For the 2023 calendar year, Missouri River Basin runoff above Sioux City, Iowa totaled 30.4 million acre-feet (MAF), 118% of average. Despite the above average runoff last year, the U.S. Army Corps of Engineers is forecasting below-average runoff into the mainstem reservoir system this year. For 2024, runoff in the Missouri River Basin above Sioux City, Iowa is forecast to be 20.1 MAF, 78% of average.