Very dry conditions in April resulted in very low runoff in the upper Missouri River Basin. The US Army Corps of Engineers says upper Basin runoff was 44% of average, which was the 9 th driest April in 123 years of record. The updated 2021 upper Basin runoff forecast is 17.8 million acre-feet (MAF), 69% of average, which, if realized, would rank as the 22 nd lowest calendar year runoff volume. “The extremely dry April, current drought conditions, and below-normal mountain snowpack has led our office to significantly lower the 2021 calendar year runoff forecast,” said John Remus, chief of the U.S. Army Corps of Engineers’, Missouri River Basin Water Management Division. “Based on this forecast, the May reservoir monthly studies indicate reduced flow support for navigation during the second half of the navigation season and a 12,000-cfs Gavins Point winter release rate. I urge all water users, particularly intake owners, to begin preparing for the possibility of lower river levels later this summer and during the fall and winter.”