Fort Peck Water Levels Expected To Drop In Month Of May

As warmer weather moves into the Missouri River Basin, spring precipitation brought some much-needed moisture throughout the basin. For the month of April, runoff was 2.1 million acre-feet, 71 percent of average, for the basin above Sioux City, Iowa.

“While the calendar year forecast remains below average, the runoff forecast continues to improve thanks to higher-than-expected rainfall in April,” said John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division. “We hope to see the precipitation trend continue to provide the much needed moisture for the region.”

The annual runoff forecast for the upper Missouri River Basin above Sioux City is 19.2 MAF, 75 percent of average, and 1.7 MAF higher than last month’s forecast. Soil moisture is above normal in South Dakota, below normal in eastern Montana and western North Dakota, and near normal for the rest of the upper Basin. Drought or abnormally dry conditions are currently present in 52 percent of the Basin. Drought conditions in most of the upper Basin are likely to persist during May.

“Despite the additional moisture, much of the upper basin remains in drought and is expected to remain in drought through the month of May. However, drought conditions in the lower Basin are expected to improve or be removed during May. The System is still recovering from drought as we continue to serve all Congressionally authorized purposes,” said Remus.

System storage is currently 49.9 MAF, 6.2 MAF below the top of the carryover multiple use zone. Basin and river conditions continue to be monitored and System regulation will be adjusted based on the most up-to-date information.

The mountain snowpack was below normal all season long and peaked approximately one week earlier than normal. The Fort Peck reach peaked at 73 percent of normal on April 9 and has 88 percent of the peak remaining as of May 1. The Garrison reach peaked at 82 percent of normal on April 10 and has 89 percent of the peak remaining as of May 1. The mountain snowpack graphics can be viewed at: http://go.usa.gov/xARQC.

Test releases from Fort Peck to assess the potential benefits of alternative management scenarios for the pallid sturgeon began on April 26 and will be completed by Sept. 1. The test includes two higher Fort Peck release periods, in late April and June, with target flows at Wolf Point. Releases were made from the Fort Peck spillway in late April and early May as part of the first higher release period. The Fort Peck releases will be adjusted depending on the runoff and reach conditions downstream of Fort Peck during the test period. The flow test may need to be modified with lower flows and a lower second peak due to the low runoff forecast. 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 at a public meeting held in Poplar, on March 28.

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.

Fort Peck Dam

Average releases past month – 6,200 cfs

Current release rate – 17,500 cfs

Forecast average release rate – 12,800 cfs

End-of-April reservoir level – 2231.3 feet

Forecast end-of-May reservoir level – 2229.3 feet

Notes: Releases will be adjusted in accordance with the Fort Peck flow test

The six mainstem power plants generated 723 million kWh of electricity in April. Typical energy generation for April is 694 million kWh. The power plants are expected to generate 8.4 billion kWh this year, compared to the long-term average of 9.4 billion kWh.