The impacts of coastal land loss threaten Louisiana’s economy, commerce, infrastructure, and culture. Furthermore, the collapse of coastal Louisiana would negatively impact the entire country – we provide protection for infrastructure that supplies 90% of the nation’s outer continental oil and gas, 20% of the nation’s annual waterborne commerce, 26% (by weight) of the continental U.S. commercial fisheries landings, and winter habitat for five million migratory waterfowl.
The Barataria and Breton Basins are two areas that have experienced significant land loss due to sediment deprivation, hydrologic alteration, subsidence, sea level rise, and salt water intrusion. Since the Mississippi River was leveed in the 1930s, the Barataria and Breton Basins and Mississippi River Delta have lost approximately 700 square miles (or 447,000 acres) of land, representing one of the highest land loss rates in the world.
The 2012 Coastal Master Plan called for eight sediment diversions along the Mississippi River. Over the past several years, CPRA has conducted in-depth analyses on the Lower Breton (50,000 cfs), Lower Barataria (50,000 cfs), Mid-Breton (35,000 cfs), and Mid-Barataria (50,000 cfs) diversion projects in order to determine which projects should be prioritized for engineering and design and construction. Each project was modeled to predict project effects on variables, such as land building, salinity, sediment transport, nutrients, and water levels. As part of this analysis, the state also considered innovative marsh creation projects that could be implemented in conjunction with sediment diversion projects in order to enhance sediment capture and build more land. This modeling effort helped inform CPRA’s decision in fall 2015 to recommend that the Mid-Breton and Mid-Barataria diversions move forward to preliminary engineering and design. Over the next several years, CPRA will work to optimize operations, formulate the final project design, and apply for appropriate construction permits in order to construct these foundational projects for the coastal master plan. At the same time, planning efforts will continue to evaluate additional diversions.