Oct 12, 2023 - News

Saltwater intrusion no longer a threat to New Orleans' drinking water

Photo shows ships on the Mississippi River building an underwater levee.

U.S. Army Corp of Engineers vessels are seen on Oct. 9 fortifying an underwater sill in the Mississippi River near Belle Chasse to help slow the salt water. Photo: Justin Sullivan/Getty Images

Metro New Orleans' drinking water is no longer expected to be contaminated by unhealthy salt levels, officials said Thursday, marking a dramatic change from last month's forecast that caused residents to wipe out bottled water supplies in stores.

Why it matters: It's good news for a region that was preparing for three months of undrinkable water that could corrode pipes and pose a serious health concern to more than 1.2 million residents.

The latest: The Army Corps of Engineers said all of Orleans and Jefferson parishes are in the clear.

  • Until Thursday's update, salt was expected to contaminate drinking water in Algiers and Gretna. Other parts of Orleans and Jefferson were put in the clear the week before.
  • The Corps attributed the improved forecast to the increased height of an underwater levee that's stopping salt water from creeping up the Mississippi River. Plus, rain increased the flow of the Red River and helped the Mississippi River.

Yes, but: Salinity levels are expected to be higher than average in Algiers, even though they won't reach the threshold to merit an advisory, says Ghassan Korban, executive director of the New Orleans Sewerage & Water Board.

  • The plan is to barge in fresh water and blend it at the intake to reduce salinity levels, he said.
Graphic: Kavya Beheraj and Brendan Lynch/Axios
Graphic: Kavya Beheraj and Brendan Lynch/Axios

Catch up quick: A drought across the Mississippi River Valley means salt water from the Gulf of Mexico is coming upriver, threatening drinking water supplies in southeast Louisiana.

  • Many municipalities in the region, including New Orleans, pull their drinking water from the river.
  • Communities further south have had salt in their water since June.

Zoom in: Salt is still expected to contaminate drinking water in Belle Chasse and St. Bernard Parish above safe levels.

  • Plaquemines Parish is using reverse osmosis machines and barged water to try to decrease salinity.
Estimated timeline for saltwater intrusion into the New Orleans metro area
Data: GOHSEP; Map: Axios Visuals

The big picture: The forecast continues to change for saltwater intrusion. So far, it has been good news for metro New Orleans, but officials acknowledge it may keep changing and it will be a concern in the future.

  • A Jefferson Parish spokesperson on Thursday told Axios that construction should wrap up by the end of next week on a temporary water pipeline to supply the West Bank if needed.
  • And New Orleans leaders are meeting with White House officials and FEMA this week to discuss permanent solutions, officials tell Axios.
Photo shows barges filled with fresh water on the Mississippi River
In an aerial view, barges filled with fresh water transfer the water to the Port Sulphur Water Plant on Oct. 9. Photo: Justin Sullivan/Getty Images

What's next: The Corps gives saltwater updates on Thursdays.

  • The New Orleans Sewerage & Water Board releases salinity data daily.

Go deeper: See the full update from the U.S. Army Corps of Engineers

Editor's note: This story has been updated with a map showing the estimated timeline for the saltwater wedge.

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