Lower Midwest braces for flood onslaught

June 16, 2008

WUSTL geologist Robert Criss warns of "serious water" that could give some areas their second worst flood on record. Photo courtesy of NOAA.

Residents of the central and southern Midwest are crossing their fingers, saying their prayers, planning evacuations, and in some cases filling sandbags in preparation for the excessive water ravishing communities in Iowa and Wisconsin.

"The flood wave is propagating down the Mississippi River towards St. Louis at about the pace of a brisk walk," said Robert E. Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis. "Some areas north of St. Louis in Missouri and southern Iowa are bracing for the second worst flood in their history. This is serious water."

Criss is a geologist. One of his specialties is hydrogeology. He said that the floodwaters are projected to crest at St. Louis at 38 feet on June 22 or 23, marking the 11th time since the Civil War that St. Louis has reached that flood stage. During the flood of 1993 waters at St. Louis crested at 49.6 feet.

The Missouri River at St. Charles on June 13 was 27.6 feet That's close to three feet above flood stage, and it is still rising.

"The water already is in place," Criss noted. "Projecting it downstream doesn't rely on weather predictions."

Indeed, more precipitation is the wild card.

"More rainfall is only going to make problems worse," Criss said. "If the region gets significantly more precipitation during the week of June 16, it could make a place like Winfield, Mo. surpass even its flood of '93 totals."

Criss said that flood projections, made "remarkably accurately" by the National Weather Service, indicate that Winfield should come within a foot or two of its 1993 totals. Crops in those areas are lost for the year, and it's too late to replant.

Criss said that rainfall in much of the Midwest this year has been inordinately high. In St. Louis, for instance, normal rainfall by the middle of June is 17 inches. But this year it is at 30 inches, roughly 75 percent of the yearly average of 38 inches.

"Our part of the nation, Missouri, Iowa, Wisconsin, Indiana, Illinois, is getting all of the country's water," he noted. ""We're surrounded by drought elsewhere. It's very odd."

Criss expects that the St. Louis area will escape the brunt of the flood's damage, but that smaller communities such as Hardin, Ill., less than 60 miles from St. Louis and reporting water damage to low-lying homes already, are more threatened.

"If we have extensive flooding on the lower Missouri, brought about by heavy rainfall, that could change the situation in St. Louis and elsewhere," Criss said. "That all is dependent on the luck of the draw. We're on the cusp of having a very interesting year."

Source: Washington University in St. Louis