The updated 2023 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa, continues to be below average.   

“Despite some improvement in basin conditions, we expect 2023 runoff to remain below average,” said John Remus, chief of the U.S. Army Corps of Engineers’, Missouri River Basin Water Management Division.  “Soil moisture has improved slightly in some areas, but drought conditions still exist across most of the basin.”

The 2023 calendar year runoff forecast above Sioux City is 21.5 million acre feet, 84% of average. The runoff forecast is based on current soil moisture conditions, plains snowpack, mountain snowpack, and long-term precipitation and temperature outlooks.  February runoff in the Missouri River Basin above Sioux City was 1.0 MAF, 86% of average.

System storage is currently 46.0 MAF, 10.1 MAF below the top of the carryover multiple use zone. 

“The System will continue to serve all Congressionally authorized purposes during 2023,” 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:

Beginning in mid-March, releases from Gavins Point Dam will be adjusted to provide flow support for Missouri River navigation.  Navigation flow support for the Missouri River is expected to be at minimum service for the first half of the 2023 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 near average rates. The March 1, mountain snowpack in the Fort Peck reach was 104% of average, while the mountain snowpack in the Fort Peck to Garrison reach was 101% of average.  By March 1, about 80% 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.  

The plains snowpack, which typically melts from mid-February into April, has widespread areas of one to six inches of snow water equivalent (SWE) across North Dakota and eastern South Dakota.  The remainder of the basin has little or no snow. 

Monthly Water Management Conference Calls for 2023:

The March 2023 monthly conference call will be held Thursday, March 9, 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.

Spring Public Meetings:

The Northwestern Division, Missouri River Basin Water Management Division will host a series of public meetings the week of April 3.  Specific dates, times and locations are listed below and can be found on the website at:  https://www.nwd.usace.army.mil/MRWM/Public-Meetings/.

Monday, April 3 – Poplar, Montana

• Start time: 10:00 a.m. (MDT)
• Fort Peck Community College
• 605 Indian Ave

Monday, April 3 – Bismarck, North Dakota

• Start time: 5 p.m. (CDT)
• Bismarck State College, National Energy Center of Excellence (NECE), Bldg. 15, Bavendick Stateroom
• 1200 Schafer Street

Tuesday, April 4 – Fort Pierre, South Dakota

• Start time: 10 a.m. (CDT)
• Casey Tibbs Conference Center
• 210 Verendrye Drive

Tuesday, April 4 – Lower Brule, SD

• Start time: 1:30 p.m. (CDT)
• Golden Buffalo Convention Center
• 307 Crazy Horse St

Wednesday, April 5 – Smithville, Missouri

• Start time: 11 a.m. (CDT)
• Jerry Litton Visitor Center, Smithville Dam
• 16311 DD Hwy

Wednesday, April 5 – Bellevue, Nebraska

• Start time: 5 p.m. (CDT)
• Bellevue University, Hitchcock Humanities Center
• 1040 Bruin Blvd

Thursday, April 6 – St. Louis, Missouri

• Start time: 10:30 a.m. (CDT)
• VUE 17
• 1034 S. Brentwood Blvd, #1700

Reservoir Forecasts:

• Gavins Point Dam
  • Average releases past month – 12,300 cfs
  • Current release rate – 12,000 cfs
  • Forecast release rate – 16,800 cfs
  • End-of-February reservoir level – 1206.4 feet
  • Forecast end-of-March reservoir level – 1206.0 feet
  • Notes: The Gavins Point release will be increased around March 18 to begin providing minimum service navigation flow support on the lower Missouri River.
     
• Fort Randall Dam
  • Average releases past month – 9,000 cfs
  • End-of-February reservoir level – 1349.6
  • 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 and to back up the Gavins Point release increases.  The reservoir will refill to elevation 1355 by the end of March.
     
• Big Bend Dam
  • Average releases past month – 13,200 cfs
  • Forecast average release rate – 13,900 cfs
  • Forecast reservoir level – 1420.5 feet
     
• Oahe Dam
  • Average releases past month – 13,300 cfs
  • Forecast average release rate – 18,400 cfs
  • End-of-February reservoir level – 1594.1feet
  • Forecast end-of-March reservoir level – 1594.9 feet
     
• Garrison Dam
  • Average releases past month – 23,300 cfs
  • Current release rate – 20,500 cfs
  • Forecast average release rate – 16,000 cfs
  • End-of-February reservoir level – 1825.7 feet
  • Forecast end-of-March reservoir level – 1825.9 feet
  • Notes – Releases are gradually being reduced from 23,500 cfs to 16,000 cfs near the beginning of March.
     
• Fort Peck Dam
  • Average releases past month – 6,700 cfs
  • Current release rate – 5,000 cfs
  • Forecast average release rate – 5,000 cfs
  • End-of-February reservoir level – 2218.6 feet
  • Forecast end-of-March reservoir level – 2218.9 feet
  • Notes: Releases were reduced from 6,500 cfs to 5,000 cfs in early March.

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 457 million kWh of electricity in February. Typical energy generation for February is 621 million kWh. Forecast generation for 2023 is 7.4 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.