After fires: Stay safe from floods and mudslides
Fire and water—they sound like natural opposites. But together, they can pack a terrible one-two punch.
That’s because after a wildfire, burnt areas are more susceptible to floods and mudslides.
If a wildfire has devastated your community, the last thing you may want to think about is how you’d respond to another natural disaster. But this is a good time to be sure you’re prepared for what may come next.
Why does this happen?
Under normal circumstances, plant life helps the ground absorb rainwater. But if a region’s plant life has been destroyed by wildfires, the ground may repel water instead. That can lead to an increased risk of flooding and mudslides in areas below the burn zone—for years after the wildfire.
Heavy rains and fast-melting snow may contribute to flash floods and mudslides. Flash floods are particularly dangerous because they happen fast—within six hours of heavy rainfall—and they’re hard to predict. And as we we’ve seen all too well recently, if the flood triggers a mudslide, the result can be deadly.
Before a flash flood
Just a few inches of floodwater can cause major damage to homes. Six inches of moving water can knock a person down. And one to two feet of rushing water can carry away most cars and trucks. So it’s key to plan ahead and know how you’ll take action in an emergency.
If you live in an area that has been affected by wildfires, the Federal Emergency Management Agency (FEMA) recommends that you buy flood insurance now. Most standard homeowners insurance policies don’t cover flood damage. You can learn more about purchasing a policy on the website of the National Flood Insurance Program.
Other smart steps to consider:
- Create an emergency plan. Know where you’ll evacuate to and what route you’ll take. Don't forget to plan for pets and livestock too.
- Store things safely. Keep a list of your valuables. And take pictures of your possessions, including the inside and outside of your home. Store important papers off-site or in a waterproof place.
- Have an emergency kit ready to go. Gather medicines, flashlights, batteries, cash, first-aid supplies, and enough food and water for at least three days.
During a flash flood
When there’s a danger of flooding, you may receive emergency alerts on your phone, radio or TV. A flood watch means flooding is possible and you should be ready. A flood warning means flooding is about to happen or already in progress and you need to get to higher ground right away.
If you’re at home:
- You may need to evacuate. Follow instructions—and don’t return home until authorities say it’s safe.
- If haven’t been evacuated, unplug electrical appliances. You may also be told to turn off your power and water supplies.
- Stay out of basements and underground garages.
- Move important items to a higher floor if possible.
If you’re away from home:
- Don’t walk, swim or drive through floodwaters. Stay away from beaches and riverbanks.
- Avoid bridges over fast-moving waters, and steer clear of low-lying areas like underpasses, underground parking lots and canyons.
- If your car is surrounded by rising water, get out quickly and move to higher ground.
Before a mudslide
After a wildfire, heavy rain or melting snow can make the ground unstable. Water softens the ground to form mudflows that can pick up trees and large rocks as they gain force.
You may be able to avoid a mudslide by knowing where they’re likely to happen. These places include:
- Steep slopes.
- The bottoms of hills or canyons.
- Hillsides developed with buildings and roads.
- Embankments along roadsides.
- Channels along streams or rivers.
- Areas where rain and other runoff converges.
- Places where there have been mudslides before.
Be aware of the land around your home and the roads you travel often. And know alternate routes in case a road is wiped out by a mudslide.
During heavy rain
Just as with flooding, if you live in an area prone to mudslides, you may need to evacuate. When in doubt, move to higher ground.
Use the radio to listen for flood warnings and traffic updates. If you’re out in the elements, watch and listen for signs of a mudslide. These include:
- A sudden increase in water level in a stream or ditch.
- Tilted trees, power poles or fences. These can warn of unstable ground.
- The sound of trees cracking, rocks knocking together or a low rumble.
- A small trickle of mud or debris.
- Muddy water in a stream that is usually clear.
Because they carry debris as well as water, mudslides can be devastating. Know the evacuation routes for your home, workplace and any other place you spend time.
Forging community from fire
Watch this moving, four-minute video about St. Helena Hospital Clear Lake’s response to the 2016 Clayton fire.