By Tim Phillips 
The Missouri River Runoff Forecast shows runoff returning to more normal levels after the below-average 2025
For the 2025 calendar year, Missouri River basin runoff above Sioux City, Iowa, totaled 19.9 million acre-feet, 78% of average. For 2026, the U.S. Army Corps of Engineers is forecasting runoff in the Missouri River basin above Sioux City, Iowa, to be near-average at 24.5 MAF, 96% of average.
The 2026 forecast is based on current runoff trends, soil moisture conditions, generally below-average plains snowpack and near-average mountain snowpack. At the start of the 2026 runoff season, which typically begins around March 1, the total volume of water stored in the Missouri River Mainstem reservoir system is expected to be 49.0 MAF, 7.1 MAF below the top of the carryover multiple-use zone. The System is designed to use the water contained within the carryover multiple use zone to support the eight Congressionally authorized purposes during extended droughts. Those purposes are flood control, navigation, water supply, irrigation, hydropower, recreation, water quality control, and fish and wildlife.
Stan Ozark