The construction of a private seawall in Sea Pines has some residents concerned about flooding of surrounding properties.
Five beachfront property owners in the Piping Plover area in the southern portion of Sea Pines have begun construction of a privately-funded seawall, according to a news release from the Sea Pines Community Services Associates.
The project received approval from the Sea Pines architectural review board, the release said.
A few months after Tropical Storm Irma hit in September 2017, the five neighbors decided something needed to be done to protect their properties in case of future storms, said Bert Ellis, one of the five.
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"We were ground zero for the (last) two storms," Ellis said Monday. "Our pool walls became our seawall."
All but a foot and a half of the seawall will be underground, Ellis said. The neighbors have already agreed to put sand over the above-ground portion, so that a new dune is created.
But in a public Facebook group, about a dozen residents expressed concern that those who live outside the seawall limits may now have exacerbated flooding.
"If we really get storm surge, that seawall will hold up as water goes on either side and floods the beach paths," said Dana Advocaat, a Sea Pines property owner. "Every single beach path (in the area) becomes a stream that goes back to the road."
According to an "Ask an Engineer" article on the MIT School of Engineering's website, seawalls are "designed to rebuff waves and maintain a consistent shoreline."
However, their effectiveness is a point of debate, the article, written by Peter Dunn, says.
"... Seawalls do prevent sand removal and dune erosion along their lengths, but with an important caveat — erosion increases in areas beyond the walls' ends," the article says. "So unless they are built according to a coordinated plan, seawalls simply pass along the effects of the waves, which end up eating more violently at the first unprotected spot."
But Rocky Browder, the town's environmental planner, said because the seawall will be underground, flooding is not a concern.
"(If) over time the beach eroded and the wall is exposed, and then we have a big storm, it'll redirect water around it," Browder said. "But the way the wall will be (underground) once completed, I don't think there are concerns with flooding."
Ellis agreed that the seawall isn't going to push the water from future storm surge elsewhere. He noted that throughout the process of acquiring approval from half a dozen agencies, none raised concerns about flooding of surrounding areas.
"By design, this isn't going to deflect the water to someone else," Ellis said. "It's going to keep the water from coming into our yards."
Advocaat said the community needs a policy to manage the effects of storms and erosion.
"We need to step forward into the 21st century and deal with the increased number of storms," she said. "We need to put in place policies that help us all — not just five houses."
CSA said in a statement sent through the Lou Hammond Group, a public relations firm, that the project is a "private property issue and there is no prohibition on this type of improvement on their private property."
Amber Kuehn, the manager of the Hilton Head Island Sea Turtle Protection Project, said her only concerns are the temporary silt fence in the construction area and a large hole in the ground while the wall is being built.
Sea turtle nesting season begins Tuesday, and the fencing and any large holes — even those left on the beach from sandcastle builders — can impede turtles as they come to shore.
The South Beach area of Sea Pines, near the five homes, was hit the hardest in Irma.