The Bureau of Reclamation has scheduled a series of fluctuating flows in the North Platte River downstream of Gray Reef Dam beginning March 31. Wyoming Game and Fish Department has requested fluctuating flows lasting for nine consecutive days to improve trout reproduction conditions in the river.
Reclamation staff will gradually evacuate storage from Gray Reef Reservoir, March 24-28, to facilitate inspection of the radial gates on March 29. Although river flows will remain at the current rate of 450 cubic feet per second (cfs) during this reservoir operation, some fine sediment will be introduced from Gray Reef Reservoir into the North Platte River. Following the gate inspection, Gray Reef Reservoir will be refilled to the normal operating level. Then flushing flows will be initiated to flush fine sediment from the spawning gravels in the river.
On March 31, flows in the river below Gray Reef Dam will fluctuate from 450 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. 450
- 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 450
This schedule will be repeated daily through April 8. The schedule may be modified depending on river ice or facility operational conditions. After completing the flushing flow on April 8, the flows below Gray Reef Dam will return to 450 cfs.
The flushing flows are expected to clean the spawning gravels of fine sediment which has accumulated over the winter. The fluctuations in the river flow will be achieved without loss of power generation and the water released from Alcova Reservoir will be restored downstream in Glendo Reservoir.
The public is urged to use caution during this period of rapid fluctuation of flows below Gray Reef Dam.
Original source can be found here.
