As the boat approaches a turn heading downriver, part of the Mississippi’s flow begins sweeping hard to the east, its choppy brown waters diverting into a newly formed channel -- and squarely into a debate about the future of Louisiana’s coast.

The channel, located across the river from Buras, is now known as Neptune Pass. Previously a small crevasse, it began to take its current form with the inordinately high rivers of 2019, creating either a problem or an opportunity, depending on whom you ask.

Scientists and coastal advocates point out that it is building new land the way the river did long ago, before levees kept it in place. They cite Neptune Pass as an example of what river diversions can do to help address the state’s land-loss crisis.


Vegetation grows on new land off Neptune Pass during a visit to the area on Feb. 28, 2024. Coastal advocates want to see more wetlands reconnected to the Mississippi River to partly address Louisiana's devastating land loss.

But for the Army Corps of Engineers, the widened pass poses hazards for shipping, and it must be addressed given the river’s role as one of the world’s most important transportation lanes.

Meanwhile, there is also a third group indirectly involved in the Neptune Pass debate that includes commercial fishers and Plaquemines Parish officials. They fear plans for a manmade river diversion on the river’s west bank will do more harm than good.

They have been urging new Gov. Jeff Landry to pull the plug on the nearly $3 billion Mid-Barataria Sediment Diversion, a land-building project at an unprecedented scale and price that would act similarly to the way Neptune Pass does naturally. Work on Mid-Barataria just got underway in August after years of planning.

All of that means Neptune Pass, which would look like little more than another gap on the map to most Louisianans, has taken on an outsized importance in the debate over what to do about the state’s rapidly receding coast.

“Let the river build land if it can,” James Karst, spokesperson for the Coalition to Restore Coastal Louisiana, said during the recent boat tour of the pass, set up by his group.

Karst noted that his organization, a pioneer in efforts to address Louisiana’s land loss, has been working for more than three decades to see the river reconnected to disappearing wetlands -- addressing the cause of coastal erosion instead of the effects, in the group’s view.

060422 Neptune Pass crevasse map

‘Said he would look at it’

The sprawling debate has taken on renewed relevance in recent weeks due to mixed signals sent by Landry’s administration regarding the Mid-Barataria project.

The first meeting of the state’s Coastal Protection and Restoration Authority under Landry’s tenure set aside time for opponents of the project to again make their case with a video and a succession of speakers. Those speaking included Lt. Gov. Billy Nungesser, who hails from Plaquemines Parish and has been a vocal critic of the diversion.

The coastal agency is now compiling a report on where all aspects of the project stand, including legal challenges. Its new chairperson, Gordon Dove, said in comments after the February meeting “we don’t have any position right now.”

The coastal authority later sought to clarify Dove’s comments, saying late Thursday that it remains committed to the landmark project and stands behind the science used to evaluate it. Landry's spokesperson signed off on the statement, but the governor has not directly addressed the issue.?

It is not even clear if the state could back out of the project at this stage. The work is being paid for with settlements linked to the 2010 BP oil spill, and various boards charged with distributing the cash have approved the money based on the project’s specifications.

Further, a hefty sum of money has already been spent on the project. While the state has not specified how much,?Nungesser contended recently that it was $300 million. It is unclear whether that money would have to be returned if the plug were pulled.


New land in the area of Neptune Pass on Feb. 28, 2024. The pass broke free in its current from after the high rivers of 2019.

The project aims to build 21 square miles of land over 50 years, roughly the land area of Metairie, by channeling river water and sediment into the Barataria Basin. While it comes at a high cost, coastal advocates say the state has little choice as Louisiana continues to lose land at a rising rate.

But oyster fishers and shrimpers in areas of the diversion will have to move farther out, which they say is unworkable and will kill their businesses. Some areas of Plaquemines will also face increased flood risk during certain times when there is more water in the basin.

The state has set aside $378 million in compensation for those affected.

Nungesser says the $3 billion would be better spent building projects such as berms, ridges and barrier islands through dredging in a shorter timeframe. While the coastal authority carries out a list of such projects each year and plans on spending over $16 billion on such projects over the next half-century, they also erode like the rest of the coast and usually have a lifespan of around 20 years.

“We need a 50-year plan? In 50 years, the Grand Isle Fishing Rodeo’s going to be right out here,” Nungesser said at the CPRA meeting, referring to its location in Baton Rouge. “I beg the governor and this board to reconsider.”

Nungesser, who once said Landry was “not a good person,” backed off his opposition to Landry’s run for governor last year after the two Republicans met in February 2023. While Nungesser says the diversion was discussed at the meeting, he stressed that Landry did not promise to derail it.

“I asked him to please look at all the pros and cons of the diversion,” Nungesser said in an interview. “And if he feels that it will do more harm than good, I'd like him to consider putting the brakes on it. And he said he would look at it, and he would absolutely look at it with an open opinion and weigh the facts.”

A Landry spokesperson did not respond to a request for comment.


Richie Blink of Delta Discovery tours guides a boat trip to Neptune Pass on Feb. 28, 2024. Blink believes the pass should be allowed to continue to build land naturally. Darrah Fox Bach of the Coalition to Restore Coastal Louisiana is seated in front of him.

‘Really bold ways’

Traveling farther down Neptune Pass, cutgrass and willow trees sprout from new spits of land that spread out in the shape of tree branches in an area called Bay Denesse. While the land there seems to have already been building up, Neptune has likely augmented it, said Alex Kolker, a coastal geologist at the Louisiana Universities Marine Consortium who has been examining the channel’s impact.

Even farther out, in what is called Quarantine Bay, a new delta has been building and Kolker will be watching closely this year to see if vegetation grows there. While much of it is still underwater when the river is high, land emerges during times of lower water.

All told, around 2,000 to 3,000 acres of either land or shallow-water habitat has been built so far, Kolker says.

As an indication of the pass’s size and growth, consider these measurements: In mid-February, the pass was capturing around 15% of the lower river’s flow, or about 113,000 cubic feet per second, he said. In 2016, it was only about 10,000 cfs.

At the same time, it appears the Corps’ efforts to stabilize the pass and limit its impact on vessels have succeeded for now. It twice took emergency actions, putting down a total of 148,000 tons of rock to form a blanket at the pass’s entrance to slow its widening, at a cost of around $6.7 million.

It was concerned about the diverted current’s pull on vessels as well as the build-up of sediment in spots of the river, causing the Corps to dredge in places it hadn’t before. The slowing of the river’s current allows sediment to drop to the bottom.

The Corps sees a portion of the land-building as a result of the bank of the pass being eroded, essentially moving that mud farther down the channel, said spokesperson Ricky Boyett. Kolker says his calculations show 27-80% of the land-building is the result of sediment from elsewhere.

The Corps is now working to come up with a long-term solution that would essentially reduce it to what it was before 2019, said Boyett. This spring, it hopes to release specifics of a new design of a sill that it would construct at the entrance that would be offered for public comment.

Coastal advocates are urging the Corps to design it so as to continue to allow natural land-building to occur, though they stress they do not want to see hazardous conditions for vessels. Boyett says the Corps must prioritize limiting the effects on shipping.

For Richie Blink, who guided the recent tour of Neptune Pass, it is time to think creatively to address the state’s devastating land loss, and allowing deltas to grow naturally, the way they used to, should be part of it.

That will result in a healthier ecosystem all around, says the 37-year-old operator of Delta Discovery tours who grew up in a fishing family.

“If Louisiana is going to head off the worst of climate change, we’re going to have to think in really bold ways,” Blink said.

Staff Writer Mark Schleifstein contributed to this story.

Email Mike Smith at or follow him on Twitter, @MikeJSmith504. His work is supported with a grant from the Walton Family Foundation, administered by the Society of Environmental Journalists.