How to Prepare for a Flood – Before, during and after

Preparing for a flood is extremely important. It’s one of the most common natural disasters in the United States (and in many other parts of the world). It occurs across the country, but those that live in areas that are lower in elevation than a nearby body of water (streams, lakes, oceans, etc.) are especially at risk. Knowing how to prepare for a flood can save you and your family.

In fact, flooding can be so dangerous, that it is one of the few disasters that I suggest building a bug out bag for.

Follow these steps to prepare for a flood:

  • Move valuable items to higher areas.
  • Use a waterproof container to store documents.
  • Take your animals with you!
  • Leave the doors to refrigerators and freezers open.
  • Turn off electricity, water, and gas.
  • Put sandbags in your toilets and over and drains.

Floods kill more people in the United States every year than lightning, hurricanes or tornadoes. They also cause roughly $5 billion a year in damages. This is due, in part, to complacency by those in vulnerable areas. Water is just not all that intimidating compared to other types of disasters and this leads people to fail to prepare for a flood.

What to do Before a Flood

If you are in a flood-prone area, get a flood insurance policy. You probably have to have it anyway, and on the off chance that your home gets damaged, you’re going to want it. Think of insurance as just another prep. You have food and water just in case something bad happens…you get insurance for the same reason.

It takes about 30 days for flood insurance to kick in. Plan accordingly!

The best way to protect yourself is to leave the area if it’s at all possible.

Prepare your house by doing the following:

  • Let local authorities know that you are moving to a safer place if you’re going to evacuate. This will prevent them from searching for you if there is a need for recovery operations in the area.
  • Move valuable items and electronics to higher areas. Put them on the second floor, beds, countertops, etc.
  • Move hazardous items to higher areas. Paints, oil, fuel, etc that may leak into the floodwater should be moved so they don’t spill and contaminate your home.
  • Use a waterproof container or bag to store any vital documents and medical supplies.
  • Take your animals with you. If you can’t, then you need to make sure they have food and water and are in the safest place that you can put them.
  • Leave the doors to your refrigerators and freezers open. This will help to prevent them from floating around and causing damage to your house.
  • Turn off electricity, water, and gas to your home.
  • Put sandbags in your toilets and over and drains in the laundry room or bathroom. This will keep sewage from backing up into your home.
  • Bring outside possessions indoors or tie them down securely. This includes lawn furniture, garbage cans, and other movable objects.

Gather disaster supplies:

  • Drinking-Water – Fill pots and pan, tubs, sinks and any other clean containers that you have.
  • Food – Make sure you have food that doesn’t need to be refrigerated or need power to prepare.
  • Money – Make sure you have access to some cash in case you need it.
  • Medications and First Aid Supplies – You should have a supply of any prescription medications and a first aid kit.
  • Clothing/Toiletries – Keep warm clothing around if the weather is cool, it’s easy to get hypothermia when you’re wet.
  • Battery-Powered Radio – A NOAA battery-powered radio will let you stay informed about the flood if you lose power.
  • Flashlights – Flashlights are important when the power goes out! Make sure you have a few in your house.
  • Extra Batteries – Have extra batteries for your radio and flashlights as well as any other battery-powered items you may need.

If you decide to stay in your home, be prepared to evacuate. 

  • Identify places that you can evacuate to.
  • Find alternate routes to travel that are in areas not likely to flood.
  • Have a plan to take care of your pets! They are your responsibility.
  • Fill the gas tanks of your vehicles. When a flood happens you may not be able to fill up.
  • If you’re instructed to evacuate, you probably should. By sticking around, you could cause emergency personnel to needlessly risk their lives to save you.

Review your family’s disaster plans.

  • Talk about flood plans with your family.
  • Decide on a rally point to meet up at if you’re separated during the flood.
  • Make sure your family has contact numbers for a family member outside of the flood area in case they can’t contact you. Make sure that family member knows that they may be contacted.

What to do During a Flood

Monitor the situation.

  • Monitor your surroundings, NOAA Weather Radio, local television, and radio stations.

Don’t drive anywhere unless you have to. If you absolutely have to drive:

  • Make sure your vehicle has enough fuel.
  • Go directly where you need to go. Do not try to see the damage in other parts of the neighborhood.
  • Avoid areas that have flooded or are being evacuated.
  • Watch for washed-out roads, earth slides, and downed trees or power lines.
  • Move during the day if possible. It’s much more difficult to judge floodwaters at night.
  • If the vehicle stalls, abandon it. In still water, you should move to safety. In moving water, you should stay in the vehicle.
  • If water rises around your car, leave the vehicle and get to higher ground as quickly as possible.
  • Never drive through flooded roadways!

Get to high ground and away from the water.

  • Stay out of areas that are already flooded.
  • Move out of low areas that could collect water.
  • Do not cross flowing floodwaters.
  • Stay away from power lines and other electronics.

Evacuate if you’re instructed to or you think that your house may flood!

  • Leave before your escape is cut off by the water.
  • Act quickly. Save yourself, not your belongings.
  • Use one vehicle to keep from getting separated and limit the number of vehicles on the road.
  • Lock all doors and windows in your home.

Never walk or swim through flowing water.

Do not go after someone who falls into or is trapped in floodwater.

What to do After a Flood

The CDC recommends that you do the following things:

Do not return until it’s safe to do so.

  • Monitor NOAA, local television, and radio stations. Do not return to flooded areas until it’s announced that it safe.

Be safe returning.

  • Follow the recommended routes. Watch for washed-out roads, earth slides, and downed trees or power lines.
  • Always avoid downed power lines.

If a building was flooded, inspect it before entering.

  • Do not enter a building if it still has water in it or the area around it is flooded.
  • Check for structural damage. Inspect foundations for cracks or other damage.
  • Turn off gas lines at the meter.

Use caution when entering buildings.

  • Wear sturdy shoes or boots. Cuts on the feet are one of the most common injuries following a flood.
  • Be on the lookout for fire hazards.  There may be broken gas lines, flooded electronics and submerged furnaces.
  • Check for gas leaks. If you smell gas quickly leave the building. Turn off the gas at the outside main valve. Call the gas company.
  • Check for electrical system damage. Turn off the electricity at the main circuit breaker if you can reach it without stepping in water.
  • Examine walls, floors, doors, windows, and ceilings for risk of collapsing.
  • Watch out for animals that might have entered when the building flooded.
  • Let the building air out.

Take plenty of pictures. These will be useful for insurance claims.

Your home may no longer be safe.

  • Any medicine, food, or water that has come in contact with floodwater should be thrown out. This includes canned foods.
  • Boil water for 10 minutes before using it. If you suspect chemicals may be in the water (this includes gas and oil), do not use it.
  • Do not allow children to play in flooded areas.
  • Keep windows and doors open to allow everything to dry out.
  • Slowly pump out water from basements. If you remove too much water at once, there could be structural damage.
  • Keep the power off until an electrician has inspected the system for safety.
  • Clean and disinfect everything that got wet.
  • Service damaged sewage systems as soon as you can!

Precautions to Take Around Floodwater

Only walk or drive through floodwaters as a last resort. Six inches of moving water can knock a person over and one foot of moving water is enough to sweep away a vehicle.

Floodwater is often contaminated with sewage and can spread diseases. You can read more about waterborne diseases in our Worst Waterborne Diseases article. Try to keep anything that touches flood water away from your mouth, nose, and eyes. Coming in contact with feces-contaminated water is one of the main ways that waterborne pathogens are spread.

Having a quality water filter on hand is a great way to ensure that you won’t run out of water. Make sure you read our article How to Choose the Best Survival Water Filter to ensure you make an educated choice when you buy one.

Even if you have a jacked-up pick-up or SUV, it’s recommended not to drive into the water. You have no idea what is under the surface and moving water can quickly erode walkways and roads.

There is a possibility that live underground or downed power lines are in standing water.

If water rises around your vehicle but is not moving, you should attempt to get to safety. You should not try to escape into running water.

Types of Floods

Floods can occur in a number of ways. The most common ways are when the ground in an area cannot absorb rain or melting snow, strong winds push seawater inland during a storm, when a waterway is blocked by ice and debris or when a man-made structure like a dam or sewer breaks.

Inland Floods – Inland flooding normally occurs during periods of extended rainfall or when dams and levees fail. The ground cannot absorb the water fast enough resulting in raised water levels.

Flash Floods – Flash floods are the most dangerous type and can occur with no warning at all. They are the number one cause of weather-related deaths. They occur when water quickly fills normally dry streams and river beds or when storm drains become overwhelmed. Areas affected by wildfires can contribute to flash flooding. Once the vegetation is burned off of an area, rainwater can flow quickly downhill sides and mountains into areas of lower elevation.

Flash flooding in canyons is another possibility. Heavy rainfall can quickly fill the canyon floor causing what can only be described as rapids for miles down the canyon.

Urban areas struck by flash flooding are especially at risk as they are normally covered in either concrete or asphalt, preventing the water from being absorbed. Runoff from buildings only compounds the effect. This channels the water over roadways and sidewalks and into low areas like underpasses, subway tunnels, parking structures, and basements.

If you are in an urban area that can experience flash flooding, DO NOT seek shelter in these areas. You could easily become trapped and drown.

River Floods – River flooding normally accompanies long periods of heavy rainfall causing water levels to rise over the top of the river bank. Severe tropical storms can cause river waters to rise in a relatively short period of time. Melting snow and ice can increase the chances of a river flood.

Coastal Floods – Floods along the coast are caused by a combination of storm surge (rising water levels caused by high winds) and heavy rainfall. If these are combined with a high tide, water levels can get especially high. Look at the pictures of the after-effects of Hurricane Katrina for an example of the possible destructive power of storm surge.

As we saw with Hurricane Irma, the storm surge can be the most disastrous potion of many major storms.

When is Flooding Likely to Occur?

Trying to predict exactly where they’ll occur is difficult unless you understand the risks associated with your area.

For the United States, June to November are considered hurricane season . This puts the coasts at higher risk during those times. Heavy rain puts the Midwest at risk in the summer, and the Southwest is at risk during the later summer. The Northeast and Northwest are at a higher risk in the spring when melting snow will add to any rainfall.

Are You At Risk of Flooding?

For those in the United States, FEMA has a website at that is designed to help you evaluate your overall risk. Unfortunately, it is currently down and redirects you to the national flood insurance program page.

For the time being, you can use their interactive map. It allows you to see the number of occurrences of floods by state and further breaks it down by county.

There is also a printable flood map available. It allows you to type in your address or Lat/Long coordinates to get a printable map of your area. This would be good to have pre-printed and stored along with any other plans you may have.

Say what you want about FEMA, but their site has a ton of useful prepping information on it if you’re willing to dig far enough.

Even if you are not at risk of flooding where you are now, make sure you take the threat into account for any bug out location you may have planned as well as along the route you will likely have to take to get there.

How Long do Flood Waters Stay Around?

The length of time that water will stay in an area will vary depending on the severity of the flood and the environmental conditions.

FEMA quotes times from 4-8 hours with longer times being common. In the end, it’s all going to come down to the severity of the event. Following Katrina, the water stayed around for weeks.

Flood Watches and Warnings

A flood watch occurs when the conditions are right for a flood to occur. A flood warning is issued when flooding is occurring or it’s about to start.

Using Sandbags to Redirect and Divert Floodwater

I’m not going to insult anyone’s intelligence by going super in-depth about sandbags. These are just some tips and best practices for general sandbag use.

Use bags around 14-18” wide and about 30-36” deep. Any purpose made sandbag will be around this size.

Fill them roughly ½ way. This makes them easy to move and set into place. It also makes them moldable enough to get a tight seal.

Don’t bother tying the bags unless you plan on storing them. It’s best to set up close to the area you’re trying to protect. Fill a bag then just lay it in place with the opening folded under itself to keep the flap closed.

Interlock the sandbags as you stack them and place the flap in the direction you think the water will be coming from. This will help to keep the bags closed in the water flow.

You can improvise a sandbag filling station with a couple of 2x4s and a traffic cone or even a ladder as you can see in the picture below. There is no need for expensive, single-purpose sandbag filling contraptions.

Lessons Learned From Hurricane Katrina and Sandy

Hurricane Katrina and Sandy were not simply hurricanes, they obviously had high winds associated with the damage they caused, but a vast amount of damage was caused by the rising waters that accompanied them. This allows us to look at them and take away some lessons learned. We should always strive to learn from disasters.

Large-scale flooding that took place during Katrina and Sandy left TONS (as in weight) of debris behind. That needs to be taken into consideration when you finally come home or as you recover from home.

A sump pump, or another way to remove the standing water in your home, may be needed when you finally make your way back home to begin recovering.

Communication channels cannot handle the sheer volume of people all trying to communicate at once when a large-scale disaster happens in a densely populated area. Other means of communication become important. Twitter was used extensively by survivors of Sandy. Be creative and think outside of the box when it comes to making contact with loved ones.

Even when the government is in power and able to direct recovery operations following an event, they can still easily be overwhelmed.

You need to be prepared for martial law or some other kind of enhanced rule of law following large-scale natural disasters.

Fuel and just in time food delivery could be interrupted for weeks. The same goes for disruptions to electrical and water services. To better prepare for long-term flooding, you can stock clean water and non-perishable food items beforehand. This can be as simple as having several days worth of bottled water and canned food stored in the back of a closet when you are preparing for a flood.


Evacuating to a government-run camp is a “use at your own risk” proposition. You’re much better off learning how to prepare for a flood and taking care of yourself!

There are far more reasons to be prepared than people like to admit. What would you do to prepare for a flood?

Related Questions

Does grass prevent flooding? Planting grass can reduce the impact of floods. The root structure of the grass will help absorb water. Research what kind of grass is the best for your area.  Once it grows in, don’t cut your lawn too short, this weakens the roots and can lead to flooding in your yard and even your home.

What can I plant to soak up water? These plants and trees are great at absorbing water to prevent flooding:

  • Willows
  • Ash Trees
  • Red Maples
  • River Birch
  • Red Osier Dogwood
  • Spice Bush
  • Highbush Blueberry
  • Winterberry
  • Jack-in-the-pulpit
  • Lily
  • Sweet Woodruff
  • Sweet Flag
  • Iris