Increasing Biological Productivity and Stabilizing the Shoreline Along the Mississippi Sound
Tetra Tech designed a living breakwater system that supports biological productivity and offsets the effects of climate change by stabilizing the marsh shoreline along the Mississippi Sound at Point aux Pins in Mobile County, Alabama.
Following the Deepwater Horizon oil spill in 2010, British Petroleum (BP) and representatives from the U.S. government and the Gulf states agreed to an Early Restoration Program (ERP). Under contract with the Alabama Department of Conservation and Natural Resources, Tetra Tech performed field investigations, design, permitting, and construction observations for the ERP-funded Point aux Pins Living Shorelines Project. Tetra Tech drew on our decades of coastal restoration expertise and two of our foundational Tetra Tech Delta technologies—Tetra.Maps and Tetra.Simulate—to attenuate offshore waves and increase biological productivity along the Mississippi Sound at Point aux Pins. Our team completed marine resource mapping and geophysical and geotechnical surveys; developed design wave and water level conditions; and designed, permitted, and provided construction oversight of a segmented offshore artificial breakwater system.
Tetra Tech completed field investigations, including bathymetric and topographic surveys, sediment sampling and geotechnical laboratory testing, and marine resource and cultural resource surveys to provide site data to support the design. Our team also performed numerical circulation and wave modeling to assess current conditions and predict wind, wave, and water levels at the project site. During the design phase, Tetra Tech completed detailed wave modeling around multiple breakwater configurations to optimize the configuration of the segmented breakwater system. The selected breakwater system consists of 200-foot-long breakwater segments separated by 80-foot gaps and a total length of 4,130 feet about 300 feet offshore of the Point aux Pins marsh shoreline. Tetra Tech performed inspections and oversight during construction in 2020 and assisted the Alabama Department of Conservation and Natural Resources through completion in November 2020.