NRCS publishes water supply outlook for the month of June

The Wyoming Basin and Water Supply Outlook, released on the first day of each month, analyzes snowpack, precipitation, streamflow and reservoir storage across the state of Wyoming. 

The report assesses the water supply outlook for the entire state of Wyoming, as well as individual basins including the Snake River, Madison Headwaters, Yellowstone River, Wind River, Big Horn River, Shoshone River, Powder River, Tongue River, Belle Fourche River, Cheyenne River, Upper North Platte River, Lower North Platte River, Laramie River, Sweetwater River, South Platte River, Little Snake River, Upper Green River, Lower Green River and Upper Bear River basins.

On June 1, the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) published the report for June 2026. 

Snowpack and precipitation

According to NRCS, snow water equivalent (SWE) across the state of Wyoming was 26 percent of median as of June 1, compared to 53 percent at the same time last year.

The Yellowstone River Basin reported the highest SWE at 65 percent of median, while the Powder, Belle Fourche, Cheyenne, Sweetwater, Lower North Platte, Laramie and South Platte river basins all posted the lowest SWE at zero percent of median. 

Over the past month, areas in Wyoming received varied precipitation, with the Laramie River Basin reporting the highest amount at 141 percent of median and the Madison River Basin reporting the lowest amount at 43 percent of median.

Streamflow yields

From June through September, median streamflow yields across all Wyoming basins – except the Little Snake River, Cheyenne River, Lower Green River and Upper Green River basins – are on track to average 62 percent of median.

Streamflow yields for these exceptions are expected to respectively average 13, 34, 34 and 54 percent of median for the months of June and July. 

Additionally, NRCS estimates median streamflow yields for the Laramie River Basin at 34 percent, the Upper North Platte River Basin at 37 percent, the Lower North Platte River Basin at 39 percent, the Sweetwater River Basin at 42 percent, the Powder River Basin at 56 percent and the Tongue River Basin at 57 percent.

Median streamflow yields for the Snake River Basin, Big Horn River Basin, Wind River Basin, Yellowstone River Basin and Shoshone River Basin are forecast to yield 70, 74, 85, 95 and 98 percent, respectively.

Reservoir storage

For the entire state of Wyoming, NRCS reports average reservoir storage at 78 percent of median, similar to the 80 percent of median reported in June 2025.

Reservoirs in the Laramie River Basin, Upper North Platte River Basin, Upper Bear River Basin, Cheyenne River Basin, Belle Fourche River Basin and Lower North Platte River Basin reported numbers below median at 33 percent, 52 percent, 60 percent, 70 percent, 78 percent and 86 percent, respectively.

Major individual reservoirs like Pathfinder Reservoir, Seminoe Reservoir, Woodruff Narrows Reservoir, Guernsey Reservoir, Keyhole Reservoir, Stateline Dam Reservoir, Meeks Cabin Dam Reservoir and Glendo Reservoir also posted numbers below median at 51, 54, 59, 64, 70, 76, 80 and 82 percent, respectively.

Reservoirs across the Lower Green River Basin, Wind River Basin and Upper Green River Basin were near median, at 90 percent, 91 percent and 93 percent, respectively. 

Individual reservoirs with numbers near median include Flaming Gorge Reservoir and Pilot Butte Reservoir, both at 90 percent of median; Fontenelle Reservoir at 92 percent of median and Boysen Reservoir at 94 percent of median.

Reservoirs in the Snake River Basin were above median at 110 percent, as were the Buffalo Bill Reservoir at 107 percent, Viva Naughton Reservoir at 105 percent and Alcova Reservoir at 101 percent.

Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.