Bayou Lafourche dredging to increase water flow progresses

By:  Meredith Burns,

October 13, 2015


In Bayou Lafourche just north of Plattenville, two dredges are working around the clock to help clear sediment from the waterway that provides drinking water to more than 300,000 people in Lafourche, Terrebonne, Assumption and Ascension parishes.

The dredge work is part of a massive project called Mississippi River Reintroduction to Bayou Lafourche that is designed to increase freshwater flow into the bayou to sustain residents’ water supply and surrounding coastal marshes.

Ben Malbrough, Bayou Lafourche Freshwater District executive director, said it’s exciting to see progress made on various components of the project, including dredging, a new railroad bridge and a saltwater control structure, all of which are expected to work together to help revitalize the bayou.

“This is their drinking water source and there really isn’t an alternate,” he said.

The second dredging phase, now about 30 percent complete, involves clearing the banks and removing sediment from 8.3 miles of the bayou between Belle Rose and Napoleonville.

It builds off of the nearly 6 miles of dredging from Donaldsonville to Belle Rose completed in 2011 during the first phase.

The roughly $20 million second dredging phase, which the state Coastal Protection and Restoration Authority is paying for with federal Coastal Impact Assistance Program money, is expected to finish up next June, Malbrough said.

As the two dredges make their way down the bayou moving a combined 3,800-6,500 cubic yards of material a day, project leaders are making progress replacing the Union Pacific Railroad Bridge in Donaldsonville.

A new five-span open bridge that allows water to flow freely underneath will replace the current restrictive bridge that has been a thorn in the side of the project for years.

“Until something’s done with this bridge, we can’t go beyond where we’re at now,” Malbrough said.

While the railroad company is overseeing the engineering and construction, the freshwater district and the state are going to split the cost of the $3.5 million to $5 million project, Malbrough said.

Designs for the new bridge are expected to be completed in January or February, and construction will take place by the end of 2016 whenCoastal Impact Assistance Program dollars expire.

“The railroad’s telling me they don’t see any issue with meeting that construction timeline and getting that bridge in place,” Malbrough said.

Further down the bayou in Lockport, contractors are expected to receive a notice to proceed with construction on a new saltwater control structure in the next three weeks, Malbrough said.

The project, which involves dismantling the Company Canal Saltwater Control Structure and using the steel barge in the new Bayou Lafourche structure, should be able to create a reservoir for all the water plants along Bayou Lafourche as needed and allow an inconveniently placed weir in Thibodaux to be removed.

Meanwhile, the freshwater district is working to obtains permits for further dredging into Thibodaux that can be completed as money becomes available.

“Conceivably, if things fall into place for us I think we can have this entire project implemented within the next eight to 10 years,” Malbrough said. “Which, in conversations with people who have been involved with this project, that’s more aggressive than I think most would have anticipated.”

Bayou Lafourche was once a free-flowing tributary of the Mississippi, but was dammed at Donaldsonville in 1904 to control flooding.

A pump station was added in the 1940s to reintroduce freshwater and satisfy drinking water demand, but Bayou Lafourche’s health has suffered as sediment has filled in parts of the waterway and threatened water supply.

The bayou’s ill health became obvious during 2008’s Hurricane Gustav when fallen trees and storm debris clogged the bayou and turned the water stagnant, causing an unpleasant odor and making it unsafe to drink for weeks.

Simone Maloz, executive director of Thibodaux-based Restore or Retreat, said the district is playing “major league ball” with the project and the aggressive implementation of a plan that affects so many people.

“The commission itself and the state have really stepped up to make the Bayou Lafourche Freshwater District be what it was always intended to be, which is the entity that takes care of something that runs through the heart of these parishes and provides a resource to them,” she said.

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