Washington  - Sandbag levees were breached Saturday in Iowa's capital Des Moines where flood waters swamped yet another midwestern city.

Authorities began to evacuate homes after a flood wall was breached near a school, broadcaster CNN reported.

At least nine rivers in the state have flooded in what authorities are referring to as a 500-year flood event.

Several other midwestern states, including Indiana, Illinois, Wisconsin and Minnesota also have areas facing major flooding according to the US Geological Survey.

A record cresting of the Iowa River in Iowa City was expected Saturday as the city called for more volunteers to heft sandbags in efforts to keep the river at bay.

Water is still flowing through neighboring Cedar Rapids downtown where some 1,200 city blocks have flooded and Friday authorities evacuated large parts of the city. More rain was forecasted there and a tornado warning was issued late Saturday.

The flooding comes after a week of heavy rains pushed the Cedar River to record highs, causing estimated damage of some 750 million dollars, according to a fire department official. The river crested at over 10 meters, six meters higher than the normal flood stage and four meters higher than the previous record. Fire Department spokesman Dave Koch estimated that it could be as long as ten days till the water is drained from the town.

Hundreds of houses in the Cedar Rapids were destroyed or severely damaged. Even a hospital with 176 patients had to be evacuated after water infiltrated the lower floors.

Emergency first responders all across the Midwest are busy monitoring river level gauges and studying maps showing the 100 and 500-year floodplains to manage the impact of the flooding and evacuation orders.

All told, 15 people have died in Iowa and thousands have been left homeless with 83 of the state's 99 counties declared disaster areas. (dpa)