Reduced releases from the Gavins Point Dam to the winter release rate on began Nov. 23 with the navigation flow support season ending on Dec. 1 at St. Louis.

“Releases from Gavins Point Dam are being reduced to the 12,000 cubic feet per second winter release rate by mid-December,” said John Remus, Chief of the Missouri River Water Management Division. “We will closely monitor river conditions, and releases will be adjusted to the extent practical to lessen the impacts of river ice formation on stages in the lower river.”  Releases were at 26,000 cfs prior to the reductions.

As the colder, winter temperatures enter the basin, USACE will closely monitor Missouri River ice conditions between the System reservoirs and downstream of Gavins Point Dam for potential ice jams that could impact river stages and water intakes.

Runoff in the upper Missouri River Basin above Sioux City, Iowa, was 0.9 million acre-feet during November, 81% of average. The 2025 calendar year runoff forecast is 19.6 MAF, 76% of average. Average annual runoff is 25.7 MAF.

The total volume of water stored in the Missouri River mainstem reservoirs on Nov. 30 was 48.8 MAF, which is 7.3 MAF below the base of the System flood control storage zone. System storage is forecast to begin the 2026 runoff season at 48.6 MAF, which is 7.5 MAF below the base of the system flood control zone.  

Releases from Fort Peck Dam are currently 5,000 cfs and are forecast to be held at that rate in January and February. Releases from Garrison Dam are currently 14,000 cfs and are forecast to be increased to 16,000 cfs in the second week of December.  Releases are forecast to remain at 16,000 cfs through the formation of a stable river ice cover at Bismarck, North Dakota and will be held at that rate through January and February. Releases from Fort Peck and Garrison are typically increased following the river freeze-in. However, releases from both reservoirs will be held at a lower rate this winter due to the unbalanced storage in the upper reservoirs.

Mountain and Plains Snowpack

Mountain snowpack in the upper Missouri River Basin is accumulating at below average levels. About 25% of the mountain snowpack typically accumulates by Dec. 1 and normally peaks in mid-April. The mountain snowpack graphics can be viewed here: https://go.mil/mr-mtn-snowpack. Currently, plains snowpack in the upper Missouri River Basin is sparse.

2025-2026 Annual Operating Plan

The comment period for the 2025-2026 Annual Operating Plan ended in November. The final AOP is scheduled for publication by the end of 2025 and will be posted on the Water Management website: https://go.mil/mr-publicmeetings

Reservoir Forecasts

• Gavins Point Dam
  • Average releases past month – 23,500 cfs
  • Current release rate – 14,000 cfs
  • Forecast release rate – 12,000 cfs
  • End-of-November reservoir level – 1207.7 feet
  • Forecast end-of-December reservoir level – 1207.5 feet
  • Notes: Releases were reduced to 14,000 cfs on Dec. 1. The winter release rate will be 12,000 cfs based on the Sept. 1 System storage check and may be adjusted to lessen the impacts of winter ice formation.
• Fort Randall Dam
  • Average releases past month – 20,700 cfs
  • End-of-November reservoir level – 1337.5 feet (down 7.0 feet during November)
  • Forecast end-of-December reservoir level – 1339.3 feet
  • Notes: Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point. The reservoir is normally drawn down to 1337.5 feet in the fall to provide space for winter hydropower generation at Oahe and Big Bend.  The reservoir will refill to the base of the flood control pool from December to February.
• Big Bend Dam
  • Average releases past month – 15,200 cfs
  • Forecast average release rate – 12,800 cfs
  • Forecast reservoir level – 1420.6 feet
• Oahe Dam
  • Average releases past month – 15,800 cfs
  • Forecast average release rate – 12,600 cfs
  • End-of-November reservoir level – 1599.8 feet (down 0.6 feet during November)
  • Forecast end-of-December reservoir level – 1600.4 feet
• Garrison Dam
  • Average releases past month – 13,900 cfs
  • Current release rate – 14,000 cfs
  • Forecast average release rate – 15,500 cfs
  • End-of-November reservoir level – 1830.4 feet (down 0.9 feet during November)
  • Forecast end-of-December reservoir level – 1829.0 feet
  • Notes – Releases will be set near 16,000 cfs prior to the river freeze-in at Bismarck, North Dakota and will remain at that rate through the winter.
• Fort Peck Dam
  • Average releases past month – 3,900 cfs
  • Current release rate – 5,000 cfs
  • Forecast average release rate – 5,000 cfs
  • End-of-November reservoir level – 2222.2 feet (down 0.1 feet during November)
  • Forecast end-of-December reservoir level – 2221.7 feet
  • Notes: Releases will remain at 5,000 cfs through the winter

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.

Hydropower

The six mainstem power plants generated 522 million kWh of electricity in November. Typical energy generation for November is 739 million kWh. The power plants are projected to generate 7.7 billion kWh of electricity this year, compared to the long-term average of 9.4 billion kWh.

To view the detailed three-week release forecast for the mainstem dams, go to https://go.mil/mr-3wk-fcast