Louisiana Begins Wetland Repair with Mississippi River Sediment

The $28.3 million project, known as The Mississippi River Sediment Delivery System at Bayou Dupont, will build and restore nearly 500 acres of marsh in Lower Jefferson and Plaquemines parishes using sediment from the Mississippi River.

Governor Jindal said, "The Bayou Dupont Project breaks new ground for coastal restoration in our state because it is the first time we have carried out a project to transport sediments from the Mississippi River through a pipeline to build wetlands outside the river's levees."

"This project is a great example of the ways the state and Environmental Protection Agency are pushing to use available sediments in the Mississippi River to build land rather than dredging them and dumping them in a wasteful way," Jindal said. "The path forward in rebuilding our coast is capturing and using sediment transported in our waterways to rebuild and strengthen our coasts."

The wetlands being restored have been destroyed by hurricanes and saltwater intrusion.

Louisiana has about 40 percent of the nation's wetlands and experiences 90 percent of the coastal wetlands loss in the entire lower 48 states.

Wetlands in Louisiana's Barataria Jean Lafitte nature preserve (Photo by Ray Devlin)

The state is losing 25 to 35 square miles of wetlands each year, nearly a football field every 30 minutes. The highest rates of loss are occurring in the Barataria and Terrebonne basins at a rate of 10 and 11 square miles per year. The Barataria basin is located immediately south of New Orleans, with the Terrebonne basin located further south and west.

As these coastal wetlands turn to open water, their ability to impede approaching storms is reduced and the risk of catastrophic loss of life and property from hurricanes is greatly increased, warns Restore or Retreat, a non-profit coastal advocacy group. The Barataria and Terrebonne basins are the two most rapidly eroding estuaries on Earth, and this erosion represents an economic and ecological crisis," the group says.

Under the project announced by the governor today, dredged material will be taken from the Mississippi River to two sites in the Upper Barataria Basin in Plaquemines and Jefferson parishes on what is called the Barataria Landbridge.

Coastal Protection and Restoration Chairman Garret Graves said, "While the levees on the Mississippi River accomplished their goal of preventing flooding and stabilizing the navigation channel that so many states rely upon, they also cut off the river sediment from nourishing and restoring our wetlands. This project takes the land-building process we learned from Mother Nature and does it much more efficiently."

The project will be built using federal and state funds from the Coastal Wetlands Planning Protection and Restoration Act program with project oversight from the Louisiana Coastal Protection and Restoration Authority and the U.S. Environmental Protection Agency.

The state is paying 15 percent of the cost, a total of $4.24 million, out of the state's coastal trust fund.

Governor Jindal said the contract for this project was awarded in February and work on building the infrastructure and laying the pipeline has begun. Marsh reconstruction is scheduled to start this summer.

In total, the pipeline will transport 2.3 million cubic yards of sediment from the Mississippi River to complete the project. After all the material is transported, native vegetation will be planted on the new marsh.

The area of the river where the sediments will be dredged was chosen because it will fill up with sediments again. Part of the pipeline infrastructure will remain in place after the project is complete so it can be used to build future projects.

Tp to 200 million tons of sediment washes down the Mississippi River every year, but only a fraction of the sediment has ever been used to rebuild land.

"This has to stop," Governor Jindal said. "Our soil and sediment is not waste. This is the same material that actually created the river delta that is Louisiana today. If it is taken from our waterways, it needs to be used to build land in our state to restore healthy marshes and protect our coastal communities."

In fact, said the governor, if all the available sediment dredged from our waterways was used beneficially, more than 18 square miles of land a year could be built in Louisiana, which would cut the state's rate of land loss by two-thirds.

Jindal said the Coastal Protection and Restoration Authority and the Department of Natural Resources currently are working on improving regulations and practices for using dredged materials from all coastal projects where sediments are dredged and removed.

The governor noted that every year the U.S. Army Corps of Engineers removes about 60 million cubic yards of sediment from Louisiana navigation channels. Now the state also is working with the Corps to utilize the maximum amount of these sediments to build land to restore and protect Louisiana coastal communities and wetlands.

Copyright Environment News Service (ENS) 2009. All rights reserved.