Introduction and summary
In July 2025, a devastating flood in Central Texas claimed the lives of at least 135 people when the Guadalupe River rose 31 feet in 90 minutes, becoming the deadliest inland U.S. flooding event in almost 50 years.1 Floods can be life-changing, and they are becoming more frequent and severe as fossil-fueled climate change is making rainfall heavier and flooding events more intense in many areas.2 As of mid-November, more than 5,000 flash flood warnings have been issued across all weather-forecasting offices nationwide—the first time the number has crossed the 5,000-warning mark in a year, and 2025 is not over yet.3
The total annual economic burden of flooding in the United States totals between $179.8 billion and $496 billion when factoring in a broader spectrum of impacts, such as annual loss in tax revenue, increases in insurance premiums, damage to ecosystem services, and damage to transit infrastructure from flooding.4 Floods can also lead to serious and often-overlooked risks to public health, upend lives, cause infrastructure damage, and bring contamination and disease—especially for those already vulnerable.5 Working-class, low-income, Black, Latino, Indigenous, and other underserved communities experience disproportionately high impacts from flooding and take longer to recover.6
Climate change and the built environment contribute to increased flooding
As the Earth warms up due to fossil-fueled climate change, flooding becomes increasingly destructive.7 A warmer world means increased evaporation, which supercharges storms to produce more rain, resulting in higher chances of flooding.8 In the United States, nine of the top 10 years for extreme one-day precipitation have occurred since 1995.9 Looking forward, one study found that extreme rainfall events in the United States could become three times more likely and up to 20 percent more severe within the next 45 years.10 Other conditions—such as drought or a recent wildfire, which climate change has also made more frequent—can make it harder for the ground to absorb water, making flooding impacts even more devastating for Americans.11
Extreme rainfall events in the United States could become three times more likely and up to 20 percent more severe within the next 45 years.
Whether the environment is built or natural also determines how severe flooding will be and how quickly communities can build back. Hardened shorelines—those reinforced with artificial structures such as bulkheads and seawalls—can cause shoreline erosion, making the risks of coastal flooding higher over time.12 Impermeable surfaces such as asphalt and concrete can also significantly increase the risk of flooding. When 10 to 20 percent of a watershed has impervious cover, the amount of runoff doubles.13 Short bursts of intense rainfall over major metropolitan areas can rapidly create flash flood conditions that overwhelm sewer systems when trash and debris clog drains.14 For example, a recent October storm in New York City broke three daily rainfall records, triggered numerous flash flood warnings that led to two deaths, left 1,500 residents without electricity, and flooded roads.15
In comparison, natural environments and ecosystems such as floodplains can reduce the impacts of flooding by providing natural flood and erosion control and by slowing runoff.16
Flooding risks vary in the United States by region and type of weather event
Flooding can occur in a variety of ways, and different regions of the United States will experience distinct climate change impacts. In the Northeast, river flooding may become larger and more frequent.17 Meanwhile, the Southwest is expected to experience more drought conditions with flooding expected to become less frequent.18
The commonality is how climate change is making flooding events worse. As global temperatures continue to rise, the atmosphere holds more moisture: For every 1-degree Celsius increase in temperature, air can hold 7 percent more moisture.19 More atmospheric moisture leads to more frequent and heavier rainfall over shorter periods of time.
Flash floods
The most dangerous type of flooding is flash floods, which happen within minutes or hours of rainfall starting.20 They occur when rainfall is no longer able to be absorbed by the ground due to factors such as drought or the presence of impermeable surfaces such as concrete roads—or when a river dam breaks.21 Forecasting precisely where a relatively small storm may cause flash flooding is difficult because the storm and local hydrological conditions can change rapidly.22 Flash floods claim an average of 100 lives each year in the United States and 5,000 lives globally.23
River flooding
River flooding, also known as inland flooding, occurs when water levels top river banks following heavy or sustained rainfall from storms and runoff from snowmelt.24 River flooding can happen at any time of the year and anywhere in the country. Sustained rainfall from tropical cyclones and hurricanes has caused disastrous floods, such as in Texas in 2019 during Tropical Storm Imelda and in North Carolina in 2018 during Hurricane Florence.25 And in 2017, human-induced climate change likely increased Hurricane Harvey’s total rainfall by at least 19 percent in the Houston area.26 Warmer temperatures can also lead to more frequent drought conditions and soil that is less able to absorb moisture.27
Coastal impacts
Rising sea levels and the increasing severity and frequency of hurricanes put coastal communities more at risk.28 Global average sea level has risen 8 to 9 inches since 1880, and that rate is accelerating as ice floes melt and warmer water temperatures cause thermal expansion due to climate change.29 One in 10 Americans live in coastal areas at risk of flooding.30 Over the next 30 years, sea levels along the contiguous U.S. coast are expected to rise by as much as 1 foot—about the same amount of sea level rise observed across the past century.31 Projected increases in sea level rise could lead to more coastal flooding events and 10 times the number of damaging flooding events over the next 30 years.32
Flooding’s harms to public health are both immediate and long term
Floods are among the most frequent and deadly climate-fueled disasters, yet their hidden toll on public health is vastly undercounted.33 Beyond the immediate danger of drowning, floods silently unleash cascading health crises that can unfold over weeks, months, and even years.
Immediate health impacts
The health threats begin the moment floodwaters rise. During flash floods and coastal floods, drowning is the leading cause of death as fast-moving water can sweep away cars and people in seconds; just 6 inches of water is enough to knock someone off their feet, and just 1 to 2 feet of rushing water is enough to carry away most cars, SUVs, and trucks.34 Rushing currents can carry raw sewage, glass, hazardous household waste, medical waste, pesticides, lumber, and farm waste.35 This toxic slurry can cause gastrointestinal illness; eye, ear, and skin infections; and long-term respiratory issues.36 Flooded areas often also contain live power lines, posing a major electrocution risk.37
In addition, flooding triggers severe disruptions to health care systems.38 Roads may be washed out, becoming unnavigable for emergency vehicles.39 Clinics and hospitals can lose power, flood, or close entirely. Supply chains can be interrupted, delaying critical medications and medical devices. In 2012, Superstorm Sandy sent floodwaters surging into Coney Island Hospital in New York, knocking out both electricity and backup generators.40 The state’s health care system was rocked by the storm, with more than 6,400 patients forced to evacuate.41 Coney Island Hospital shut down for three months and redirected patients to nearby facilities—many of which were also overwhelmed with patients and the storm’s impact on infrastructure or were damaged by the storm.42 In total, six hospitals and 26 residential care facilities in New York City alone closed due to Sandy.43
Disease and outbreaks—particularly waterborne illnesses such as cholera, typhoid, and leptospirosis—are huge health concerns after a flood because of exposure to contaminated water.44 Stagnant pools become breeding grounds for mosquitoes, which can spread diseases such as malaria, Zika virus, and dengue fever.45 After heavy monsoon flooding in Bangladesh in 2020, for instance, dengue fever cases spiked to more than 100,000, killing nearly 200 people.46 Higher temperatures due to climate change are increasing the incidence of dengue fever, particularly in places where it was once uncommon, such as California, Texas, Hawaii, Florida, and Europe.47
See also
Long-term health impacts
As floodwaters recede, additional threats emerge. New research estimates that in the year following major floods, the United States saw more than 22,000 excess deaths.48 Flooding also creates dangerous conditions for respiratory health.49 Mold and dampness can quickly overtake water-damaged homes, triggering respiratory flare-ups, allergic reactions, and fungal infections, especially in people with asthma or compromised immune systems.50 The risk grows for flood-displaced individuals living in overcrowded shelters.51 Poor ventilation and limited sanitation increase exposure to airborne pathogens and fungi, compounding health risks and prolonging recovery.
Floods can also leave deep psychological scars that often go uncounted. Although the physical destruction of flooding is immediately visible, its mental health toll can emerge slowly and last for years.52 Survivors commonly experience anxiety, depression, post-traumatic stress disorder, insomnia, and even psychosis—especially when recovery is prolonged or support systems falter. Research from the United Kingdom found that people affected by floods were 4 to 8.7 times more likely to suffer long-term mental health issues than those who were not.53 In some cases, even rainfall can retraumatize people.54 The cleanup and rebuilding process itself is a major stressor, particularly when compounded by inadequate government or private-sector response.55
Jackson, Mississippi
In August 2022, heavy rainfall and a slow-moving weather system caused the Pearl River to flood parts of central Mississippi including the capital city of Jackson.56 The river rose almost 20 feet, nearly reaching a major flood stage.57 The area is situated in a low-lying delta that is prone to sinking land and repeated flooding.58
While the immediate damage to homes and neighborhoods was minimal, the flood waters inundated Jackson’s main water treatment facility, overwhelming the pump system and causing it to fail.59 The shutdown cut off safe drinking water to more than 180,000 people for weeks and exposed the majority-Black population to pollutants.60
As climate change causes flooding to increase, aging infrastructure across the country will become more vulnerable to failures that put communities at risk.61 A recent report found that investments in making infrastructure more resilient, such as protecting wastewater treatment facilities, can return as much as $31 per dollar invested.62
Economic risks
As flooding grows more frequent and severe, the economic risks are no longer confined to isolated disasters; they are systemic, compounding, and reverberate throughout a community. Recent major floods have devastated countless communities, and once-rare disasters have turned into regular financial shocks. The total annual economic burden of flooding in the United States is estimated to range from $179.8 billion to $496 billion,63 or as much as 2 percent of the country’s gross domestic product (GDP) in 2023 dollars, when accounting for often-overlooked costs such as crop losses, increased insurance premiums, costs associated with flooding deaths, and damages to uninsured homes. According to the National Oceanic and Atmospheric Administration (NOAA), the average cost of each flooding event is $4.5 billion.64 Even minor flooding can trigger major costs: The Federal Emergency Management Agency (FEMA) estimates that just 5 inches of water in a home can cause more than $25,000 in damage.65 These losses are not only staggering in scale; they are growing, compounding, and unequally distributed.66
The total annual economic burden of flooding in the United States is estimated to range from $179.8 billion to $496 billion.
Each sector in the U.S. economy faces flood impacts, but the agricultural industry, in particular, experiences major losses. Most crops in North America are not flood tolerant, and flooding may lead to conditions that favor disease development.67 In 2024, one study found that flooding caused more than $6 billion of estimated total crop losses in the United States.68 Hurricane Helene alone caused more than $5 billion in damages for the agriculture and forestry industry in the state of Georgia.69 As climate change increases the frequency of heavy precipitation that can erode soil and deplete nutrients, food security may change for some households.70
Flood insurance
Flood insurance is a critical pillar of the nation’s flood response. However, across the United States, millions of homes and buildings face far greater flood risk than accounted for in conventional planning and insurance models.71 New analyses that factor in sea level rise, rainfall intensity, and previously overlooked inland waterways show that more than 14 million properties—far more than previous estimates—are now at risk from a so-called 100-year flood.72 This hidden vulnerability is especially pronounced in cities such as Chicago, Buffalo, and Chattanooga, where tens of thousands of properties face previously unrecognized flooding threats.73
Millions of households remain uninsured, ineligible for federal assistance, or undersupported by existing aid programs, leaving residents vulnerable to financial ruin after a flood.74 The National Flood Insurance Program (NFIP), designed to help property owners recover from flood losses, has faced growing financial strain in the face of worsening disasters.75 Between 2007 and 2017, the NFIP paid out an average of $2.9 billion per year in flood-related claims, with costs spiking in years marked by severe storms.76 After Hurricane Ian hit Florida in 2022, the program fielded more than 37,000 flood insurance claims.77 As the frequency and intensity of flooding increase, the gap between insured losses and total damages is expected to widen, further exposing households, small businesses, and local governments to unsustainable economic risk.
Communities face unequal impacts from floods
Flooding can happen almost anywhere, but resources for preparedness and recovery vary widely. Climate change creates unequal burdens on communities, especially harming communities of color, lower-income households, older adults, children, and people experiencing homelessness.78 These communities often face a greater likelihood of flood damage, costly repairs, and health disparities and are slower to financially recover than wealthier communities.79
Discriminatory housing policies such as redlining have placed communities of color in poorly maintained floodplains; the lowest-lying land; or areas that lack adequate stormwater infrastructure, which increases the risk for flooding.80 For example, Hispanic residents are 50 percent more likely to live in a 500-year floodplain, while Black communities are forecasted to have a disproportionate share of future flood damages.81 An analysis of nearly 10 years of NFIP data found that almost 20 percent of flood relief claims were paid to ZIP codes where at least 25 percent of the residents are Black—despite Black Americans making up only 13 percent of the U.S. population during the same time period.82 Average annual losses in census tracts with a population of at least 20 percent Black residents are projected to roughly double that of census tracts where Black residents make up less than 1 percent of the population.83
There are countless other examples of communities of color at increased risk for flooding:
- Many Indigenous communities live in areas at risk for coastal and river flooding.84 In October, Typhoon Halong devastated Indigenous communities in western Alaska when a storm surge and high winds caused water levels to rise 6 feet above the highest normal tide line, sweeping away homes in low-lying communities. Kipnuk, one of the affected villages, had been a recipient of a $20 million grant through the U.S. Environmental Protection Agency (EPA) Community Change Grants Program.85 This program, which was recently canceled, aimed to help low-income and disadvantaged communities address climate risks such as erosion and flooding.
- In Chicago, a study found that a staggering 87 percent of more than 225,000 insurance claims from urban flooding over nine years were from households of color.86
Low-income populations are also more vulnerable to inequities in flooding response and recovery. Mobile homes—an affordable housing option for many families—face a higher risk of flooding than other housing types: One out of 7 mobile homes are in high-flood risk census tracts, compared with 1 out of 10 for other housing types.87 While renters are able to receive financial assistance through FEMA after a disaster, access is often complicated by factors such as renters not having a formal lease agreement, the complicated application process, and language barriers. Those without access to a car are also less likely to evacuate, reach evacuation centers, or even return home once flooding recedes.88 Disasters increase wealth inequality over time: Families already financially struggling can experience harms to credit scores, increases in debt, and higher chances of defaulting on loans or declaring bankruptcy after disasters.89
Ways to address the impacts of floods
Floods pose a growing threat to the American economy, public health, and lives while disproportionately affecting already vulnerable communities. Government leaders must prioritize investments in and the implementation of solutions to alleviate these increasingly devastating consequences.
Investing in resilience
The escalating costs of flooding underscore the value of investing in resilience. In recent years, landmark legislation—including the Inflation Reduction Act, the Infrastructure Investment and Jobs Act , and the Water Resources Development Act of 2022—has delivered major funding to help communities adapt to climate-driven flooding.90 These investments are not only necessary but also cost-effective: Every $1 spent on flood protection can yield between $5 and $8 in avoided damages.91
Every $1 spent on flood protection can yield between $5 and $8 in avoided damages.
Smart investments in flood mitigation, infrastructure upgrades, and natural protections can deliver outsized benefits, often saving many times more than the investments cost. To avoid escalating losses and protect long-term economic security, policymakers must prioritize forward-looking flood resilience across federal, state, and local levels, treating it not as a one-time expense but a national economic imperative.
Funding scientific research and access to disaster relief
NOAA, FEMA, and other agencies that provide weather and climate monitoring and disaster relief need to be adequately funded and staffed. FEMA is a critical agency in disaster response and recovery, and NOAA provides scientific assessments and data along with forecasting.92 Programs such as the NOAA Global Systems Laboratory, National Weather Service, and National Hurricane Center are vital in disaster preparedness and response.93
See also
Incorporating nature-based solutions
Nature-based solutions are a powerful, underutilized tool in cutting flood risk. Wetlands, marshes, and mangroves can reduce storm surge and absorb excess water, offering flood protection with long-term economic and environmental benefits.94 Conserving and restoring coastal habitats can help protect communities from extreme weather while also supporting wildlife and providing ecosystem services.95 Increasing usage of living shorelines and permeable surfaces can help reduce risks of catastrophic flooding and can both protect coastal areas from severe storms and help improve coastal resiliency.96 A recent study found that every $1 invested in restoring coastal wetlands can generate $7 in direct flood reduction benefits.97 During Hurricane Sandy, coastal wetlands in the northeastern United States prevented an estimated $625 million in direct flood damages.98
Improving risk assessment, pricing, and planning
Measures can be taken before a flood to mitigate property damage and economic risk. Insurers should be required to account for proven mitigation measures in their pricing decisions.99 Flood disclosure laws should also be improved so that prospective renters and homebuyers are well-informed about a property’s flood history.100 Additionally, reforms to the NFIP should be made to avoid incentivizing development in high-risk areas while ensuring policies remain affordable.101 FEMA’s flood risk maps should also be updated to include risk from increased rainfall.102 And in some cases, managed retreat efforts should be considered to help communities relocate out of flood-prone areas.103
Conclusion
The impacts of floods on communities do not end when the waters recede. Improvements can be made to how the United States handles flooding before, during, and after the event. As climate change fuels more and increasingly intense flooding events, it is critical to ensure that communities are well-equipped to withstand the harmful economic and health impacts while also making sure that working-class, low-income, Black, Latino, Indigenous, and other underserved communities are not overlooked.
Acknowledgments
The authors would like to thank Margaret Cooney, Jessica Ordóñez-Lancet, Jill Rosenthal, Mariam Rashid, Alex Thornton, Shannon Baker-Branstetter, Trevor Higgins, Cody Hankerson, Devon Lespier, Anh Nyugen, Cindy Murphy-Tofig, and the entire CAP Digital Communications team.