Flooding

What it is

A flood is water covering land that is usually dry. It can build over days as rivers rise, or arrive in minutes as a flash flood after heavy rain, a dam or levee failure, or storm surge from the sea.

Who is at risk

Floods happen in every US state. Risk is highest near rivers, streams and coasts, in low-lying areas and below dams, and in places where recent wildfires have burned the ground. Just 6 inches of moving water can knock you down, and 1 foot can sweep a car away.

Get ready now

1. Find out if your home is in a flood zone at the FEMA Flood Map Service Center.
2. Ask about flood insurance. Most home insurance does not cover floods, and new policies usually take 30 days to start.
3. Learn the difference between a flood watch (be prepared) and a flood warning (take action now).
4. Plan where you will go if you need to reach higher ground, and how you will get there.
5. Keep important documents in a waterproof container and make digital copies.
6. Move valuables, and anything you need, off basement floors.
7. Pack a go-bag with water, food, medicine, a flashlight and chargers.

When it happens

1. Turn around, don't drown. Never walk, swim or drive through flood water.
2. Move to higher ground right away if told to, or if water starts to rise.
3. If you are trapped in a building, go to the highest level. Only go onto the roof if you must, and call 911.
4. If your car is caught in rising water, get out and move to higher ground if you can do so safely.
5. Stay off bridges over fast-moving water.
6. Turn off power at the main breaker only if you can do it without standing in water.

After

1. Go home only when officials say it is safe.
2. Stay out of flood water. It can hide sharp objects, sewage, chemicals and live electrical wires.
3. Don't use tap water until your utility says it is safe; follow any boil-water advice.
4. Throw out food, medicine and baby formula that touched flood water.
5. Dry your home within 24 to 48 hours if you can, to stop mold. Wear gloves, boots and an N95 mask.
6. Never run a generator or grill inside, even in a garage.
7. Photograph damage and contact your insurance company.

Official sources

• Ready.gov: Floods
• National Weather Service: Flood safety
• CDC: Floods
• American Red Cross: Flood safety

This guide summarises public advice. Always follow instructions from local officials and emergency services.