Last saltwater wedge forecast released by USACE

Published Jan. 25, 2024

The U.S. Army Corps of Engineers, New Orleans District released today the last Saltwater Wedge Timeline forecast of the 2023 low water event, which began in June and lasted 209 days.

USACE uses the National Weather Service 28-day Lower Mississippi River forecast, daily river observations and computer modeling to project the progression of the saltwater intrusion as it relates to the multiple municipal water treatment facilities along the river. 

Based on the latest forecast and current position of the toe of the saltwater wedge, no municipal water treatment facilities along the Mississippi River are expected to experience chloride levels above 250 parts per million. 

The updated Saltwater Wedge Timeline is available on the New Orleans District website here:

With rising flow rates, the saltwater wedge has moved downriver toward the Gulf of Mexico and was last measured at river mile 11 on Jan. 22. Erosion has begun at the underwater sill constructed, and augmented, to arrest progression of the saltwater intrusion. USACE will continue to survey the site until the sill has eroded to the river bottom.

In addition to construction of the underwater sill, USACE also barged 153 million gallons of water and deployed four reverse osmosis water purification units to impacted water treatment facilities during the 2023 low water event.

USACE will now begin further evaluation of the performance of the augmented sill, its emergency support efforts to the state and local governments and regional communication approaches to identify and apply lessons learned to future low water events. 

Unless conditions change, this week’s timeline will be the final scheduled announcement regarding progression of the saltwater intrusion. 


Matt Roe

Release no. 24-009