Capt. Eric Carrero, the director of western rivers and waterways for Coast Guard District Eight, said in a statement that there had been an increase in commercial vessel groundings associated with the low water levels. The Coast Guard temporarily shut the Mississippi River to traffic at Stack Island, Miss., and Memphis, Tenn. for U.S. Army Corps of Engineers emergency dredging. Those sections have since reopened, and the Corps has also been dredging at other points to keep the river navigable while the water level remains low. A Corps spokesperson could not immediately say where else dredging may be performed, but the Corps is responsible for maintaining a 9-ft-deep, 300-ft-wide channel in the Mississippi River.

The Coast Guard also issued a low water safety advisory for more than 500 miles of Mississippi River between Louisiana and Tennessee, recommending drafts of no greater than 9.5-ft and barges configured to no more than five wide. Officials additionally issued advisories for low water conditions at other points beyond that section of the river. 

Low water is also impacting other parts of the river system, according to Ingram Marine Group, which posts daily updates of river conditions. On the Ohio River, Luhrs Bros. Inc. is conducting dredging operations near Mound City, Ill., until Oct. 20 as part of a contract with the Corps. The Coast Guard is asking mariners to call the dredge in advance if they will need to pass because of the difficulty of moving the dredge aside in the extreme low water conditions.

The low water level is a cause of concern for others besides shippers. The Corps New Orleans District began constructing an underwater sill across the bed of the river near Myrtle Grove, La., this week to prevent salt water from moving upriver, where it could potentially threaten drinking water and industrial water supplies. Heath Jones, the New Orleans Corps office's emergency management director, said during a news conference that this is a natural phenomenon that occurs about once every 10 years due to low water levels. The project is expected to finish in early November, he said.

Forecasters say the low water levels will continue and approach record lows within the next month. The National Weather Service’s Lower Mississippi River Forecast Center gauges show the river at or below the low-water threshold between Cairo, Ill., and Vicksburg, Miss. The center is predicting the water level at some points in the river could fall below the level seen during a low-water event in 2012, and near the record lows reached in 1988 within the next 28 days. Dry conditions are expected to continue, according to the U.S. Drought Monitor. Forecasters with the monitor say nearly three-quarters of the Midwest is abnormally dry, and nearly a third is experiencing drought.