(NAFB.com) – January runoff in the Missouri River Basin above Sioux City, Iowa, was one million acre-feet, which is 132 percent of the average. Runoff was above average for all the reaches in the upper Missouri River Basin, even though most of the upper Basin had below-normal precipitation. This was due to above average temperatures causing early snowmelt. The updated 2026 calendar year runoff forecast for the Missouri River Basin above Sioux City continues to be below average. “Runoff into the reservoir system was above-average for the month of January despite the dry conditions across the basin,” said John Remus of the U.S. Army Corps of Engineers. “With the below-average plains and mountain snowpack, we are forecasting a below-average runoff year for the Basin, resulting in reduced flows from the reservoirs, particularly in the upper basin.” The 2026 calendar year runoff forecast above Sioux City is 23.4 million acre-feet, 91 percent of the average.
