Gulf Shoreline Stabilization Project on Display

With construction in progress for the Gulf Shoreline Stabilization Project at Rockefeller Wildlife Refuge, the Louisiana Department of Wildlife and Fisheries (LDWF) and other partners celebrated last week the work done to minimize coastal erosion in the refuge, located in Cameron and Vermilion parishes.

Image source: LDWF

The scheme, funded by the Coastal Wetlands Planning Protection Restoration Act (CWPPRA), features a series of breakwaters along the coast of Rockefeller Wildlife Refuge.

One of the sections of the project, dubbed ME-18 and located beginning at Joseph Harbor Outlet moving westward, began in July earlier this year at a cost of $34.3 million.

CWPPRA is federal legislation enacted in 1990 that is designed to identify, prepare and fund construction of coastal wetlands restoration projects. Since its inception, 210 coastal restoration or protection projects have been authorized, benefiting approximately 100,000 acres in Louisiana.

Gathering at last week’s event included participants from CWPPRA’s five federal managing agencies (U.S. Army Corps of Engineers, Environmental Protection Agency, U.S. Fish and Wildlife Service, USDA Natural Resources Conservation Service and NOAA National Marine Fisheries Service), the Louisiana Coastal Protection and Restoration Authority (CPRA), LDWF, state and local representatives and members of the public.

Rockefeller Wildlife Refuge is considered an erosional hotspot on Louisiana’s coastline with erosion rates averaging more than 50 feet a year. The refuge manages large marsh impoundments primarily for migrating waterfowl and other neotropical migrants.

Before the project was funded, experimental breakwaters were constructed utilizing different types of material. These experimental breakwaters were employed along Rockefeller’s coastline in 2011. These trials were conducted because most sites along Rockefeller’s shoreline cannot support the heavy weight of boulder style breakwaters utilized in other areas.

After testing various models, a specific style of breakwater was selected. Large pillow mats are filled with small, porous rocks called light-weight aggregate rock. These large pillows full of rock are laid as a foundation for the breakwater.

The breakwater is then capped with larger rock to absorb wave energy from the Gulf. The pillow mats beneath the breakwater provided a strong enough foundation to stabilize the breakwater without increasing the breakwater’s weight to a point of subsidence.

The project, originally planned for nine miles along Rockefeller’s western coastline, would have cost an estimated $90 million. Current funding from CWPPRA will secure construction for approximately 4-5 miles of Rockefeller’s coastline. Additional funding is being proposed.