Photo By Eileen Williamson | Runoff into the reservoir system was below average for the month of March and...... read more read more
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The updated 2025 calendar year runoff forecast for the Missouri River Basin above Sioux City, Iowa, continues to be below average. March runoff in the Missouri River Basin above Sioux City was 2.3 million acre-feet, 76% of average.
“Runoff into the reservoir system was below average for the month of March and conditions across most of the basin remain dry,” said John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division. “Mountain snowpack has improved over the last few weeks but is still below average. We are forecasting a below-average runoff year for the basin.”
The 2025 calendar year runoff forecast above Sioux City is 21.9 MAF, 85% of average. The runoff forecast is based on current soil moisture conditions, plains snowpack, mountain snowpack, and long-term precipitation and temperature outlooks.
The volume of water stored in the Missouri River Mainstem Reservoir System is currently 50.8 MAF, 5.3 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 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 4,000 cubic feet per second below full-service for the first half of the 2025 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, 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 below average rates. The April 6 mountain snowpack in the Fort Peck reach was 94% of average, while the mountain snowpack in the Fort Peck to Garrison reach was 97% of average. By April 1, about 97% of the total mountain snowfall has typically accumulated, normally peaking near April 17. The mountain snowpack graphics can be viewed at: http://go.usa.gov/xARQC.
Monthly Water Management Conference Calls for 2025:
The May 2025 monthly conference call will be held Thursday, May 8, to inform key 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 Missouri River Basin Water Management Division held two virtual public meetings the week of April 7. The meetings provided a status update of basin conditions, mountain snowpack, runoff, and planned operations for the year to meet the authorized purposes for the reservoir system. The recording of the meeting and supporting slides will be available on our website at: https://www.nwd.usace.army.mil/mrwm/public-meetings/.
Reservoir Forecasts:
Gavins Point Dam
Average releases past month – 17,800 cfs
Current release rate – 25,000 cfs
Forecast release rate – 27,000 cfs
End-of-March reservoir level – 1206.6 feet
Forecast end-of-April reservoir level – 1206.0 feet
Notes: The Gavins Point release will be adjusted as needed to provide navigation flow support on the lower Missouri River.
Fort Randall Dam
Average releases past month – 15,400 cfs
End-of-March reservoir level – 1353.8
Forecast end-of-April reservoir level – 1355.1 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.
Big Bend Dam
Average releases past month – 19,900 cfs
Forecast average release rate – 26,600 cfs
Forecast reservoir level – 1420.7 feet
Oahe Dam
Average releases past month – 20,300 cfs
Forecast average release rate – 26,400 cfs
End-of-March reservoir level – 1598.7 feet
Forecast end-of-April reservoir level – 1597.3 feet
Garrison Dam
Average releases past month – 17,600 cfs
Current release rate – 18,000 cfs
Forecast average release rate – 18,000 cfs
End-of-March reservoir level – 1831.4 feet
Forecast end-of-April reservoir level – 1831.2 feet
Fort Peck Dam
Average releases past month – 5,600 cfs
Current release rate – 7,000 cfs
Forecast average release rate – 7,000 cfs
End-of-March reservoir level – 2227.6 feet
Forecast end-of-April reservoir level – 2227.5 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.
Hydropower:
The six mainstem power plants generated 610 million kWh of electricity in March. Typical energy generation in March is 636 million kWh. Forecast generation for 2025 is 8.9 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.
| Date Taken: | 04.09.2025 |
| Date Posted: | 04.09.2025 12:34 |
| Story ID: | 494935 |
| Location: | OMAHA, NEBRASKA, US |
| Web Views: | 240 |
| Downloads: | 0 |
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