DONALDSONVILLE — A state district that manages the diversion of Mississippi River water into Bayou Lafourche is edging closer to building a major component in a long-standing plan to increase fresh water flow down the historic bayou.

Officials with the Bayou Lafourche Fresh Water District want to build a new $60 million fresh water pumping station that will double their ability to siphon water from the river and send it down the bayou. Though the district has only $35 million in state funding so far, other steps needed for the station are moving along.

Last week, District Director Ben Malbrough hashed out a rough agreement with Donaldsonville city officials to find an appraiser to determine the value of a city-owned batture where the district wants to build the new station.

The district has already completed engineering plans that will allow it to seek permits from the U.S. Army Corps of Engineers to build on the land between the levee and the river. District officials don't believe that process will require major modifications to the proposed station's location along the river, Malbrough said.

"And that's why we're coming with this request now. We feel pretty strong in the proposed location of the pump station that it's not going to change," Malbrough told the City Council about the need to start the appraisal process.

Bayou Lafourche, whose name means "the fork" in French, was originally a distributary of the Mississippi that carried water from the river to the Gulf of Mexico. Access was cut off in 1904 when a flood protection levee was built across the bayou's connection to the river.

The water district was formed in 1950 to restore some of the river's flow into the bayou, and the existing pump station was built in 1955.

Over the past quarter of a century, though, district officials and leaders in communities downstream in Assumption, Lafourche and Terrebonne parishes have come to see the need for increased fresh water flow to nourish Louisiana's fading coast line.

Further underscoring the urgency for increased water pumping, Archie Chaisson III, Thibodaux's public works director, estimated nearly 400,000 people in Thibodaux and other communities now rely on the bayou for drinking water.

"We recognize if that bayou is not a sustainable source of fresh water, we need to start looking elsewhere for fresh water, which is not going to be an easy thing," said Chaisson, the son of a former fresh water district director.

Under a master plan designed to improve fresh water flow, the district has already spent close to $40 million primarily in federal funding through the Coastal Protection and Restoration Authority to dredge Bayou Lafourche between Donaldsonville and Napoleonville. Another $5 million using primarily U.S. Interior Department money was spent to build a new Union Pacific railroad bridge in Donaldsonville in 2016. 

The silted-in bayou and the old culverts that once served as the old railroad crossing kept district officials from using the pumps' full capacity without, at times, also posing a flood risk for Donaldsonville. The narrow culverts have been replaced with wide bridge spans under which the bayou water can pass.

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The district still has plans to dredge the bayou to Thibodaux, improve stormwater drainage in Donaldsonville and make other improvements farther down the bayou. But Malbrough said the combination of the dredging so far and the new bridge is allowing construction of a bigger pump station with a capacity of 1,000 cubic feet per second, up from the 450 to 500 cubic feet per second the existing station can supply. 

Malbrough said the increased flow will ensure bayou water levels are high enough miles downstream from Donaldsonville to supply municipal water plants. A small dam, or weir, in Thibodaux keeps water levels up in the bayou now, but officials want to remove the weir to enhance fresh water flow farther downstream.  

Malbrough said the district plans to continue to use the existing pump station in Donaldsonville, which went through $4 million in upgrades completed in late 2014, as long as it is economically feasible. 

Donaldsonville Mayor Leroy Sullivan said that a decade ago, city officials would have opposed increased fresh water pumping from the Mississippi into Bayou Lafourche due to flooding concerns.

At that time, added pumping would have raised bayou water levels in Donaldsonville too high, potentially affecting critical highway underpasses beneath the Union Pacific bridge. But the bayou dredging, plus separate stormwater drainage pumps the district also plans for the city, have offered some assurance the impact will be mitigated, Sullivan said.

Last Monday night, Malbrough met with city officials about buying 3.25 acres of land next to the existing station on the river for the new station.

While Malbrough suggested that the city could donate the land — a comment that drew a few muffled laughs — he and council members discussed the broad outlines of a potential land purchase and the need to agree on an appraiser first.

"I just would like to get that process going," Malbrough said.

Among the details Malbrough shared with the council was that the new station's water pipes will have to go over the levee, taking out about 300 feet of a city levee-top trail finished a few years ago.

Under council questions, Malbrough said the district would rebuild that section of trail with a route around the pumps and also be willing to work with city officials on the design of the new station's brick facade.

The council agreed to provide Malbrough a list of appraisers and select one to value the batture. The council made no commitments, however, that it would sell the property.

Malbrough said he is hopeful to have the appraisal done in about a month.

Asked in a later interview about a possible land sale to district officials, Mayor Sullivan said, "We're open to the concept … with the idea that we're always going to be very cautious to make sure that whatever they do is not going to affect Donaldsonville" as far as flooding risk. 

Follow David J. Mitchell on Twitter, @NewsieDave.