What’s the most common natural disaster in the United States? Tornadoes? Hurricanes? Earthquakes? Nope. It’s floods. Flooding can strike almost anywhere, putting most homeowners, renters, and property owners at risk.
If you’ve never considered your flood risk before, now’s the time to educate yourself. This article presents 10 facts about floods you should know. How often they happen, how much damage they cause, and why your homeowners’ insurance probably won’t bail you out when the water comes rushing in. With these facts, and you can better prepare and protect your home from floods.
Key Takeaways
- Floods are the most common, and costly, natural disaster in the U.S. They happen in every state, even in deserts.
- Just six inches of moving water can knock you down; two feet can sweep away an SUV.
- Standard homeowners’ insurance doesn’t cover flood damage, so you’ll likely need a separate flood policy.
- Flooding costs the U.S. hundreds of billions of dollars every year.
- SERVPRO is available 24/7 to help homeowners recover if flooding strikes.
10 Facts About Floods You Should Know
A flood happens when water covers land that’s normally dry, including your basement, crawl space, or any other area of your home. You may think only homeowners on the Florida or Louisiana coasts need to worry about flooding, but floods happen almost everywhere in the U.S. and take many forms. They can build slowly over several days or arrive in just minutes, giving you and your family little time to react.
1. Floods Are the Most Common Natural Disaster in the U.S.
Of all the facts about floods, this might be the most important one to know: Floods are the most common and costly type of natural disaster in the United States. According to FEMA, floods or flash floods have happened in all 50 states in the past five years, not just in coastal or riverside communities.
Flooding also carries legal weight. It’s one of the qualifying disaster types under federal law, which means flood events can trigger official disaster declarations and open the door to federal aid.
2. Six Inches of Moving Water Can Knock Down an Adult
While flooding can certainly cause a lot of financial damage, the greatest risk of all is to human life and safety. Critical facts about floods you need to know:
- Two inches of fast-moving water can knock an adult off their feet
- 12 inches of rushing water can carry away most cars
- Just two feet of rushing water can sweep away most SUVs and trucks
3. Floods Can Happen Anywhere – Even in the Desert
The desert seems like the last place you’d expect a flood, but dry, hard, packed ground often makes flash flooding worse. Heavy rainwaters don’t get absorbed into the rock-hard ground, rushing across the surface instead of soaking in. This is exactly what happened during Arizona’s 2017 monsoon flash floods near Phoenix.
Over the past 20 years, 99% of counties in the United States have experienced a flood event, proving that no location is truly safe from floods.
4. Heavy Rain Causes Most Floods, But It’s Not the Only Reason
As you can probably imagine, the most common cause of flooding is heavy rain, but plenty of other factors can lead to floods. Some of the main causes of flooding:
- Heavy rain
- Rapidly melting snow
- Coastal storms
- Storm surges
- Dam or levee failures
Urban areas can be prone to floods when storm drains and sewers get overwhelmed and can’t move water away fast enough. To make matters worse, closely bunched rooftops can funnel rainfall to the ground while paved surfaces keep the ground from absorbing the water.
5. Coastal Areas and River Basins See the Most Flooding
Location plays a big role in your specific flood risk. Where do floods occur the most? Coastal regions along the Gulf are extremely vulnerable to storm surges, largely due to a wide, flat continental shelf and low-lying land extending well inland. This puts hurricane-prone states like Florida, Louisiana, Texas, and the Carolinas at the top of the list.
Inland, major river systems create their own risk. The 2019 Midwest floods triggered federal disaster declarations in Illinois, Missouri, South Dakota, and Iowa. The incident showed how the Mississippi and Missouri Rivers can flood entire regions.
6. Flooding Can Happen Any Time of Year
There’s no true “flood season” in the U.S. Each season brings its own risk:
- Spring: Rapid snowmelt combined with heavy spring rain, sometimes worsened by ice jams, drives some of the country’s most widespread flooding.
- Summer: July and August are prime months for thunderstorm-induced flash flooding.
- Fall: Hurricane season peaks during this time, bringing storm surges and heavy rainfall to coastal states.
- Winter: Ice jams form when melting snow and ice clump together and block a river’s flow, while atmospheric rivers bring extreme rainfall and flooding to the West Coast.
7. A Flood Can Last from Hours to Weeks
How long do floods last? Not all floods behave the same way. Flash floods develop and recede quickly. During the 2025 Texas Hill Country flood, the Guadalupe River rose 26 feet in just 45 minutes, and the worst of the flooding was over within hours.
On the other end of the spectrum, river floods can act very differently. The 2019 spring flooding along the upper Mississippi and Missouri River basins stretched on for weeks, as rain and snowmelt kept pushing water downstream and prolonging the danger, causing over $1 billion in water damage losses.
8. Flash Floods Are Deadly
Flash floods happen when water rises fast, usually because of a slow-moving storm system. A flash flood can turn a dry street or creek bed into a dangerous current within minutes, often before people have time to prepare.
More than half of all flash flood deaths happen when someone’s swept away while driving into flooded roads. That’s why the National Weather Service says that it’s NEVER safe to drive or walk into flood waters. The Texas Hill Country flood fit this pattern closely. It struck overnight, rose with almost no warning, and left little time for people to reach safety.
9. Standard Homeowners Insurance Doesn’t Cover Flood Damage
Don’t assume your homeowner’s insurance policy will cover you in the event of the flood. Chances are it won’t. To protect your home and property from flood damage, you’ll very likely need a separate flood insurance policy, typically through the National Flood Insurance Program (NFIP).
Keep in mind there’s usually a 30-day waiting period for an NFIP policy to go into effect. That means you can’t grab a policy just before a big storm barrels through your area. Another important thing to know is that most flood insurance policies don’t cover any personal belongings that might be damaged in a flood. They also don’t include full mold remediation services. Always check your policy or ask your insurance agent if your policy covers cleaning flood-damaged items.
10. Floods Cause Billions of Dollars in Damage Every Year
Given the fact that flooding is the most common natural disaster in the U.S., it’s not surprising that floods also wreak a huge financial toll on the country. The Joint Economic Committee estimates that flooding costs the U.S. between $179.8 and $496 billion every year. Even at the lower end, that’s a staggering amount.
That number also has a personal impact. About one in every 67 insured homes makes a property damage claim caused by water or freezing every year. It’s a big part of why flooding remains such a financial burden for U.S. homeowners.
Stay Prepared with SERVPRO
Knowing these important facts about floods can help you appreciate the risk floods present no matter where you live. The right knowledge about floods can also help you prepare and respond more quickly if the waters ever start rising near you.
If a flood strikes your area, you don’t have to face it alone. SERVPRO is here to provide complete water damage restoration to return your home to normal after a flood.
Contact your local SERVPRO today.
FAQs
How Often Does a Flood Occur?
Floods happen almost every single day in the United States. Since the year 2000, at least one flood has occurred in the U.S. on nearly 300 days per year. Flooding isn’t rare or seasonal. It’s a near-constant risk somewhere in the country.
What Are the Main Reasons for Floods?
Often, it’s heavy rain that causes flooding. But floods can also happen due to rapidly melting snow, coastal storms, storm surges, or dam and levee failures.
What Should You Do During a Flood?
Get to higher ground and avoid walking, swimming, or driving through flood waters. Stay off bridges over fast-moving water and follow evacuation orders immediately. Keep a battery powered radio nearby for updates and never attempt to cross a flooded road, even if it looks shallow.
Is Flood Insurance Worth It?
For many homeowners, the answer is yes. Since 99% of U.S. counties have experienced flooding, even low-risk homes carry some exposure. It’s a good idea to check out FEMA’s flood maps to get a better idea of your home’s unique flood risk.