The tragedy on the Guadalupe River in Texas proved that catastrophic flooding isn’t just a coastal problem. From Houston bayous to Vermont mountain valleys, millions of Americans live where rising water is a matter of when, not if. Here are 12 hotspots experts say deserve extra vigilance right now.
Texas Hill Country (Guadalupe River)
After surging 26 feet in 45 minutes and killing at least 43 people, the Guadalupe joined an infamous list of flash-flood rivers where rocky terrain and narrow canyons give residents little warning.
Houston & Harris County, Texas
Ranked the most flood-prone county in America, Harris County has endured Allison, Harvey, and nine federally declared floods since 2000—despite more than $5 billion in mitigation work.
New Orleans & Mississippi River Delta, Louisiana
The Mississippi is cresting at its highest level in two decades, forcing daily levee inspections to protect more than one million residents behind floodwalls and pumps.
Mid-Mississippi Corridor (St. Louis, MO–IL)
Mayors along the river have watched “once-in-a-century” floods arrive every few years, prompting new insurance pilots after November 2024 storms submerged highways on Election Day.
Sacramento–San Joaquin Valley, California
The Central Valley’s aging levee system is undergoing a multibillion-dollar upgrade, yet state engineers warn that a mega-storm could still overtop defenses protecting the capital and vast farmland.
Miami & South Florida
Sea-level rise is pushing groundwater up from below; scientists say even “sunny-day” high tides could create ponds in inland Miami-Dade neighborhoods long before 2050. Miami has largely dodged the worst tropical storms, but there’s no guarantee they’ll continue to be so lucky.
Nashville & Cumberland River Basin, Tennessee
Metro officials mail annual flood-risk notices after the 2010 disaster, and the Army Corps now juggles dam releases to offset increasingly intense storms feeding the Cumberland.
Red River Valley (Fargo, ND–MN)
With its north-flowing, ice-prone channel and flat topography, the Red River routinely reaches major-flood stage; new diversion projects aim to protect 235,000 people.
Vermont Mountain Valleys
The July 2023 “Great Vermont Flood” swamped downtown Montpelier and highways statewide, underscoring how steep terrain funnels extreme rainfall into narrow riverbeds. :
Chehalis Basin & I-5 Corridor, Washington
Washington restarted its environmental review of a major flood-reduction dam after 2024 design changes; the Chehalis regularly cuts Interstate 5, Washington’s main north–south artery.
Kanawha River Basin, West Virginia
Congress fast-tracked Corps feasibility studies here after 2016’s deadly floods; lawmakers warn climate-driven downpours could overwhelm coal-era towns tucked in steep hollows.
New York City Metro Area
From Ida’s 2021 tunnel floods to record cloudbursts in 2023, extreme rainfall now stresses sewers and subway pumps; city planners project higher surge and precipitation risks through 2100. In fact, a 2024 report from the city’s Department of Health and Mental Hygiene said flooding was New York City’s most imminent threat.
