(Bloomberg) — Record high-tide flooding washed over U.S. coasts in the past year, and rising sea levels are expected to send the deluges into streets, homes and businesses even more frequently over the next decade, the National Oceanic and Atmospheric Administration said.
The surges, sometimes referred to as “sunny day” or “nuisance” floods, are becoming increasingly common as the increase in sea levels continues, the agency said in an annual report. Damaging floods that used to happen mainly during storms now happen during regular events such a full-moon tide or with a change in prevailing winds.
High waters are flowing into coastal economies and crucial infrastructure like waste and storm water systems, with those areas seeing twice as many high-tide flooding days than they did 20 years ago. The trend is expected to continue into 2022 and beyond without improved flood defenses, NOAA said.
“NOAA’s tide gauges show that 80% of locations where we collect date along the Southeast Atlantic and Gulf coasts are seeing an acceleration in the number of flood days,” said Nicole LeBoeuf, the newly appointed director of the National Ocean Service.
Flood records were set in Texas, Florida, South Carolina, and Georgia, NOAA said. Galveston and Corpus Christi, Texas, along with Bay Waveland, Mississippi, had a record 20 days with high-tide flooding from May 2020 to April 2021. Twenty years ago these locations would typically only flood two or three days a year.
By 2030, long-range projections call for 7 to 15 days of flooding along coastal communities nationally, the report said. By 2050, that rises to 25 to 75 days.