CHICAGO, Dec 10 (Reuters) - Shipping will be disrupted on astretch of the Mississippi River as workers remove rocks “overthe next few months,” the U.S. Army Corps of Engineers said.

Workers on Tuesday began a project to remove about 2,800cubic yards of rock from the mid Mississippi River at Thebes,Illinois, the Army Corps said in a statement. The rocks threatennavigation when water levels are low and will be removed duringdaylight hours.

Shipping is expected to be restricted initially to one-waytraffic, with a limit of 15 barges per tow and a no-wakerestriction, the Army Corps said. Other restrictions may include"anticipated part-time channel closures,” the statement said.

Barge traffic on the river near Thebes is important formoving grain to export facilities at the Gulf of Mexico fromMidwest farms. More than 100 million tons of cargo pass throughthe mid-Mississippi River annually, including 60 percent of U.S.agricultural exports, according to the Army Corps.

“It’s going to slow things down significantly,” said DebraColbert, senior vice president for the Waterways Council, anindustry group that represents shippers. “There are going to bebarges and tugboats waiting in the queue to get through.”

An Army Corps spokesman was not immediately available forcomment.

The project continues work the Army Corps began last year,when water levels dropped near record lows from St. Louis southto the confluence of the Mississippi and Ohio rivers because ofa historic drought. Last year, the Army Corps removedapproximately 1,000 cubic yards of rock in an effort focused onproviding adequate depth in the river.

The latest project will focus on providing the width neededfor barge traffic to continue when the river narrows as waterlevels drop.

Despite the disruptions, shippers said they supported theproject because it will facilitate river traffic in the event ofanother severe drought.

“The bottom line is that we really feel it’s in our bestinterest to get the rocks out of there,” said Ann McCulloch,spokeswoman for the American Waterways Operators.