For the 2024 calendar year, Missouri River basin runoff above Sioux City, Iowa totaled 23.3 million acre-feet, 91% of average. Dry conditions continue to affect the upper Missouri River Basin at the start of the 2025 calendar year, so the U.S. Army Corps of Engineers is forecasting below-average runoff into the mainstem reservoir system. For 2025, runoff in the Missouri River basin above Sioux City, Iowa is forecast to be 20.2 MAF, 79% of average.