Environmental

Corps completes flow test at Fort Peck Dam, resumes normal operations

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Corps completes flow test at Fort Peck Dam, resumes normal operations
(photo courtesy U.S. Army Corps of Engineers)

The U.S. Army Corps of Engineers reported that test flows from Fort Peck Dam will be ending earlier than expected.

Fort Peck Lake Dam consists of an earthen embankment, an outlet tunnel for releasing stored water, two powerhouses, and 16 gates on a concrete-lined spillway to the west of the dam. The first powerhouse was completed in 1951 and the second in 1961. Cumulatively, the projects have a capacity of 185.3 MW and produce an average of 1.1 billion kWh of electricity annually.

The 2024 flow test from Fort Peck Dam was the first in a series of test flows intended to comply with the 2018 Biological Opinion.

Test flows were intended to determine if alternative water management scenarios from Fort Peck would improve conditions for the pallid sturgeon and identify the potential impacts of alternative management scenarios.

The 2024 flow test was comprised of the following:

Attraction flow, which began April 26 and continued through early May, and was intended to encourage pallid sturgeon to enter that reach of the Missouri River.

Retention flow of release rates lower than the attraction flow and designed to keep the fish in the designated river reach.

Second spawning peak release in late June and early July, intended to encourage spawning.

Drift flow to allow larval sturgeon to develop.

Through the course of the test flows, extensive monitoring of several pallid sturgeon took place but, there was no indication of any spawning.

“Because there was no spawning there is no need for a drift flow, therefore the test flows will end and Fort Peck Dam operations will begin what would be normal releases for this time of year, had there been no test,” said John Remus chief of the Missouri River Basin Water Management Division.

Beginning as soon as possible, releases from Fort peck Dam will be increased from an average daily flow of 8,000 cubic feet per second (cfs) to an average daily flow of 9,000 cfs.

As per the 2023-2024 Annual Operating Plan, these flow rates will be maintained until the middle of September. Although the 2024 test flow is ending early, monitoring will continue as planned.