A northern stretch of the Illinois River that has been closed since Saturday for emergency lock repair work may reopen to commercial navigation as soon as Tuesday evening, the U.S. Coast Guard and Army Corps of Engineers said.

A portion of the major barge shipping waterway was closed as the Army Corps drew down the pool of water above the Marseilles Lock and Dam near Seneca, Illinois, to reduce currents enough to construct a rock dike and remove three sunken barges.

Two of the dam's gates were severely damaged when seven barges broke loose from a tow and hit the structure during historic flooding on April 18. Four of the barges were removed last month and crews are working to remove the three that sank.

The pool drawdown, which made the river too shallow for most commercial vessels, was scheduled to end on Tuesday afternoon if barge salvage work goes as planned. Commercial barge traffic may resume as soon as 8:00 p.m. CDT (0100 GMT), the Army Corps and Coast Guard said in a release.

Commercial navigation in the restricted area between river mile markers 240.6 and 252 will only be allowed during nighttime hours as salvage and repair work continues at the lock. Recreational vessel traffic in the restricted area will remain prohibited without Coast Guard approval.

The Illinois River bisects the country's No. 2 corn- and soybean-producing state from Chicago to its confluence with the Mississippi River near Alton, Illinois. Both rivers are critical shipping arteries linking grain producers in the Midwest with export terminals at the Gulf, the exit point for about 60 percent of all U.S. grain exports.