HORRY COUNTY, S.C. (WBTW) — Coastal economies and properties are already at risk due to rising sea levels — with 60 miles of coastline along the Grand Strand that are already seeing impacts.
Sea levels have risen by more than a foot in the last century. In recent years those impacts along the Grand Strand can manifest as king tides or just heavy rain. Those events can devastate local dunes, which are the first line of defense to protect infrastructure and habitats.
In a five-year period, the amount of acreage lost in the U.S. was 80,160 acres per year, which is five times larger than the U.S. Virgin Islands. At this rate, an additional 16% will be lost by 2100.
“We talk about global change as it’s kind of an abstract concept but it’s sneaking in on us,” said Dr. Paul Gayes, a marine science and geology professor at Coastal Carolina University.
Gayes and CCU students research environmental impacts on Waites Island, an undeveloped barrier island in Horry County. The use of drone LIDAR systems map the dunes of the island. The high-resolution findings are able to show how healthy the dunes are, how well they’ll hold up against a storm, and track the behavior of the coast.
Another impact of rising sea levels is long-term beach erosion. According to West Carolina University’s beach nourishment database, as of 2021, $569,245,080 has been spent on beach renourishment.
“By putting sand back in the system, it basically sets the clock back,” Gayes said. “It gives you a little bit more time as it continues to waste away, but it’s not dealing with the elevation of sea-level rise. You’ll start to see this effect of flooding from the backside, in places like Cherry Grove and Garden City.”
It’s not just people who live on the beachfront that need to be concerned. Sea level rise coupled with warming temperatures and more intense storms is causing more inland flooding.
“It’s overtime, sort of this creeping effect,” said Doug Marcy, of the National Oceanic and Atmospheric Administration office of Coastal Management. “You’re gonna start seeing more and more damage,”
NOAA is working on mapping sea-level rise around the country for the National Climate Assessment, which updates sea level predictions every four to five years.
The information can be used to help communities develop a strategy.
Marcy worked with the city of Charleston on its plans.
“They’re making good decisions based on that science and can start to amend things like their stormwater plan to include sea-level rise for future projects,” Marcy said. “When we build new structures, including freeboard in there one or two feet above the base flood elevation.”
The report also highlights using natural ways to save shorelines, like utilizing oysters.
The South Carolina Department of Natural Resources is working on that through its South Carolina Oyster recycling and enhancement program, or SCORE.
The agency has used more than 11 hundred tons of oyster shells to create 225 reefs.
Rachel Hawes with the Coastal Conservation League works closely with DNR on the project.
“It’s kind of a one-two punch where they’re breaking up that energy and that wave energy that’s hitting our coast, and preventing erosion and they increase the amount of salt marsh which helps with flooding,” Hawes said.
Hawes said restoring oyster beds is even more critical now with more development on the coast and rising sea levels.
“We need to pay attention to what borders our coast and sometimes people put up hardened structures, and rock walls which aren’t great because it blocks that salt marsh and oysters and reverberates that wave energy and does not allow the natural process to happen,” Hawes said.
The National Climate Assessment reports the worst-case scenario could be more than eight feet of global sea-level rise by 2100.
That same report said the current financial resources devoted to adapt to or mitigate coastal climate change impacts are insufficient to meet the projected challenges ahead.
Gayes said change doesn’t happen on the turn of a dime.
“The problem is we just don’t have as much time as we used to,” Gayes said. “We can’t wait 30 years.”