With flash floods listed as the number one cause of weather related fatalities, driving in flood waters is simply far too dangerous to ever be deemed worth the considerable risk. The vast majority of these fatalities are a direct result of the driver trying to drive through flood waters rather than go around them. Many of the drivers who have been rescued from flood waters admit that they drove into water because they were in a hurry to get home and out of harm’s way, ironically enough.
Appearances can often be deceiving when it comes to flood waters. Vehicles can float in as little as 12 inches of water and roads that have been covered by water are often prone to collapse. Sometimes it is impossible to determine how deep the water truly is because the road may have been washed away beneath what looks to be little more than a few inches of water. Even if the road is intact beneath the water, driving into the water can cause your engine to stall leaving you as the sitting duck should the flood waters rise quickly, not to mention the potential damage to your car by trying to force the engine to start. If you are attempting to drive through water and your car stalls, you should immediately abandon it and seek out higher ground.
Flood waters can rise extremely rapidly and cars that are swept away tend to roll or flip over. If your car is swept up, you may have only a matter of seconds with which to escape. Even if you manage to escape your vehicle, you could be injured by floating debris or pulled under by a strong current.
In addition to the immediate physical danger of drowning or becoming injured in flood water, contact with flood waters can include deadly bacteria that can contaminate the water. Raw sewage, human and animal waste and other pollutants may make their way into the flood waters and ingesting them or even coming into direct contact with them can be hazardous to your health.
Floods can also knock down power lines and leave live wires exposed. Wading or driving through flood waters puts you at serious risk of being subjected to electrical shock as strong currents and debris threaten to knock over power lines.
Resouces:
Flood Safety: Driving Into Flood Waters
Flood Driving Safety Tips. Progressive
The Dangers of Flood Water. Emergency Preparedness Tips.