Volunteers were evacuated from the area as water started coming through at about 2 a.m., the St. Louis Post-Dispatch reported. "It's a gradual inundation, no immediate threat to life, but if the levee were to open up wider, there would be problems," said Jon Carney, a National Weather Service meteorologist. "They have holes in the levee and water is gradually filling up that area."

The river continued to rise Tuesday in Missouri and Illinois after the expected crest.

Weather forecasts predicted the crest at places such as hard-hit Lincoln County, Mo., Wednesday. Meanwhile, emergency workers in Winfield, Mo., kept up desperate efforts to plug leaks in saturated levees, the Post-Dispatch said.

"We had to kick it back into gear and keep it going," Kelly Hardcastle, head of the county's emergency services, told the newspaper.

At Winfield, muskrats had burrowed into the levee, creating holes that let water through, the U.S. Army Corps of Engineers said.

The corps' commanding general toured flood-stricken areas Monday and heaped praise on the area's local governments and lauded the courage of volunteers.