MYRTLE GROVE — What the Mississippi River used to do naturally in flooding its banks and depositing sediment in the marsh areas of south Louisiana is now being done in a more concentrated way.
Just south of Myrtle Grove in Plaquemines Parish, sediment is being dredged from the Mississippi River and transported by pipe across the river levee, La. 23 and into a five-mile pipe ending in an area just south of Lake Hermitage.
This $38 million project, funded through the federal-state Coastal Wetland Planning, Protection and Restoration Act, will help build about 550 acres of new marsh land that separates the lake from the more open water to the south.
“This area has seen significant (land) loss and we still see significant loss,” said Brad Inman, program manager for CWPPRA at the U.S. Army Corps of Engineers New Orleans district.
Luckily, the area is close to a large supply of sediment via the Mississippi River, he said.
In addition to the work being done by Pine Bluff Sand and Gravel Company, more marsh building has been added to the project thanks to restoration funding as a result of the Deepwater Horizon/BP disaster in 2010.
That restoration funding is part of a $1 billion down payment BP committed to in 2011 to help start restoration work before the completion of the Natural Resource Damage Assessment, a process that could take years to complete. The Natural Resource Damage Assessment is the official process to determine what damage an oil spill has caused and what it will cost to repair that resource.
The first round of funding from this early restoration fund was announced in December 2011 by combining two projects: $28 million to restore 850 acres of oyster beds in Louisiana and $14.4 million to add 104 acres of marsh to the Lake Hermitage project.
Combining the projects could save money on the cost of transporting equipment to and from the area, said Barry Richard, construction, operations and maintenance manager with the state Coastal Protection and Restoration Authority.
“Because of that cost savings, CWPPRA can add another 300 acres because the state helped with the mobilization and demobilization (of equipment cost),” Inman said.
In total, the project will end up building 653 acres of new marsh.
In addition, state and federal partners are hoping that another project or two can be finalized in time to keep the dredge and the pipeline working to build even more marsh area to a total of 1,200 to 1,300 acres, Inman said.
Work on the CWPPRA portion of the project started in March 2012 in building containment berms that help keep the dredged material in place while it settles. Actual dredging for the land creation started just over a week before Hurricane Isaac hit the state in 2012, creating a number of delays.
“They’ve had a few setbacks. Hurricane Isaac forced them to stop,” while they spent time doing repairs Inman explained.
Steady dredging resumed in November, and work is continuing on filling in the first section of 367 acres of marsh land. The U.S. Fish and Wildlife Service is the federal sponsor for the project and the state is the local sponsor, which means paying 15 percent of the cost.
The crew at the site is pumping about 18,000 yards of sediment a day to a primarily open water area that could be anywhere between three and five feet deep.
In the 24-hour work day, the crew from Pine Bluff Sand and Gravel pumps for about 17 hours, with the other hours of the day used for things like moving the pipelines from one place to another, said Ryan Ruiz, who is with a BCG/Dewberry joint venture in a contract with the state to do on-site observations.
Dredging on this portion of the project is expected to be completed in the spring, he said. If other projects in the area get their permits and funding ready, that dredging operation could move a little to the east and keep going, he said.
The area in the river where the dredge is taking the material has from 8 million to 9 million cubic yards of sediment available for the work, Richard said.
“The borrow area is replenishing itself as we are building,” Richard said. They expect to use about 6 million cubic yards for the project. A larger area will use about 4 million cubic yards, a smaller area will use about 2 million cubic yards and the section being added on by the NRDA funding of about 100 acres will use about one million cubic yards.
“Out of the New Orleans office we’re lucky because we have the Mississippi River as a resource,” Richard said.
Although many of the barrier island restoration projects have used sediments dredged from off shore, the river sediments seem to hold up better for marsh creation.
“The sand doesn’t suspend as easily,” he said.
Editor’s note: This story was modified on July 31, 2013, to correct the spelling of Brad Inman’s last name. The Advocate regrets the error.
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