Near the Mississippi’s mouth, scientists are trying to predict the future. ‘A massive effort.’

Down at a bend near the , Claire Kemick keeps a close eye on a laptop as the boat that brought her here maneuvers the currents.

A patchwork of colors lights up on the computer screen as an instrument lowered into the mighty waterway delivers data marking a key contrast.

“Here’s the wedge,” says Kemick, a Tulane University researcher, pointing to blotches of dark blue indicating slower-moving water along the river bottom, signifying salt water. “And then here is the fresh water.”

It was not a shocking discovery. Saltwater creeps up the Mississippi River at varying degrees around this time every year.

But Kemick and her colleagues were not focused on this trip alone. They’ve taken measurements repeatedly at various spots in the Mississippi since 2024, part of a vast research project that will supply a first-of-its-kind look at the changing lower river, including saltwater intrusion.

The data collected from around 200 sites, from about 50 miles downriver of New Orleans to the Mississippi's mouth, will feed into complex models aimed at projecting the river’s evolution. The results will carry implications on everything from drinking water to hurricane protection and global shipping.

NO.saltwedge.adv.1857.JPG — Claire Kemick, a Tulane University researcher, points to data showing the saltwater wedge in the Mississippi River in Plaquemines Parish on Thursday, Sept. 24, 2026. (Staff photo by Brett Duke, The Times-Picayune)
STAFF PHOTO BY BRETT DUKE

Some of the modeling is expected to be complete in the early part of next year, and the scientists from an array of institutions working on the $22 million, five-year project hope it serves as an important planning tool for government agencies.

How long can the fading Bird Foot’s Delta, where the river empties into the Gulf, be sustained as erosion and subsidence tear away at its structure? How does the saltwater intrusion that regularly threatens drinking water systems for southeast Louisiana, including New Orleans, behave under varying conditions?

The aim of the modeling is to provide the most detailed insight yet on those questions and others vital to Louisiana -- and, in certain cases, the nation.

“The science goal on the project is to say, ‘What does the future between now and 2100 hold for the Bird’s Foot,” Mead Allison, a Tulane geologist and one of the two scientists leading the expansive project known as MissDelta, said as he motored a 22-foot boat past shrimp trawlers toward the Venice Marina last week.

“And what can we do to forestall -- lessen -- the negatives that are coming.”

Breaks in the river

The river’s importance to the state as well as the country is hard to overestimate. It built south Louisiana in the first place with its sediment, and now provides drinking water to around 1 million people in the region while serving as one of the world’s most important shipping channels.

But it has been roughly a century since the modern lower river took shape with the construction of the vast levee system along its banks, and a series of challenges are emerging in managing it.

NO.saltwedge.adv.1585.JPG — Mahtab Panhwar, a University of Louisiana at Lafayette graduate student, left, and Mead Allison, a professor in Tulane UniversityÕs Department of River-Coastal Science and Engineering, collect a water sample in a cut off the Mississippi River in Plaquemines Parish on Thursday, Sept. 24, 2026. (Staff photo by Brett Duke, The Times-Picayune)
STAFF PHOTO BY BRETT DUKE

The MissDelta project is delving into some of those challenges. Funded by proceeds from the 2010 BP oil spill, through the National Academies of Sciences, Engineering and Medicine, it is protected from the budget cuts hitting research across the nation under the Trump administration.

It includes 14 institutions, led by Allison and ��Ĵ�ý geologist Sam Bentley.

Some of its research has already been published. Modeling overseen by Tulane professor Ehab Meselhe has up the river has worsened in recent years.

His team found that crevasses, or widening breaks in the lower river’s banks, have been the biggest factor. The deepening of the channel for shipping and sea level rise have also played roles.

The crevasses bleed off flow from the main stem of the river, slowing its momentum. That limits its power to keep the heavier saltwater at bay, allowing it to crawl along the Mississippi’s bottom in the shape of a doorstop when flows drop in the late summer and fall.

If the salt wedge threatens to move too far upriver, the Army Corps of Engineers builds a sill – essentially an underwater levee – across the lower Mississippi to slow its advance, hopefully providing time for higher flows to return.

The sill had previously been required about once a decade, but it was needed every year between 2022-2025. This year may finally break that streak, though it is too early to say for sure.

The Corps has reduced the flow of the biggest crevasse, known as Neptune Pass, located across from Buras. It was at one point taking as much as 16% of the river’s flow, but rocks installed at its entrance have reduced it by about half.

Corps spokesman Matt Roe said however that this year’s improvement in conditions had more to do with nature than the new rocks. Low flows on the river “have not been sustained for extended durations,” he said.

Significant rain in the Mississippi and Ohio river basins is also making its way down, which will help as well, said state climatologist Jay Grymes.

The Corps is doing its own modeling of the salt wedge, including employing a model in a lab at Vicksburg, Miss.

A threat that emerged in 2023 brought new attention to the problem: Initial projections then showed the salt water reaching New Orleans, setting off an emergency declaration from the White House and a scramble for a temporary solution.

The saltwater didn’t get that far, though communities farther downriver were severely affected.

'A massive effort'

Managing the crevasses are complex for a number of reasons. For one, coastal advocates prefer to keep them open since they are

Some in the shipping industry would like to see them all closed, but doing that may simply result in new ones forming during high river years.

Part of the MissDelta project involves examining conditions in the crevasses. Last week, Allison navigated his boat into Neptune Pass, past the new rocks put in place by the Corps.

NO.saltwedge.adv.3930.JPG — People fish in a cut off the Mississippi River as a ship travels nearby in Plaquemines Parish on Thursday, Sept. 24, 2026. (Staff photo by Brett Duke, The Times-Picayune)
STAFF PHOTO BY BRETT DUKE

With the help of team member Mahtab Panhwar, he took water samples and flow data that will feed into the larger modeling. He then swung over to where the pass has been effectively building a new delta, near an area known as Bay Denesse.

“This is all freshwater marsh,” Allison said as ibis flew over mats of elephant ear on emerging land. “So you'd think you're right down here in the Gulf of Mexico, it would be saline marsh. But it’s the river influence.”

Kemick and her colleague Tian Zhao were on a separate, larger boat, focusing their efforts on the river’s main stem and using a set of more sophisticated instruments. One was made of bronze and shaped like a mini-torpedo, while another carried a variety of tools, including an underwater camera.

They approached the bank about 40 miles upstream, near the ruins of 200-year-old Fort Jackson, and began collecting data across the width of the river. During low-water periods, like now, there is far less sediment in the river; when the Mississippi is high, sediment sampling is also an important part of the project.

Up close, as researchers fill plastic bottles with river water and record flow data by hand in waterproof notebooks, it is difficult to see what it will all foretell. But the ambition is to produce something on a scale never done before.

“It takes 38 (principal investigators), hundreds of students,” Allison said. “We're talking a massive effort of all the different field teams. This is just one subtask in the overall.”

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