Water flows downhill naturally and, over time, will make a river change from one path to another. As sediment moved and elevations changed over the last 7 millennia, the Mississippi River has emptied into several historic delta complexes: Maringouin, Teche, St. Bernard, Lafourche, Plaquemines-Balize, and Atchafalaya. Each of the deltas built up part of Louisiana’s coast to what we see today, but now that natural process has been interrupted . After the great Mississippi flood of 1927 that caused $1 billion worth of damages (almost $1 trillion in today’s dollars), the US Army Corps of Engineers built the world’s longest levee system under the Flood Control Act of 1928. The Levee system was constructed to reduce flood damages and allow for more control of the Mississippi .
Image 1: Historic Deltas of the Mississippi River
An unforeseen and unfavorable side effect to taming the river was that all the water is kept moving too quickly to deposit sediment, and now sediment is lost to the Gulf of Mexico rather than deposited into our coastal wetlands . Our Louisiana coastline is dependent on new sediment to nourish wetland ecosystems. Without sediment delivery, there is no material for natural land gain or replenishment, which will continue to contribute to our retreating coastline. The solution is not as simple as removing the levee system, however, since so much of Louisiana is populated now, and removing the levees containing the Mississippi would displace millions of residents from their homes. Instead, CWPPRA and our partners in restoration use man-made systems to create marsh, nourish wetlands, and maintain hydrologic connectivity so that we can protect and restore Louisiana’s coast.
Image 1 from https://www.nationalgeographic.org/photo/miss-delta-formation/
Featured image from https://phys.org/news/2015-04-future-mississippi-delta.html
On November 18th, residents and visitors in St. Bernard Parish were treated to live music, cooking demonstrations, and the chance to sample wild boar recipes prepared by teams vying for bragging rights. Hosted by the Coastal Division of St. Bernard Parish, the first Cook-Off for the Coast was held at Docville Farm in Violet, Louisiana with proceeds benefiting the St. Bernard Wetlands Foundation. In addition to evaluating the food of the six competing teams, visitors watched local celebrity chefs prepare everything from gumbo to snapping turtle and talked with a range of coastal organizations about the importance of protecting southeast Louisiana’s coastal wetlands.
Sinead Borchert and Mirka Zapletal from the Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA) Outreach Office were in attendance with information about restoration projects in St. Bernard Parish, activity books, posters from the #ProtectOurCoast series, and recent issues of WaterMarks magazine. They also invited children and adults alike to match Louisiana wildlife with the correct wetland habitat. St. Bernard’s coast is vulnerable to storms, subsidence, erosion, and invasive species, putting wildlife habitat and coastal communities at risk. CWPPRA projects work to support Louisiana’s coastal wetlands and the people and wildlife that depend on these habitats.
This area is undergoing shoreline erosion, interior wetland
loss, overwash, and breakup. The Gulf shoreline erosion rate
has doubled from 1988 to 2006. Project area marshes also
are being eroded at -11.8 ft/yr between 2003 to 2006 as well
as being converted to open water from internal breakup.
Restoration would expand the Gulf shoreline structural
integrity and associated protection by tying into two recently
constructed projects to the east and address one of the
remaining reaches of the Barataria/Plaquemines shoreline.
The design includes fill for a beach and dune plus 20-years
of advanced maintenance fill, as well as fill for marsh
creation/nourishment. The location of the type and amount
of sediment needed to construct this project already has been
identified under the East Grand Terre Project that is presently
under construction. Approximately 127 acres of beach/dune
fill would be constructed and approximately 259 acres of
marsh creation/nourishment would be constructed. Intensive
dune plantings would be conducted by seeding and installing
approved nursery stock. About half of the
marsh platform would be planted with cordgrass and
portions of the dune, swale, and marsh would be planted
with appropriate woody species. Containment dikes would
be breached no later than year three to allow tidal exchange
with the created marsh.
The project is located in Region 2, within the Barataria Basin
portion of Plaquemines Parish.
This project is on Project Priority List (PPL) 19.
The Cheniere Ronquille Barrier Island Restoration project sponsors include:
Keep up with this project and other CWPPRA projects on the project page.
More than a seafood delicacy, oysters are an incredible natural resource. They are extremely helpful to our environment by filtering water, providing habitat, and controlling erosion. Adult oysters may filter up to two and a half gallons of water per hour, which in turn improves water quality. Oysters build reefs that provide habitat for fish, shrimp, crabs, and other aquatic animals. Oyster larvae need the hard, shell surface for settlement and growth. A special focus that has been put on oysters recently is their ability to control land erosion.
Oyster reefs have been constructed along eroding shorelines in an effort to lessen wave energy and ultimately reduce erosion. Seven of our nation’s fifteen largest shipping ports are located along the Gulf of Mexico. The wakes created by the cargo ships heighten erosion along an already disappearing coastline.
Globally, it is estimated that 85% of oyster reefs have been lost. Large-scale restoration projects can create man-made oyster reefs that duplicate many of the benefits of natural reefs. Oysters and the massive reefs provide a foundation for a healthy ecosystem. The Coalition to Restore Coastal Louisiana (CRCL) founded the Oyster Shell Recycling Program in 2014. This program collects shells from New Orleans area restaurants and utilizes the shells to restore fading oyster reefs that protect Louisiana’s coastline. A majority of shell removed from the coast is not returned back to the waters. It is vital to Louisiana’s disappearing coastline that oyster shells are brought back to help as a line of defense for coastal restoration.
Did you know:
CWPPRA has protected, created, or restored approximately 96,806 acres of wetlands in Louisiana.
The Coastal Wetlands Planning, Protection, and Restoration Act has funded coastal restoration projects for 26 years. Presently, CWPPRA has 153 total active projects, 108 completed projects, 17 active construction projects, 23 projects currently in Engineering and Design and has enhanced more than 355,647 acres of wetlands . These projects provide for the long-term conservation of wetlands and dependent fish and wildlife populations. Projects funded by CWPPRA are cost-effective ways of restoring, protecting, and enhancing coastal wetlands. CWPPRA has a proven track record of superior coastal restoration science and monitoring technique in Louisiana. The success of the CWPPRA program has been essential in providing critical ecosystem stabilization along Louisiana’s coast and has provided pioneering solutions for land loss.
Visit CWPPRA’s website for more information!
Found at the interfaces of land formations and water, smooth cordgrass (Spartina alterniflora) is an herbaceous, native grass that densely inhabits shorelines. Compact, vegetative smooth cordgrass colonies grow along shorelines and inter-tidal flats of coastal wetlands such as canal banks, levees, marshes, barrier islands, and other regions of soil-water interface. This grass is highly adaptable to a variation of water depths and salinity levels making it a resilient species heavily used for coastal restoration. With an extensive rhizome system, smooth cordgrass is also highly effective as a soil stabilizer for loose soils, contributing to anchorage of the plants and sediment, as well as decrease of erosion effects. Smooth cordgrass acts as a natural buffer which dissipates energy of storm surge and wind impact to interior lands.
The Coastal Wetlands Planning, Protection, and Restoration Act frequently uses smooth cordgrass plugs during vegetative plantings due to the plant’s insensitivity to water and salinity levels, and its success in significant erosion protection to shorelines.
Did you know:
Coastal wetland plants are indicators of soil and hydrologic conditions.
Wetlands and vegetation go hand-in-hand when it comes to the success of a healthy coastal ecosystem. The diminished well-being of a wetland plant community often beacons unfavorable conditions of soil or water quality.
Wetland vegetation reduces erosion primarily by damping and absorbing wave and current energy and by binding and stabilizing the soil with roots. Also, plants are the base of the food chain and can build new layers of material on top of wetlands that support sustainability. The Coastal Wetlands Planning, Protection, and Restoration Act uses the vegetative planting technique involving flood- and salt-tolerant native marsh plants to establish erosion reduction, soil stabilization, and accelerated wildlife habitat development.