Watch Out for Flash Floods!

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What do you think of when you hear the word "flood?" The Mississippi River overflowing its banks? Waves from the Atlantic Ocean pushed inland by Hurricane Sandy? While many floods do result from the overflow of a body of water, flash floods can occur anywhere--even in a desert.

The National Oceanic and Atmospheric Administration defines flash flood as a short-term event that takes place within six hours of the incident (rainstorm, levee break etc.) that caused it.

Flash floods often occur when rainwater collects in low-lying areas. Slow-moving storms are more likely to cause flooding than storms that move quickly.

As its name suggests, a flash flood can happen without warning. It can also form amazingly fast. How can you know if your business is vulnerable to a flash flood? Floods are more likely to cause injury or damage when certain other hazards exist.

Small Streams

Many flash floods occur when a small stream is overwhelmed by heavy rain or snowmelt. Thus, it's important to identify any streams or creeks that are in close proximity to your business. This includes any creek beds that are dry during the summer months. Dry creek beds can become raging torrents after filling with rainwater or melting snow.

Dams and Levees

The collapse of a dam or levee can cause flash flooding. Levees are particularly vulnerable to breaking because they are usually made of earth.

They are typically placed parallel to a river or other body of water to protect a community against flooding. If the levee leaks, cracks or collapses, the community may be inundated by a flash flood.

Impervious Surfaces

Another factor that can affect your firm's vulnerability to a flash flood is impervious surfaces.

Many small businesses are located in areas that contain a large number of paved surfaces. These may include streets, parking lots, sidewalks, bridges, overpasses and various other structures. Most, if not all, of these structures are likely to be made of concrete, asphalt or a similar material.  Because they are impermeable, such materials can generate considerable runoff. This runoff can overwhelm storm drains, triggering a flash flood.

Another problem with impervious materials is that they tend to collect pollutants. Particulate matter from vehicle exhaust and the breakdown of vehicle parts (such as tires and brakes) sticks to concrete and other hard surfaces. When a flash flood occurs, these pollutants enter the water and may contaminate your property.


Vehicles are especially prone to damage by flash floods. For one thing, they are often stored in low-lying areas, like underground parking garages. Moreover, vehicles contain electrical systems that are easily damaged by water.

Vehicles also create life safety risks. Suppose you are driving when a flash flood occurs. What should you do? First, remember that a vehicle is not a safe place to be in a flash flood! According to the NOAA, almost half of the deaths that occur in flash floods take place in vehicles.

Here are some safety tips to keep in mind:

  • Pay Attention to Weather Reports Don't drive if your local weather service has issued a flash flood warning (meaning a flood is imminent). Be extra cautious if a flood watch (which means a flood is possible) or a small steam advisory has been issued.
  • Don't Drive into Standing Water If you are driving and encounter standing water, don't just drive into it. If possible, turn around and leave the area immediately. If that's not an option, then try to gauge the water's depth. If it's six inches or more, abandon your vehicle and run for higher ground. Don't underestimate the power of moving water! Six inches of water can disable your vehicle and a foot of water can wash it away.
  • Drive Slowly If you are driving in water a few inches deep, drive very slowly. If your vehicle stalls, get out and move to higher ground.

    Insurance Coverage

    Autos your company owns that have suffered flood damage should be covered if you have purchased Comprehensive coverage under your commercial auto policy. Flood is also a covered peril under Specified Causes of Loss coverage. The latter is an alternative to Comprehensive coverage when insuring trucks.

    Any damage to buildings or contents caused by a flash flood is likely to be excluded under your commercial property policy. Most policies contain a broad "water" exclusion that applies to flood, including flash flood. To protect your property against damage due to floods of any kind, you'll need to purchase flood insurance.

    Evacuation Plan

    Finally, you or your employees may be injured if you are forced to flee your workplace due to a flash flood. You can minimize such injuries by establishing an evacuation plan before a flood takes place. You can find instructions for setting up a plan on websites of government agencies such as OSHA, FEMA and the CDC.