flash flood vehicleThe Atlantic hurricane season runs through November 30. Although it is expected to be less severe than normal in 2015, the National Oceanic and Atmospheric Administration (NOAA) predicts six to 11 named storms and the potential for at least a few hurricanes.

Flash floods can happen anywhere. They can be caused by heavy rains, ice or debris jams, or the failure of levees or dams. Flash floods are especially common in the western United States, where low-lying or desert areas can go from dry to flooded in a matter of minutes. In urban areas, flash floods can happen because concrete does not allow water to penetrate the soil. A flash flood can cause a mountain creek in a narrow valley to go from six inches to 10 feet deep in less than an hour.

If you find yourself driving in rising flood waters, your first concern should be your safety. A small car can be carried off in just 12 inches of flowing water, and 18 to 24 inches of water can carry off a large vehicle. Over half of the flood-related deaths reported each year occur in vehicles. Some owners of newer luxury cars may be at even greater risk because airtight vehicles will float away.

Many people underestimate the depth of water and drive through it, resulting in so much damage that their vehicles are a total loss. When water gets into an engine, it often causes hydrostatic lock. This occurs when water is compressed in one or more cylinders, locks the piston in place, overloads the connecting rod, and causes a bending failure of the rod and engine damage.

A car that is parked in an underground garage where water is rising is at risk for severe engine damage. Just a little water in the interior can damage electronic controls under the seats. Even if the car dries out, electronic failure in one area can cause future problems in other areas. More advanced technological systems are often the first to be damaged by water.

If you are driving and notice rising water, don’t underestimate its depth. If you are unsure, turn around and take a different route. If you normally park underground and heavy rain is in the forecast, park in a location on higher ground. Don’t drive through water near downed power lines or with items flowing downstream. If your car stalls in water, you may need to restart it, but that could cause permanent engine damage.