News Releases

Below average runoff forecast for the upper Missouri River Basin in 2024

Missouri River Water Management Division
Published Feb. 6, 2024
Two tables the first showing Missouri River Mainstem Reservoir Data with the Pool Elevation at the end of the month and how much the elevation has changed during the month and how much water is in storage at the end of the month compared to the average and how much the amount of water in storage has changed in for the month. 

The second table shows water releases and energy generation in May at each reservoir. There are three columns of data Average releases in 1000 cubic feet per second, volume of releases in acre feet, and how much power was generated from releases at each project. The data is provided in the photo caption.

MISSOURI RIVER MAINSTEM RESERVOIR DATA Pool Elevation (feet above mean sea level) On January 31 Change in January Water in Storage (1,000 acre-feet) On January 31 % of 1967-2023 Average Change in January Fort Peck 2229.4 0.0 13,832 96 -14 Garrison 1836.9 -1.8 17,568 99 -560 Oahe 1600.0 -0.1 16,454 93 -24 Big Bend 1420.8 -0.2 1,675 98 -12 Fort Randall 1345.3 +4.3 2,658 80 +268 Gavins Point 1207.4 -0.6 360 93 -14 Total 52,547 95 -356 WATER RELEASES AND ENERGY GENERATION FOR JANUARY Average Release in 1,000 cfs Releases in 1,000 acre-feet Generation in Million kWh Fort Peck 5.6 341 49 Garrison 18.3 1,128 172 Oahe 16.3 1,005 147 Big Bend 16.2 997 57 Fort Randall 12.1 742 73 Gavins Point 14.4 885 42 Total 540

The graphic is a split screen with a snowscape showing plains snow and mountain snow with snow in the clouds. and statements that say. Plains Snow - snowmelt is typically complete by mid-April. Snow Melt - the rate of snowmelt and how much becomes runoff can be impacted by rainfall, air temperatures, and soil moisture. Mountain Snow - begins to accumulate in October. Snowmelt is typically complete by July. Base Flows - river stages will be higher when the soil is saturated and lower when the soil is dry. The left side of the graphic is the Mountain snow accumulation - Mountain Snowpack Water Content 2022-2023 with comparison plots from recent high and low years. At the bottom right is the current forecast.

The runoff into the reservoir system was well-below average for the month of January,” said John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division. “This fact in conjunction with the below-average plains and mountain snowpack indicates a below-normal runoff year for the basin.” The 2024 calendar year runoff forecast above Sioux City is 18.8 MAF, 73% of average. The runoff forecast is based on current soil moisture conditions, plains snowpack, mountain snowpack, and long-term precipitation and temperature outlooks.

The updated 2024 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa, continues to be below average.   

January runoff in the Missouri River Basin above Sioux City was 0.4 million acre-feet, 56% of average. Runoff was well-below-average due to much-below-normal temperatures over the whole Missouri River Basin and below-normal precipitation over most of the upper basin.

“The runoff into the reservoir system was well-below average for the month of January,” said John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division. 

“This fact in conjunction with the below-average plains and mountain snowpack indicates a below-normal runoff year for the basin.”

The 2024 calendar year runoff forecast above Sioux City is 18.8 MAF, 73% of average. The runoff forecast is based on current soil moisture conditions, plains snowpack, mountain snowpack, and long-term precipitation and temperature outlooks.

At the start of the 2024 runoff season, which typically begins around March 1, the total volume of water stored in the Missouri River Mainstem Reservoir System is expected to be 52.7 MAF, 3.4 MAF below the top of the carryover multiple use zone.

To conserve water in the System, releases from Gavins Point Dam are scheduled to be 13,000 cfs this winter while still serving the needs of the municipal, industrial and powerplant water intakes along the lower river. 

“While the target winter release from Gavins Point Dam is 13,000 cfs, releases were increased to 15,000 cfs in mid-January to mitigate some of the effects of the much colder temperatures across the lower basin,” said Remus.  Releases were reduced to 13,000 cfs at the end of the month and will be held at that rate through February.

“With weather conditions and river stages forecast to be more seasonal over the next few weeks, System releases are returning to the target winter rates,” said Remus.

Basin and river conditions continue to be monitored, including plains and mountain snow accumulation, and System regulation will be adjusted based on the most up-to-date information.

Navigation:
Navigation flow support for the Missouri River is forecast to be at 1,500 cfs below full-service for the first half of the 2024 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 well-below average rates. The Feb. 1, mountain snowpack in the Fort Peck reach was 51% of average, while the mountain snowpack in the Fort Peck to Garrison reach was 64% of average.  By Feb. 1, about 60% of the total mountain snowfall has typically accumulated.  Mountain snow normally peaks near April 17. The mountain snowpack graphics can be viewed at: http://go.usa.gov/xARQC.  

Fort Peck Flow Test:
Test releases from Fort Peck that would assess the potential benefits of alternative management scenarios for the pallid sturgeon are currently planned to be implemented in 2024.  The test includes two higher Fort Peck release periods, in late April and June, with target flows at Wolf Point, Montana.  The Fort Peck releases will be adjusted depending on the runoff and reach conditions downstream of Fort Peck during this period. The test will likely require spillway releases from Fort Peck.  The test releases will not affect the regulation below the reservoir system.

Monthly Water Management Conference Calls for 2024:
The February 2024 monthly conference call will be held Thursday, Feb. 8, 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 our website at https://go.usa.gov/xARQv.

Reservoir Forecasts:

  • Gavins Point Dam
    • Average releases past month – 14,400 cfs
    • Current release rate – 13,000 cfs
    • Forecast release rate – 13,000 cfs
    • End-of-January reservoir level – 1207.4 feet
    • Forecast end-of-February reservoir level – 1205.9 feet
    • Notes: The winter release rate will be at least 13,000 cfs and may be adjusted to lessen the impacts of winter ice formation.
       
  • Fort Randall Dam
    • Average releases past month – 12,100 cfs
    • End-of-January reservoir level – 1345.2
    • Forecast end-of-February reservoir level – 1349.7 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 2023 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 – 16,200 cfs
    • Forecast average release rate – 14,700 cfs
    • Forecast reservoir level – 1420.6 feet
       
  • Oahe Dam
    • Average releases past month – 16,300 cfs
    • Forecast average release rate – 14,500 cfs
    • End-of-January reservoir level – 1600.0 feet
    • Forecast end-of-February reservoir level – 1602.1 feet
       
  • Garrison Dam
    • Average releases past month – 18,300 cfs
    • Current release rate – 24,000 cfs
    • Forecast average release rate – 24,900 cfs
    • End-of-January reservoir level – 1836.9 feet
    • Forecast end-of-February reservoir level – 1834.4 feet
    • Notes – Releases were set at 16,000 cfs prior to the river freeze-in at Bismarck, North Dakota. Releases are gradually being increased to 25,000 cfs as downstream conditions permit to benefit winter hydropower generation and to better balance storage in the upper three reservoirs.
       
  • Fort Peck Dam
    • Average releases past month – 5,600 cfs
    • Current release rate – 5,000 cfs
    • Forecast average release rate – 5,000 cfs
    • End-of-January reservoir level – 2229.4 feet
    • Forecast end-of-February reservoir level – 2229.7 feet
    • Notes: Releases will remain at 5,000 cfs in 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 540 million kWh of electricity in January. Typical energy generation for January is 707 million kWh. Forecast generation for 2023 is 8.6 billion kWh 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 http://go.usa.gov/xVgWr.

MISSOURI RIVER MAINSTEM RESERVOIR DATA

 

Pool Elevation
(feet above mean sea level)

Water in Storage
(1,000 acre-feet)

 

On January 31

Change in January

On January 31

% of 1967-2023 Average

Change in January

Fort Peck

2229.4

0.0

13,832

96

-14

Garrison

1836.9

-1.8

17,568

99

-560

Oahe

1600.0

-0.1

16,454

93

-24

Big Bend

1420.8

-0.2

1,675

98

-12

Fort Randall

1345.3

+4.3

2,658

80

+268

Gavins Point

1207.4

-0.6

360

93

-14

 

 

Total

52,547

95

-356

 

WATER RELEASES AND ENERGY GENERATION FOR JANUARY

 

Average Release in 1,000 cfs

Releases in 1,000 acre-feet

Generation in Million kWh

Fort Peck

5.6

341

49

Garrison

18.3

1,128

172

Oahe

16.3

1,005

147

Big Bend

16.2

997

57

Fort Randall

12.1

742

73

Gavins Point

14.4

885

42

 

 

Total

540


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

Release no. 24-002