Many along US East Coast to see tidal floods triple by 2030, say researchers

The US East Coast can prepare for many more so-called “100-year” flooding events, according to a group of scientists and engineers.

A new report from the Union of Concerned Scientists concludes that tidal flooding during the next 15 to 30 years will be much more common — especially for the East Coast and increasingly on the Gulf Coast — due to global warming.

“High tides are having a greater impact on US communities today than in decades past for two reasons,” said the nonprofit organization said. “First, our shores are more heavily developed, so higher tides affect more people and infrastructure. Second, these tides are now occurring on top of elevated—and rising—sea levels.”

Two-thirds of the 52 communities the Union of Concerned Scientists analyzed on the East and Gulf coasts can expect to experience triple the amount of tidal flooding by 2030. More than half can expect to average more than 24 tidal floods each year.

If accurate, a tripling in the number of tidal flooding events could mean a flood of this kind more than once per week. In places like Annapolis, Maryland or Washington DC could be wading in an average of 150 tidal floods every year. Sandy Hook, Cape May and Atlantic City in New Jersey can expect to flood 80 or more times per year.

The news isn’t better further into the future.

By 2045 many coastal communities are expected to experience sea levels rise 1 foot. This means one-third of the 52 locations would start to face tidal flooding more than 180 times a year, on average.

“In this future, days without high-tide floods could start to become the exception in certain places,” said the Union of Concerned Scientists. “Without sensible preparation for these disruptions, conducting daily life in such flood-prone areas would become, at best, unreliable and, at worst, dangerous.”