DES MOINES, IOWA (AP) -- Residents of Ottumwa are being asked to conserve water after heavy rains caused a sewer to back up and flooded a pump room in the city's water plant.

Officials say limiting water usage is critical. The city is opening water distribution centers to provide safe drinking water.

Major employers have also shut down for the day.

City Administrator Andrew Morris says water use is leveling and fears the city would run out of water are being calmed. Residents, however, are being told to use a little water as necessary.

The National Weather Service says up to 8 inches of rain fell across the region between Thursday and Friday, creating flash flooding in at least six counties.

Meanwhile, sandbagging is under way in Keosauqua because of the rising Des Moines River. The river is expected to crest at more than 32 feet this afternoon, more than 10 feet above flood stage.

David Miller of Iowa Homeland Security and Emergency Management says up to 2 feet of water could flood the town when the river crests.

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