Missouri River Runoff Near Average in September

September brought mixed results for precipitation across the Missouri River Basin. Parts of Montana, North and South Dakota, and Nebraska received above-average rainfall, while the remainder of the upper basin and lower basin were below average.

September runoff in the Missouri River Basin above Sioux City, Iowa, was 1.3 million acre-feet, 109 percent of the long-term average. The annual runoff forecast for the upper Missouri River Basin above Sioux City is 29.1-million-acre feet, 113 percent of average, and the same as last month’s forecast.

“Rainfall was above average in portions of the Upper Missouri River Basin during September,” says John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division. “Runoff was above average or near average in every reach except Sioux City, which was below average. He also says soil moisture conditions have improved in parts of the basin, but many parts remain abnormally dry.