They Dredged the Mississippi River for Trade. Now a Water Crisis Looms
Dredging exacerbates saltwater intrusions like the one threatening New Orleans' drinking water, according to a Bloomberg News review of US Army Corps studies.
New Orleans is staring down a potential water crisis. A wedge of saltwater from the Gulf of Mexico is moving up the Mississippi River, and is expected to reach the Louisiana city’s main water supply intake by Oct. 28, according to a US Army Corps of Engineers forecast. If ambitious emergency measures don’t pan out as needed, the wedge could force nearly a million people to find alternative drinking water for weeks or even months.
Known as a “saltwater intrusion,” this type of event occurs naturally whenever river flows drop below a certain threshold, and has long been a problem for communities near the Gulf that get their water from the lower Mississippi River. But the region now faces its worst saltwater intrusion in decades, in large part due to record heat and drought, rising sea levels and weaknesses along the river banks.