Army Corps to reduce Gavins Point releases around Nov. 22
In two virtual public meetings held Nov. 2, U.S. Army Corps of Engineers’ Missouri River Water Management Division presented current hydrologic conditions and planned operation of the Missouri River mainstem reservoir system for the remainder of 2020.
Public meetings are held each fall and spring to update the region on current conditions and planned operations. The Nov. 2 meetings included draft plans for operating the system during 2021.
“We will continue to make releases from Gavins Point Dam to meet full service Missouri River navigation flow targets through the end of the navigation flow support season,” said John Remus, chief of the USACE Missouri River Water Management Division.
Gavins Point release reductions are scheduled to begin around Nov. 22. Releases will be stepped down by approximately 3,000 cubic feet per second each day until reaching the winter release rate of 17,000 cfs.
The navigation flow support season normally ends on Dec. 1 at the mouth of the Missouri River. Gavins Point Dam winter releases normally range from 12,000 - 17,000 cfs.
Despite cold, snowy weather in October, precipitation was well-below normal in much of the upper basin. The 2020 calendar year runoff forecast for the upper basin, updated on Nov. 2, is 30.2 million acre-feet, 117% of average. Average annual runoff for the upper basin is 25.8 MAF.
As of Nov. 5, the total volume of water stored in the System was 57.1 MAF, occupying 1.0 MAF of the System’s 16.3-MAF flood control zone. System storage peaked at 61.8 MAF on July 16 and is expected to continue to decline in the late fall and winter. All 16.3 MAF of flood control storage is expected to be available prior to the start of the 2021 runoff season.
Most of the basin is experiencing some form of drought. The latest National Drought Mitigation Center drought monitor shows drought degradation over large areas of Montana and North Dakota. The basin continues to have large areas of Extreme Drought in Colorado, Wyoming, and western Nebraska, with severe to moderate drought in large areas of Montana, North Dakota, South Dakota, Nebraska, and Iowa.
As previously announced, the July 1 System storage check indicated flow support for the second half of the navigation season would be at least at the full-service level for a full-length 8-month flow support season. Full-service flow support is designed to work in tandem with the Missouri River Bank Stabilization and Navigation Project to provide a 9-foot deep by 300-foot wide navigation channel from Sioux City, Iowa to the mouth of the river near St. Louis, Missouri. Flow support is expected to end on the dates indicated below:
Sioux City, Iowa: Nov. 22
Omaha, Nebraska: Nov. 24
Nebraska City, Nebraska: Nov. 27
Kansas City, Missouri: Nov. 27
Mouth near St. Louis, Missouri: Dec. 1
Fall Public Meetings
Recordings of the fall virtual public meetings held Nov. 2 and meeting materials are available online.