SCIENCE

Building On A Barrier Island

These accumulations of sand aren’t permanent but are home to whole communities

August 30, 2011

Irene created a new channel across a North Carolina barrier island Courtesy of flickr user NCDOTcommunications

When I first learned about barrier islands, back in high school, I couldn’t believe that people would live on one. That’s because barrier islands aren’t permanent; they’re just accumulations of sand that form off the coast (many can be found on the U.S. East Coast). And it’s a natural state for these islands to grow and erode and get washed away. A strong enough storm can cut an island in half, as seen after Irene in the photo above, or take away the wide swath of beach that had been between homes and the ocean. What had been prime beachfront property one day can be open ocean the next.

And people can compound the problem. The point of buying beachfront property is to get a great view of the ocean, but destroying the sand dune to get closer to the beach eliminates the feature that protects the beach from erosion. In addition, building jetties and adding sand in attempts to keep an island stable can hasten erosion elsewhere. Building on a barrier island can also limit the island’s usefulness in protecting the mainland coast from powerful storms as well as eliminate important ecosystems, such as dunes and salt marshes.

The best way to limit development on these fragile islands is probably not to outlaw it, though. There’s so much development already on these islands that there’s no possibility of clearing it all away and letting nature take over. But we could add more of these islands to the Coastal Barrier Resources System. People are not prohibited from developing land in this system. Instead, the act that created the system “limits the Federal financial assistance for development related activities such as spending for roads, wastewater systems, potable water supply, and disaster relief,” NOAA explains. In other words, you can build here, but you’re not getting any help from the feds.

As a result of this program, NOAA estimates that U.S. taxpayers saved $1.3 billion between 1982 and 2010. People do build on CBRS land, but it’s more expensive to do so without federal assistance, so less development occurs. And because the land is less developed, these ecosystems often stay intact, providing homes for migratory birds, rare plants and animals. The land is also allowed to grow and erode naturally and serve as the barrier it is meant to be.