The U.S. Army Corps of Engineers St. Louis District will soon begin work on the Middle Mississippi River at Thebes, Ill., to remove rocks that pose a threat to navigation during low river stages.
Contractors working for the Corps will remove approximately 2,800 cubic yards of rock as a permanent improvement to the navigation channel over the next few months, with options for additional removal in future years. The rock removal project continues work begun last year when river levels dipped to near-record lows from St. Louis south to the Ohio River confluence.
The rocks are part of a large natural formation, most of which was removed in the late 1980s. With improvements in survey technology, the Corps discovered remaining outcroppings – referred to as pinnacles – along two stretches of the river near Grand Tower and Thebes, Ill. Last year the Corps removed approximately 1,000 cubic yards of rock.
The Corps of Engineers is responsible for providing a reliable channel for navigation nine feet deep and at least 300 feet wide, with additional width in river bends. Last year’s removal efforts focused primarily on providing adequate depth in the channel, while this year, work will provide the needed width for barge traffic to continue when the river narrows during low water.
River navigation is critical to the nation’s economy: more than 100 million tons of cargo passes through the Middle Mississippi River annually, including 60 percent of our nation’s agricultural exports.
The Corps is working with the U.S. Coast Guard and the barge industry to minimize the impact on river navigation. Work will occur during daylight hours and traffic is expected to be restricted initially to one-way traffic with a limit of 15 barges per tow and a no-wake restriction. Other restrictions may be needed, including anticipated part-time channel closures. Vessels in the area can use marine channel 13 to coordinate passing river traffic.
Rock removal is one of many operations the Corps and U.S. Coast Guard are undertaking along the river to maintain a safe channel for river navigation. Dredging has been ongoing since July to preserve the channel, as well as continued surveys and channel patrols to keep commerce safely moving on the Middle Mississippi.
Coast Guard, Corps and local safety officials remind anyone planning to be near the river that sandbars and places revealed by low water are unstable. Signage and other warning notices may not be immediately visible since many may have been placed when the river was at a higher stage.
Press Release, December 11, 2013