Maintenance of city sewer lines is causing quick bursts of water to splash out of residents' toilets.

The problem has affected about 20 of Frankenmuth's 1,200 households.

"It's just real strange," City Manager Charles Graham told The Saginaw News for a story Friday.

The maintenance usually causes only mild gurgling, Graham said. But in some homes, water has burst onto walls and floors in the city 70 miles north of Detroit.

Department of Public Works crews use a spray nozzle to boost the water pressure in sewer pipes each year to flush out the pipes.

The city previously had placed notices in a local newspaper to alert residents about the work. But because of the recent splashing, the city decided to post notices on residents' doors urging them to take precautions.

The maintenance still is under way and usually takes about a week.

The city is not sure when this year's work will end because Public Works employees are busy plowing snow and salting roads.