Initial Results After Buxton Beach Nourishment Survey Find that Shoreline is Adapting Quickly

A survey of the 2017 / 2018 Buxton Beach Nourishment Project was recently conducted by project manager Coastal Science and Engineering (CSE), and while the detailed results are still forthcoming, the early impression is that the shoreline has adapted very quickly to the influx of sand.

The goal of the project, which began in the summer of 2017, was to widen a stretch of beach that extended for 2.94 miles in northern Buxton. 2.6 million cubic yards of sand was deposited on the shoreline from an offshore ridge located 1.7 miles offshore – a site that was identified and specifically chosen for its sand quality, and consistency with the rest of the local shoreline – and the dredging was officially completed on February 27, 2018.

Just days after completion, the Buxton Beach Nourishment project underwent an immediate test as four nor’easters pounded the Outer Banks throughout the month of March. Though the exact results of the survey are expected to be finished by August, Dr. Haiqing Liu Kaczkowski, Senior Coastal Engineer for Coastal Science and Engineering (CSE), estimates that this battering of storms sped up the sand distribution process.

“The early impression is that the initial volume has adapted very fast, especially during the March nor’easters,” says Dr. Kaczkowski. “Those events really sped up the initial adjustment of the profile and shape of the new beach. This adjustment includes sand spreading to the north and especially to the south, as that’s the main direction of longshore sediment transport, as well as a volume movement offshore. The storm events also left rhythmic variations in the beach width, resulting in some narrower sections along Buxton.”

Immediately after a beach nourishment project finishes, the targeted shoreline appears abnormally wide. It’s up to Mother Nature to transform the shoreline to appear consistent with neighboring beaches, and to change and adapt the newly placed sand as storms blow through the area.

The area where the sand moves within the project – known as the sand box – includes the beach itself, as well as the ocean waters up to 2,000 feet offshore. After conducting the survey, the sand adjustment within the sand box is occurring as expected, with sand being distributed both along the beach and in the waters close to the shoreline, although at a faster rate due to the series of spring storms.

“The overall impression is that the project has served its original purpose, which is to protect N.C. Highway 12,” says Dr. Kaczkowski. “Since the volume [of sand] was put in place, Highway 12 has not been [impassible], even during the September hurricanes and March nor’easters. The volume has adjusted faster than it would in a normal year. Because the groins at the south end of Buxton have deteriorated and have little capacity to hold more sand, the sand loss to the south has been much higher than the historical average. The detailed reasons as to why will be evaluated.”

When possible, surveys are conducted of a beach nourishment project immediately after it concludes to ensure that the total volume of sand deposited aligns with the original project specs. However, due to the tricky nature of the Hatteras Island shoreline, the survey had to wait until weather conditions were optimal for obtaining the most accurate results.

The survey is conducted in two parts, as it is measuring both the width of the beach, as well as the depth of the waters within the sand box. The surveyors examine the land on foot with handheld equipment, and also the nearshore waters with a boat equipped with GPS and tools that examine the underwater topography.

The final results will be given to Dare County once the data has been closely examined and reviewed, but based on first impressions, the Buxton Beach Nourishment Project seems to be doing its job.

Janet Morrow Dawson, owner of the Cape Hatteras Motel in Buxton, has had a front row seat for the project since it first began in the summer of 2017, and she says that the goal of protecting N.C. Highway 12 has been successful.

“Overall, we’re very satisfied,” she says. “We were very sad when the nor’easters came in March – at that time, it was difficult to ascertain what the end result would be. But over time, [the beach] has been built back, and it looks like it’s where the engineers intended it to be.”

“Had we not had the nourishment, when the storms came in March and April, it would have been very, very bad on the north end of Buxton,” she adds. “Even though we did have some overwash, without the nourishment, it would have been devastating. So, in that regard, it worked.”

Longtime visitors to Cape Hatteras Motel have noticed the change as well. “Our guests are happy,” says Dawson. “People have mentioned how much better it is this year than last year, and we also don’t have the uncertainty of the pipe [and equipment] being around this summer.”

There’s still a little more behind-the-scenes work going on, too. Contractor Weeks Marine has been working roughly 1,000 feet offshore to remove sublines that were buried and which have been inaccessible until this recent wave of good weather. (All of the equipment on the beach and close to shore was removed shortly after the project’s completion.)

And while the data from the recent survey is still being processed, for those close to the project, the shoreline is more or less adjusting as expected – although perhaps a bit quicker than intended.

“The survey is to evaluate how the project performed 12 months after we first started pumping,” says Dr. Kaczkowski. “What we see [so far] from the recent survey is that the nor’easters definitively sped up the sand adjustment within the sand box, but that it is adapting as expected. The longshore sediment transport direction is from north to south in the Buxton area. With leaking groins at the south end of Buxton, it is inevitable that a significant amount of sand will leave the sand box and shift to the south.”