OMAHA, Neb. — The amount of water released into the lower Missouri River will increase this month as expected but will be less than the amount usually released in March, a move that could affect river shipping and offers mixed news on whether drought will ease or worsen this year.
The Army Corps of Engineers on Tuesday stood by last month's prediction that winter runoff from melting snow and rain into the river above Sioux City, Iowa, will be 80 percent of normal this year. That forecast helped the corps determine how much water to release from the Gavins Point dam on the South Dakota-Nebraska border.
The corps announced in a conference call from Omaha that starting Monday, the amount of water will be increased from about 14,000 cubic feet per second to between 23,000 to 28,000 cubic feet per second to help support barge traffic on the river. The corps said it plans to increase water releases over several days until the river's navigation channel reaches the 8-foot-by-200-foot mark.
But that amount will provide only enough water for a minimal channel. A normal navigation channel is 9 feet deep and 300 feet wide, so barges may not be able to carry full loads this spring. Currently, the river is at a level that does not allow barge traffic.
The corps also anticipates shortening the Missouri River navigation season by four days this year, based on the runoff forecast, said Jody Farhat, chief of the corps' Water Management Division for the Northwestern Division.
"But if we get much less runoff and things really dry out, our lower basin study indicated that the navigation study could be shortened by as much as 27 days," Farhat said.
The decision on whether to shorten the season will be made on July 1, based on the volume of water stored in the Missouri River reservoir system.
Typically, the corps releases enough water to allow barges to navigate the river until Dec. 1. This year, that could end as soon as early November if the drought worsens.
While the drought persists in most of the river basin that covers large parts of Montana, North Dakota, South Dakota, Nebraska, Iowa, Kansas and Missouri, recent rains and snow have improved drought conditions in the basin, said Doug Kluck, regional climate services director for the National Oceanic and Atmospheric Administration.
Temperatures should remain below normal for the next two weeks and the region could see more precipitation through the end of March, Kluck said. But temperatures in the late spring and summer are expected to be above normal, and experts are unable to predict whether the region will get more or less precipitation than normal in that time.
"We're really not able to key on any strong climate signal that would help us narrow that down," Kluck said. "As time goes on, we'll be able to do a little bit better."
The unpredictability of spring rains has plagued the corps before. Melting snow and heavy rains in 2011 led to historic flooding along the Missouri River. The onslaught lasted for more than 100 days, flooding farmland in Kansas, Missouri, Nebraska and Iowa. Only a year later, the same area was plagued by drought.