Floods and Flash Floods

What is a Flood?

Floods are the most common and widespread of all natural disasters--except fire. Most communities in the United States can experience some kind of flooding after spring rains, heavy thunderstorms, or winter snow thaws. Floods can be slow, or fast rising but generally develop over a period of days.

Dam failures are potentially the worst flood events. A dam failure is usually the result of neglect, poor design, or structural damage caused by a major event such as an earthquake. When a dam fails, a gigantic quantity of water is suddenly let loose downstream, destroying anything in its path.

What is a Flash Flood?

Flash floods usually result from intense storms dropping large amounts of rain within a brief period. Flash floods occur with little or no warning and can reach full peak in only a few minutes.

A Flash Flood Watch

...means it is possible that heavy rains will cause flash flooding in your area.

You should:

• Be alert and be prepared for a flash flood emergency.
  
• Look for signs of heavy rain (thunder and lightning), both where you are and upstream.
  
• Watch for rising water levels.
  
• Know where high ground is and be prepared to get there quickly if you see or hear rapidly rising water.
  
• Do not camp or park your vehicle along streams and washes.
  
• Fill bathtubs, sinks, and jugs with clean water in case water becomes contaminated.
  
• Bring outdoor belongings, such as patio furniture, indoors.
  
• Move valuable household possessions to the upper floors or to safe ground if time permits.
  
• If you are instructed to do so by local authorities, turn off all utilities at the main switch and close the main gas valve.
  
• Stay tuned to local news for the latest information.
  
• Be prepared to evacuate.

A Flash Flood Warning

... means that flash flooding has been reported or is imminent

You must act quickly!

You may have only SECONDS to save yourself and your family!

• Go to higher ground immediately! Get out of areas subject to flooding such as dips, low spots, canyons, washes, and areas along streams and creeks. In urban areas, stay away from clogged storm drains and underpasses. If advised to evacuate, do so immediately!
  
• Avoid areas that are already flooded.
  
• Do not attempt to cross flowing streams or walk through any floodwaters. If it is moving swiftly, as little as 6 inches of water can sweep you off your feet.
  
• NEVER drive through flooded roadways! Turn around and go another way. If your vehicle stalls, leave it immediately and seek higher ground. Rising water can quickly engulf the car and sweep it away. It only takes a foot of rapidly moving water to drag a car into deeper waters or flip it over.
  
• Be especially cautious at night when it is harder to recognize flood dangers.
  
• Tune into local news for the latest information.

Emergency Information

1. Flood waters can be extremely dangerous. The force of six inches of swiftly moving water can knock people off their feet. The best protection during a flood is to leave the area and go to shelter on higher ground.
   
2. Flash flood waters move at very fast speeds and can roll boulders, tear out trees, destroy buildings, and obliterate bridges. Walls of water can reach heights of 10 to 20 feet and generally are accompanied by a deadly cargo of debris. The best response to any signs of flash flooding is to move immediately and quickly to higher ground.
   
3. Cars can be easily be swept away in just 2 feet of moving water. If flood waters rise around a car, it should be abandoned. Passengers should climb to higher ground.

Danger Zones

Floods and flash floods occur within all 50 states. Communities particularly at risk are those located in low-lying areas, near water, or downstream from a dam.

Mitigation pays. It includes any activities that prevent an emergency, reduce the chance of an emergency happening, or lessen the damaging effects of unavoidable emergencies. Investing in mitigation steps now such as constructing barriers such as levees and purchasing flood insurance will help reduce the amount of structural damage to your home and financial loss from building and crop damage should a flood or flash flood occur.