Temporary fluctuation of North Platte River flow to improve trout reproduction and test dam gates

MILLS, Wyoming - The Bureau of Reclamation will implement a series of fluctuating flows in the North Platte River below Gray Reef Dam beginning March 5 at the request of the Wyoming Game and Fish Department. The ten-day operation is intended to improve trout reproduction conditions in the river and includes scheduled testing of Gray Reef Dam's radial gates. Members of the public are urged to use caution due to rapidly changing river flows during this period.

February 27 to March 2

• Alcova Powerplant will reduce releases to gradually evacuate storage from Gray Reef Reservoir in preparation for radial gate testing.
• River flows will remain at the current rate of 500 cubic feet per second (cfs) during this reservoir operation.
• Some fine sediment will be introduced from Gray Reef Reservoir into the North Platte River.

Tuesday March 3

• Gate testing will occur at Gray Reef Dam.
• Following testing, Gray Reef Reservoir will be refilled to the normal operating level.
• After refilling is complete, flushing flows will be initiated to flush fine sediment from the spawning gravels in the river.

Thursday March 5

Flows in the river below Gray Reef Dam will fluctuate from 500 cubic feet per second (cfs) to 4000 cfs according to the following schedule:

HOURS GRAY REEF OUTFLOWS (cfs)

00:01 to 01:00 a.m. 500

01:00 to 03:00 a.m. 2,000

03:00 to 07:00 a.m. 4,000

07:00 to 08:00 a.m. 3,000

08:00 to 09:00 a.m. 2,000

09:00 to 10:00 a.m. 1,000

10:00 to midnight 500

This schedule will be repeated daily through Saturday, March 14, 2026, and may be adjusted depending on river ice or facility operational conditions. Following completion of the flushing flows, releases below Gray Reef Dam will return to 500 cfs.

The flushing flows are designed to remove fine sediment that has accumulated in spawning gravels over the winter. Flow fluctuations will be implemented without loss of power generation, and water released from Alcova Reservoir will be restored downstream in Glendo Reservoir.

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