Mississippi River levee breaks

Floods on the upper Mississippi River could slow U.S. coal exports because of stalled barge traffic and disrupted rail shipments, some industry sources said on Tuesday.

Other experts said problems will diminish as the flood crest moves to the lower Mississippi, which unlike the upper reaches is not dependent on locks to raise and lower vessels. These experts said the impact on coal should be limited.

Major U.S. railroads have reported problems due to flooding. But it has been possible to route most domestic coal deliveries around high water, electric utility watchers said.

World food prices are expected to remain at historically high levels as a result of crop losses from serious flooding in the US midwest.

The floods have devastated at least 10 per cent of the corn crop in the US state of Iowa and have had an equally devastating effect on this year's soybean harvest.

Authorities closed a bridge connecting Illinois to Iowa over the swollen Mississippi River, as levees along the country's second-longest river were being topped with sandbags Tuesday to defend against rising water.

About 400 people in that county were evacuated after a 300-foot area of a levee near the village of Gulfport breached shortly before 5 a.m.

"We had some people who were actually out sandbagging at the time this occurred," said Patti Thompson, communications manager for the agency.

"At this point, it appears everyone was safely rescued and there were no injuries or deaths. I believe there were some people evacuated from nearby homes. A fairly small number. It's more agricultural flooding with some homes affected," Thompson said.

The breach on the Illinois side near Gulfport, opposite Burlington, Iowa, prompted the closure of the bridge across the river into the city, she added.

In much of the state there were small signs of a return to normalcy: Interstate 80 reopened near Iowa City in eastern Iowa for the first time in days, with Interstate 380 to the north scheduled to reopen early Tuesday. On the University of Iowa campus, officials began to take stock of the damage.

And in Des Moines, where a levee failure Saturday sent water pouring into the Birdland neighborhood, some residents returned for the first time to see the damage.

"It's really bad. I mean, I can't believe this," said Gloria Ruiz, whose home suffered flood damage.

Ruiz pointed to a dirty line about 5 feet up on her basement wall showing how high the water rose. Her washer, dryer and boiler, and most of her children's toys, including a stereo and an Xbox video game system, were ruined.

Floodwaters lingered about 50 feet from her driveway.

"We don't know how long it will stay like that," she said.

Where floodwaters remained, they were a noxious brew of sewage, farm chemicals and fuel. Bob Lanz used a 22-foot aluminum flatboat to navigate through downtown Oakville, where the water reeked of pig feces and diesel fuel.

"You can hardly stand it," Lanz said as he surveyed what remained of his family's hog farm. "It's strong."

LeRoy Lippert, chairman of emergency management and homeland security in nearby Des Moines County, warned people to avoid the floodwaters: "If you drink this water and live, tell me about it. You have no idea. It is very, very wise to stay out of it. It's as dangerous as anything."