Figure Eight groin impact studied

by Cole Dittmer
Wednesday, November 21, 2012

Staff photo by Allison Potter

Tom Jarrett presents an update about the Figure Eight Island terminal groin project during the North Carolina Beach, Inlet and Waterway Association conference at the Blockade Runner Beach Resort on Tuesday, Nov. 20.



Project engineer Tom Jarrett of Coastal Planning and Engineering presented updated plans for a terminal groin for Figure Eight Island during the North Carolina Beach, Inlet and Waterway conference at the Blockade Runner Beach Resort on Tuesday, Nov. 20. Jarrett said the justification for a terminal groin at the north end of the island arose from the natural erosion that jeopardizes approximately 10-15 homes and the perennial depletion of beach renourishment projects every two to three years. The sand deposited on the north end during the renourishment projects is swept back into Rich’s Inlet after two months. Jarrett said the Figure Eight Island Homeowners Association is considering a terminal groin as a permanent solution. 

The proposed terminal groin would extend a total of 1,600 feet, with 900 feet onshore and 700 feet into the ocean. On land, the terminal groin would not be visible buried in a two-foot deep trench. However, the ocean portion would be a concrete wall submerged underwater, much like the first section of the jetty on the north side of Masonboro Inlet. Jarrett said the landward side of the terminal groin would be topped with small rocks that would both allow sediment to pass through initially, but would eventually build up to a natural berm on the beach. 

As part of the environmental impact study (EIS) Coastal Planning and Engineering was required to submit to the United States Army Corps of Engineers, Jarrett said the five-year computer models showed that the same scenario would occur if there was or was not a terminal groin. After five years, the sandspit on the north end of Figure Eight Island would completely erode into the inlet in both cases; however, a larger amount of sand would build up on the island’s beach immediately south of the terminal groin if it were built. 

Currently, Coastal Planning and Engineering is addressing the many questions Jarrett said the corps of engineers raised in its review of the EIS and that the project is still a long way from completion. 

One of the things that could further delay or shut down the project would be litigation against the terminal groin by the North Carolina Coastal Federation. The NCCF has consistently fought against terminal groins in the state, claiming that static structures create unnatural movements in inlets and shorelines and that this terminal groin could lead to an entire terminal groin field on the island. 

At a Sierra Club of the Cape Fear meeting in October, NCCF coastal advocate Mike Giles said sand trapped by the terminal groin would be robbed from other areas — notably the strand of beach on the island immediately south of the area that would benefit, and possibly Wrightsville Beach.

“The cost of these structures to protect a few houses far exceeds any benefit,” Giles said. “Our problem with terminal groins is they are like a potato chip, you can’t stop at one; natural shorelines and wetlands are the best seawalls.”

Despite the NCCF’s efforts, Jarrett believes his side would win a legal battle.

“The modeling is solid and there is much more evidence of these things working than there is of them not working,” he said. 

David Kellam, administrator for the Figure Eight Island HOA, said he believes a terminal groin is the best solution for this situation. 

“We are just following the process and making sure we are doing the right things,” Kellam said. “This isn’t a slippery slope, we don’t support groin fields because engineering has shown that they are not needed.”

Before the HOA and Coastal Planning and Engineering would have to fight any legal action, the first steps are to finalize the EIS and acquire the necessary state permits — a process Jarrett said could take another six months. 


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