The U.S. Army Corps of Engineers projects no "significant interruption in navigation" on the Mississippi River due to low water levels, U.S. Senator Dick Durbin said on Monday, easing concerns about the potential for a crippling shutdown to river commerce.

The Army Corps briefed Durbin, the No. 2 Democrat in the Senate; other elected officials; and members of the agricultural industry on Monday on its efforts to keep the river open following the worst U.S. drought in more than 50 years.

Some shippers of grain, coal and steel have been concerned that the river will be closed to navigation on a busy stretch between St. Louis and Cairo, Illinois, due to low water. Declining water levels have already forced barge tows to lighten loads or risk groundings.

"There's no anticipated closure of the river," Durbin said in an interview after the meeting.

The river and its tributaries are critical for commerce because they draw on a region that produces 90 percent of U.S. farm exports, a key for the U.S. balance of trade. Sixty percent of grain exports go through New Orleans.

To boost water levels, the Army Corps during the weekend began releasing more water into the river from a lake in southern Illinois. The move is projected to raise the river by six inches at Thebes, Illinois, by Dec. 24.

Thebes, which is about 130 miles southeast of St. Louis, is a key location where rock formations can damage barges when water levels drop too low.

The Army Corps has started demolishing hazardous rock pinnacles along a 15-mile stretch of river near Thebes to aid navigation.

U.S. President Barack Obama helped speed up the hiring of contractors by the Corps to do the blasting when he discussed concerns about the river during a meeting last week, Durbin said.

Initially, the Corps warned it might not be able to hire contractors until February or March, said U.S. Representative Jerry Costello, who attended the briefing with Durbin. Costello is a Democrat who, like Durbin, is from Illinois.

"In a week's time, the Corps has felt some pressure from above, and they have started work much earlier," said Ross Prough, an at-large director for the Illinois Soybean Association and another attendee at the briefing. "We're certainly pleased with that development." (Reporting by Tom Polansek; Editing by Jeffrey Benkoe and Lisa Von Ahn)