South Lake Lery Shoreline & Marsh Restoration (BS-16)

Reasons for Restoration:

According to USGS-land loss analysis, much of the southern and western shorelines of Lake Lery and the surrounding wetlands were heavily damaged in 2005 by Hurricane Katrina. In the years following this storm, wind induced waves within the lake have begun to cause further damage to the lake’s shorelines. Currently the shorelines have become so damaged that the interior emergent marshes that are still intact are being exposed to the damaging waves. This has caused an increased loss of emergent marsh habitat. Even with the benefits of the Caernarvon Diversion Structure, without some type of restoration in this area, these marshes may not be able to fully recover.

Restoration Strategy:

This is a marsh creation and shoreline restoration project. The marsh creation aspect of the project will have a hydraulic dredge extract material from the Lake Lery water bottom and pump that material into contained marsh creation cells located south and west of the southern and western Lake Lery shorelines. This will create and/or nourish approximately 642 acres of intertidal intermediate marsh. The shoreline restoration component of the project will  have a barge-mounted dragline excavating material from the bottom of Lake Lery and placing that material along the southern and western shorelines. This restored shoreline will have a 50 foot crown width and be built to a height considered high intertidal marsh.

Progress to Date:

This project received Phase II funding in January 2012. Construction began in the spring of 2015 and is expected to be complete in the summer of 2018. All marsh creation is complete. Earthwork and vegetative plantings associated with the lake rim embankments are complete. There are ongoing discussions regarding erosion concerns along lake rim embankments.

This Project is on Project Priority List 17.

The Sponsors for this Project include:

Federal Sponsor: U.S. Fish and Wildlife Service

Local Sponsor: CPRA

 

Pass Chaland to Grand Bayou Pass Barrier Shoreline Restoration (BA-35)

Reasons for Restoration:

Prior to construction, wetlands, dune, and swale habitats within the project area had undergone substantial loss due to subsidence, absolute sea-level rise, and marine- and wind induced shoreline erosion. In addition, oil and gas activities, such as pipeline construction, also contributed to the loss.

Marine processes acting on the abandoned deltaic headlands rework and redistribute previously deposited sediment. Fragmentary islands develop due to breaches in the barrier headland. Subsequently, increased tidal prism storage (the total volume of salt water that moves in and out of a bay with the tide) and storm-related impacts have led to inlet and pass formation across the newly formed islands. The Bay Joe Wise beach rim was receded and decreased to a critical width that was susceptible to breaching.

Land area in the project area had decreased from 1932 to 2000. Storms occur approximately every 8.3 years along the Barataria shoreline. Because approximately 100 feet of shoreline is eroded with each storm, shorelines of 100 feet or less are considered in imminent danger of breaching.

Restoration Strategies:

The project’s objectives were: 1) preventing the breaching of the Bay Joe Wise shoreline by increasing barrier shoreline width; 2) increasing back-barrier, emergent marsh area by some 226 acres to maintain the barrier shoreline; and 3) creating emergent marsh suitable for tidal aquatic habitats.

The Project features included a constructed beach and dune platform along approximately 2.7 miles of the gulf shoreline. Constructed landward of the beach and dune was a marsh platform with an average width of 860 feet spanning the entire project length. A water exchange channel was incorporated on the western end of the Project to facilitate flushing of Bay Joe Wise through Pass Chaland. The Project created over 420 acres requiring 2.95 million cubic yards of fill dredged from ebb shoal borrow areas. Other project features included installation of sand fencing concurrent with dune construction, dune and marsh vegetative plantings, and post-construction gapping of retention dikes.

 Above image from lacoast.gov

Location:

The project is located in the Barataria Basin, between Pass Chaland and Grand Bayou Pass in Plaquemines Parish, Louisiana.

This project is on Priority Project List (PPL) 11.

• Federal Sponsor: National Marine Fisheries Services: http://sero.nmfs.noaa.gov/
• Local Sponsor: CPRA: Coastal Protection and Restoration Authority

 

Source: 

Louisiana Coastal Wetlands Conservation and Restoration Task Force “Pass Chaland to Grand Bayou Pass Barrier Shoreline Restoration (BA-35)”. 2 March 2018, https://www.lacoast.gov/reports/gpfs/BA-35.pdf.