Preserving and Restoring the Louisiana Coastline

The Rockefeller Wildlife Refuge experiences an average rate of 15 metres of erosion per year, and the State of Louisiana has been aggressively combating the 55 to 91 square kilometres of coastal habitat loss that occurs annually in Louisiana. Since 2002, we have been working with the Louisiana Coastal Protection and Restoration Authority, Louisiana Department of Wildlife and Fisheries, and National Oceanic and Atmospheric Administration National Marine Fisheries Service on the Rockefeller Refuge Gulf Shoreline Stabilisation Project (ME-18) to help preserve and restore the area’s coastline.  

Project challenges included extremely soft soils exposed to an open Gulf high-wave energy environment. Therefore, before the project could move forward, experimental breakwater alternatives had to be tested. Our initial alternatives analysis included over 50 shoreline protection options that were reduced to three demonstration projects built in 2009.

Monitoring data and lessons learned during the demonstration project construction were used to design a 5-kilometres portion of the overall project. The final design features a series of breakwaters with a core of encapsulated lightweight aggregate to reduce the overall weight of the breakwaters while providing shoreline protection from waves and erosion. Construction of the project was funded through the Coastal Wetlands Planning, Protection, and Restoration Act, a program that provides federal funding for coastal restoration projects in Louisiana. Due to the low price of the construction bid, an additional mile of the breakwater was added to the project for a total of 6.5-kilometres of shoreline stabilisation. Construction of the project was completed in early 2020.