Saltwater Intrusion Study
A first-of-kind longitudinal study proposal on saltwater intrusion into the Greater New Orleans water supply and its health impacts on 1.2 million residents.
When the river could not push back.
In the fall of 2023, the Mississippi River's flow dropped to dangerously low levels — reaching 130,000 to 150,000 cubic feet per second when the safe threshold is approximately 300,000 cfs. As the river's freshwater flow weakened, a saltwater wedge from the Gulf of Mexico advanced upstream along the riverbed, threatening to reach the drinking water intake for the Greater New Orleans metropolitan area.
The U.S. Army Corps of Engineers constructed an emergency underwater sill — a physical barrier on the riverbed — to slow the saltwater's advance. Water utilities issued advisories. The crisis raised existential questions about the long-term viability of New Orleans's water supply as climate change intensifies drought conditions along the Mississippi.
This was not a hypothetical scenario. For weeks, salinity levels crept toward the intake point. If the wedge had reached the treatment plant at Carrollton, the city would have faced a drinking water emergency for 1.2 million people.
First-of-kind longitudinal study.
The Saltwater Intrusion Study (SWIS) proposes a longitudinal research framework to examine the health impacts of saltwater intrusion events on municipal water systems — an increasingly urgent research need as climate change alters hydrology patterns across the Mississippi River basin.
The study would track salinity levels, chloride concentrations, and disinfection byproduct formation in treated water during and after intrusion events, correlating these measurements with health outcomes in the exposed population — including hypertension, kidney function, and cardiovascular endpoints.
Research Questions
- •How do acute saltwater intrusion events affect treated water chemistry?
- •What are the cardiovascular and renal health impacts of elevated sodium in municipal water?
- •Do current water treatment processes adequately mitigate salinity during intrusion events?
- •What monitoring infrastructure is needed for early warning and adaptive response?
Saltwater wedge dynamics.
As river flow decreases, the denser saltwater from the Gulf of Mexico pushes upstream along the riverbed. Drag the slider to simulate different flow rates and observe the wedge advancing toward New Orleans.
A preview of the future.
The Greater New Orleans metropolitan area depends on Mississippi River water treated at the Carrollton plant.
Similar low-flow conditions occurred in 2012 and 2023, suggesting increasing frequency as drought patterns intensify.
No long-term health study has ever tracked the impacts of saltwater intrusion on a municipal water supply population.