Overflowing Ohio, Mississippi Rivers Raise Specter of Midwest Flooding

(Bloomberg) -- An onslaught of rains over several months has raised water levels for the Ohio and Mississippi Rivers, threatening floods along banks in the U.S. Midwest.

The Ohio River at Cairo, Illinois, is forecast to crest 1.5 feet (0.5 meter) above major flood stage by Sunday, its 12th-highest in records going back to at least 1882. All that water will flow into the Mississippi River, raising flood concerns there for the next few weeks, according to the National Weather Service.

The torrent could raise some shipping concerns along the Mississippi, which is a major transportation route, through the middle of March. About 60 percent of all exported U.S. grain travels the river and the farmland along in its watershed accounts for 92 percent of the nation’s agriculture exports, according to the National Park Service. The Mississippi River drains parts of 32 states and two Canadian provinces, making it the fourth-largest watershed in the world.

The flood threats come after the contiguous U.S. had its wettest August to January on record, according to the National Centers for Environmental Information in Asheville, North Carolina. The saturated soils haven’t had a letup, with flooding rains arriving this week and another system expected to drop rain throughout the South and Midwest this weekend.

While about 45 percent of the 279 river gauges in the southern Mississippi area are close to or above flood stage, conditions probably won’t be as bad as last year, said Jeff Graschel, a hydrologist with the Lower Mississippi River Forecast Center in Slidell, Louisiana. Tributaries flowing into the Mississippi in Louisiana are actually running lower, so that is taking pressure off the channel along Baton Rouge and New Orleans, which is lined with refineries and chemical plants.

Graschel said more rain and a quick melt of the snowpack across the upper Midwest could pose additional flooding problems later this spring.

“We have to keep an eye on that additional rain,” Graschel said.

To contact the reporter on this story: Brian K. Sullivan in Boston at bsullivan10@bloomberg.net

To contact the editors responsible for this story: Millie Munshi at mmunshi@bloomberg.net, Joe Richter

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