News Releases

Corps steps down releases from Gavins Point Dam, November runoff slightly below normal

Published Dec. 5, 2013
The Missouri River Water Management office releases a report at the beginning of each month to the public documenting the monthly river forecast and release schedule. The Missouri River Water Management Division is part of the Northwestern Division of the U.S. Army Corps of Engineers and is located in Omaha, Nebraska.

The Missouri River Water Management office releases a report at the beginning of each month to the public documenting the monthly river forecast and release schedule. The Missouri River Water Management Division is part of the Northwestern Division of the U.S. Army Corps of Engineers and is located in Omaha, Nebraska.

Omaha, Neb. — Gavins Point releases are currently being stepped down to minimum winter release rates as part of Missouri River Mainstem Reservoir System water conservation measures.

“In mid-November Gavins Point releases were set at 30,000 cubic feet per second (cfs) to meet the navigation flow targets on the Missouri River. After the navigation season ended, releases were stepped down to 14,000 cfs on Dec. 3,” said Jody Farhat, Chief of the Missouri River Basin Water Management Division. “Releases from Gavins Point will be gradually reduced to a minimum of 12,000 cfs this winter to conserve water in the reservoir system, as outlined in the Master Manual.” 

Gradual reductions from 14,000 cfs to 12,000 cfs will be made in coordination with the intake operators downstream from Gavins Point to the mouth to ensure water supply is served to the extent reasonably possible. Temporary increases above 12,000 cfs may be necessary to keep water intakes along the lower river operational particularly during periods of ice formation.

Runoff into the Missouri River Basin above Sioux City, Iowa, was 88 percent of normal during November. “After a wet October in the upper basin, with runoff more than twice normal, November’s runoff returned to more normal levels,” said Farhat. The forecast for annual runoff is near normal at 25.1 million acre feet (MAF),” said Farhat. Normal annual runoff is 25.2 MAF.

System storage declined 0.9 MAF in November. “Our current studies indicate that we will likely begin the 2014 runoff season more than 5 MAF below the base of the annual flood control and multiple use zone,” said Farhat. The annual flood control pool is the desired operating zone for the system because it allows the Corps to fully serve all eight congressionally authorized purposes. Fort Peck, Garrison and Oahe are expected to start the runoff season approximately 4 to 11 feet below the desired operating level.

Due to the below normal system storage, it is likely that the Corps’ flow support for Missouri River navigation will be slightly above minimum service for the first half of next year’s navigation season as a drought conservation measure. Minimum service flow support is designed to provide an 8-feet-deep by 200-feet-wide navigation channel rather than the 9 feet by 300 feet supported with full service flows. The actual service level will be set based on the March 15 system storage in accordance with guidelines in the Master Manual. With dry conditions next spring, flow support for the second half of the navigation season, as well as the navigation season length, may be reduced based on the July 1 storage check.

As of the end of November, the mountain snowpack was 112 percent of normal in the reach above Fort Peck and 113 percent of normal in the reach from Fort Peck to Garrison.

The comment period on the draft 2013–2014 Annual Operating Plan closed Nov. 15. The final plan will be published by the end of December. It will be published in the Reports & Publications section of the Water Management website at: http://www.nwd-mr.usace.army.mil/rcc.

Monthly Conference Calls to begin January

As was done in 2013, the Corps will begin monthly informational calls in 2014 as part of efforts to communicate more frequently and broadly with the basin stakeholders. The first call is scheduled for Jan. 9. During the calls, the Corps will discuss current basin conditions and the reservoir release plans and forecasts with Federal, state, county and local officials, Tribes, emergency management officials, independent experts and the media. Audio files of the conference calls will be made widely available.

Discontinuation of Hardcopy News Releases

The Corps has announced that January’s news release will be the last in hardcopy format. “We encourage interested parties to read our news releases on our website or they can sign up to have the news release emailed to them,” said Farhat. News releases are published under the Information section of the Water Management website at: http://www.nwd-mr.usace.army.mil/rcc. Interested parties also can sign up for the email version at the website by clicking on “Add Me to your Email List at the bottom of the home page.

Reservoir Forecasts

Gavins Point releases averaged 26,400 cfs during the month of November. Releases were gradually reduced from 30,000 cfs starting on Nov. 23 and reached 15,000 cfs on Nov. 27. Releases were held at that rate for six days before being reduced to 14,000 cfs on Dec. 3. The reservoir behind Gavins Point Dam ended November at elevation 1207.6 feet. It is expected to decrease to elevation 1207.5 by the end of this month.

Fort Randall releases averaged 24,100 cfs during November. Releases were stepped down approximately one day prior to Gavins Point releases and reached 13,000 cfs on Dec. 2. Releases will range from 10,000 cfs to 13,000 cfs for the remainder of December as necessary to maintain the elevation at Gavins Point. The reservoir ended November at elevation 1339.6 feet msl, down 6.9 feet during the month. The reservoir is expected to remain nearly steady during December. The reservoir is normally drawn down to elevation 1337.5 feet msl in the fall to provide space for winter hydropower generation at Oahe and Big Bend.

Big Bend releases averaged 16,600 cfs during the month of November. They are expected to average near 11,000 cfs this month. The reservoir will remain near its normal elevation of 1420 feet msl during December.

Oahe releases averaged 18,300 cfs during the month of November. Releases are expected to average near 10,000 cfs this month. The reservoir ended November at elevation 1601.0 feet msl, down 1.0 feet during the month. The reservoir is expected to rise about 1 foot during the month of December.

Garrison releases averaged 13,200 cfs in November. Releases were increased from 14,000 cfs to 16,000 cfs on Dec. 2 in advance of possible river freeze-in. Releases will remain at that rate during December and will be gradually increased to 18,000 cfs in January after an ice cover is established. Garrison ended November at elevation 1834.1 feet msl, down 0.5 foot from the end of September. It is expected to drop about 1 foot during December.

Fort Peck releases averaged 5,000 cfs in November. Releases were increased from 5,000 cfs to 6,500 cfs in early December and will remain at that rate through the month. The reservoir ended November at elevation 2223.6 feet msl, down 0.3 feet from the previous month. The reservoir is forecast to drop less than 1 foot during December.

The forecast reservoir releases and elevations discussed are not definitive. Additional precipitation or lack of precipitation in the basin could cause adjustments to the reservoir release rates.

The six mainstem power plants generated 590 million kilowatt hours (kWh) of electricity in November. Typical energy generation for the month of November is 742 million kWh. The power plants are projected to generate 7.5 billion kWh of electricity this year, compared to the normal of 10 billion kWh.

To view the detailed three-week release forecast for the mainstem dams, go to: http://www.nwd-mr.usace.army.mil/rcc/reports/twregfcast.pdf.

  

MISSOURI RIVER MAINSTEM RESERVOIR DATA

 

 

Pool Elevation

 (ft msl)

Water in Storage - 1,000 acre-feet

 

On Nov. 30

Change in November

On Nov. 30

% of 1967–2012 Average

Change in November

Fort Peck

2223.6

-0.3

12,734

90

-59

Garrison

1834.1

-0.5

16,702

95

-125

Oahe

1601.0

-1.0

16,744

101

-286

Big Bend

1420.5

-0.1

1,652

98

-1

Fort Randall

1339.6

      -6.9

2,307

98

-439

Gavins Point

1207.6

-0.1

365

86

-3

 

 

 

50,504

95

-913

 

 

WATER RELEASES AND ENERGY GENERATION FOR NOVEMBER

 

 

Average Release in 1,000 cfs

Releases in 1,000 af

Generation in 1,000 MWh

Fort Peck

5.0

295

47

Garrison

13.2

784

118

Oahe

18.3

1,088

158

Big Bend

16.6

988

61

Fort Randall

24.1

1,433

135

Gavins Point

26.4

1,570

71

 

 

 

590

 

 

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Contact
Michael Coffey
503-808-3722
michael.a.coffey@usace.army.mil

Release no. 20131205-001