August Streamflows in Wyoming Below Average

Average streamflows for the month of August were below average across most of Wyoming, according to the U.S. Geological Survey (USGS). Statewide, streamflows during August were about 64 percent of the monthly average. The average is based on long-term USGS gaging stations with 30 or more years of streamflow data. The State is currently experiencing its fifth consecutive year of hydrologic drought.

As during May, June, and July, average August streamflows were lowest in the northeast part of the State. At long-term USGS gaging stations in the Tongue, Powder, and Cheyenne River Basins, August streamflows were about 41 percent of the monthly average. "July generally marks the end of the period where streams in Wyoming see most of their flow from melting mountain snowpacks," noted Kirk Miller, USGS Hydrologist. "Because of the low streamflows in the Tongue and Powder Rivers during the last three to four months, it is likely this years annual flows in those rivers will be the lowest on record for the last 70 years." Annual streamflows are determined by the water year, which runs from October to September.

Elsewhere in Wyoming, August streamflows at long-term USGS gaging stations ranged from about 57 percent of average in the North Platte River Basin to about 91 percent of average in the Wind River Basin. August streamflows were about 60 percent of average in the Bighorn River Basin and about 67 percent of average in the Green River Basin. Streamflows at some stations are influenced by upstream reservoirs or diversions.

Data, tools, and references on drought in Wyoming and the West are available at the click of a mouse. The USGS's Wyoming Drought Watch has been updated and features cumulative runoff graphs and other useful information for drought managers. Visit the site at: http://wy.water.usgs.gov/projects/drought/ .

The USGS serves the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.