- Floods are one of the most common hazards in the United States.
- Flood effects can be local, impacting a neighborhood or community, or very large, affecting entire river basins and multiple states.
- Floods can develop slowly or over a period of days.
- Flash floods develop quickly, sometimes in just a few minutes and without any visible signs of rain. Flash floods often have a dangerous wall of roaring water that carries rocks, mud and other debris and can sweep away most things in its path.
- Overland flooding occurs outside a defined river or stream, such as when a levee is breached, but still can be destructive.
- Flooding can also occur when a dam breaks, producing effects similar to flash floods.
- Even very small streams, gullies, creeks, culverts, dry streambeds or low-lying grounds that appear harmless in dry weather can flood.
- Every state is at risk from this hazard.
What to Do?
- Listen to the radio or television for information.
- Be aware that flash flooding can occur. If there is any possibility of a flash flood, move immediately to higher ground. Do not wait for instructions to move.
- Beware of streams, drainage channels, canyons and other areas known to flood suddenly. Flash floods can occur in these areas with or without such typical warnings as rain clouds or heavy rain.
- Secure your home and move essential items to an upper floor.
- Turn off utilities at the main switches or valves if instructed to do so.
- Do not touch electrical equipment if you are wet or standing in water.
- Do not walk through moving water. Six inches of moving water can make you fall.
- If you have to walk in water, walk where the water is not moving.
- Do not drive into flooded areas. You and the vehicle can be quickly swept away.
- Six inches of water will reach the bottom of most passenger cars, causing loss of control and possible stalling.
- A foot of water will float many vehicles.
- Two feet of rushing water can carry away most vehicles, including sport utility vehicles (SUVs) and pickups.
- Water flooding a road may hide a missing segment of roadbed or a missing bridge.
- Roads weaken under floodwater, and drivers should proceed cautiously after waters have receded, since the road may collapse under the weight of the vehicle.