Floods are one of the most common hazards in the United States. Flood effects can be local, impacting a neighborhood or community, or widespread, affecting entire river basins and multiple states.
Not all floods are alike. Some develop slowly, sometimes over a period of days. But flash floods can 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.
Be aware of flood hazards no matter where you live, but especially if you live in a low-lying area, near water or downstream from a dam. Every state is at risk from this hazard.
Before a Flood
- Avoid building in a flood-prone area unless you elevate and reinforce your home.
- Elevate the furnace, water heater, and electric panel if susceptible to flooding.
- Install "check valves" in sewer traps to prevent water from backing up into the drains of your home.
- Contact community officials to find out if they are planning to construct barriers (levees, beams, floodwalls) to stop water from entering the homes in your area.
- Seal the walls in your basement with waterproofing compounds to avoid seepage.
During a Flood
If a flood is likely in your area, you should:
- Listen to the radio or television for information.
- Be aware that flash flooding can occur. If there is any possibility of that in your area, move immediately to higher ground. Do not wait for instructions to move.
- Be aware 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.
If you must prepare to evacuate, you should do the following:
- Secure your home. If you have time, bring in outdoor furniture. Move essential items to an upper floor.
- Turn off utilities at the main switches or valves if instructed to do so. Disconnect electrical appliances. Do not touch electrical equipment if you are wet or standing in water.
- If you have to leave your home, remember these evacuation tips:
- 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. Use a stick to check the firmness of the ground in front of you.
- Do not drive into flooded areas. If flood waters rise around your car, abandon the car and move to higher ground if you can do so safely. You and the vehicle can be quickly swept away.
After a Flood
The following are guidelines for the period following a flood:
- Listen for news reports to learn whether the community’s water supply is safe to drink.
- Avoid flood waters; water may be contaminated by oil, gasoline, or raw sewage. Water may also be electrically charged from underground or downed power lines.
- Avoid moving water.
- Be aware of areas where flood waters have receded. Roads may have weakened and could collapse under the weight of a car.
- Stay away from downed power lines, and report them to the power company.
- Return home only when authorities indicate it is safe.
- Stay out of any building if it is surrounded by flood waters.
- Use extreme caution when entering buildings; there may be hidden damage, particularly in foundations.
- Service damaged septic tanks, cesspools, pits, and leaching systems as soon as possible. Damaged sewage systems are serious health hazards.
- Clean and disinfect everything that got wet. Mud left from floodwater can contain sewage and chemicals.
Floods and flash floods occur within all 50 states and can be extremely dangerous. They are the most common and widespread of all natural disasters next to fire, so knowledge and preparation is extremely important and will help keep losses to a minimum.