Rain is threatening already strained levees and creating new river crests in parts of the U.S. Midwest, officials said Thursday.

Up to 12.7 centimetres of rain fell in parts of Iowa on Thursday. Parts of northeast Missouri and west-central Illinois received up to 2.5 centimetres of rainfall Wednesday night into Thursday, following strong downpours the night before.


In this June 17, 2008 photo, Mike Brewer works on securing the levee along the Mississippi River in Clarksville, Mo. The sandbags remain in place for now, just in case. ((Seth Perlman/Associated Press))

The levee in Canton, Mo., remained in good shape despite locally heavy downpours over the past two days, while the rain has been more damaging to levees south of the town, Canton emergency management director Jeff McReynolds said.

Meteorologist Marc Russell of the U.S. National Weather Service said rivers in southeast Iowa are still in the major flood category and any more rain, just a few centimetres, could cause flash flooding. The same goes for the Cedar Rapids and Iowa City areas, which suffered major flooding, Russell said.

The storms have prompted some area residents and businesses to delay plans to remove millions of sandbags.

Jo Anne Smiley, mayor of Clarksville, Mo., said it would be the end of July before officials in the town of 500 even think about taking down the sandbags.

Mayor John Spring of Quincy, Ill., said after a couple of days of not sandbagging, "We're going full-tilt once again."

Dry sandbags can safely be kept for future use. Once they're wet, however, they often become smelly, contaminated with bacteria and chemicals from river water.

The Army Corps of Engineers recommends that communities remove their wet sandbags and take the filthy sand to the dump once the threat of flooding has passed.

The storms and flooding from heavy rains that began in late May are blamed for killing 24 people and injuring nearly 150 others.

Floodwaters have caused more than $6 billion US in crop damage alone in Iowa, Indiana, Illinois, Missouri and Nebraska, according to the American Farm Bureau Federation.

With files from the Associated Press