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Posted 3/10/2014

Release no. 20140310-001


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

Omaha, Neb. — The 2014 runoff forecast in the Missouri River Basin above Sioux City, Iowa, has increased to 30.6 million acre feet (MAF), 121 percent of normal.  Runoff of this magnitude is expected to occur on average once every four years.   The average annual runoff is 25.2 MAF.  Runoff during the month of February was 1.2 MAF, 112 percent of normal. 

“Above normal mountain snowpack, high soil moisture conditions and deep frost depths were factored into our increased runoff forecast,” said Jody Farhat, Chief of the U.S. Army Corps of Engineers Missouri River Basin Water Management Division.  “Mountain snowpack has increased steadily during the last several weeks and colder than normal temperatures continued through February.  Wet soil conditions and deeply frozen soils increase the potential for runoff when snow melts or spring rainfall occurs.”

As of March 7, mountain snowpack was 127 percent of normal in the reach above Fort Peck and 135 percent of normal in the reach between Fort Peck and Garrison.  “Mountain snowpack is at about the same level it was at this time in 2011, but still far below where it peaked in 2011.  Light plains snowpack has accumulated in the eastern Dakotas and parts of Montana, but the remainder of the basin has little or no plains snowpack,” said Farhat.  Typically about 80 percent of the peak mountain snowpack accumulation has occurred by early March. 

View mountain snowpack graphic here: http://www.nwd-mr.usace.army.mil/rcc/reports/snow.pdf

The total volume of water stored in the Missouri River Mainstem Reservoir System is currently 50.6 MAF, compared to 56.1 MAF at the base of the flood control zone.  Reservoir storage is down due to the lingering effects of the 2012 drought.  “The full 16.3 MAF flood control storage zone along with an additional 5.5 MAF of conservation storage is available to manage runoff from this year’s snowpack and rainfall,” said Farhat.  The upper three reservoirs, Fort Peck in eastern Montana, Garrison in North Dakota, and Oahe in South Dakota, remain 5 to 11 feet below the desired operating levels.

“River ice may be an issue in some locations during the spring runoff season.  The Corps will continue to monitor snowpack, rainfall-runoff and basin soil conditions to fine tune the regulation of the reservoir system based on the most up-to-date information,” said Farhat.

Beginning on or around March 17, releases from Gavins Point Dam will be gradually increased to begin providing flow support for navigation.  Generally, releases are increased 3,000 cubic feet per second (cfs) per day until navigation target flows are reached.  Ice cover on the Missouri River between Gavins Point Dam and Sioux City, Iowa may reduce the rate of increase and lengthen the number of days it takes to reach the desired release rate. 

Based on the projected March 15 storage check, navigation flow support will likely be 3,000 cfs below full service for the first half of the Missouri River navigation season.  At that support level, navigation flow targets for the first half of the season would range from 28,000 cfs at Sioux City, Iowa to 38,000 cfs at Kansas City, Mo.  Full service navigation flow support is generally sufficient to provide a 9-foot deep by 300-foot wide channel; minimum service generally provides an 8-foot deep channel.  Flow support for the second half of the navigation season and the season length will be determined following the system storage check on July 1.  The navigation season opening dates are as follows:

March 23 – Sioux City, Iowa

March 25 – Omaha, Neb.

March 26 – Nebraska City, Neb.

March 28 – Kansas City, Mo.

April 1 – Mouth near St. Louis, Mo.

Five public meetings will be conducted throughout the basin between April 8 and 10 to update stakeholders on current hydrologic conditions and the planned operation of the reservoir system.  For those unable to attend the meetings in person, a conference call will be held on April 11 to present the same information.  Meeting times and locations are listed below.

April 8, 1 pm             NWS Training Center, 7220 NW 101st Terrace, Kansas City, Mo.

April 8, 7 pm             Lewis and Clark Center, 100 Valmont Drive, Nebraska City, Neb.

April 9, 11 am           Capitol Lake Visitor Center, 650 East Capitol Ave, Pierre, SD

April 9, 7 pm             Bismarck Civic Center, 315 S 5th St, Bismarck, ND

April 10, 10 am         Fort Peck Interpretive Center, Yellowstone Road, Fort Peck, Mont.

April 11, 1 pm           Conference call; call-in details to be provided at later date

Monthly Water Management Conference Calls

The Corps will host its third conference call of 2014 on Tuesday, March 11 to inform basin stakeholders about reservoir operations, basin forecasts and weather conditions.  The call is intended for Congressional delegations; Tribes; state, county and local government officials; and media. It will be recorded in its entirety and made available to the public as a free podcast in iTunes. Subscribe at: http://itunes.apple.com/podcast/missouri-river-basin-water/id508457675. Or, simply search for Missouri River Basin Water Management in iTunes. The audio file will also be posted to the Omaha District’s Facebook page following each call.

Reservoir Forecasts

Releases from Gavins Point Dam averaged 15,100 cfs during the month of February.  Releases were reduced to 14,000 cfs in early March.  Releases will remain at that rate until mid-March when they will be increased to provide flow support for the navigation season.  The reservoir behind Gavins Point Dam ended February at elevation 1206.2 feet.  The reservoir will remain near elevation 1206 feet during March.

Fort Randall Dam releases averaged 12,400 cfs during February.  Releases will be stepped up in mid-March corresponding with the start of navigation support and will be adjusted as necessary to maintain the desired elevation at Gavins Point Dam. The reservoir ended February at elevation 1349.0 feet, up 5.3 feet during the month.  The pool is expected to reach elevation 1355 feet in early April.  The refill of the reservoir is designed to provide increased winter hydropower generation at Oahe and Big Bend Dams.

Big Bend Dam releases averaged 15,100 cfs in February.  Releases are expected to average 18,500 cfs this month.  The reservoir will remain near its normal elevation of 1420 feet during March.   

Releases from Oahe Dam averaged 16,300 cfs during the month of February.  Releases are expected to average 18,100 cfs this month.  The reservoir ended February at elevation 1602.7 feet, up 0.8 feet during the month. The reservoir is expected to rise 2.2 feet during the month of March.

Garrison Dam releases averaged 17,900 cfs in February.  Releases will be gradually stepped down from 18,000 cfs to 16,000 cfs in mid-March.  Ice conditions in the Bismarck area will be monitored closely during the thaw and additional adjustments to Garrison releases will be made, if conditions dictate.  The reservoir ended the month at elevation 1831.6 feet, down 0.7 feet from the previous month.  It is expected to rise 2.5 feet during March.

Releases from Fort Peck Dam averaged 6,900 cfs in February.  Releases will remain at 7,000 cfs during March.  The reservoir ended February at elevation 2222.5 feet, down 0.2 feet from the previous month.  It is forecast to rise 2.4 feet during the month.

The forecast reservoir releases and elevations discussed above are not definitive. Additional precipitation, lack of precipitation or other unknown circumstances could cause adjustments to the reservoir release rates.

The six mainstem power plants generated 499 million kilowatt hours (kWh) of electricity in February. Typical power generation for the month of February is 639 million kWh. The power plants are projected to generate 8.9 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 Feb. 28

Change in February

On Feb. 28

% of 1967-2013 Average

Change in February

Fort Peck

2222.5

-0.2

12,520

91

-44

Garrison

1831.6

-0.7

16,009

97

-195

Oahe

1602.7

+0.8

17,222

101

+232

Big Bend

1420.4

+0.2

1,645

96

+12

Fort Randall

1349.0

     +5.3

2,926

86

+301

Gavins Point

1206.2

-1.4

332

89

-33

 

 

 

50,654

96

+273

 

 WATER RELEASES AND ENERGY GENERATION FOR FEBRUARY

 

 

Average Release in 1,000 cfs

Releases in 1,000 acre-feet

Generation in 1,000 MWh

Fort Peck

6.9

383

58

Garrison

17.9

994

146

Oahe

16.3

902

133

Big Bend

15.1

839

52

Fort Randall

12.4

688

70

Gavins Point

15.1

840

40

 

 

 

499

 

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Missouri River Water Management US Army Corps of Engineers