Runoff in the Missouri River Basin above Sioux City, Iowa, in July 2026 was 61% of average– or 2 million acre-feet (MAF). According to the U.S. Army Corps of Engineers, the 2026 calendar year runoff forecast for the upper Missouri River Basin 60% of average– or 15.4 MAF,– nearly the same as la st month’s forecast. If realized, this forecast would be the 11th lowest runoff in the period of record. The Corps says runoff was below-normal to well-below-normal in the Oahe, Garrison and Fort Peck reaches due to lack of precipitation, dry soils, and below-average mountain snowpack. Runoff was above normal in the Fort Randall and Gavins Point reaches and near normal in the Sioux City reach. The U.S. Drought Monitor indicated 80% of the basin is still considered abnormally dry or in drought conditions. By the end of October, indicators show drought conditions are likely to persist or expand in South Dakota, North Dakota, Nebraska and Iowa, while they’re expected to improve for much of Montana, Wyoming and Colorado. The six mainstem power plants generated 747 million kWh of electricity in July, 199 million kWh lower than the typical energy generation for July which is 946 million kWh. The power plants are expected to generate 7.1 billion kWh this year, compared to the long-term average of 9.3 billion kWh. Reservoir Forecasts: Big Bend Dam Average releases past month – 24,400 cfs Forecast average release rate – 26,900 cfs Forecast end-of-August reservoir level – 1420.8 feet Oahe Dam Average releases past month – 23,800 cfs Forecast average release rate – 27,300 cfs End-of-July reservoir level – 1596.0 feet (down 1.9 feet from June 30) Forecast end-of-August reservoir level – 1593.7 feet The forecast reservoir releases and elevations discussed above are not definitive. Additional precipitation, lack of precipitation or other circumstances could cause adjustments to the reservoir release rates. To view the detailed three-week release forecast for the mainstem dams, go to https://go.mil/mr-3wk-fcast. The Missouri Basin Web App provides links to these reports and others that are updated more frequently. https://go.mil/mr-webapp. ...read more read less