By Rebecca Hersher / NPR News / August 7, 2024
High tide floods – when water collects in streets or even seeps into buildings on days without rain – are increasingly common in coastal areas as sea levels rise, a new report warns.
MICHEL MARTIN, HOST: Tropical Storm Debby has flooded the southeastern U.S. this week. Many of the hardest-hit areas also have the fastest sea level rise in the country. Nicole LeBoeuf is the director of the National Ocean Service.
NICOLE LEBOEUF: These areas are already under the thumb of sea level rise, making the combination of Debby’s rainfall and storm surge potentially catastrophic.
MARTIN: Rebecca Hersher from NPR’s climate desk has learned of a new report that warns those sea level changes are accelerating.
REBECCA HERSHER, BYLINE: Sea level rise makes flooding from hurricanes worse because the water is already closer to people’s houses. Storm surge does more damage. But even on sunny days, sea level rise means more and more flooding in coastal areas, says Leboeuf.
LEBOEUF: Bottom line, over the past year, we’ve seen record coastal flooding.
MARTIN: In the last year, 34 places in the U.S. tied or broke their records for the number of so-called high tide flood days, when water collects in the street or even gets into buildings without a rainstorm. That includes St. Petersburg, Fla., Atlantic City, N.J., and Charleston, S.C., as well as multiple cities on the Gulf Coast. William Sweet is an oceanographer at NOAA.
WILLIAM SWEET: You know, our communities, many of which have been built on fill centuries ago, but right up to the edge of the ocean.
HERSHER: As sea levels rise, saltwater is ending up in places that it never used to and causing major damage and disruptions. Even a few inches of water can cause sewage to back up, force businesses to close, and damage vehicles and underground pipes. Karen Kavanaugh is a NOAA oceanographer.
KAREN KAVANAUGH: Talking about people living in the Keys or Annapolis or Norfolk – they’re facing traffic delays dropping their kids off to school or getting to work, because there’s water that’s flooding the streets, and not necessarily because of a storm.
HERSHER: It’s not just coastal residents who are affected, she points out. When roads and ports flood, it affects supply chains across the country. Forecasters predict that if sea levels continue to rise as projected, by 2050, the average number of high tide flood days in the U.S. will top 45, which would be almost one sunny-day flood per week. Local governments in many coastal areas are racing to improve sewers and drainage and find ways to pay for the costs of more frequent floods.
I know a local is gonna say, ‘hey, it always floods in OB every other year or so,’ but the overall point needs to be appreciated.