The latest 2024 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa shows slight improvement.   

“The overall lack of snowpack in both the plains and the mountains has led to a below average runoff forecast for the Missouri River Basin,” said John Remus, chief of the U.S. Army Corps of Engineers’, Missouri River Basin Water Management Division. “The soil is dry across much of the basin with over 60% of the basin experiencing drought.”

The 2024 calendar year runoff forecast above Sioux City is 17.5 million acre-feet (MAF), 68% of average. The runoff forecast is based on current soil moisture conditions, mountain snowpack, and long-term precipitation and temperature outlooks. March runoff in the Missouri River Basin above Sioux City was 1.8 MAF, 59% of average.

“While the forecast remains below average, the basin has shown some improvement in runoff conditions since

the March forecast. Given reach runoff and basin conditions, we expect runoff in April to remain below normal for all reaches, but this will depend on precipitation and temperatures,” said Remus.  The March forecast was 17.0 MAF.

“Even with the lower than average runoff forecast the hydrologic conditions are sufficient to conduct a flow test from Fort Peck Dam” said Remus.  “The flow test is a requirement of the 2018 Biological Opinion and is meant to determine if there is a Fort Peck Dam water management scenario that could benefit the Pallid Sturgeon.”

System storage is currently 54.0 MAF, 2.1 MAF below the top of the carryover multiple use zone. 

Basin and river conditions continue to be monitored, including plains and mountain snow accumulation and melting, and System regulation will be adjusted based on the most up-to-date information.

Navigation:

Beginning in mid-March, releases from Gavins Point Dam were adjusted to provide flow support for Missouri River navigation. Navigation flow support for the Missouri River is at 500 cfs below full service for the first half of the 2024 season, which began April 1 at the mouth of the river near St. Louis, Missouri. The service level was based on the total volume of water stored within the System on March 15, which was 54.1 MAF, 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 System storage on July 1.

Mountain and Plains Snowpack:

Mountain snowpack in the upper Missouri River Basin has remained low throughout the 2023-2024 winter and spring seasons. The April 1 mountain snowpack in the Fort Peck reach was 74% of average, while the mountain snowpack in the Fort Peck to Garrison reach was 84% of average. The Fort Peck reach is close to the minimum observed mountain snowpack over the past 30 year-period of 1991 to 2020. The Garrison reach is slightly above the minimum observed mountain snowpack. By April 1, about 95% 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.  

Fort Peck Flow Test:

Test releases from Fort Peck to assess the potential benefits of alternative management scenarios for the pallid sturgeon will begin on April 26.  The test includes two higher Fort Peck release periods, in late April and June, with target flows at Wolf Point, Montana.  The Fort Peck releases will be adjusted depending on the runoff and reach conditions downstream of Fort Peck during this period. The test will likely require spillway releases from Fort Peck.  The test releases will not affect river stages below Gavins Point Dam.  The flow test has been extensively coordinated with local stakeholders and was discussed in depth a public meeting held in Poplar, Montana on March 28, 2024.  The U.S. Army Corps of Engineers will host weekly virtual meetings during the flow test to update the public on test progress and planned operations.  Information on accessing the public meetings can be found at https://www.nwd.usace.army.mil/MRWM/Public-Meetings/.     

During the flow test a number of monitoring activities will be conducted to include fish monitoring, lidar and aerial photography, physical surveys, cultural resource surveys, and water quality sampling.  Interested parties can also provide information through a web-based application that can be found at https://hydroviz.ca/fort-peck-feedback.

Monthly Water Management Conference Calls for 2024:

The next monthly conference call will be held Wednesday, April 10, 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 held a series of public meetings in the upper basin the week of March 25. Meetings for the lower basin are scheduled to be held on April 16 in both Smithville, Missouri and Bellevue, Nebraska.  The meeting times and venues are as follows:

Smithville

Start time: 11 a.m. CT
Jerry Litton Visitor Center
16311 DD Hwy
Smithville, MO 64089

Bellevue

Start time: 1600 CT
Bellevue University
Hitchcock Humanities Building,
1040 Bruin Blvd, Criss Auditorium
Bellevue, NE 68005

Reservoir Forecasts:

• Gavins Point Dam
  • Average releases past month – 20,800 cfs
  • Current release rate – 30,000 cfs
  • Forecast release rate –32,000 cfs
  • End-of-March reservoir level –1206.7 feet
  • Forecast end-of-April reservoir level –1206.0 feet
     
• Fort Randall Dam
  • Average releases past month – 19,200 cfs
  • Forecast average release rate – 28,800 cfs
  • End-of-March reservoir level – 1352.9 feet
  • Forecast end-of-April reservoir level – 1355.0 feet
     
• Big Bend Dam
  • Average releases past month – 20,000 cfs
  • Forecast average release rate – 30,500 cfs
  • Forecast reservoir level – 1420.8 feet
     
• Oahe Dam
  • Average releases past month –20,300 cfs
  • Forecast average release rate – 30,300 cfs
  • End-of-March reservoir level – 1603.5 feet
  • Forecast end-of-April reservoir level – 1600.8 feet
     
• Garrison Dam
  • Average releases past month –16,000 cfs
  • Current release rate –16,000 cfs
  • Forecast average release rate –16,000 cfs
  • End-of-March reservoir level – 1835.3 feet
  • Forecast end-of-April reservoir level – 1834.8 feet
     
• Fort Peck Dam
  • Average releases past month – 5,000 cfs
  • Current release rate – 5,000 cfs
  • Forecast average release rate – 6,400 cfs
  • End-of-March reservoir level – 2231.2 feet
  • Forecast end-of-April reservoir level – 2231.5 feet
  • Notes: Releases will be stepped up in late April as part of the test flows.

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 625 million kWh of electricity in March. Typical energy generation for March is 636 million kWh. Forecast generation for 2024 is 8.5 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.