Parts of areas in and around Des Moines, the capital of Iowa, were ordered to be evacuated by Friday evening after the state received information about river levels due to flood, a local TV reported.
The evacuations are for parts of Des Moines in what is called the 500-year flood plain, an area near the Des Moines and Raccoon Ribers, according to the report by KCCI TV channel.
The order was released after Army Corp. of Engineers projected lever along the Des Moines River would be close to the top of the levees on Friday.
Des Moines Mayor Frank Cownie said that the river would crest in downtown at 8 p.m. on Friday and continue through midnight.
"Very significant areas of our city need to evacuate their homes and businesses immediately," city police chief Judy Bradshaw told the TV.
He also said that policemen had been deployed to notify residents door-to-door in addition to a reverse 911 telephone callas emergency alert tool.
However, the evacuation order was still voluntary, said Public Works Director Bill Stowe, adding that it could turn mandatory if it is required by conditions.