Unusually high water along the lower Mississippi and Atchafalaya rivers this summer could come to an end in the next couple of weeks as water levels along the Ohio River start to fall.

Water levels have stayed at flood level at Red River Landing, Baton Rouge and Morgan City for weeks.

“It’s been a pretty flat condition from Arkansas City to New Orleans,” said Jeff Graschel, coordination hydrologist for the Lower Mississippi River Forecast Center in Slidell.

Hydrologists watch river gauges on the Ohio River at Cairo, Illinois, to get an idea of what water levels in lower Mississippi River will do, he said.

“We’re actually starting to get some pretty good falls at Cairo,” he said.

Forecasts call for a drop of 7 or 8 feet at Cairo over the next five days.

“That’s really what’s going to let the river stage drop,” Graschel said.

Falling water levels at Cairo usually take between 10 and 14 days to start showing up in water levels in Louisiana, but the levels won’t drop quickly.

“It’s going to take several months to get down to levels we consider normal for the lower Mississippi River,” he said.

In Baton Rouge, the river was at 38.8 feet on Friday and is expected to stay at that level for several days but should start to fall by Aug. 4. In New Orleans, the levels should start falling by Aug. 6.

On the Atchafalaya River, Morgan City has seen higher than normal water levels as well because of the additional flow from the Mississippi River and the Red River. Heavy rainfall in Oklahoma in May and June swelled the Red River and caused flooding concerns in north Louisiana.

“It’s not something that’s typical for this time of year,” Graschel said.

Normally, high water in the lower Mississippi and Atchafalaya rivers reach their peak in March, maybe into June, he said.

“This is pretty unusual to have a crest at this time of year,” he said.

Follow Amy Wold on Twitter, @awold10.