Even though some farmland in the region is already flooded from recent heavy rains, the experts say below-normal runoff is expected in the Missouri River basin during the months ahead.
Jody Farhat, chief of the U.S. Army Corps of Engineers office in Omaha, says they are carefully monitoring the changing conditions.
“The reservoir system is well positioned to provide good support for all of the authorized purposes this year, including flood control,” Farhat says. “We’ll continue to monitor conditions in the basin and be prepared to make necessary adjustments in response to rainfall events, particularly in portions of the basin where soil moisture levels are much wetter than normal.”
Widespread rain late last month increased flows on many of the tributaries that join the Missouri River below the reservoir system. That caused river levels to rise above flood stage. Farhat says they have limited options to control that downstream flooding.
“When possible, releases from the mainstem reservoirs will be adjusted to reduce the impacts of these events and sufficient flood control capacities exist in the reservoir system to do so,” she says. “The Corps’ ability to significantly reduce flood risk along the lower Missouri River diminishes at locations further downstream due to the large uncontrolled drainage area and the travel time from Gavins Point Dam.”
The Corps says runoff in the Missouri River basin above Sioux City, Iowa, was two-point-six million acre feet during April, which is only 89% of average. The runoff forecast for the year ahead is 22-point-five million acre feet, which is also 89% of average.
By Jerry Oster, WNAX, Yankton