Flash floods can be caused by several things, but most often it is due to extremely heavy rain. Some other causes are failures to dams, levee breaches, and mudslides (debris flows).

The National Weather Service states “flooding that begins within 6 hours, and often within 3 hours, of the heavy rainfall (or other cause)” qualifies as a flash flood.

Rainfall intensity, the location and distribution of the rainfall, the land use and topography, vegetation types and growth/density, soil type, and soil water content can all determine how quickly flash flooding and where it may occur.

A school bus caught in a flash flood in Bentonville, AR on April 28, 2021.

What To Do If You Are Caught In A Flash Flood

If the forecast calls for possible flash flooding, be sure to remain weather aware. If you see a flood while driving, remember the saying “turn around, don’t drown”. If you get caught in a flash flood, here is what you should do:

  • If you are in a low-lying area during a flood, get to higher ground quickly. Avoid areas that can channel water, causing it to rise faster.
  • Do not try to cross flooded roads or streams on foot. 6-inches of fast moving water is powerful enough to knock an adult off their feet.
  • If your vehicle is suddenly caught in rising waters, leave immediately as long as you can do it safetly.
  • If your vehicle is swept away and it’s filling up with water – DON’T PANIC! Remain calm and wait for your vehicle to fill up with water. Wait, what!? Yes, let the water fill the vehicle. If you try to open the door, the water pressure will force the door shut. As water comes in, the pressure will weaken and you will eventually be able to open the door. Just make sure you unlock the car doors immediately in case the car loses power (especially if you have powered locks). Once you are able to open the door, hold your breath and swim to the surface.
  • If you are swept into floodwaters outside of a vehicle, point your feet downstream. Go over obstacles, never try to go under.
  • If you become stranded on something above the water (ex. tree or building), stay where you are. Do not enter the floodwaters.
  • When rescuers arrive, stay calm and listen to the team’s instructions.
Flash flooding under an I-49 bridge on highway 102 on April 28, 2021. Image: Ma Xiong.

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