Flash floods generally dissipate as quickly as they begin. However, the flood waters aren't always the only issue:
Death or Serious Injury
The very nature of flash floods makes them fast and very difficult to predict. Since they can occur without warning, it is no surprise that people can be seriously injured or killed by these natural disasters. Also, many flash floods occur at night while people are sleeping adding to the risk. Flash floods are the #1 weather-related killer in the U.S. according to the National Weather Service.
Immediate Property Damage
In addition to the force of the water, flash floods can carry large debris such as boulders. This combination can cause heavy structural damage to homes making them uninhabitable and can carry away large pieces of property such as vehicles.
Long-Term Property Damage
Rooms, vehicles, and other property that came in contact with flood waters may not be salvageable. Homes that were flooded can be susceptible to harmful molds. Vehicles that were submerged usually have irreparable water damage to the engine and other critical components.
Loss of Critical Infrastructure
Large debris and floodwaters can cause structural damage to bridges and roadways, making travel impossible. Power, telephone, and cable lines can be taken out by flash floods as well. Flood waters can disrupt or contaminate ground water, making tap water unfit for consumption.
Deposited Sediment & Silt
Flood waters carry along with them sand, silt, and other debris as they travel. When the velocity of the flash flood slows, it begins depositing this debris. Floods can leave behind large amounts of silt and other debris that can make travel difficult and can be costly to remove.
Uninsured or Under-insured Homeowners
Being infrequent and unpredictable, many homeowners do not consider flash floods when insuring their homes. Your regular homeowner's or renter's insurance does not cover flood damage; for that you need flood insurance through the National Flood Insurance Program (NFIP). View information on flood insurance, calculating your risk for floods, and interactive demonstrations of potential flood damage.
Depending on the damage caused, it may prevent local businesses from opening or keep customers from getting to those businesses.