Water supply outlook released 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 (USDA) Natural Resources Conservation Service (NRCS) released the report for June 2024. 

Snowpack and precipitation

In the report, NRCS notes snow water equivalent (SWE) across the state of Wyoming as of June 1 was 132 percent of median. 

The Tongue River Basin reported the highest SWE at 380 percent of median, while the Yellowstone River Basin reported the lowest SWE at 91 percent of median. 

Over the past month, areas in Wyoming have received varied precipitation, with the Wind River Basin reporting the highest precipitation at 148 percent of median, and the Upper North Platte River Basin reporting the lowest amount of precipitation at 19 percent of median.

Streamflow yields

From June through September, median streamflow yields across all Wyoming basins – except the Cheyenne River, Green River and Little Snake River basins – is forecast to average 108 percent of median.

Streamflow yields for these three exceptions are expected to respectively average 55 percent, 90 percent and 120 percent of median for the months of June and July. 

Additionally, both the Snake River and Yellowstone River basins should expect to see streamflow yields at 95 percent of median, while the Shoshone River Basin will likely see yields at 96 percent of median. 

NRCS estimates yields for the Laramie River Basin, Wind River Basin, Tongue River Basin, Big Horn River Basin, Sweetwater River Basin, Powder River Basin and Upper North Platte River Basin will be at 103 percent, 106 percent, 112 percent, 113 percent, 115 percent, 116 percent and 117 percent, respectively. 

The agency also forecasts streamflow yields in the Lower North Platte River Basin to be 125 percent of median. 

Reservoir storage

During the past month, reservoir storage across the entire state was 101 percent of median. 

Reservoirs in the Lower North Platte River, Belle Fourche River, Wind River, Upper Green River and Big Horn River basins reported numbers below median at 87 percent, 94 percent, 95 percent, 95 percent and 96 percent, respectively. 

Both the Cheyenne River Basin and Lower Green River Basin reservoirs were at 100 percent of median, while Snake River Basin reservoirs, the Buffalo Bill Reservoir on the Shoshone River and Upper North Platte River Basin reservoirs reported numbers above median at 105 percent, 107 percent and 112 percent, respectively.  

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