Construction on a 13-mile pipeline that will deliver Mississippi River sediment into the Barataria Basin to create coastal land could start later this year.
The long-distance sediment pipeline project involves building a structure that goes over the Mississippi River levee and crosses under La. 23 and a railroad, which will stay in place. A contractor will then build a pipeline that will head south and southwest from the river to two project locations.
“We’re going to take sand out of the river and put it where it’s needed,” said Kenneth Bahlinger, state Coastal Protection and Restoration Authority project manager.
The pipeline will be put in place primarily over land for a distance of about 13 miles from where a dredge in the Mississippi River will take up sand from the river bed. Approximately, 8.2 million cubic yards of material will be mined from the river sediment and placed at the sites.
Although there are three borrow sites in the river that have been permitted, it’s estimated that the projects will only require the use of one of those borrow sites, Bahlinger said. It is estimated that it will take two years to complete the projects.
“It mimics what Mother Nature is doing in the first place,” Bahlinger said about how the Mississippi River used to build land along the coast before the levees were built and contained the river floods. “And it’s a renewable resource.”
Currently, the state is working on a final plan and project specifications with the hope the project will be put out for bid in February with a notice to proceed to construction released in May, Bahlinger said.
The pipeline will only cross one waterway, Bayou Dupont, and at this location the pipeline will be buried under the bayou so there won’t be any navigation effects, he said.
The two projects to be built with this pipeline will be the Bayou Dupont Ridge Creation and Marsh Restoration project and the Long Distance Sediment Pipeline project in Jefferson and Plaquemines parishes.
The projects were combined into one effort to help save money and to be more efficient because a large part of project costs come from the setting up and taking out of equipment.
It’s about nine miles from the river to the Bayou Dupont and ridge creation, and then the pipe will be extended another four miles to create marsh at the Long Distance Sediment Pipeline project.
Bayou Dupont will create 196 acres of marsh, nourish 93 acres of existing marsh — including 20 acres of maritime ridge.
At the Long Distance Sediment Pipeline project area, there will be 415 acres of marsh created, Bahlinger said.
Sediment from the river is being used instead of offshore or a more local source for several reasons, he said.
Taking sand out of the river means that it will be new material introduced to the system instead of just moving around sediment that already exists in the area.
Secondly, the material that can be dredged from the river is good quality material for building coastal land.
Money for the project will come from the Coastal Wetlands Planning, Protection and Restoration Act; Coastal Impact Assistance Program; parish money; and state surplus funds.
Bahlinger said the project is going to bid soon, but a cost estimate has yet to be established.
However, at an August state Coastal Protection and Restoration Authority meeting, authority Chairman Garret Graves said it was a $70 million project. The comment came during a discussion with the corps about the federal use of sediment to build a saltwater barrier in the river.
Representatives from the three parishes involved in sharing in the cost with the state agree that the project is one that they’ve wanted for a long time.
“I think it’s just a great project. I think it’s going to help so much,” said Marnie Winter, director of the Jefferson Parish Department of Environmental Affairs. “It’s something we’ve envisioned for a long time.”
One of the big benefits will be the effect of keeping saltwater in the south from continuing to affect fresh water marshes in the northern part of the basin, she said.
The use of sediment from the river is also a great benefit, she said.
“We really want to get sediment out of the river rather than the basin,” Winter said. “We don’t want to rob Peter to pay Paul.”
In Plaquemines Parish, officials said this type of project is exactly what the parish plans to do as part of it’s own comprehensive plan in terms of taking sediment from the river to build land.
“Plaquemines Parish is not against all these (freshwater) diversions but we’ll never create enough land in our lifetime or our children’s lifetime,” Parish President Billy Nungesser said. “The only way we’ll get ahead of the game is sediment pumping from the river.”
The third parish in the partnership, Lafourche Parish, at first balked at adding $1 million to the project because this phase would not actually reach the parish’s boundaries.
“The fight here in Lafourche is: ‘Why would we give money for a project that’s not in Lafourche,’” Parish President Charlotte Randolph said. The answer was, “It still protects us.”
The hope is that if future money is found that the state will extend the land building to connect with the parish, but in the meantime, the work will be beneficial, she said.
“We feel the same way about projects in Terrebonne (Parish),” Randolph said. “Anything that protects our flanks.”