Sandbag replacement project on Ocracoke Island begins

A project has begun to replace sandbags along N.C. Highway 12 on northern Ocracoke Island after a series of winter storms caused routine ocean overwash during the month of February, resulting in sporadic road closures.

The project will replace approximately 800 sandbags that were recently damaged or displaced in order to restore the protective barrier between N.C. Highway 12 and the Atlantic Ocean.

The North Carolina Department of Transportation (NCDOT) awarded the $489,000 contract to Barnhill Contracting of Rocky Mount, and mobilization officially began on Monday.

According to Tim Hass, Communications Officer for NCDOT Division I, the contractor and subcontractor, Cape Dredging, will start placing sandbags on the highway on Thursday, March 7.

The contractor expects the work to take 3 to 4 weeks, depending on the weather, and single-lane closures will be in effect during the project as needed.

The material for the sandbags is collected via a pump system that connects with the local Ocracoke Island shoreline.

“The sand for the sandbags does not come from [a] spoil site,” said Hass. “When we fill sandbags on all of our bag projects, we typically utilize a pump designed to move both water and solids. The pump is suspended in the swash zone of the surf, and pulls a mixture of sand and water that is then pumped into the bags.”

“The bags are capable of allowing the water to filter out, leaving the sand behind inside the bags. Wave action restores the contours of the beach in the surf zone.”

At some point after the sandbags have been placed, additional sand will likely be placed on top of the bags to create a sand dune and a higher, more protective berm, though the timeframe for this secondary project is unknown.

“The sand that we normally utilize to build the dunes atop the bags on Ocracoke typically comes from the Ferry Dredge Spoil site. We sort through what has been placed there via maintenance dredging to find sand that is compatible in color and gradation, to be utilized for dune reconstruction,” said Hass, referring to the spoil pit that is located next to the Hatteras-Ocracoke ferry terminal on the north end of the island.

“However, at this time the dredge spoil site is devoid of sand. We have used everything that is suitable for dune building,” said Hass. “The Agencies have agreed to allow the Department to make repairs to the bags at this time, and delay rebuilding the dunes until such time as dredging replenishes our sand source.”

In February 2020, 2,500 sandbags were placed along 4,200 feet of roadway on the north end of the island in response to the lingering effects of 2019’s Hurricane Dorian.

In March 2022, an emergency dredging project took place via a distinctive bucket-and-barge operation, which was designed to collect material to replenish the northern Ocracoke Island spoil site.

An upcoming state pipeline dredging project is expected at South Dock on Ocracoke Island in the near future, which will result in an additional 37,000 cubic yards of sand that could be deposited on top of the sandbags, but there is not yet a concrete date on when this work will begin.