Drought conditions continue to impact the upper Missouri River Basin above Sioux City, Iowa (upper Basin). July runoff in the upper Basin was 34% of average. July runoff above Fort Peck Dam was the lowest in 123 years of record-keeping.
The updated 2021 upper Basin runoff forecast is 14.6 million acre-feet (MAF), 57% of average. If realized, this runoff amount would be the 10th driest year in the upper Basin since 1898. System storage on August 1 was 53.9 MAF, 2.2 MAF below the base of the Annual Flood Control and Multiple Use Zone. System storage is expected to decline further into the Carryover Multiple Use Zone during the remainder of 2021.