Latest saltwater wedge forecast released by USACE

USACE MVN
Published Oct. 19, 2023

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. 

Changes based on the latest forecast:

  • Boothville:  No change
  • Port Sulphur:  No change
  • Pointe A La Hache:  No change
  • Belle Chasse:  Nov. 13 (previously Oct. 27)
  • Dalcour:  Nov. 18 (previously Nov. 1)
  • St. Bernard:  Not anticipated to experience chloride levels exceeding 250 ppm (previously Nov. 8)
  • New Orleans Algiers:  No change
  • Gretna:  No change
  • West Jefferson:  No change
  • New Orleans Carrollton:  No change
  • East Jefferson:  No change

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 changes in the forecast can be attributed to the augmentation of the 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 has remained at river mile 63.9, the approximate location of the sill, since Oct. 9.

The new forecast shows delayed impacts at facilities upriver, but treatment facilities in Port Sulphur and Pointe A La Hache continue to experience impacts from saltwater intrusion.

USACE began barging water 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 23 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. 23-038