OCRACOKE — As contractors rebuilt N.C. 12 after Hurricane Dorian last fall, they also restored the narrow ridge of sand that stands between the highway and the Atlantic Ocean.
But even before the road could reopen, another coastal storm washed away some of the dune. Now the N.C. Department of Transportation is rebuilding it — again.
Contractors will soon begin laying 2,500 sandbags along about three-quarters of a mile of N.C. 12 near the north end of the island. The bags are 5 feet wide, 2 feet tall and 15 feet long, each capable of holding 5 cubic yards of sand — or about half a dump truck’s worth.
The plan is to stack the bags three deep, then rebuild the dune on top of them, to a total height of 10 feet. The bags at the base of the dune are meant to prevent water from undermining the road and damaging the pavement, according to Tim Hass, a spokesman for the N.C. Department of Transportation.
“Although the entire system (dune and bags) are there to protect the road, the bags are the main line of defense,” Hass wrote in an email to The News & Observer. “It isn’t uncommon for the dune to wash away, as during Dorian, the November nor’easter, or pretty much any coastal storm with a Southeast wind.”
The new dune will replace one that was initially washed away by Dorian in September. The storm surge that flooded the island covered the road in several places and buckled about 1,000 feet of pavement.
Contractors rebuilt the dune and repaved the highway, which reopened Dec. 5, three months after the storm. The reopening had been delayed by the nor’easter in November, which breached the dunes again in several places, covering the pavement with sand and water.
Rebuilding N.C. 12 on Ocracoke cost the state about $1.8 million. The new sandbags and dune construction will cost another $1.6 million, Hass said.
There’s plenty of sand on hand to fill the bags and rebuild the dune. Contractors will pump a slurry of sand and water from the surf into the bags, which are just porous enough to let the water seep out, Hass said.
While the bags will be buried under the dune, the DOT insists that the fabric be sand-colored so they will blend in if and when they get uncovered by the next big storm.
The restoration work should take three months and won’t require closing the road. If bad weather causes delays and the work can’t be finished by mid-May, it will be suspended until after Labor Day so it doesn’t interfere with summer traffic, Hass said.
N.C. 12 extends about 12 miles from Ocracoke Village to the north end of the narrow barrier island, where residents and visitors catch ferries to and from Hatteras Island.