Flooding to close 9 locks on Mississippi River

CHICAGO, June 11 (Reuters) - Rising flood waters will force the closure of nine locks and dams on the upper Mississippi River starting on Thursday, the U.S. Army Corps of Engineers said Wednesday.

The closures will halt barge traffic on more than 200 miles of the most important U.S. commercial waterway, which transports millions of tonnes of grain, petroleum products and coal each year.

All three of the U.S. Midwest's major rivers -- the Missouri, Illinois and Mississippi -- are above flood stage. Levees were breached or overtopped, sending flood waters coursing into some small towns in Iowa, Illinois, Indiana and Wisconsin.

And the National Weather Service forecast another round of thunderstorms coming from the northern plains on Wednesday. [ID:nN10402439]

Lock 16 in Illinois City, Illinois, will be the first to close on Thursday. The last to close will be Lock 25 in Winfield, Missouri.

The locks are expected to be closed at least 10 days and possibly until early July. All the locks are above St. Louis, where the Missouri and Illinois rivers flow into the Mississippi River. The confluence of rivers makes St. Louis a major center for grain trading and barge traffic.

The Mississippi River is the main channel for grain flowing from production areas in the Midwest to the export terminals at the Gulf and transported 68 million tonnes of farm goods in 2006, according to the Army Corps. The Mississippi also moved 48 million tonnes of petroleum products and 5 million tonnes of coal.

LOCK CLOSURE SCHEDULE:

June 12: Locks 16, 17, 18