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Flash Flood

A flash flood is defined as the rapid flooding of geomorphic, low lying areas such as rivers, dry lakes, and basins.  It may have different causes….heavy rain associated with hurricanes or tropical depressions, melting snow, or the breaching of dams or levees.

Many people underestimate the damage potential of flash floods.  The power of water is deceptive, and what looks like a shallow band crossing a roadway may hide the fact that the roadway is in fact no longer there.  It takes only two feet of water to float a vehicle, and people die every year by being swept away in their vehicles as the result of flash flood conditions.  In fact, more people die annually in floods than by lightning, tornadoes, or hurricanes.  The National Weather Service gives the advice “Turn Around, Don’t Drown”, basically saying that you should vacate the area in the event of a flash flood event.

Warning signs for flash floods are obvious, but sometimes still overlooked.  Unusually hard rain over a period of several hours may precede the occurrence of a flash flood.  Likewise for heavy rains in conjunction with a spring thaw, or a monsoon or similar tropical system in your area.  In addition, rapidly rising levels in streams or rivers can be a good indication that something is amiss.

Be especially cautious at night.  Darkness has a way of hiding the threats posed by flood waters.  If you are caught unawares, move immediately to higher ground.  Trying to outrun a flash flood is a race that you are destined to lose.