Water supply outlook published for June

The U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) published the June 2025 Wyoming Basin and Water Supply Outlook Report on June 1. 

This report analyzes snowpack, precipitation, streamflow and reservoir storage across the state of Wyoming. 

The report also 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.

Snowpack and precipitation

As of June 1, snow water equivalent (SWE) across the state was 53 percent of median. The highest SWE was reported in the Tongue River Basin at 118 percent of median, and the lowest SWE was reported in the Sweetwater River Basin at zero percent of median. 

The report notes the Tongue River Basin also had the highest precipitation recorded for the month at 124 percent of median, while the Lower Green River Basin saw the lowest precipitation at 54 percent of median.

Streamflow yields 

NRCS forecasts streamflow yields from June through September across Wyoming basins – excluding streamflow in the Cheyenne, Little Snake, Lower Green and Upper Green river basins – to average 73 percent. Streamflow yields at these four basins are expected to respectively average 40 percent, 46 percent, 66 percent and 82 percent from June through July. 

Median streamflow yields for June through July are forecast to average 48 percent for the Lower North Platte River, 61 percent for the Sweetwater River, 69 percent for the Upper North Platte River, 76 percent for both the Laramie and Powder rivers and 78 percent for both the Big Horn and Snake rivers. 

The report also shows yields will average 83 percent for both the Wind River and Shoshone River, 88 percent for the Yellowstone River and 89 percent for the Tongue River.

Reservoir storage

For the entire state of Wyoming, NRCS reports average reservoir storage at 80 percent of median. 

According to NRCS, reservoirs in the Upper North Platte River Basin, Cheyenne River Basin, Belle Fourche River Basin, Lower North Platte River Basin, Wind River Basin and Upper Green River Basin reported numbers at 73 percent, 81 percent, 87 percent, 90 percent, 94 percent and 99 percent, respectively. 

Additionally, reservoirs in the Lower Green River and Big Horn River basins both reported numbers at 101 percent of median, while the Buffalo Bill Reservoir on the Shoshone was at 104 percent of median and reservoirs in the Snake River Basin were at 109 percent of median.

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