Coastal infrastructure"uisance flooding” becoming problem for many U.S. coastal communities

Scientists say that floods and surges will become a regular feature of life in many coastal U.S. cities, even when the weather is not particularly bad or stormy.

As Student Science reports, some communities along the East Coast are flooding even in calm, clear weather, indicating a trend of “nuisance floods” which will increasingly plague many parts of the U.S. coast in the future.

“Over the next few decades, climate change is poised to drive seal levels even higher,” said William Sweet, and oceanographer at the National Oceanic and Atmospheric Administration (NOAA). “So today’s flooding problems promise to become only more widespread and more frequent. Sooner or later, nuisance floods are something that all coastal communities are going to have to deal with.”

East Coast cities like Annapolis, Maryland, the home to the U.S. Naval Academy, have seen a big increase in swamping rats. From 1957 to 1963, flooding hit the city about 3.8 days a year. From 2007 to 2013, that average had increased to 39.3 days a year.

Trends such as those seen in Annapolis are becoming more and more common across the coast. Erika Spanger-Siegfried, a data analyst at the Union of Concerned Scientists (UCS), has co-authored a report which combines data harvested by Sweet and others. The paper suggests that thirty years from now, the increases in flooding seen in Annapolis over the past fifty years will be replicated all across the coast from Maine to Florida.

“These floods are not life-threatening,” she said, “Still, these floods are disruptive. There’s a limit to the number [of flood events] that an area can tolerate.”

A bigger problem is how the increase in flooding will combine with subsidence, or the sinking of coastal lands. This may exacerbate the problem of nuisance flooding, and hasten the increase in the number and severity of floods caused by sea-level rise.

Aware of what the future holds, many coastal communities are working now to prepare for and bunt the worst of these swamping conditions.

New York City has begun work on a $23 million project to improve drainage along major roads. Charleston is spending hundreds of millions of dollars to improve drainage along its historic Market Street, including a new seawall.

Even smaller towns like the Tybee Island community near Savannah, Georgia are working to improve their defenses. The township is spending $450,000 to reinforce and protect its water treatment plant, as well as fortifying other basic utilities that could be affected by nuisance flooding.

“Sea-level rise is like a slow-motion storm surge, except that it doesn’t go away,” said Paul Wolff, the mayor of Tybee.