Midwest sees more floods

MADISON, Wisconsin (Reuters) - A dam near the Wisconsin Dells resort area broke on Monday, sweeping away some homes, as torrential rains caused more flooding across parts of the U.S. Midwest, authorities said.

No deaths or injuries were reported, though residents living beside a few rain-swollen rivers in central Wisconsin were urged to evacuate, the Columbia County Sheriff's office said.

The failure of the Delton Dam on Lake Delton caused mudslides that swept away a few homes. The water rushed to form a new tributary to the Wisconsin River, which eventually empties into the Mississippi River.

Police issued a warning about debris swept into rivers from collapsed buildings and roads.

Other dams in the Wisconsin Dells region, which is famous for its scenic lakes and resorts, were also threatened by a series of drenching storms in recent weeks, authorities said.

Gov. Jim Doyle declared a state of emergency in 30 counties in the southern half of Wisconsin. Similar declarations have been made in recent days in Iowa and Indiana, with flooding also affecting parts of Illinois, Michigan and Minnesota.

"This is an area that's been bombarded with rain over the weekend, anywhere from 5 to 10 inches, and you're dealing with saturated soils. So any rain that falls becomes run-off," the National Weather Service's Pat Slattery said.

Nearly one-third of Iowa's 99 counties were experiencing flooding, according to Gov. Chet Culver.

Flood damage estimated in the tens of millions of dollars were being added to recent storm damage in Iowa, including a tornado that flattened the town of Parkersburg two weeks ago.

The water treatment plant Mason City, Iowa, was swamped this weekend by the Winnebago River, three of four bridges in the town of Charles City were swept away by flooding of the Cedar River, and the town of New Hartford was evacuated.

Many corn and soybean acres were under water in Midwestern states, hurting farmers' prospects after a wet spring that had already delayed planting in many places.

Iowa and Illinois alone produce one-third of U.S. corn and soybeans, usually the world's biggest harvests of those crops.

National Guard troops were called out in Indiana, where flooding forced hundreds of people to evacuate homes across the central and western parts of the state.

(Reporting by Jeff Mayers in Wisconsin, Kay Henderson in Iowa; Writing by Andrew Stern; Editing by Cynthia Osterman)