The U.S. Army Corps of Engineers is raising the height of an emergency barrier sill by 25 ft to slow progression of a wedge of saltwater creeping up the Mississippi River from the Gulf of Mexico, which could render local water supplies in New Orleans undrinkable by the end of November.
Saltwater wedges are a naturally occurring phenomenon but have become more common with low-water levels caused by climate change-related drought. Last year, the Corps successfully halted the progression of a similar wedge with an underwater barrier built near Myrtle Grove, La.