
Across much of the United States, the flood risk is greater (in some cases, far greater) than what government estimates and maps currently show. As a result, millions of homes and properties and many millions of people are facing a threat they have not thought they faced and may not have known about when they purchased or rented a property–a flooding threat that will only grow as climate change deepens.
Federal flood maps are managed by the Federal Emergency Management Agency or FEMA. These maps “have long drawn concerns that they underestimate flood risk. Part of the problem is keeping the maps up to date, which is not only costly and labor intensive, but further complicated as climate change has worsened the dangers. In addition, FEMA’s maps aren’t designed to account for flooding caused by intense rainfall, a growing problem” as the changing climate causes the atmosphere and oceans to warm.
The FEMA maps are also politicized, because federal flood insurance costs are based on them. “When FEMA does issue updated maps, politicians and homeowners often object, hoping to avoid higher federal flood insurance rates.”
New maps from the First Street Foundation “estimate that 14.6 million [U.S.] properties are at risk from what experts call a 100-year flood, far more than the 8.7 million properties shown on federal government flood maps.” The new maps take into account “sea-level rise, rainfall and flooding along smaller creeks not mapped federally.”
Many U.S. cities–including cities away from the coasts–show this previously unacknowledged flooding risk. “In Chicago alone, 75,000 properties have a previously undisclosed flood risk. And minority communities often face a bigger share of hidden risk.”

“In more than two-thirds of states, First Street found that areas with more minority residents also had a greater share of unmapped flood risk than the statewide average … cities seem to invest more in flood protection in areas with higher incomes and property values.”
See the article —
Flavelle, Christopher, Lu, Denise, Penney, Veronica , Popovich, Nadja & Schwartz, John. (2020, June 29). New Data Reveals Hidden Flood Risk Across America. New York Times.
See also —
Sea level rise and climate change (bibliography)
The Midwestern U.S. is still flooding
The impact of sea level rise on Florida–and the world
Why don’t we do anything about climate change?
Large, intense thunderstorms will happen more frequently
Questions? Please let me know.