CASPER, Wyo. — The Wyoming Game and Fish Department cautions anglers to be aware of sizeable increases in water flows in the North Platte River for 10 days beginning Monday, March 20 as part of a flushing flow project.
Game and Fish has requested the flushing flow to improve fish spawning habitats and to increase the production of invertebrates that fish depend on for food. The Bureau of Reclamation will begin releasing additional water from Gray Reef Reservoir in the early morning hours beginning Monday, March 20. Flows will increase from approximately 450 cubic feet per second to 4,000 ft³/s and will then gradually decrease back to 450 ft³/s each day, with the maximum flow occurring between 3 and 7 a.m. Flows from Gray Reef Dam will return to 450 ft³/s at 10 a.m. each day. The schedule will be repeated through Wednesday, March 29. The flows below Gray Reef Dam will then be stabilized at approximately 450 ft³/s following the completion of the 10-day cycle.
“Data show these flows are critically important to trout spawning and the sustainability of wild trout populations in the river,” said Matt Hahn, Game and Fish fisheries supervisor for the Casper region. “In the past, the trout populations would often fall to less than 400 trout per mile and could only be maintained through stocking several hundred thousand fingerling trout annually. Annual flushing flows began in 1995, and now the trout population averages over 3,500 per mile.”
The Game and Fish Department advises anglers and recreationists to know the potential dangers of flushing flows. Because the flush will span the weekend, there is potential for more people to be wading or floating the river. In addition, those using the river during the flushing flow should consider the fluctuating water levels and be aware that areas that can be waded effectively at 450 ft³/s may not be safe at 4,000 ft³/s.
Flushing flows are normally scheduled for completion in March to maximize benefits for spawning rainbow trout.