There is widespread historic and continued rapid land loss within the East Leeville Marsh Creation and Nourishment project site and surrounding areas resulting from subsidence, wind erosion, storms, and altered hydrology. The wetland loss rate is -1.53% / year based on USGS data from 1984 to 2015. Furthermore, the limits of Southwestern Louisiana Canal are difficult to determine in some areas because land loss is causing the coalescence of the canal with adjacent water bodies. Natural tidal flow and drainage patterns which once existed are currently circumvented by the increasing area of open water. Data suggests that from 1932 to 1990, the basin lost over 245,000 acres of marsh, and from 1978 to 1990, Barataria Basin experienced the highest rate of wetlands loss along the entire coast.
The project goal is to create approximately 358 acres and nourish 124 acres of saline marsh east of Leeville. After consideration of three potential alternatives, features and an alignment were selected to establish an arc of wetlands along the north side of Southwestern Canal, Lake Jesse, and the west side of South Lake. This is to begin rebuilding the structural framework of wetlands east of Leeville and provide protection for Leeville from southeasterly winds and tides. A robust engineering and design cost was included for full flexibility during Phase I to expand the project if cost allows or to assess alternative configurations, if necessary. The proposed features consist of hydraulically mining sediment from a borrow source in Little Lake west of Leeville and pumping dredged material to create and nourish marsh east of Leeville. The disposal area would be fully contained during construction to facilitate establishment of tidal connection and function. Additionally, a portion of the created marsh acres would be planted with smooth cordgrass following construction to help stabilize the created platform by increasing the rate of colonization.
This project is primarily located in Region 2, Barataria Basin in Lafourche Parish; however, the project site is also in Region 3, Terrebonne Basin of Lafourche Parish.
The East Leeville Marsh Creation and Nourishment project was approved for Phase I Engineering and Design in January 2016.
This project is on Priority Project List (PPL) 25.
The East Leeville Marsh Creation and Nourishment’s sponsors include:
- Federal Sponsor: National Marine Fisheries Service
- Local Sponsor: Coastal Protection and Restoration Authority