The worst U.S. drought in 56 years has caused the river to flow at its lowest levels since 1988. Flooding of the river in 2011 led to an increased deposition of silt in some sections, which now require additional dredging. Shippers have been told to reduce their cargo by up to 30 percent on barges to allow the containers to float higher and decrease the chances for running aground.
An area of the river south of Memphis, Tennessee, shown in the satellite images above, is several inches below 2011 levels. The loss of just one inch in draft means a barge should carry 17 tons less cargo than it normally would, a costly reality for shippers who already have to run fewer barges at a slower pace. A paper published in the Bulletin of the American Meteorological Society in 1989 estimated that barge companies lost close to $1 billion because of low-water conditions in 1988.