Tuesday, March 3, 2026 |
Photo – Bureau of Reclamation logo – Courtesy Bureau of Reclamation
The Bureau of Reclamation will begin a flushing flow, north of Alcova Reservoir, later this week.
In what is essentially a spring-cleaning project, the United States Bureau of Reclamation, at the request of the Wyoming Game and Fish Department, will increase water flowing through the Gray Reef Dam. Beginning Thursday, March 5th, and continuing through the 14th, discharge rates will rise during the early morning hours into the afternoon from 500 cubic feet per second, about the volume of a large hot tub, to 4,000 cubic feet per second, roughly comparable to a medium sized swimming pool. Flows will return to normal in the evening, and the process will begin again the next morning.
Dams like Gray Reef block the natural floods that normally flush a waterway, allowing fine silt and sediment to accumulate over time and clog the gravel river bottom. Speaking to Bigfoot99 during last year’s flushing flow, Wyoming Game and Fish Casper Region Public Information Specialist Janet Milek said the Bureau of Reclamation increases water discharge rates at the Gray Reef Dam to create a strong enough current to clear sediment from trout spawning areas.
The Bureau of Reclamation conducts the flushing flow at this time every year. Game and Fish Casper Region Fisheries Supervisor Matt Hahn said the schedule is set to ensure the work happens just before peak trout spawning season.
Hahn said studies show that the flows are critically important to trout spawning and to sustaining wild trout populations in the North Platte River. In the past, trout numbers often fell below 400 fish per mile and could only be maintained by stocking several hundred thousand fingerlings every year. Since annual flushing flows began in 1995, the river’s population has risen to an average of more than 3,500 trout per mile.
Every day for ten consecutive days, the Bureau of Reclamation will increase water flows from the Gray Reef Dam to eight times the normal rate. Fisheries Supervisor Matt Hahn said the flush begins in the middle of the night and finishes by the next morning. Since work occurs overnight, anglers at Gray Reef Dam are unlikely to notice the increased flow. However, those fishing the North Platte River near Casper will see the river rise by early afternoon.
Given the direction of flow on the North Platte River, anglers in areas south of the Gray Reef Dam, including Saratoga, will not be affected by the flushing flow. Casper Region Public Information Specialist Janet Milek, however, warned people traveling to the Alcova Reservoir over the next week to be aware of the rising water levels.
The Gray Reef Dam flushing flow is scheduled to begin this Thursday, March 4th, and last until Saturday, March 14th.
