Flash Flooding Is Becoming More Common—Here's How To Prepare and Stay Safe

Flash floods are the second deadliest of all weather-related hazards. Experts share tips on how to be prepared for such events.

JACKSON, KY - JULY 29: Flooding from the North Fork of the Kentucky River came over Bert T Combs Mountain Parkway outside of Jackson, Kentucky on July 29, 2022 in Breathitt County, Kentucky. At least 16 people have been killed and hundreds had to be rescued amid flooding from heavy rainfall. (Photo by Michael Swensen/Getty Images)
Photo: Michael Swensen/Getty Images

The recent floods in Kentucky left at least 37 people dead and hundreds more missing. And even as those numbers were being finalized, another round of storms was on the horizon, threatening to bring more rainfall, more flash flooding, and more damage to a region still trying to regain its footing.

While flash flooding has always been a threat in many parts of the country and the world, experts say certain regions are seeing an increased frequency of heavy rainfall and extreme rainfall rates due to climate change. And this may continue to be the case as climate change worsens.

"A warmer atmosphere driven by climate change results in greater levels of moisture within the atmosphere, so it's not a surprise to see excessive rainfall events increasing in frequency and impact," Jonathan Porter, chief meteorologist and senior vice president of AccuWeather, told Health.

But what makes flash floods so life threatening? And how can you prepare for them and protect yourself and your family? Here's a closer look at some of these questions.

Why Are Flash Floods So Dangerous?

Here's a startling fact: floods are the second deadliest of all weather-related hazards in the United States, accounting for about 98 deaths per year (most due to drowning), according to the Centers for Disease Control and Prevention (CDC). Flash floods and flooding connected with tropical storms result in the highest number of deaths.

These types of extreme weather events can be dangerous because streams can rise very quickly, making anybody living or traveling near the stream susceptible to flood risk, Mark Fuchs, senior vice hydrologist for the National Weather Service in St Louis, Missouri, told Health.

What's more, many flash floods happen at night, which can make motorists more defenseless in flooded roadways, said Fuchs.

"Motorists might not be able to see the danger a flooded roadway poses until their vehicle is immobilized," Fuchs said. "We try to remind people if water is crossing a roadway, you might not know the depth of the water and often the size of your vehicle is irrelevant."

Adding to that point, Porter said the number one reason people tragically lose their life during a flash flooding emergency is because of vehicle-related incidents.

"Many times these tragedies are avoidable because they involve people driving into areas where water covers the road and you just never know how fast that water is flowing or how deep the water is," Porter explained. "Believe it or not, 12 inches of rapidly moving water is enough to dislodge a vehicle and send a car down in torrents of water."

In addition, because water is so powerful, it can destroy homes, businesses and other properties very quickly, Porter said.

How to Assess Risk Where You Live

When it comes to assessing risk in your immediate surroundings and broader community, the first step is to understand the geography of where you live. For example, in cities or on hilly terrain where there's large stretches of impervious surfaces, there can be a significant problem relative to flash flooding, Porter said.

"In a city, there's a lot of concrete and pavement, which means there's not a place for the ground to soak it up, so all the water can do is run off. That's what we saw a few days ago in St. Louis— and New York City last year—with tropical rainstorm Ida," Porter pointed out.

People should also know where the nearest stream is and whether or not their property is in a flood-prone area by looking at a flood map, Katie Wilkes, an American Red Cross spokesperson, told Health. Knowing this information can inform individuals and communities about their local flood risk.

The Federal Emergency Management Agency (FEMA)'s flood mapping tool can be used to identify whether your home or community is at some level of risk, particularly in relation to extreme flooding events. Risk Factor is another website that can be used to determine flood risks in your area.

Additional ways to assess your risk include staying aware of the latest weather forecast and radar information for your area and leaving your mobile phone on at all times in order to be able to receive weather alerts and notifications.

"If a considerable or catastrophic flash flood warning is issued for your location and you have cell phone service, your cell phone will alert you to that danger through the wireless emergency alert (WEA) system," Fuchs said. "It is the same type of an alert you would get for a Tornado Warning or an Amber Alert."

Supplies To Keep On Hand

In addition to understanding the flood risks around your home and community, another proactive step to take is making sure your home is stocked with a few critical supplies that can help during a flash flood emergency. Experts say the following items can help individuals survive on their own for a few days in the aftermath of a flood disaster:

  • Non-perishable food
  • At least a three-day supply of water
  • Medications that you require on a daily basis
  • Extra batteries for medical devices such as hearing aids
  • Flashlight
  • Battery-powered radio
  • Portable cell phone charger
  • Blankets
  • Spare clothing
  • Tools to turn off utility valves
  • Life jackets
  • Generator
  • Cash (if power goes down a credit card may not work)
  • Insect repellent and sunscreen

Additional essential items to consider having available during an emergency or disaster can be found on the website Ready, which is maintained by the U.S. government and provides instructions on building emergency preparedness and disaster supplies kits.

"It's best practice to have a go-to bag with key items like photographs, prescriptions, extra cash, electronics and other things in case you need to leave your home quickly, '' Porter said. "You're not going to be able to take everything but think about what is most important that you would need."

Do's and Don'ts During Flood Events

To maintain your safety when a flood event occurs, it's important to understand the do's and don'ts. Here are some of the top tips from Porter, Fuchs, and Wilkes.

Things you should do during a flood event:

  • Know the difference between a flood or flash flood watch and a warning.A watch means that a flood is possible, while a warning means flooding is occurring or will soon occur and you should take immediate precautions.
  • Stay tuned to and updated on local weather alerts and know what they mean
  • Keep an emergency kit ready to go in case of an emergency, particularly in your car
  • Move to higher ground as quickly as possible if you are caught on a flooded road or area
  • Dispose of any food that comes into contact with flood water due to potential contamination
  • Avoid areas that are prone to flooding, including underpasses, dips, low spots and canyons
  • Stay off bridges during a flash flood because they can be washed away without warning
  • Be aware of snakes and other wildlife during and after a flood
  • If you're in a car in fast-moving water, either stay in the vehicle or climb onto the roof of the vehicle
  • If evacuation is recommended, evacuate immediately

Things to avoid during a flood event:

  • Don't play or go near a stream that is flooded or through flowing water. Even six inches of fast flowing water can knock you over
  • Don't camp or park along streams, rivers, creeks and other areas typically prone to flooding or heavy rainfall
  • Don't use gas or electrical appliances that have been flooded
  • Don't leave utilities on or plugged in if you need to evacuate
  • Never drive your car in a flood zone. Just two feet of water can float a car
  • Do not drive around road barriers, as roads and bridges may be washed out or structurally unsafe

Steps to Take After a Flood Event

After a flood emergency event takes place, individuals should continue to monitor the media for emergency information and only return home when public health officials and authorities say it's safe to do so, Wilkes said.

"It can be incredibly tempting to go back before then, but even if a home appears safe on the outside, there could be hidden dangers like downed power lines and animal hazards—such as snakes—buried beneath flood water," Wilkes explained. "Parts of the home may have collapsed or been damaged."

If you return home and smell gas or hear a hissing noise, leave immediately and call their local fire department, Wilkes added.

During the cleanup process, it's a good idea to wear thick-soled, rubber shoes, heavy work gloves and protective clothing, Fuchs added. Face coverings and masks may also be necessary when cleaning mold and other debris. Those who have asthma, other lung conditions or immune suppression should avoid cleaning near indoor water leaks or areas of mold growth.

It's also important to avoid using contaminated water to wash dishes, cook, wash hands, and make ice or baby formula. People should contact their local or state public health department for specific recommendations for boiling and treating water as well, Wilkes said.

Additional Resources

The following resources can be useful when searching for information during a flood or flash flood emergency.

The National Oceanic and Atmospheric Administration (NOAA) Weather Radio is a great way to get the latest weather information.

The National Weather Service provides the latest weather forecast information

Red Cross Emergency Mobile Apps monitors and sends real-time alerts in your area and has checklists to keep individuals safe

You can also call 9-1-1 to report emergencies including downed power lines or gas leaks and 2-11 to obtain shelter locations and other disaster information.

"With disasters happening more often and more intensely, now is the time to be prepared for when an emergency hits your area," Wilkes said. "You'll feel more equipped and ready to handle an emergency when you aren't scrambling for supplies last-minute and can focus on getting everyone to safety."

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