Maintenance on Oahe Dam hydropower units begins Monday; Supplemental releases to exit via outlet tunnels

The US Army Corps of Engineers continues to steadily release water from the Upper Missouri River Dam System in an effort to have flood control storage space empty before the water freezes over later this year.

Mike Swenson with the Missouri River Water Management Division in Omaha says the Oahe reservoir is at elevation 1616.4 feet, down .3 feet in the last week.


Swenson says a maintenance project on one of the hydropower units at Oahe will start Monday (Aug. 26).


Swenson says there’s no change to the overall release amount, only a change to where the water is being released.


The Fort Randall reservoir is at elevation 1361.8 feet, down 0.6 feet since last week. The reservoir is more than 6 feet above its normal summer operating level. Releases are 68,000 cubic feet per second and will remain near that rate over the next week.

Releases from Gavins Point Dam will remain at 70,000 cfs into September to continue evacuating flood water.

Upper Missouri River Dam System storage has declined about 0.6 million acre feet in the past week, with 10.5 MAF currently occupying the system’s flood control zones.

Lake Oahe has played a pivotal role in this year’s runoff season by capturing flood waters from upstream mountain snowmelt and heavy rainfall in the Yellowstone River basin, which fell in May and June. The Corps used Oahe’s storage capacity to hold water, helping to mitigate flooding along southern parts of the Missouri River following heavy rain events. The Garrison Dam near Riverdale, ND, and the Oahe Dam at Pierre/Fort Pierre, SD, are the two biggest reservoirs along the upper Missouri River Dam System having nearly 50-million acre feet of combined water storage.

To view the detailed three-week release forecast for the mainstem dams, go to

Missouri River Basin daily update:

All US Army Corps managed dams–reservoir levels, inflows and releases: