Latest saltwater wedge forecast released by USACE

USACE MVN
Published Nov. 22, 2023

Please note: Out of consideration of the holiday the saltwater wedge forecast is being released on Wednesday, Nov. 22, this week instead of Thursday.

The U.S. Army Corps of Engineers, New Orleans District released today the latest Saltwater Wedge Timeline forecast of when water treatment facilities may be impacted by saltwater intrusion. 

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:

Chloride levels are expected to remain above 250 parts per million through 28-day forecast at:

  • Boothville
  • Port Sulphur
  • Pointe A La Hache

Not anticipated to experience chloride levels exceeding 250 parts per million at:

  • Belle Chasse
  • Dalcour
  • St. Bernard
  • New Orleans Algiers
  • Gretna
  • West Jefferson
  • New Orleans Carrollton
  • East Jefferson

The updated Saltwater Wedge Timeline is available on the New Orleans District website here:  https://www.mvn.usace.army.mil/Missions/Engineering/Stage-and-Hydrologic-Data/SaltwaterWedge/

The river conditions can be attributed to the augmentation of the underwater sill coupled with flows on the Mississippi River that are higher than initially forecasted.  As a result of the sill augmentation and river flows, the toe of the saltwater wedge was lasted measured at river mile 63.2 on Nov. 20.

The forecast shows facilities upriver may not see impacts, but treatment facilities in Port Sulphur and Pointe A La Hache continue to experience impacts from saltwater intrusion.

USACE began barging water in early October to the Port Sulphur and Pointe A La Hache treatment facilities to blend with water from the intakes to bring the chloride down to treatable levels. To date, USACE has delivered more than 80 million gallons of water. USACE has also mobilized Reverse Osmosis Units to support processing at water treatment facilities impacted by saltwater intrusion.

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Contact
Ricky Boyett
ricky.d.boyett@usace.army.mil

Release no. 23-043