The U.S. Army Corps of Engineers said they will start reducing releases of water today from upper dams on the Missouri River.
Water releases from Gavins Point Dam in South Dakota will be reduced from 58,000 cubic feet per second to 55,000 cfs, and will be incrementally reduced over the next few weeks to winter release rates ahead of the river's icing-in in the upper portions of the river basin.
Releases from Gavins Point are forecast to be 20,000 cfs by Dec. 11. Corps officials added releases from Gavins Point are forecast to be higher than average, in the 20,000 cfs range, through the winter.
That's because the 2018 runoff year for the Missouri River Basin upstream from Sioux City, Iowa, is on track to be the third highest since recordkeeping began in 1898. The 2018 runoff forecast is 41.4 million acre feet. The highest runoff occurred in 1997 at 49 million acre feet.
"Although higher than average river levels have presented a challenge to those along the river on a few occasions, we were able to reduce releases when it would lessen flooding impacts from downstream rain events," said John Remus, chief of the Corps' Missouri River Basin Water Management Division.
Current system storage is 58 million acre feet with 1.9 million acre feet of stored runoff that still needs to be released before the 2019 runoff begins. System storage is projected to decline an additional 1 million acre feet by Dec. 1 with the remainder being released gradually through the winter.
"We have to clear most of the stored runoff before the river up north freezes over in December," Remus said. "The higher than average winter releases are necessary to evacuate the remainder of the 2018 runoff before the 2019 runoff begins."
As of Friday, the Missouri River was at 13.7 feet in Jefferson City and the National Weather Service forecast shows the river would stay at that level through next week.