Coastal Protection and
Restoration Authority

Location

The project area is located in the Barataria Basin in an area referred to as the “West Pointe a la Hache Mapping Unit,” which is south and east of Lake Hermitage in Plaquemines Parish, Louisiana.

Issue Addressed

The Lake Hermitage Marsh Creation project includes two project components, a base project developed through the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) program and a Natural Resource Damage Assessment (NRDA) increment.

The base CWPPRA project intends to address issues of significant marsh loss on the south and east of Lake Hermitage and along the eastern lake shoreline. Additional deterioration of the lake rim will expose interior marshes to the wave energy of Lake Hermitage and increase tidal exchange. The West Pointe a la Hache Mapping Unit referenced above has lost 38 percent of its marsh from 1932 to 1990. By the year 2050, 28 percent of the 1990 marsh acreage is expected to be lost.

The Lake Hermitage Marsh Creation – NRDA Early Restoration Project intends to create new brackish marsh. The ecological services gained by this project are anticipated to help compensate for brackish marsh injuries or losses due to the Deepwater Horizon oil spill. The created marsh would be constructed in the Barataria Hydrologic Basin, which was heavily impacted by the oil spill.

Project Goals

The primary goals of the Lake Hermitage Marsh Creation base CWPPRA Project are (1) to restore the eastern Lake Hermitage shoreline to reduce erosion and prevent breaching into the interior marsh and (2) to re-create marsh in the open water areas south and southeast of Lake Hermitage. Specific objectives of the CWPPRA project are to: (1) create 549 acres of marsh by filling open-water areas and fragmented marsh with dredged material; (2) restore approximately 6,106 linear feet of the eastern Lake Hermitage shoreline; and (3) create 5 acres of emergent habitat by constructing 7,300 linear feet of earthen terraces. The terrace field proposed in the CWPPRA project consists of approximately 104 acres.

Throughout the engineering and design phases of the CWPPRA project, the project team considered incorporating an additional 104 acres of marsh creation in the footprint of the terrace field. However, due to funding constraints, the project team completed final design of the CWPPRA project with the 7,300 linear feet of earthen terraces

The Lake Hermitage Marsh Creation - NRDA Early Restoration Project will create approximately 104 acres of brackish marsh in lieu of the 7,300 linear feet of earthen terraces that was included in the final design of the base CWPPRA project. This additional marsh area will be constructed entirely within the base CWPPRA project's terrace boundary. Sediment will be hydraulically dredged from a borrow area in the Mississippi River, and pumped via pipeline to create new marsh in the project area. Over time, natural dewatering and compaction of dredged sediments should result in elevations within the intertidal range which would be conducive to the establishment of emergent marsh. The 104-acre fill area will be planted with native marsh vegetation to accelerate benefits to be realized from this project.

Project Status

Construction began in March of 2012 with dredging activities beginning the following August. Hurricane Isaac caused some damage to the project in late August of 2012 leading to construction delays. Fill cell A (blue area above right) should be completed during Fall 2013, and the contractor will begin fill work into the NRDA fill cell.