WEST ALTON, Mo. (KSDK) - West Alton, Mo. residents were ordered to evacuate after water overtopped a levee and a temporary barricade set up by the Missouri Department of Transportation failed.

PHOTOS:West Alton residents ordered to evacuate

Colene McEntee, public affairs coordinator for the St. Charles County government, said warning sirens were activated Monday night, and all residents needed to leave the area.

Fire Chief Richard Pender said water started to cover Route 67 earlier Monday after a temporary flood barricade gave way. They closed the road, and started to create another barrier, but were unsuccessful.

PHOTOS:Missouri flooding

Corps of Engineers spokesperson Mike Peterson said the Consolidated North County Levee did not breach in West Alton and that there's no major concern that it will fail.

Rivers Pointe Fire Protection District firefighters have a map book and created a grid system. They started going street-to-street and door-to-door notifying residents around 8:30 p.m. Monday. They started with homes that could be affected first, and then spreading out.

If water makes it to Highway 94, the decision may be made to shut down the trestle.

PHOTOS:Illinois flooding

Chief Pender says water could head south on Route 67, and if it gets to the train trestle, that will be its direct route into town. He says residents have hours before the water reaches homes, but does not have a more exact time.

NewsChannel 5's Art Holliday says residents are apprehensive about property loss, but are leaving the area.

The population of West Alton is 573.