Thunderstorms are another danger in our part of the country, often coming hard on the heels of dust storms. The desert sand doesn’t soak up much water, so our dry washes suddenly fill with fast moving, deep water. It creates a very dangerous situation, especially when the thunderstorm occurs miles away and the wash fills with no warning. (For newcomers, a “wash” is created by rainwater running off the desert sand in sheets, gathering in low spots and carving out these miniature “canyons” that range from three to over fifteen feet deep.)
In 2012, four people in Arizona lost their lives in flash floods and annually there are one to three such fatalities that are vehicle related.[i] Half of all fatalities in flash floods are people who attempted to drive through flooded washes. Numerous people are injured when they try to drive through a wash with swift-moving water. Even if they’re not injured, they often lose their vehicles.
The owners of huge SUVs or pickups, and we have quite a few of those around here, frequently attempt to drive through running washes. I don’t advise it. Don’t assume, if they’re successful, that you can follow them in your Prius. Everyone should think safety first. That wash will probably be empty, or the flow will be greatly diminished, within thirty minutes to an hour. Taking a chance and trying to drive through it, just to save thirty minutes, is simply not worth the risk.