Flooding and Landslides

Anywhere it rains, it can flood. And landslides can occur in all of the U.S. states and territories. Educate yourself, get insured, safeguard your possessions and prepare your home.

Anywhere it rains, it can flood. Landslides can occur in all of the U.S. states and territories. Just because you haven't experienced a flood in the past, doesn't mean you won't in the future. Flood risk isn't just based on history; it's also based on a number of factors: rainfall, river-flow and tidal-surge data, snow, topography, flood-control measures and changes due to building and development.

Flood Preparation

Educate yourself. Find out if you live in a flood zone by checking FEMA's local flood hazard maps or contacting your local Emergency Management agency.

Get insured. The National Flood Insurance Program (NFIP) offers flood insurance to homeowners, renters and business owners if their community participates in the NFIP. Learn more about coverage from the NFIP by visiting Floodsmart.org.

Safeguard your possessions. Conduct a household inventory to and keep copies of all of your critical documents. Knowing what you have and having it documented will make an insurance claim easier to handle should your home be affected by a flood.

Prepare your home and property. Here are some steps you can take to prepare your home and property in case of a flood:

  • Get information early on in the event by following Multnomah County Emergency Management on social media and by also signing up for Public Alerts
  • Keep drains, culverts, gutters, streets and driveways clear of leaves and other debris to prevent localized flooding.
  • Store flood lighting supplies like plastic sheeting, lumber and sandbags. Contact your local city or county to find out where you can get sandbags.
  • Elevate the furnace, water heater and electrical panel above flooding level.
  • If you have a basement, make sure your sump pump is working and has a battery-operated backup.
  • If you have time, move furniture, valuables and important documents to a safe place.

Get a kit and make a plan.

  • Plan and practice a flood evacuation route with your family. Know safe routes from home, work and school that are on higher ground.
  • Ask an out-of-state relative or friend to be your emergency family contact.
  • Put together a "Go-kit" for each family member and your animals. You may need to leave your home suddenly if a flood is imminent and a Go-kit will have all of the items you might need for at least 72 hours.

During a Flood
Photo courtesy of the FEMA photo library

  • Go to higher ground and avoid areas subject to flooding.
  • Do not attempt to swim, walk, or drive, across flowing streams or flooded roadways. Turn around, don't drown!
  • If trapped in a building, then go to its highest level. Do not climb into a closed attic. You may become trapped by rising floodwater. Go on the roof only if necessary. Once there, signal for help.
  • Listen to a battery-operated radio for the latest storm information.
  • Turn off all utilities at the main power switch and close the main gas valve if advised to do so.
  • If you come in contact with floodwaters, wash your hands with soap and disinfected water.

After a Flood

  • If your home has suffered flood damage, call your insurance agent to file a claim.
  • Don't re-enter your home until flood waters have receded, you are cleared to return to your home and you have checked for structural damage.
  • Take pictures and an inventory of any damage to your home or possessions.
  • Keep power off until an electrician has inspected your system for safety.
  • Boil water for drinking and food preparation until you are informed that your water supply is safe.
  • Remove wet contents immediately to prevent mold.
  • Wear gloves and boots while cleaning or disinfecting

More information about flooding, flood preparation and response can be found at Ready.gov and Floodsmart.gov.

Landslides, Rock Slides, Mud, and Debris Flows
Oso Mudslide
Photo Courtesy of the FEMA Photo Library.

Landslides occur in al US states and territories. In a landslide, masses of rock, earth, or debris move down a slope. They can be small or large, slow or rapid. Landslides are activated by storms, earthquakes, volcanic eruptions and the modification of land by humans.

Debris and mud flows are rivers of rock, earth and other debris saturated with water. They occur when water accumulates quickly in the ground, during rainfall and rapid snow melt, and change the earth into a flowing river of mud. They can flow very rapidly and often with little or now warning at high speeds.

Rock Slides are landslides involving bedrock in which the rock that moves remains largely intact for at least a portion of the movement. Rock Falls are landslides where a mass of rock detaches from a steep slope by sliding, spreading or toppling and descends mainly through the air by falling, bouncing or rolling

For materials you can print please view this document "Protect Your Home and Property: A Homeowner's Guide to Landslides for Washington and Oregon"

Landslide Preparation

Here are steps you can take to protect yourself from the effects of a landslide

or debris flow:

  • Don't build near or on a steep slope, close to mountain edges, near drainage ways or natural erosion valleys.
  • Get a ground assessment of your property.
  • Consult a professional expert for advice on how to correct any issues on your property that may cause a landslide.

Recognize Landslide Warning Signs

  • Changes in the landscape like storm-water drainage on slopes, land movement, small slides, flows or progressively leaning trees.
  • New cracks appear in plaster, tile, brick or foundations.
  • Outside walls, walks or stairs begin pulling away from the building.
  • Developing and widening cracks appear in the ground or on paved areas.
  • Water breaks through the ground in new locations.
  • Fences, utility poles or trees tilt or move.
  • The ground begins to shift in a downward slope.

During a Landslide

The following are guidelines for what you should do if a landslide or debris flow occurs:

  • Move away from the path of a landslide or debris flow as quickly as possible.
  • Curl into a tight ball and protect your head if escape is not possible.

After a Landslide

The following are guidelines for the period of time following a landslide:

  • Stay away from the slide area and do not re-enter your home until cleared to do so by authorities.
  • Check for injured and trapped persons near the slide and direct rescuers to their locations.
  • Watch for broken electrical, water, gas and sewage lines and damaged roadways and railways.
  • Seek advice from a geotechnical expert to reduce any remaining landslide hazards and risk.
Last reviewed May 20, 2024