This Drought Is So Bad Salt Water Is Flowing Up the Mississippi, Threatening NOLA's Water Supply - Brian Resnick - The Atlantic: Saltwater has been flowing from the Gulf up the Mississippi River, and that's as much of a problem as you might think.
Due to the historic drought still searing the Midwest and taxing the heart of our agricultural economy, the Mississippi River is at its lowest flow rate in years. In Memphis, for instance, the river is 8.9 feet below baseline. While the low flow has been grounding barges and creating pockets of quicksand, it is also allowing the Gulf of Mexico to flow nearly 90 miles upstream from the mouth of the Mississippi.