Some residents in the central Wisconsin town of Portage fled their homes after a levee started to fail, sending water from the rain-swollen Wisconsin River onto a major roadway in one neighborhood and threatening to leave some people stranded in their houses.

It wasn't clear how many of the roughly 300 residents remained in the Blackhawk Park area after the only road into and out of the neighborhood was closed. Officials said part of the levee south of Highway 33 had eroded Sunday and water was leaking out, although the levee had not completely collapsed.

Kathy Matavka said she was taken from her home by boat after she received a second call urging her to evacuate.

"If I didn't sit there and take the boat, I would be stuck. I would not be able to get groceries. I would not be able to get medications I need to take," Matavka told WISC-TV in Madison.

The levee is part of the Caledonia-Lewiston Levee System — several dikes built mainly out of sand during the 1890s by homeowners living near the river, according to the Wisconsin Department of Natural Resources.

Kevin Remus told the Portage Daily Register that he and his wife decided to leave their home with their 17-month-old daughter because they were concerned about being cut off from the outside word. Their house wasn't likely to flood because it's on a hill, but the access road was already covered in 6 inches of water by the time the family was ready to leave.

His wife, Lindsay, said the family planned to stay in a motel for a few days.

"It's kind of a feeling of hopelessness," she said. "The water is out of control."

The Wisconsin River is swollen from thunderstorms last week that dumped several inches of rain in southern Minnesota and central Wisconsin.

The Columbia County Emergency Management Office warned residents in the Blackhawk Park area that emergency vehicles, including police, fire and ambulances, would not be able to reach those who stayed behind.

"The residents down there are used to having high water and dealing with high water a lot but this could be something that they've never seen, with this amount of water," said Kathy Johnson, deputy director of the Columbia County Emergency Management Office.

Johnson said those who evacuated might be out of their homes for up to a week, and the Red Cross opened a shelter at a local church.

Elsewhere, in the small South Dakota town of Renner, just north of Sioux Falls, thousands of sandbags were being filled to deal with any unexpected rise of the Big Sioux River.

The National Weather Service expects the river to crest Monday morning about 4 feet over flood stage.

The Big Sioux River has been running high all summer. Heavy rain last week pushed the river over its banks from Brookings south to Sioux Falls.

In Minnesota, residents of Zumbro Falls and Hammond — two of the cities hardest-hit by flooding from last week's heavy rains — got a chance to briefly go to their homes to fetch medications or other essentials. It was the first look many had of the damage.