A crucial 200-mile stretch of the Mississippi River may be on the verge of shutdown to barge traffic, a move that could paralyze commerce on the USA's most vital inland waterway and ultimately drive up consumer prices.

"What's at stake is potentially shutting down one of the most important navigation arteries in the world," says Rick Calhoun, president of Cargo Carriers, Cargill's barge business.

The temporary closure of the Mississippi from St. Louis to Cairo, Ill., could result from an Army Corps of Engineers plan to reduce water flow from a reservoir into the Missouri River starting today, shipping companies and industry groups warn. The Missouri flows into the Mississippi near St. Louis.

The corps annually decreases water releases to ensure adequate reservoir levels and to prevent ice buildup and flooding. This year, already-low river levels caused by drought could shrink to the point that barges carrying grain, coal and other products won't be able to navigate the Mississippi, says Debra Colbert of the Waterways Council, which represents ports and shippers.

"This is an impending economic crisis" that could delay shipment of $7 billion in commodities in December and January, she says. Missouri Gov. Jay Nixon and Illinois Gov. Pat Quinn, both Democrats, and members of Congress have asked the White House to intervene.

Monique Farmer, a corps spokeswoman, says water releases from the reservoir at Gavins Point Dam on the Nebraska-South Dakota border will drop gradually starting today from 36,000 cubic feet per second to 12,000 by Dec. 11. "We need to begin conserving water in our system," Farmer says. It's like turning down a faucet: Less water moves into the Missouri, which feeds the Mississippi, so Mississippi levels also drop.

Because of the drought, most vessels on the Mississippi are now limited to a 9-foot draft - their depth in the water - says Andrew Carter of Knight Hawk Coal in Percy, Ill. "If we go to 6-foot drafts, the river is effectively closed," Carter says.

The effects would be widespread, Calhoun says: It would be difficult to transport grain to ports for shipment overseas, get road salt upriver and deliver fertilizer to the Midwest for spring planting. Putting fertilizer on trucks or trains instead of cheaper barges would increase farmers' prices, says Rod Weinzierl of the Illinois Corn Growers Association.

Marty Hettel of AEP River Operations in Paducah, Ky., says some shippers already are seeking other ways to move products. "The additional cost," he says, "is going to hit the consumer at some point."

USA Today