High tide flooding is already causing headaches for coastal communities in North Carolina and South Carolina, but rising sea levels will make the problem worse, federal scientists say.
The most recent high tide flooding outlook, released every July by the National Oceanic and Atmospheric Administration, says “sunny day” flooding will increase for the foreseeable future.
“Coastal communities across the U.S. continued to see increased high tide flooding last year, forcing their residents and visitors to deal with flooded shorelines, streets and basements — a trend that is expected to continue this year,” NOAA said in a press release.
“We cannot wait to act,” Nicole LeBoeuf, acting director of NOAA’s National Ocean Service, said during a call with reporters this week. “This issue gets more urgent and complicated with every passing day.”
Flooding from king tides has doubled since 2000, according to NOAA. The problem is especially apparent in places like Norfolk, Virginia, one of the hardest-hit cities from sea-level rise, LeBoeuf said.
In North Carolina, Wilmington broke a record for days with high-tide flooding in 2018. There were 14 flood days, according to NOAA, with water rising up with the high tide in the Cape Fear river to flood low-lying areas. That’s up from an average of one flood day per year in 2000.
High tide flooding causes beach erosion, and it can overwhelm storm water and sewer systems, close roads, salt farmland, damage infrastructure and hurt property values, the NOAA report says.
“Impacts are likely to be chronic sooner rather than later” if cities don’t adapt, according to William Sweet, lead author on this year’s study.
“It’s really starting to take its toll,” Sweet said.
Cities like Norfolk, Virginia; Charleston, South Carolina; and Miami are considering ways to combat rising tides, including the possibility of raising roads and building seawalls.
NOAA predicts three to seven flood days in Wilmington this year. But by 2050, that number is expected to jump to somewhere between 15 and 65, according to data available on NOAA’s new interactive map.
The group uses sea level gauges to measure tides in specific areas, with four along the North Carolina coast where scientists will make forecasts for tidal flooding.
Beaufort had two flood days last year, according to NOAA, and is forecast to see up to four days with high-tide flooding this year. By 2030, NOAA projects, the historic port town could see between six and 15 days of high-tide flooding, and 25 to 100 days each year by 2050.
On the Outer Banks, the Oregon Inlet had four tidal flooding days last year and could see at least 35 days per year by 2050. Duck could see seven to 12 days this year, with an average of at least 55 days of high-tide flooding per year by 2050, NOAA predicts.
“High tide flooding, often referred to as ‘nuisance’ or ‘sunny day’ flooding, is increasingly common due to years of relative sea level increases,” according to NOAA. “It no longer takes a strong storm or a hurricane to cause flooding in many coastal areas.”