Determination of Local Ground-Water and Surface-Water Interactions In and Near Fish Creek, Wyoming

In cooperation with the Teton Conservation District, a study was begun in 2004 to examine interactions between ground water and surface water in and near Fish Creek. Fish Creek is a 15-river-mile long tributary to the Snake River, located on the western side of Jackson Hole, near the base of the Teton Range.

The project has two components. The first part of the project estimated the magnitude of gains and losses in streamflow over six independent reaches of Fish Creek. This was accomplished through a series of discharge measurements made during two different flow regimes. The first measurements were made in August, when the stream discharge was high and affected by irrigation infiltration and return flows. The next measurements were made in November, when the stream was at base-flow conditions and the primary source of water gain to the stream was from ground water. Results of this part of the study are described in the report, Seepage investigation on selected reaches of Fish Creek, Teton County, Wyoming, 2004.

The objectives of the second part of the project are to develop an improved understanding of ground-water surface-water exchanges at three separate reaches, and to develop a two-dimensional ground-water model to describe the flow in the ground water near Fish Creek for one year. Temperature and pressure data are being collected at different depths within monitoring wells at three cross-sections of Fish Creek, as well as in the creek itself. These data will be input into a two-dimensional model, VS2DH. The model output will be used to estimate aquifer properties, such as apparent hydraulic conductivity and seepage velocity of the water moving in or out of the creek, as well as the timing and location of streamflow gains or losses to the creek.

Study area (click on image for a larger version, 3.6 mb PDF)

Discharge measurement on Fish Creek, Wyoming (click on image for a larger version, 101 kb, JPG)