What are the hazards of driving into floodwater?
Floodwater is dangerous when you're driving because there's no way to judge how deep or rapid the water is until it's too late and you've put yourself and any passengers in danger. This is even more true when you're driving in heavy rain or at night when your vision is limited.
When your vehicle is in floodwater, you may think that it’s too heavy to float, but that’s not the case. The force of the moving water can cause your vehicle to be pushed sideways in a flooded road, according to the National Oceanic and Atmospheric Administration (NOAA). This can make driving even a large vehicle into floodwater extremely dangerous, because it may flip on its side or roll over completely, giving you just seconds to escape.
In addition, a flooded road can become washed out as a result of rapidly flowing water, further increasing the danger.
Over half of all flood-related drownings happen when people drive vehicles into floodwater. It only takes 12 inches of rushing water to carry away a small car. Two feet of rushing water can carry away most vehicles.
Why is walking into floodwater dangerous?
For the same reasons, walking into floodwater is dangerous. Just 6 inches of rushing water can knock an adult over – and it takes even less to knock over a child.
Floodwater can also expose a person to injury or to illness from infectious diseases (caused by sewage overflow and other contaminants), chemical wastes and sharp objects, according to the Centers for Disease Control and Prevention. You may also encounter downed power lines due to high winds and other hazards such as snakes.