Living shoreline aims to protect Hatteras Harbor

By on January 14, 2011

Durant's Point is the area north of the opening to Hatteras Harbor. (Coastal Federation photo)

If all goes as planned, work will begin this spring on a granite barrier just off Durant’s Point and local students will help plant marsh grass along the shoreline behind it.

The project, called a living shoreline, will demonstrate an alternative to bulk-heading that is better for the marine environment, the North Carolina Coastal Federation says.

It will also provide some insurance for Hatteras Harbor.

“If Durant’s Point washes out, the protection of the harbor will be gone,” Coastal Advocate Jan DeBlieu recently told the Dare County Board of Commissioners. “And that is why we believe that there’s an abiding interest to the county to protecting Durant’s Point.”

DeBlieu was making a pitch to the commissioners to guarantee maintenance of the rock barrier, or sill, so that the Coastal Federation could qualify for a grant. Besides enhancing the environment, she said, the project will stabilize the shoreline.

Durant’s Point, a sliver of land that runs up the north side of the entrance to Hatteras Harbor, has been eroding rapidly in recent years. DeBlieu said the Coastal Federation had sought a maintenance guarantee from the U.S. Army Corps of Engineers “and they told us it would take an act of Congress. So we kind of gave up on that one.”

After some initial problems, a living shoreline at Edenton flourishes. (Coastal Federation photo)

Commissioners were wary about the unknown cost of maintaining the sill, which will be 318 feet long, or about the length of a football field, and rise six to 12 inches above the surface.

But DeBlieu said there was only one instance of a failure among several similar projects, and it was after an unusually severe storm. The Coastal Federation went back for another grant to correct an engineering defect, DeBlieu said, and has since refined its construction methods.

“We have never had any huge maintenance problems with these projects,” she said.

Living shorelines have been around for more than 20 years, said Federation Coastal Scientist Erin Fleckenstein. One at Jockey Ridge uses bagged oyster shells as a sill. Another is on the shoreline at Wanchese Seafood Industrial Park. There is also a living shoreline at Roanoke Island Festival Park.

Because of its exposure to wind and tide, the Durant’s Point project needed a heavy-duty sill. So granite was chosen, Fleckenstein said.

Commissioner Allen Burrus, who represents Hatteras Island, said the erosion rate at Durant’s Point has been 100 to 150 feet in the past two or three years.

Although the point is private property under several owners, they would not benefit financially from the project, Fleckenstein told the commissioners. The owners were unwilling to guarantee maintenance because the property, which is not used for homes or any other structure, would be worth less than the rock barrier.

The impetus was Hatteras Harbor.

“It really wasn’t the landowners driving it,” Fleckenstein said in a later interview.

The board agreed to guarantee the structure at Durant’s Point. The sill will run north of a Corps of Engineers rock revetment at the entrance of the harbor, which is north of the ferry docks.

A solid structure like a bulkhead causes scouring at the bottom and is not conducive to marine habitat. The design of the living shoreline allows more ebb and flow, allowing habitat areas to form behind the still.

The grant would come from NOAA in partnership with the non-profit Restore America’s Estuaries. Work on the project will be done in two phases, one this spring, and the other next year.

Phase one, which includes the sill and some marsh planting, will cost $65,000, Fleckenstein said. The second phase will cost about $22,000.

Planting will be part of a school project for some students at Cape Hatteras Secondary School. The students have been studying about coastal habitats, and planting at Durant’s Point will be an end-of-year field trip.


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