Your Vehicle Can Be Your Worst Enemy In a Flash Flood

Eric Chaney and Jonathan Belles
Published: August 30,2016
Most of us think of our vehicles as safe places. They're tested in a hundred different ways to be sure they're safe. They're rated on how safe they are. They carry us safely to and from work and school and hundred other places day in and day out.
It's a tough mindset to break.
But that same mindset can make your vehicle your worst enemy during a flash flood event.  In China recently, a flash flood swept more than two dozen vehicles out of car park as if they were so many toys, leaving behind a jumbled mess of half-submerged cars and SUVs.
People think, "Oh, that won't happen to me. My car is big enough, or the water isn't deep enough, and besides I have to get my child to school or make that important meeting."

Percent of flood-related deaths by situation from 1995-2010, excluding Hurricane Katrina flood deaths.

But according to FEMA, just a foot of water is enough to float a vehicle,  and just two feet can carry away most any passenger cars, including those we think of as heavy-duty such as SUVs and pickup trucks.
Even semi-trucks aren't immune. Video from recent flooding in Lousiana shows a tanker truck being swept from a roadway in the blink of an eye.
An average of 82 people have died in the U.S. from flash floods each year from 2006-2015, according to the National Weather Service. That's more than double the average death toll from lightning.
In 2015, 155 people died from flooding, and it was the number one cause of weather-related fatalities in 2015.
Almost two out of every three U.S. flash flood deaths from 1995-2010, excluding fatalities from Hurricane Katrina, occurred in vehicles, according to Dr. Greg Forbes, severe weather expert for The Weather Channel.

We Aren't Learning Our Lesson

It's easy to misjudge the depth of floodwater, particularly at night. Sometimes the bridge or road masked by floodwater may have been undermined or completely washed out.
In some cases, the flash flood event occurs over such a localized area, say one part of one county or city, that driving conditions may go from dry roads to high water in a matter of a few miles or within minutes.
According to the U.S. Geological Survey, water 1 foot deep typically exerts 500 pounds of lateral force on a vehicle.
Once your vehicle is floating, the floodwater becomes your steering wheel. If that water is moving, your vehicle could be swept away, tipped on its side or flipped.

(MARIANA MENDEZ/AFP/Getty Images)

Rising water can enter your vehicle in a manner of minutes, even seconds.
The best advice we can give is to never drive through floodwater of unknown depth. As the National Weather Service has campaigned for years: "Turn around, don't drown!"
If you are stuck in your vehicle underwater, you need to act quickly:
- Find a pocket of trapped air, usually against the rear window or roof.
- Roll a window down slowly, take a deep breath and be ready to swim.
- If the window won't open, break the window with a rescue tool (Swiss Army knife, for example).

Don't Wade Through Floodwater, Either

If floodwater is powerful enough to float and/or trap your vehicle, trying to wade through it is also a bad idea.
Just 6 inches of flowing water can knock you off your feet. If you slip and fall face first, you might drown before you regain consciousness. This is particularly dangerous situation for babies and small children.
Flowing at just 6 mph, water exerts the same force per unit area as air blowing at EF5 tornado wind speeds, according to Dr. Forbes. Water moving at 25 mph has the pressure equivalent of wind blowing at 790 mph, faster than the speed of sound.
Forbes says the fastest floodwater speeds are thought to be around 67 mph, which may occur in steep, elevated terrain.
Not to mention, who knows what is flowing in the water besides you if you do decide to get in.

Your Responsibility: Be Aware

Awareness of the weather can save your life in a flash flood.
Download The Weather Channel app for your smartphone and tablet or use NOAA Weather Radio to make sure you have a method of receiving flood watches and warnings.
Next time there is a risk of flash flooding, take it seriously. Stay out of the water. Don't become a statistic.
(MORE:  WeatherREADY flood tips | 6 Incredible U.S. Rain Records | 10 Wettest U.S. Cities)

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