Agency Cooperation Creates Restoration Results
Synergy Among CWPPRA Projects Shores Up the Coast
A dozen miles of wetland separate the freshwater marshes of the northern Barataria Basin from the salty Barataria Bay.
Called the Barataria Basin Landbridge, that slender band of wetland “is just melting away,” say coastal scientists.
“The landbridge is subsiding and eroding at an alarming rate — as much as 100 feet per year,” says Quin Kinler of the Natural Resources Conservation Service (NRCS). That land loss threatens not only fish and wildlife habitat but also oil and gas infrastructure and numerous communities — Barataria, Lafitte, even the west bank of New Orleans.
“Without the landbridge, the entire basin would be subjected to greater intrusion from the Gulf of Mexico, including hurricane storm surge,” says Cheryl Brodnax of the National Oceanic and Atmospheric Administration (NOAA).
To restore the fragile marsh, agencies partnering under the Coastal Wetlands Planning, Protection and Restoration Act of 1990 (CWPPRA), commonly called the Breaux Act, developed a series of complementary projects, each rebuilding or protecting a different piece of the landbridge. “When completed, these 12 projects will rebuild or protect from loss more than 5,000 acres of wetland,” Kinler explains.
Along the east bank of Bayou Perot in Jefferson Parish, erosion claims up to 100 feet of marsh per year. To stop this rapid land loss, Phases 1 and 2 of the Barataria Landbridge Shoreline Protection projects (BA-27) built rock dikes along the bayou's east bank.Courtesy of Dale Garber, USDA-NRCS
The projects installed rocks weighing an average of 250 pounds along the bayou's shoreline. Where the soil is too soft to support rock dikes, concrete panel structures are being installed to buffer wave energy.
Courtesy of Dale Garber, USDA-NRCS Rebuilding the Landbridge
Two types of projects are needed to save the landbridge, Brodnax says, “those that replace what has been lost, and those that protect what is left.”
Joint efforts of the NRCS and the Louisiana Department of Natural Resources (DNR), the Barataria Basin Landbridge Shoreline Protection projects (BA-27, BA-27c and BA-27d) shore up fragile bayou banks by installing rock dikes and concrete panel structures that reduce wave energy and slow erosion. When finished, the projects will protect more than 20 miles of shoreline.
Meanwhile, Kinler says, “other NRCS projects on the landbridge have installed water control structures to restore a more natural flow of water through the basin and reduce saltwater intrusion.”
A future project of the DNR and the U.S. Fish and Wildlife Service (USFWS), Dedicated Dredging on the Barataria Basin Landbridge (BA-36), will use the structures installed under BA-27 to contain marsh-building sediment. “This project will deposit dredged sediment to create over 1,200 acres of wetland,” says USFWS biologist Kevin Roy.
To replace 500 acres of lost landbridge marsh, a NOAA project, Little Lake Shoreline Protection/ Dedicated Dredging Near Round Lake (BA-37), pumped sediment into open-water areas. “We then nourished 450 acres of subsiding marsh nearby with a thin layer of sediment,” Brodnax says. The project re-established the south rim of Little Lake, which was damaged by the 2005 hurricanes.
“The project was designed to maintain one of the few continuous land masses in the basin by keeping Little Lake and Barataria Bay separate,” Brodnax says. “Protecting the marshes that separate the lake from the bay is critical for buffering the projects elsewhere on the landbridge. All of these projects work together to fortify this fragile part of the Barataria ecosystem.”
Along the southern rim of Little Lake, CWPPRA restored nearly a thousand acres of wetland, its largest completed marsh creation and nourishment project to date. Rock protection installed along five miles of Little Lake shoreline slows the rate of erosion, explains Cheryl Brodnax of the National Oceanic and Atmospheric Administration. "Gaps in the rock dikes allow fish and other marine organisms to access the marshes, which provide vital habitat." Courtesy of Louisiana Department of Natural Resources
The project used dredged sediment to rebuild marsh that had converted to open water. "Over the next few months, water will drain from the newly placed sediment, revealing solid ground. We will then plant these areas with smooth cordgrass to hold the sediment in place," Brodnax says.Courtesy of NOAA
The Power of Partnership
“The Barataria Basin Landbridge is an example of a big problem that CWPPRA is working to solve by breaking it down into smaller steps,” Kinler says. “One of CWPPRA’s strengths is identifying places in the coastal landscape where a series of small steps can be very effective.”
The work on the landbridge is made possible by the relationships the Breaux Act fosters among federal, state and local government agencies and with the public. “Coastal restoration programs are implemented with consensus from stakeholders. For 16 years, CWPPRA has been building relationships across agencies, while at the same time educating the public about the wetlands’ importance. That creates cooperation among all these groups,” Kinler explains.
“Restoring the landbridge is beyond the scope of any single project or agency,” he continues. “The combined efforts of CWPPRA partners are a means to protect this important section of the coast.”
The narrow band of wetland that separates the northern Barataria Basin from the Gulf of Mexico is dissolving, as erosion and subsidence allow salt water to flow deep into the basin’s marshes. “As salt water moves into areas of the basin that were historically fresh water, it kills marsh vegetation, converting wetlands to open water,” says Quin Kinler of the Natural Resources Conservation Service.
To preserve the fragile landbridge, a dozen CWPPRA projects protect eroding shorelines, create marsh and restore the wetlands’ natural hydrology.
Courtesy of USDA - Natural Resources Conservation Service, Lafayette, LA