Lake Hermitage Marsh Creation Program


Louisiana
 

This Louisiana Coastal Protection & Restoration Authority (CPRA) program was sponsored by U.S. Fish and Wildlife as part of the Coastal Wetlands Planning, Protection and Restoration Act. The goal was to create 1,000 acres of restored and new tidal marsh, located on the west bank of Plaquemines Parish between Lake Hermitage and the Jefferson Canal. The program re-creates marsh habitat in the open water areas along the southern rim of Lake Hermitage. This will maintain the lake-rim function along this section of shoreline, especially southeast of Lake Hermitage, where very little land is present between the lake and the oil field canals. Interior ponding, subsidence, and shoreline erosion of the lake rim are the major causes of wetland loss. Shoreline protection/restoration will reestablish the integrity of the eastern lake rim to prevent breaching into the interior marshes.

CPRA selected Ardurra to provide engineering and construction phase services, including engineering during construction and resident inspection. The program consisted of 4 fill areas features estimated to be 3,725,784 cubic yards of fill, spread across 549 acres of marsh land; 7,300 LF of earthen terrace structures; and 278,496 cubic yards of shoreline restoration; as well as the installation of 4 settlement plates, 34,268 LF of containment dike, and the installation of a 42- inch casing pipe. The project fill material, consisting of sand and silt, was hydraulically dredged from a borrow area in the Mississippi River and pumped via pipeline to create new marsh in the project area. The project’s 24-inch pipeline corridor included a floating/submerged river line. The pipeline corridor length ranged from 15,500’ to 39,500’ with the use of two booster pumps over the life of the project.