The experts predict higher-than-average runoff into the Missouri River this summer, but they’re quick to add, the waterway should stay well below flood stage and remain within its banks.
Kevin Stom an engineer in the U.S. Army Corps of Engineers water control office in Omaha, says they have adjusted their forecasts.
“The 2014 calendar year forecast for July 1 is 33-million acre feet, 131% of normal, above Sioux City, and 30.1-million acre feet or 131% of normal above Gavins Point,” Stom says. “Compared to the June forecast, this is an increase of 1.9-million acre feet above Sioux City or 0.8-million acre feet above Gavins Point.”
With all of the heavy rain, Stom says run-off has increased in the past couple of months.
“June runoff was 8.3-million acre feet above Sioux City, or 153% of normal, and 1.2-million acre feet greater than forecast,” Stom says. “However, about 0.8-million acre feet of this additional runoff occurred in the Gavins Point to Sioux City reach as a result of the record flooding on the Big Sioux River.”
Corps engineer Alex Flanagan says there’s still plenty of water storage space in the upstream reservoirs.
“We have 60.6-million acre feet stored and this is 4.5-million acre feet above the top of the carryover and multiple use zone,” Flanagan says. “At this current storage level, 11.8-million acre feet of the 16.3-million acre feet total flood control storage is available to benefit flood risk reduction.”
Forecasters say precipitation across the Missouri River basin is expected to be above-normal for the next three months.
By Jerry Oster, WNAX, Yankton