Missouri River Basin Runoff Sees Improved Conditions
The Northwestern Division, Missouri River Basin Water Management Division will host a series of public meetings the week of March 25, including one on Thursday, March 28, in Poplar. Additional information, with specific times and venues, will be provided in a future news release and will also be posted to the website at https://www.nwd.usace. army.mil/MRWM/Public- Meetings/. Increased snowmelt and runoff in the Missouri River Basin above Sioux City, Iowa, has led to improved conditions, but forecasters with the Missouri River Basin Water Management Division say levels are still below average. February runoff was 1.8 million acre-feet, 16 percent of average with above average runoff in every reach except Sioux City, which was near average. The updated 2024 calendar year runoff forecast for the basin continues to be below average.
The 2024 calendar year runoff forecast above Sioux City is 17.0 MAF, 66 percent of average. The runoff forecast is based on current soil moisture conditions, plains snowpack, mountain snowpack and long-term precipitation and temperature outlooks.
System storage is currently 53.9 MAF, 2.2 MAF below the top of the carryover multiple use zone.
“The system will continue to serve all Congressionally authorized purposes during 2024,” said a press release from MRBWMD. “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.”
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 500 cubic feet-per-second below full service for the first half of the 2024 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 snowpack in the upper Missouri River Basin is accumulating at below average rates. The March 3, mountain snowpack in the Fort Peck reach was 73 percent of average, while the mountain snowpack in the Fort Peck to Garrison reach was 78 percent of average. By March 1, about 80 percent 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, is almost nonexistent in the Basin. Trace to 1” of snow water equivalent is modeled in eastern North Dakota.
The March 2024 monthly conference call was held Thursday, March 7, to inform basin stakeholders of current weather and runoff forecasts and the planned operation of the reservoir system in the coming months. Presentation materials are available via webinar. The call is intended for Congressional delegations; Tribes; state, county and local government officials; and the media. It was recorded in its entirety and made available to the public on our website at https://go.usa.gov/xARQv.
Reservoir Forecasts for the Fort Peck Dam are as follows: Average releases past month – 5,400 cfs; Current release rate – 5,000 cfs; Forecast average release rate – 5,000 cfs; End-of-February reservoir level – 2230.4 feet and Forecast end-of-March reservoir level – 2230.9 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.
