Levee breaks in Iowa's flooded capital
A mandatory evacuation was ordered for homes in the Birdland Park area after a 30-metre gap opened in the levee.
Crews later created a temporary mound of earth in an effort to stop the water from flowing into more populated neighbourhoods.
The breach came only hours after the Des Moines River had crested and began to drop slightly.
On Friday afternoon, city officials issued a voluntary evacuation request for parts of the downtown area near the river.
Meanwhile, a 400-block area of downtown Cedar Rapids, about 160 kilometres northeast of the state capital, remained under water on Saturday.
The Cedar River crested on Friday and started to recede, but officials said it would be about four days before water levels drop enough to allow crews to start pumping water.
It's estimated about 20,000 people have been forced from their homes in the city, which has a population of 120,000.
No deaths or serious injuries have been reported in Iowa because of the flooding, the result of heavy rain.
With files from the Associated Press