Coastal Engineering Project

Atlantic Harbor, North Carolina, Living Shoreline

Atlantic Harbor Living Shoreline

Scenic installed the wave attenuator, a living shoreline wave attenuation system, to help mitigate coastal erosion as part of the Carteret County’s and the North Carolina Coastal Federation’s Atlantic Harbor maintenance dredging and living shoreline project.

The Atlantic Harbor project is funded primarily by a $1.1 million grant the North Carolina Coastal Federation obtained in 2018 from the National Fish and Wildlife Foundation and Carteret County, North Carolina to build living shorelines. The Coastal Federation has promoted and built living shorelines for years as a cost-efficient and environmentally friendly alternative to bulkheads, jetties, and other hard structures to prevent shoreline erosion and channel shoaling.

The wave attenuator system is installed on the seaward side of openings in a granite rock sill (living shoreline) that was constructed around White Point, in Core Sound, just offshore from Atlantic Harbor. The openings in the structures allow fish to pass through the rock sill, which, along with planted vegetation, provides a habitat for non-sessile life, such as fish, and a surface for oysters and other sessile life to attach.

The wave attenuator is comprised of six individual concrete disks stacked on a 12” diameter composite fiberglass pile. A total of six units were installed. The concept is a water flow-through wave attenuation technology that dissipates wave energy in three ways: (1) wave energy reflects back into open water from the front face of the structure; (2) wave energy collisions occur along the sides of the octagonal structure; and, (3) water energy dissipates as it’s directed through the system.

The legs on the water-facing front side of the structure of the Ecodisks tray direct water to the fiberglass piling. The piling speeds up the wave energy, and when the water reaches the ‘landward’ side of the structure, the water exits the structure. The wave energy dissipates because the flow is no longer concentrated, and, if there is sediment in the water column, the sediment drops out and accretes on the shoreline.