US Army Corps of Engineers
Northwestern Division

News Releases

2019 runoff forecast above average; Public meetings set for April 9-11

Northwestern Division
Published March 7, 2019
Missouri River Basin Weekly Update March 5

System storage is 56.1 MAF, at the base of the Annual Flood Control and Multiple Use Zone, which means that all 16.3 MAF of flood storage is available. The upper Basin runoff forecast for 2019 is 28.4 MAF, which is 112% of average. Plains snow conditions vary throughout the upper Basin: moderate in Montana and the western Dakotas, and moderate-to-heavy in the central and eastern Dakotas (upper right graphic). Mountain snowpack accumulation is slightly above average (lower right graphic). The Gavins Point release will be increased to 20,000 cfs later this week.

Mountain snowpack accumulation through March 4 is slightly above average.

Mountain snowpack accumulation through March 4 is slightly above average.

The 2019 runoff forecast in the Missouri River Basin above Sioux City, Iowa, is 28.4 million acre feet (MAF), 112 percent of normal, according to the U.S. Army Corps of Engineers (Corps) Missouri River Water Management Division. “The forecast increased about 10 percent from last month due to the continued accumulation of mountain and plains snowpack in the upper basin. Gavins Point releases will be increased from 18,000 cubic feet per second (cfs) to 20,000 cfs this week,” said John Remus, Chief of the Missouri River Basin Water Management Division.

As of March 1, the mountain snowpack was 108 percent of average in the reach above Fort Peck and 103 percent of average in the reach from Fort Peck to Garrison. The mountain snowpack increased during February as a result of colder-than-normal temperatures and above-normal precipitation. Normally the mountain snowpack peaks in mid-April.

Plains snowpack is currently heaviest in central and eastern North Dakota and north central and eastern South Dakota. The snowpack’s liquid content, or snow water equivalency (SWE), ranges from 2 to 5 inches. The rest of the upper basin has accumulated 1 to 3 inches of SWE while the lower basin ranges from 0 to 2 inches of SWE. The Corps is cooperating with other agencies to acquire plains snow measurements in the upper basin.

Navigation:
Beginning in mid-March, releases from Gavins Point Dam will be adjusted to provide flow support for Missouri River navigation. Current studies indicate that flow support will be at the full service level for the first half of the 2019 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, or System storage, 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. Flow support is generally sufficient to provide a 9-foot-deep by 300-foot-wide channel. Full navigation flow support is expected at the dates and locations shown below:

  • Sioux City, IA : March 23
  • Omaha, NE : March 25
  • Nebraska City, NE : March 26
  • Kansas City, MO : March 28
  • Mouth near St. Louis, MO : April 1

River ice: 
River ice conditions below all System projects will be closely monitored throughout the winter and spring break-up seasons. 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.
Weekly updates on basin conditions, reservoir levels and other topics of interest are made available by Tuesday of each week.

Monthly Water Management Conference Calls:
The third monthly conference call of the 2019 runoff season will be held today, March 7, to inform basin stakeholders on current weather and runoff forecasts and the planned operation of the System. Presentation materials will be posted on the MRBWM website. 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.

Spring Public Meetings:
Six public meetings will be conducted throughout the basin April 9-11. The purpose of these meetings is to update the region on current hydrologic conditions and the planned operation of the mainstem reservoir system during the coming months. Meeting times and locations are listed below.

Tuesday, April 9 – Fort Peck, Montana
Start time: 11 a.m. (MDT)
Fort Peck Interpretative Center
Lower Yellowstone Rd.

Tuesday, April 9 – Bismarck, North Dakota
Start time: 6 p.m. (CDT)
Bismarck State College, National Energy Center of Excellence (NECE), Bldg. 15, Rm 335
1200 Schafer Street

Wednesday, April 10 – Fort Pierre, South Dakota
Start time: 10 a.m. (CDT)
Casey Tibbs Conference Center
210 Verendrye Drive,

Wednesday, April 10 – Sioux City, Iowa
Start time: 4 p.m. (CDT)
Sioux City Lewis & Clark Interpretive Center
Betty Strong Encounter Center
900 Larsen Park Rd.

Thursday, April 11 – Smithville, Missouri
Start time: 11 a.m. (CDT)
Jerry Litton Visitor Center
16311 DD Hwy

Thursday, April 11 – Nebraska City, Nebraska
Start time: 4 p.m. (CDT)
Lewis and Clark Interpretive Center
100 Valmont Drive

Reservoir Forecasts

  • Gavins Point Dam
    • Average releases past month – 19,100 cfs
    • Current release rate – 18,000 cfs
    • Forecast release rate – 20,000 cfs this week
    • End-of-February reservoir level – 1205.9 feet
    • Forecast end-of-March reservoir level – 1206.0 feet
    • Notes: Due to scheduled maintenance on the hydropower units, releases may be made from both the powerhouse and spillway.
  • Fort Randall Dam
    • Average releases past month – 17,100 cfs
    • End-of-February reservoir level – 1350.7 feet (up 6 feet from January)
    • Forecast end-of-March reservoir level – 1355.2 feet
    • Notes: Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point.
  • Big Bend Dam
    • Average releases past month – 20,300 cfs
    • Forecast average release rate –19,000 cfs
    • Forecast reservoir level – 1420.0 feet
  • Oahe Dam
    • Average releases past month – 22,100 cfs
    • Forecast average release rate – 18,400 cfs
    • End-of-February reservoir level – 1606.8 feet (rising 0.9 feet from January)
    • Forecast end-of-March reservoir level – 1608.5 feet
    • Notes: River ice conditions continue to be monitored below the dam and releases will be adjusted accordingly to minimize flood risk caused by river ice.
  • Garrison Dam
    • Average releases past month – 25,900 cfs
    • Current release rate – 20,000 cfs
    • Forecast average release rate – 18,000 cfs
    • End-of-February reservoir level – 1837.3 feet (down 1.3 feet from January)
    • Forecast end-of-March reservoir level – 1838.4 feet
    • Notes: River ice conditions continue to be monitored below the dam and releases will be adjusted accordingly to minimize flood risk caused by river ice.
  • Fort Peck Dam
    • Average releases past month – 12,200 cfs
    • Current release rate – 6,500 cfs (decreased from 12,000 cfs the first week in March)
    • Forecast average release rate – 12,000 cfs
    • End-of-February reservoir level – 2234.4 feet (down 1 foot from January)
    • Forecast end-of-March reservoir level – 2235.5 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.

The six mainstem power plants generated 716 million kWh of electricity in February. Typical energy generation for February is 617 million kWh. The power plants are projected to generate 10.0 billion kWh of electricity this year, compared to the long-term average of 9.4 billion kWh.

The detailed three-week release forecast for the mainstem dams is updated each Wednesday, or more frequently if needed.

MISSOURI RIVER MAINSTEM RESERVOIR DATA

 

Pool Elevation
(feet above mean sea level)

Water in Storage
(1,000 acre-feet)

 

On February 28

Change in February

On February 28

% of 1967-2018 Average

Change in February

Fort Peck

2234.4

-1.4

14,874

103

-298

Garrison

1837.3

-1.6

17,689

99

-466

Oahe

1606.8

+0.9

18,459

104

+301

Big Bend

1420.6

+0.3

1,669

98

+24

Fort Randall

1350.7

+6.0

3,053

91

+433

Gavins Point

1205.8

+1.5

324

82

+34

 

 

Total

56,068

101

+28

 

WATER RELEASES AND ENERGY GENERATION FOR FEBRUARY

 

Average Release in 1,000 cfs

Releases in 1,000 acre-feet

Generation in Million kWh

Fort Peck

12.2

675

112

Garrison

25.9

1,439

212

Oahe

22.1

1,227

179

Big Bend

20.3

1,129

69

Fort Randall

17.1

952

97

Gavins Point

19.1

1,063

47

 

 

Total

716


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