Prior studies and reports have documented degradation in the Caillou Lake (known locally as "Sister Lake") project area and have demonstrated the need for ecosystem restoration that simulates historical hydrological conditions.

The shoreline in the Caillou Lake Land Bridge project area is eroding as much as 18 feet per year at the marsh edge along the Gulf of Mexico. Without intervention, the marsh will continue to erode and degrade, allowing increased influence of Gulf of Mexico waters that would adversely affect the state-designated oyster seed ground in Caillou Lake. The goal of this project is to reduce the current trend of marsh degradation between the Gulf of Mexico and Caillou Lake.

The project area is located in Terrebonne Parish, Louisiana, approximately 38 miles southeast of Morgan City, Louisiana. A low, marshy area functions as a land bridge that separates Caillou Lake from the Gulf of Mexico. The project area covers this land bridge and the surrounding marshes. The study area covers approximately 60 square miles in south central Terrebonne Parish. The land bridge area is approximately 2,800 acres.