The River Reintroduction into Maurepas Swamp is a diversion project designed to restore and sustain the natural hydrology of one of the largest remaining forested wetlands along the Gulf Coast.

Located west of Lake Pontchartrain, Maurepas Swamp was once naturally connected to the Mississippi River and received a steady freshwater input that maintained a nutrient-rich, healthy ecosystem. However, logging, digging of nearby canals, and the introduction of manmade levees along the Mississippi River have had detrimental impacts on the marsh. The levees cut off the swamp from the river's rejuvenating floodwaters and allowed saltwater to penetrate the swamps interior. Each of these factors has contributed to the swamp's degradation over the last century.

As the first river diversion in Louisiana designed to restore swamp forest, this project will feature gates placed in the river levee that will open throughout the year to allow fresh, oxygenated water and fine-grain sediment from the Mississippi River. Water will move through five miles of canal into the swamp and wetlands. To be located on the East Bank of the Mississippi River near Angelina and Garyville, the diversion will benefit more than 45,000 acres of coastal marsh, forests, and wetlands in Ascension, Livingston, St. James, and St. John the Baptist parishes.

The 220-square-mile Maurepas Swamp is the second largest coastal forest remaining in Louisiana and is a quality habitat to native plants, trees, birds, and other wildlife. Recognized as a continentally Important Bird Area by the National Audubon Society, many species of ducks, herons, egrets, and songbirds, as well as bald eagles, can be found within its borders.

Additionally, restoring the health of the Maurepas Swamp fortifies its role as an important buffer for coastal communities, increasing resilience against storms for areas spanning from New Orleans to the River Parishes and into the Greater Baton Rouge region.

The U.S. Army Corps of Engineers (USACE) announced in January 2023 that the River Reintroduction into Maurepas Swamp Project would also serve as a mitigation feature for unavoidable wetland loss resulting from the West Shore Lake Pontchartrain (WSLP) Hurricane Protection System project. Notably, simultaneous construction of the WSLP and the River Reintroduction into Maurepas Swamp project is expected to provide cost savings and storm surge protection that is collectively greater than if built separately.