Officials behind a series of multi-million dollar projects to enhance the flow of Mississippi River water down Bayou Lafourche say they are closing in on the removal a 50-year-old low-water dam across the bayou, possibly sometime next year.
Known as the Thibodaux weir, the dam was built in 1969 to maintain water levels in the bayou for drinking water treatment plants and sugar cane mills upstream.
Recreational and other groups say the weir, which holds back some water but also allows some to flow over its top, blocks boating access and a more fulsome downstream flow on the historic 106-mile waterway.
"For years and years, we have been hearing about the weir being removed. People are anxiously waiting for it to happen," said Ryan Perque, executive director of the Friends of Bayou Lafourche.
The nonprofit advocates for the bayou's health and coordinates projects to add recreational access to the waterway.
Ben Malbrough, executive director of the Bayou Lafourche Fresh Water District, said Monday the agency recently hired Duplantis Design Group to start planning the removal of the weir and to begin seeking state and federal regulatory permits.
The project is budgeted for construction in 2020 at a cost estimated at $1.5 million. District officials say they are hoping to get the permits in fewer than six months.
"Unfortunately, those things are difficult to predict," Malbrough said.
The weir's removal is one piece in a multi-step plan underway for several years to remove obstructions in the bayou and increase the flow of water down the bayou, which serves as a drinking water source for more than 300,000 people in Houma, Thibodaux, Assumption Parish and western Ascension Parish.
The district also agreed last month to a financing plan to build a new $65 million pump station along the Mississippi in Donaldsonville. It will triple the amount of water that can be siphoned from the river and sent down Bayou Lafourche. The new station will be built next to the existing station on the river batture.
Poor water flow and water quality on the bayou after Hurricane Gustav in 2008 highlighted the risk that a variety of upstream blockages had posed both for downstream communities and for the health of the waterway and surrounding swamps.
But increasing flow, clearing blockages and also ensuring enough water remains in the waterway at all times have required a balancing act. With millions of dollars flowing from the state through the Coastal Protection and Restoration Authority, the Fresh Water District has focused on removing obstructions through past dredging and bridge replacement projects but also on adding new floodgates to protect water supplies in the bayou during low flow conditions.
One of those gates, in Lockport, was finished in 2016. Construction of the other gate, farther upstream in Labadieville, is expected to start in November.
Malbrough said Sealevel Construction, the contractor, has already started ordering equipment and fabricating parts of the new floodgate, which, like the Lockport gate, will remain open for bayou water traffic unless needed.
Once the Labadieville floodgate is finished and can be shown to operate as planned, the district is expected to start on removal of the weir, assuming the necessary permits are in hand, Malbrough said.