A ‘Wedge’ of Saltwater Is Making Its Way Up the Mississippi

For much of its history, the Mississippi River has been a churning mass of water, the collected output of a watershed that stretches across 32 American states and two Canadian provinces. Its power is unquestionable; when the Mississippi meets the Gulf of Mexico, the sheer force of the river keeps the saltwater of the Gulf from making its way upstream.

Except for right now. Drought in the central U.S. has made the Mississippi drop to near-record lows, and the Gulf of Mexico is encroaching upwards. A “wedge” of saltwater at the bottom of the river has been making its way upstream, threatening to inundate drinking water plants in and around New Orleans (CNN has a good graphic that shows what the wedge looks like). This is a big problem: As Colbi Edmonds reports in TheNew York Times, water treatment plants aren’t designed to handle water with high salinity levels, which can corrode pipes.

Governor Jon Bel Edwards of Louisiana has requested a federal emergency declaration, and Mayor LaToya Cantrell of New Orleans has already signed a city-level emergency declaration. The Army Corps of Engineers, meanwhile, is hard at work trying to raise an underwater sill it had built in the river back in July to protect against the saltwater; officials say they want to make the sill 25 feet higher, though even that will only serve to buy about 10 or 15 days rather than stop the saltwater altogether. The only thing that can really stop the saltwater is rain, and none is forecasted for the near future.

This isn’t the first time saltwater has made its way upriver (it also happened in 1988), but this is the second year in a row where drought has made the river’s water levels drop so dramatically. In 1988, the saltwater intrusion was solved with an unexpected burst of water on the river; this time around, officials think the problem could last until January. And if the drought continues into next year, it’s likely they’ll be facing the same problem then.

In the meantime, the Corps is also organizing barges to transport drinking water to New Orleans and the other communities that stand to be affected. In a press conference on Friday, Governor Edwards urged people not to stock up on drinking water; a representative of the Army Corps told CNN that it “fully anticipates the capability to meet the need of up to 36 million gallons per day that could be required.”