The Corps, aware that barge traffic could be disrupted as early as next week because of low water levels caused by drought conditions, said it is using several methods to maintain a 9-foot-deep channel near Thebes, Ill., CNN reported Friday.
Blasting to remove 890 cubic yards of limestone began Dec. 9 and will continue until the end of January, said St. Louis District Corps spokesman Mike Petersen. Dredging has been going on since July.
A historic drought and high heat reduced water levels and seared a wide section of the Midwest this year. Flooding in 2011 may have worsened the situation on the Mississippi by leaving silt and debris in areas that typically would be clear, CNN said.
Two trade groups expressed concern Thursday that the portion of the river near Thebes may be impassable for many vessels Jan. 3-4, and urged the Obama administration to release water from upstream reservoirs.
"This potential supply-chain disruption could amount to a staggering loss for the U.S. economy, affecting nearly 20,000 jobs," the American Waterways Operators and the Waterways Council Inc. said in a joint statement.
Mark Fuchs, a National Weather Service hydrologist in St. Louis, said extremely cold air forecast in Minnesota and Iowa was expected to freeze much of the flow from the Upper Mississippi late this week, CNN said.
"However, that may not have much impact on levels this far south unless the ice makes significant progress ... roughly past Iowa," Fuchs said Friday.
In late November, U.S. Sen. Claire McCaskill, D-Mo., and other senators from the Midwest and South called on President Obama to ensure commercial navigation of the river.
"Significant curtailment of navigation ... will threaten manufacturing industries and power generation, and risk thousands of related jobs in the Midwest," their letter to Obama said.