Bruna Alves
Research lead covering environment and sustainability
Floods in the U.S. - statistics & facts
The 2020s are shaping up to be a record-breaking decade for flood disasters in the United States. From 2020 to 2024, there were 80 major flood disasters declared by the Federal Emergency Management Agency (FEMA), half of the figure recorded in the previous decade in just four years. With heavy precipitation events expected to grow in a warming climate, the economic and social toll of floods in the U.S. is set to increase in the coming decades.
While economic damage from floods can severely burden people and businesses financially, their most critical impact is human fatality. In 2023, roughly 80 lives were lost due to floods in the U.S. California and Pennsylvania were the most affected states that year, each with 10 deaths recorded. The two largest shares of casualties happened while driving or at home.
As the number of flood events in the U.S. continues to break records, and more people find themselves living in flood-prone areas, mitigation and adaptation funding and strategies will be crucial to reduce the toll of floods to the U.S. population.
Where is the water coming from?
Floods are one of the most common weather-related disasters in the U.S., partially due to the many different causes behind them. In 2023, the North American country recorded four billion-dollar flood disasters caused by river basin or urban flooding due to excessive rainfall. The frequency of such events has increased in recent decades, with more than half of the disasters recorded between 1980 and 2023 occurring since 2010. The storm surge from tropical cyclones is also a frequent cause of floods, with Hurricanes Katrina, Harvey, and Sandy behind the most expensive flood disasters in the U.S. in the past half-century.The toll of flooding events
The property and crop damage caused by floods in the U.S. stood at just over two billion U.S. dollars in 2023. Nevertheless, a series of other indirect costs arise from floods, including the temporary closing of businesses, and the loss of revenue and salaries. In fact, indirect damage results in almost as much economic damage to commercial buildings as direct damage.While economic damage from floods can severely burden people and businesses financially, their most critical impact is human fatality. In 2023, roughly 80 lives were lost due to floods in the U.S. California and Pennsylvania were the most affected states that year, each with 10 deaths recorded. The two largest shares of casualties happened while driving or at home.
What looms ahead?
By 2052, the number of buildings at risk of flooding damage in the U.S. is forecast to increase by over 20 percent in states like Virginia, Florida, and South Carolina. Likewise, the economic damage to commercial buildings is also expected to grow by some 30 percent in the same period. Despite the growing risk, flood-prone counties in the U.S. saw a net-inflow of more than 400 thousand residents between 2021 and 2022.As the number of flood events in the U.S. continues to break records, and more people find themselves living in flood-prone areas, mitigation and adaptation funding and strategies will be crucial to reduce the toll of floods to the U.S. population.
