Are beach groins harmful or helpful?
Wed, 02 May 2012 22:15:47 GMT —
Preserving the beach is a top priority for coastal communities. One of the ways that's achieved is through the use of groins, a wall of rocks placed perpendicular to the shore that helps keep sand in one place.
But a state committee says they do more harm than good and don't want any more built.
Not everyone on the Blue Ribbon Committee on Shoreline Management agrees with the recommendation. One of the most vocal opponents is Bill Otis, the mayor of Pawleys Island.
Two dozen groins line the beach along Pawleys Island. Originally built in 1950, the walls of wood and rock are structures Otis says are crucial to maintaining their town.
"These groins have helped stabilize the beaches and protect Pawleys Island through Hurricane Hazel and Hurricane Hugo they're still here and they're still doing their job of protecting the island," explains Otis.
In fact, Otis says the physical proof of their effectiveness is in plain sight. Stairs from many of the towns homes have been extended farther out to meet the shore since the groins were improved 13 years ago.
"The dune line has moved 75 feet toward the ocean and a whole new dune line has been created," adds Otis.
But with every solution there's a drawback. For groins it's called downdrift erosion.
"The currents are going to move what they can move and you can obstruct it locally and trap some but it's going to excavate on the other side to make up the difference. So you kind of push the problem around," says Dr. Paul Gayes, Director of Coastal Carolina University's Center for Marine and Wetland Studies.
Dr. Gayes says the issue of the effectiveness of groins is being discussed in other areas as sea level continues to rise, "It's a national issue, it's playing out a little different in different states depending on the language of the law. A lot of people are wrestling with it."
"If downdrift erosion is in fact that significant of an issue then certainly at least one or more groins might've been required to be removed but they haven't," says Otis. "1194 feet further down than what it was so that sand came from somewhere we didn't block all the sand going south, there's a lot of sand down there."
It's up to the General Assembly to make the recommended changes to state law. Otis is happy the committee agreed that existing groins should be able to be maintained.
More than 150 groins are in place from Hilton Head Island to Garden City.