Omaha, Neb. — The U.S. Army Corps of Engineers (Corps) Missouri River Basin Water Management Division reports May runoff in the Missouri River Basin above Sioux City, Iowa, was 3.7 million acre feet (MAF), 110 percent of normal. The 2015 runoff forecast has increased to 22.5 MAF, 89 percent of normal. Average annual runoff is 25.2 MAF.