July runoff in the Missouri River basin above Sioux City, Iowa, was 3.3 million acre-feet, 99 percent of the average. Runoff was near or above average in all reaches except the Fort Peck reach, which was 68 percent of the average.
“Soil moisture conditions deteriorated in Montana, North Dakota, and northern South Dakota over the last month and improved across southern South Dakota and into the lower basin,” says John Remus, Army Corps of Engineers Chief of the Missouri River Basin Water Management Division. Precipitation was below normal over most of the upper Missouri River basin last month except for small areas in Wyoming and southern South Dakota. The lower basin saw a mix of above-and-below-normal precipitation.
The annual runoff forecast above Sioux City is 28.5-million-acre feet, 111 percent of average. System storage on August 1 was 56.3-million-acre feet, 0.2-million-acre feet above the base of the Annual Flood Control and Multiple Use zone.