News Releases

Corps continues preparing reservoir system for 2020 runoff season

Northwestern Division
Published Jan. 7, 2020
Upper basin runoff for 2019 was 60.9 MAF, 0.1 MAF below the record.
Runoff for 2020 is forecast to be 36.3 MAF. If realized, this would be the 9th largest runoff year in 122 years of record.
System storage is 56.8 MAF; 0.7 MAF of the 16.3 MAF of flood control storage is occupied. Based on the updated forecast, increased system releases will be required as we attempt to evacuate the entire 16.3 MAF of flood storage.
Mountain snowpack is accumulating at below average rates in the Fort Peck and Garrison reaches (upper right quadrant).
Around 1 to 3 inches of snow water equivalent (SWE) remain in central and eastern South Dakota, and 2 to 4 inches of SWE remain in south central North Dakota (lower right quadrant).

Upper basin runoff for 2019 was 60.9 MAF, 0.1 MAF below the record. Runoff for 2020 is forecast to be 36.3 MAF. If realized, this would be the 9th largest runoff year in 122 years of record. System storage is 56.8 MAF; 0.7 MAF of the 16.3 MAF of flood control storage is occupied. Based on the updated forecast, increased system releases will be required as we attempt to evacuate the entire 16.3 MAF of flood storage. Mountain snowpack is accumulating at below average rates in the Fort Peck and Garrison reaches (upper right quadrant). Around 1 to 3 inches of snow water equivalent (SWE) remain in central and eastern South Dakota, and 2 to 4 inches of SWE remain in south central North Dakota (lower right quadrant).

Missouri River Water Management Monthly Update - Each month, from January through the end of the runoff season, Missouri River water managers and weather forecasters report the conditions of the Missouri River Basin.

Missouri River Water Management Monthly Update - Each month, from January through the end of the runoff season, Missouri River water managers and weather forecasters report the conditions of the Missouri River Basin.

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.

OMAHA, NE – The U.S. Army Corps of Engineers continues to prepare the Missouri River Mainstem System for the 2020 runoff season. Gavins Point releases will be increased from 27,000 cubic feet per second to 30,000 cfs this week. Gavins Point Dam winter releases normally range between 12,000 and 17,000 cfs.

“The higher-than-average winter releases from Gavins Point will continue to empty stored water from the 2019 runoff season,” said John Remus, chief of the Corps’ Missouri River Basin Water Management Division.

“Warmer-than-average temperatures and higher-than-average forecast runoff during January and February led to the increase in Gavins Point releases. Even with the 30,000 cfs Gavins Point release, current forecasts show that approximately 0.4 MAF of the 2019 runoff will remain in storage. Releases from all projects will remain as high as basin conditions permit during the remainder of winter. We will continue to monitor the basin conditions and will remain aggressive in our releases to the extent it is practicable,” added Remus.

The 2019 calendar year runoff was 60.9 million acre feet, the second highest runoff in 121 years of record-keeping (1898-2018), exceeded only by the 61.0 MAF of runoff observed in 2011. As of Jan. 6, the total volume of water stored in the System is 56.8 MAF, occupying 0.7 MAF of the 16.3 MAF combined flood control storage zones. Based on current soil moisture conditions, current plains and mountain snowpack, and long-term temperature and precipitation outlooks, the 2020 calendar year runoff forecast is 36.3 MAF above Sioux City, Iowa, 143%of average. Average annual runoff is 25.8 MAF. The runoff forecast will be updated on a monthly basis, and more often if warranted, throughout 2020.

Navigation:

Current studies indicate that flow support for Missouri River navigation will be above full service levels for the first half of the 2020 season, which begins on April 1 at the mouth. The actual service level will be based on the total volume of water stored in 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 actual July 1 System storage.

Ice Conditions:

River ice conditions below all System projects will be closely monitored throughout the winter season. Garrison releases were reduced last week in response to river ice conditions near Bismarck, North Dakota. River stages near Bismarck are now dropping to expected levels; Garrison releases will be increased this week to continue evacuating stored flood waters. The Corps will also continue to monitor basin and river conditions, including plains and mountain snow accumulation, and will adjust System regulation based on the most up-to-date information. The river ice report is available here: https://go.usa.gov/xpZZX.

Mountain Snowpack:

The mountain snowpack accumulation period is underway. Mountain snowpack is currently slightly below average in both reaches; however, the mountain snowpack accumulation period is less than 50% complete. The mountain snowpack normally peaks near April 15. The mountain snowpack graphics can be viewed here: https://www.nwd-mr.usace.army.mil/rcc/reports/snow.pdf.

Weekly updates on basin conditions, reservoir levels and other topics of interest can be viewed here: https://www.nwd-mr.usace.army.mil/rcc/reports/pdfs/weeklyupdate.pdf.

Final 2019-2020 Annual Operating Plan

After reviewing comments received on the draft, the Missouri River Basin Water Management Division has prepared the Final Annual Operating Plan for the Missouri River Basin for 2019–2020. When release, the plan will be posted at: https://www.nwd.usace.army.mil/MRWM/Public-Meetings.

Monthly Water Management Conference Calls

Water management calls include an update from the National Weather Service’s Missouri Basin River Forecast Center, an update on the Missouri River mainstem reservoir system operations, and updates on the ongoing and planned flood recovery efforts in both the Omaha and Kansas City districts. The first call for 2020 will be held Tuesday, Jan. 7 for Congressional delegations; Tribes; state, county and local government officials, levee and drainage districts; and the media. Calls will be recorded in their entirety and made available to the public on the Defense Video and Imagery Distribution System at www.dvidshub.net/unit/usace-nwd.

Reservoir Forecasts

  • Gavins Point Dam
    • Average releases past month – 37,700 cfs
    • Current release rate – 27,000 cfs (as of Jan. 6)
    • Forecast release rate – 30,000 cfs (first week of January)
    • End-of-December reservoir level – 1207.2 feet
    • Forecast end-of-January reservoir level – 1207.5 feet
    • Notes: Releases will be increased to 30,000 cfs in January where they will remain for the rest of winter, basin conditions permitting.
  • Fort Randall Dam
    • Average releases past month – 32,600 cfs
    • End-of-December reservoir level – 1339.8 feet (up 1.9 feet from November)
    • Forecast end-of-January reservoir level – 1344.9 feet
    • Notes: Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point. The reservoir will continue to be refilled throughout the winter.
  • Big Bend Dam
    • Average releases past month – 30,600 cfs
    • Forecast average release rate – 30,200 cfs
    • Forecast reservoir level – 1420.5 feet
  • Oahe Dam
    • Average releases past month – 31,800 cfs
    • Forecast average release rate – 29,900 cfs
    • End-of-December reservoir level – 1607.9 feet (falling 2.2 feet during December)
    • Forecast end-of-January reservoir level – 1607.3 feet
  • Garrison Dam
    • Average releases past month – 20,500 cfs
    • Current release rate – 23,000 cfs
    • Forecast average release rate – 24,500 cfs
    • End-of-December reservoir level – 1839.2 feet (rising 0.1 foot during December)
    • Forecast end-of-January reservoir level – 1838.5 feet
  • Notes – Releases will be increased to 24,500 cfs during January once an ice cover is reestablished.
  • Fort Peck Dam
    • Average releases past month – 13,700 cfs
    • Current release rate – 13,000 cfs
    • Forecast average release rate – 13,000 cfs
    • End-of-December reservoir level – 2237.1 feet (down 1.8 feet from November)
    • Forecast end-of-January reservoir level – 2235.7 feet

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 919 million kWh of electricity in December. Typical energy generation for December is 684 million kWh. The power plants are projected to generate 11.5 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://www.nwd-mr.usace.army.mil/rcc/reports/twregfcast.pdf.

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 1967-2019 Average

Change in December

Fort Peck

2237.0

-1.8

15,442

107

-383

Garrison

1839.2

+0.1

18,259

102

+50

Oahe

1607.9

-2.2

18,785

106

-538

Big Bend

1421.5

+0.9

1,680

99

+40

Fort Randall

1339.8

+1.9

2,320

69

+122

Gavins Point

1207.2

+0.5

356

91

+12

 

 

Total

56,842

102

-697

 

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

13.7

841

132

Garrison

20.5

1,260

192

Oahe

31.8

1,954

280

Big Bend

30.6

1,883

109

Fort Randall

32.6

2,007

150

Gavins Point

37.7

2,321

56

 

 

Total

919


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

Release no. 20-001