Located west of Lake Pontchartrain, the Maurepas Swamp was once naturally connected to the Mississippi River and received a steady freshwater input that maintained a nutrient-rich, healthy ecosystem. Logging, digging of nearby canals, and introducing manmade levees, which cut off the swamp from the river’s rejuvenating floodwaters and allowed salt water to seep in, contributed to the swamp's degradation over the last century.

The first construction increments of the River Reintroduction into Maurepas Swamp include clearing, excavating, and building guide levees through approximately three miles of Hope Canal between U.S. 61 and Interstate 10. CPRA awarded the construction contract for this phase in July 2024. River Reintroduction into the 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.

With the goal of reversing detrimental impacts, the central component of the River Reintroduction into Maurepas Swamp project will be the construction of gates along the Mississippi River levee that will open throughout the year to allow fresh, oxygenated water, nutrients, and fine-grain sediment to move through five miles of canal into the swamp and wetlands. Located on the East Bank of the Mississippi River, 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 serves as a quality habitat for 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.

The total cost of construction for the MSP project is over $300 million and will utilize $190 million in funds from fines associated with the Deepwater Horizon oil spill as well as other state-only funds.

The River Reintroduction into Maurepas Swamp project is expected to be completed in 2028.