News Releases

Dry Conditions expected to persist for the Missouri River Basin

Missouri River Water Management
Published Jan. 6, 2022
Runoff can enter the Missouri River anywhere and anytime in the basin. Only when runoff occurs in the upper Missouri River basin can it be captured by the mainstem system of dams. Even then, where runoff is captured depends upon where precipitation falls.

Runoff can enter the Missouri River anywhere and anytime in the basin. Only when runoff occurs in the upper Missouri River basin can it be captured by the mainstem system of dams. Even then, where runoff is captured depends upon where precipitation falls.

The six dams on the main stem of the Missouri River capture runoff from parts of Montana, North Dakota, South Dakota, Wyoming, and northern Nebraska.

The six dams on the main stem of the Missouri River capture runoff from parts of Montana, North Dakota, South Dakota, Wyoming, and northern Nebraska.

The 2021 calendar year runoff summation for the Missouri River basin above Sioux City, Iowa was 15.2 million acre-feet, 59% of average. The ongoing drought shows no relief in sight and the U.S. Army Corps of Engineers is predicting runoff into the mainstem reservoir system will remain below normal. This was the 10th lowest annual runoff for the Missouri River Basin in 123 years of record-keeping.

Based on current runoff trends, soil moisture, and plains and mountain snowpack, the dry conditions are expected to continue. The 2022 runoff in the Missouri River basin above Sioux City, Iowa is forecast to be 21.7 million acre-feet, 84% of average. At the start of the 2022 runoff season, which typically begins around March 1, the total volume of water stored in the mainstem reservoir system is expected to be 48.2 MAF, 7.9 MAF below the top of the carryover multiple use zone. The mainstem Missouri River reservoir system is designed to use the water contained within the carryover multiple use zone to provide service to the eight Congressionally authorized purposes during extended droughts. Those purposes are flood control, navigation, water supply, irrigation, hydropower, recreation, water quality control, and fish and wildlife.

Service to the authorized purposes will be reduced to conserve water in the reservoir system should drought conditions persist. Primary drought conservation measures outlined in the Master Manual include reducing winter releases and flow support for navigation. Flow support to navigation was reduced on July 1, 2021. A significant portion of the water stored in the multiple use zone was used in 2021 to serve the authorized purposes and resulted in implementation of water conservation measures.

To further conserve water in the Missouri River Mainstem reservoir system, minimum releases from Gavins Point Dam are scheduled this winter while still serving the needs of the municipal, industrial and powerplant water intakes along the lower river. 

Releases from Gavins Point were temporarily increased from 12,000 cfs to 16,000 cfs in late December and early January to mitigate some of the effects of the much colder temperatures across the lower basin.  Releases are currently at 14,000 cfs. 

“Releases were increased to replace water that was being locked up in river ice.  We plan to return to the scheduled winter release after this next round of cold weather,” said John Remus, Chief of the Missouri River Basin Water Management.

”Weather and river conditions will continue to be monitored, and releases from Gavins Point Dam will be adjusted to the extent possible to help mitigate the any negative effects of the cold weather. The Corps is aware of the importance of our operations to water supply.  There is and will be enough water in the river to serve the water supply needs.  Access to the water is the facility owner/operator’s responsibility.”

Navigation:

Navigation flow support for the Missouri River is forecasted to be at minimum levels for the first half of the 2022 season, which begins April 1 at the mouth of the river near St. Louis, Missouri. The actual service level will be based on the total volume of water stored within the System on March 15, in accordance with the guidelines in the Master Manual. Flow support for the second half of the navigation season, as well as navigation season length, will be based on the storage in the system on July 1.

Mountain and Plains Snowpack:

Mountain snowpack in the upper Missouri River Basin is accumulating at a below-average rate. The Jan. 4 mountain snowpack in the Fort Peck reach was 88% of average, while the mountain snowpack in the Fort Peck to Garrison reach was 86% of average. More than half of the mountain snowfall typically occurs from Jan. 1 to mid-April, and it normally peaks near April 15. The mountain snowpack graphics can be viewed at: http://go.usa.gov/xARQC.  Currently, plains snowpack in the upper Missouri River Basin is sparse.

Final 2021-2022 Annual Operating Plan Released:

The final Annual Operating Plan for the Missouri River Basin for 2021–2022 has been posted at https://www.nwd.usace.army.mil/MRWM/Reports/

Monthly Water Management Conference Calls Begin for 2022:

The first 2022 monthly conference call will be held Thursday, Jan. 6, to inform basin stakeholders of current weather and runoff forecasts and the planned operation of the reservoir system in the coming months. Presentation materials will be available via webinar. The call is intended for Congressional delegations; Tribes; state, county and local government officials; and the media. It will be recorded in its entirety and made available to the public on the Defense Video and Imagery Distribution System at https://go.usa.gov/xARQv.

Reservoir Forecasts:

  • Gavins Point Dam
    • Average releases past month – 12,400 cfs
    • Current release rate – 14,000 cfs
    • Forecast release rate – 12,000 cfs
    • End-of-December reservoir level – 1207.5 feet
    • Forecast end-of-January reservoir level – 1207.5 feet
    • Notes: The winter release rate will be at least 12,000 cfs and may be adjusted to lessen the impacts of winter ice formation.
       
  • Fort Randall Dam
    • Average releases past month – 9,800 cfs
    • End-of-December reservoir level – 1339.3
    • Forecast end-of-January reservoir level – 1344.6 feet
    • Notes: Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point.  The reservoir was drawn down to 1337.5 feet near the end of November 2021 to provide space for winter hydropower generation at Oahe and Big Bend. The reservoir will refill to the base of the flood control pool by the end of February.
       
  • Big Bend Dam
    • Average releases past month – 12,000 cfs
    • Forecast average release rate – 15,300 cfs
    • Forecast reservoir level – 1420.9 feet
       
  • Oahe Dam
    • Average releases past month – 15,300 cfs
    • Forecast average release rate – 20,000 cfs
    • End-of-December reservoir level – 1607.0 feet (down 1.5 feet during November)
    • Forecast end-of-January reservoir level – 1606.3 feet
       
  • Garrison Dam
    • Average releases past month – 15,700 cfs
    • Current release rate – 16,000 cfs
    • Forecast average release rate – 16,000 cfs
    • End-of-December reservoir level – 1828.2 feet
    • Forecast end-of-January reservoir level – 1827.6 feet
    • Notes – Releases were set at 16,000 cfs in anticipation of the river freeze-in at Bismarck, North Dakota and will be maintained at that rate in January.
       
  • Fort Peck Dam
    • Average releases past month – 8,300 cfs
    • Current release rate – 9,000 cfs
    • Forecast average release rate – 9,500 cfs
    • End-of-December reservoir level – 2225.0 feet
    • Forecast end-of-January reservoir level – 2223.3 feet
    • Notes: Releases will remain at 10,000 cfs in January and February.

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 463 million kWh of electricity in December. Typical energy generation for December is 686 million kWh. Total energy generation for 2021 was 9.6 billion kWh of electricity, compared to the long-term average of 9.5 billion kWh. Forecast generation for 2022 is 7.8 billion kWh.

To view the detailed three-week release forecast for the mainstem dams, go to: http://go.usa.gov/xAVmW.

MISSOURI RIVER MAINSTEM RESERVOIR DATA

 

Pool Elevation
(feet above mean sea level)

Water in Storage
(1,000 acre-feet)

 

On
December 31

Change in
December

On
December 31

% of 1967-2020
Average

Change in
December

Fort Peck

2225.0

-1.6

12,988

89

-316

Garrison

1828.3

-1.3

15,051

84

-350

Oahe

1597.0

+0.5

15,627

88

+181

Big Bend

1420.6

-0.1

1,663

98

-5

Fort Randall

1339.2

+2.3

2,287

69

+124

Gavins Point

1207.5

-0.3

362

93

-7

 

 

Total

47,978

86

-373

 

WATER RELEASES AND ENERGY GENERATION FOR DECEMBER

 

Average Release in 1,000 cfs

Releases in 1,000 acre-feet

Generation in Million kWh

Fort Peck

8.3

513

82

Garrison

15.7

966

139

Oahe

12.0

738

105

Big Bend

12.0

735

42

Fort Randall

9.8

605

58

Gavins Point

12.4

763

37

 

 

Total

463


Contact
Eileen Williamson
402-996-3802
eileen.l.williamson@usace.army.mil

Release no. 22-001