The Saltwater Wedge: New Orleans' Fight for Fresh Water

By Sustainability Awakening

February 1, 2026

The River is Running Backward? New Orleans faces a terrifying new reality. It’s not a hurricane this time. It’s the ocean coming for the tap water.

The Midwest Drought When rain stops in the Midwest (Ohio Valley), the Mississippi River loses its power. Without a strong flow to push it back, the heavy Gulf of Mexico water pushes in.

Saltwater is denser than freshwater. It creeps along the river bottom like a ghost, sliding underneath the river flow. It can travel nearly 100 miles upriver, right to the city's intake pipes.

If the salt reaches the treatment plants, the water becomes unsafe to drink. Danger: Salt corrodes lead pipes, potentially leaching heavy metals into the supply.

To stop the wedge, the Army Corps of Engineers built an "Underwater Sill"—a massive levee on the river floor. It acts like a speedbump to block the heavy saltwater.

Desperate Measures During the peak crisis, millions of gallons of fresh water had to be barged in to dilute the salt at treatment plants.

Not a One-Time Event This used to be rare. But it happened in 1988, 2012, and 2023. Trend: Frequency is increasing.

Why It Will Happen Again It is the perfect storm: Rising Sea Levels (pushing harder) + Hotter Droughts (weaker river flow). This is the new normal for the Delta.