

Make evacuation plans

  • Plan at least two evacuation routes since roads may become blocked or closed.

Learn to recognize the landslide warning signs

  • Doors or windows stick or jam for the first time.
  • New cracks appear in plaster, tile, brick or foundations.
  • Outside walls, walks or stairs begin pulling away from the building.
  • Slowly developing, widening cracks appear on the ground or on paved areas.
  • Underground utility lines break.
  • Bulging ground appears at the base of a slope.
  • Water breaks through the ground surface.
  • Fences, retaining walls, utility poles or trees tilt or move.
  • You hear a faint rumbling sound that increases in volume as the landslide nears. The ground slopes downward in one specific direction and may begin shifting in that direction under your feet.

During a landslide:

If inside a building

  • Stay inside.
  • Take cover under a desk, table or other piece of sturdy furniture.

If outdoors

After a landslide

  • Run to the nearest high ground in a direction away from the path.
  • If rocks and other debris are approaching, run for the nearest shelter such as a group of trees or a building.
  • If escape is not possible, curl into a tight ball and protect your head.
  • Remember that flooding may occur after a mudflow or a landslide.
  • Stay away from the slide area; there may be danger of additional slides.
  • Check for injured and trapped persons near the slide area. Give first aid.
  • Remember to help your neighbors who may require special assistance – infants, elderly people, and people with disabilities.
  • Listen to a battery-operated radio or television for emergency information.
  • Check for damaged utility lines. Report any damage to the utility company.
  • Check the building foundation, chimney, and surrounding land for damage.
  • Replant damaged ground as soon as possible. Erosion caused by loss of ground cover can lead to flash flooding.

Other languages (All files are PDF.)

DOH Pub 821-035
Revised - March 2008
Reviewed annually

This document was produced in cooperation with the Emergency Management Division of the Washington State Military Department.