Shifting Sand

Sep 18 • Eco-life, News, NEWS & VIEWSNo Comments on Shifting Sand

CAN’T SURF THIS TUBE: The pipe on Wrightsville Beach during the renourishment project four years ago. Photo by John Wolfe

Carolina Beach is getting thinner—and, no, I’m not talking about beach-goers’ waistlines. The stroll from the wooden stairs over the dunes to the water’s edge has gotten noticeably shorter in the past few years. It’s due to the natural process of erosion, which removes sand from the beach with every retreating wave.

For owners of beach houses and other waterfront properties, this is bad news. The steadily advancing waterline poses a threat to anything manmade in its way. To combat it, cities dump more sand in front of beach houses. It’s a quick fix—something which I wrote about a few weeks ago, expressing its negative impact on shorebird populations.

Dr. Paul Hosier, a coastal plant ecologist and 4-year professor of biology at UNCW, has studied plant ecology and the impact of hurricanes and humans on local beaches like Masonboro and Cape Lookout. He says renourishment projects started in the mid ‘60s.

“Hurricane Hazel probably was the trigger,” he claims, referring to the devastating Category 4 storm that struck North Carolina in 1954. “After houses were destroyed and the ocean boundary was altered dramatically during these hurricanes, the federal government came in and said, ‘We need to protect these shorelines.’”

The New Hanover County (NHC) Board of Commissioners met on September 4th to approve a Memorandum of Agreement (MOA) with the US Army Corps of Engineers regarding the renourishment of Carolina and Kure beaches. This agreement is different from past ones; its terms make the county responsible for any liabilities and cost overruns. Typically, the federal, state, and county governments would split these unforeseen expenses. The terms have changed because New Hanover is the first county in the country to utilize contributing authority, allowed by recent legislature passed by Congress.

“The benefit of contributing authority is that we can use federal permits to conduct a larger nourishment project than Congress funded,” Vice Chairman Jonathan Barfield, Jr. explained. “Doing so is good for the overall management of sand and protects more of the beach longer. However, the consequence in using this new authority is the aforementioned exposure of owning 100 percent of any cost overruns or project liabilities.”

A nourishment project typically happens in this area every three years. Sand is taken from a reservoir (usually a shoal at the intersection of the ICW and an inlet) and is pumped through an enormous pipe to the beach being renourished. Hosier calls it a “win-win” scenario.

“The boaters get clear access and obstructions moved out of the channels, and the homeowners and users of the beach get a wider beach in front of their homes to frolic and have a good time on,” he says.

Ted Davis Jr., chairman of the New Hanover County Board of Commissioners, echoes this sentiment. He called the approval of the memorandum a “fantastic example of people working together,” citing the nourishment’s benefit to the local economy.

“Beaches and waterways are so critical to our tourism,” Davis said in the September 4th meeting. “We’ve got to do everything we can to keep our beaches replenished and our waterways dredged so that people can travel in them safely. This tourism will keep coming and our economy will keep booming because of that.”

But it’s not an easy process. “You have to be careful of what you do and how you do it,” Hosier explains. “It takes a lot of careful engineering—a lot of things can go wrong.” Potential hazards include sand that is too fine, sand that is too coarse and organic matter getting mixed in with the particles. Hosier relates the story of a project near Bogue Banks where old car tires dumped off shore had contaminated the reservoir and wound up on the beach with the sand.

Renourishment projects have been occurring on local beaches for over 50 years, and in this span of time there have been many independent studies completed. Hosier says typically these studies are short-term and site-specific. Often, there’s no pre- or post-study done to compare the before with the after.

“Many times it’s: ‘What happens after we dump some sand on the beach?’” Hosier says. There have been no comprehensive studies completed on the long-term environmental effects of beach renourishment. “We probably don’t know as much as we should know about what the impacts are,” he says, “both positive and negative.”

Among the long-term studies not completed are studies on the impact nourishment projects have on local wildlife. “If you’ve got mole crabs and coquina clams residing in the intertidal zone, they’re going to get buried by that process,” Hosier says.

If you dig out a handful of sand under a receding wave, you’re likely to catch a few mole crabs. They’re tiny filter-feeding crustaceans that fishermen like to use for bait because they’re at the base of the food chain. Although the populations do appear to bounce back fairly quickly after the nourishment project, no studies have been completed that examine whether or not they recover to the same levels as before.

The coast is a very dynamic environment, Hosier is quick to stress. The shoreline is constantly changing locations, moving further landward or seaward due to natural processes and occurrences like erosion and hurricanes. Hosier has seen beaches near inlets migrate as much as 30 feet in one day. “The beach is always going to be there,” he notes. “That’s a basic tenet. It’s just not going to be in the same place.”

Developers who build down here don’t always recognize this. Hosier gives the example of people from Raleigh or Durham who live on the same plot of land their as their great-grandparents.

“Their father could go out and see where the four stakes were that marked their property,” he says. “And then his son could do the same thing, and his son could do the same thing because it doesn’t change. You take that philosophy of, this is my piece of land, my piece of heaven, and you transport it down to the coast; it doesn’t always work. You have to have a different philosophy. That’s what leads us to the need for [shoreline structures and nourishment projects.] We’re saying, ‘We’re not changing the corners of our property, so we’re putting up a structure to keep those four corners intact. This piece of land is here now, and it’ll be here forever.’ But that’s not true.”

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *


*

« »