Current Streamflow Conditions
News and Highlights
A Groundwater Availability study in the Williston Basin is highlighted in a new USGS Science Feature. Science team includes Water Science Centers from WY, MT, and SD.
Oil-well pads dotting the landscape of typical badland topography. Thousands of new wells are drilled into the Bakken and Three Forks annually, making this one of the most productive plays in the Nation. Photograph by Seth Haines, U.S. Geological Survey
A precipitation-runoff model for simulating natural streamflow in the Smith River watershed, Montana was constructed in cooperation with the Meagher County Conservation District. The USGS Precipitation-Runoff Modeling System model was used to examine the hydrology of the Smith River watershed from 1996-2008, including quantification of precipitation, evapotranspiration, and streamflow; quantifying the sources of streamflow from runoff and groundwater contributions; and quantifying contributions to streamflow from the different parts of the watershed.
During this study period, simulated mean annual precipitation across the Smith River watershed was 16 inches, out of which 14 inches evaporated or transpired directly back to the atmosphere and 2 inches exited the basin as streamflow via the Smith River. During most of the year, surface runoff accounts for less than 10 percent of the total streamflow. Groundwater flow through the shallow sediments and deeper geologic units contributes the remaining portion of water directly to the Smith River and its tributaries.
The model can be used to estimate potential changes in natural streamflow under changed watershed conditions or in response to drought. The precipitation-runoff model can be combined with a groundwater model and water-use information to further investigate interactions between surface water and groundwater under current and future irrigation scenarios.
Find out more about the project
Major floods in 1996 and 1997 intensified public debate about the effects of human activities on the Yellowstone River. In 1999, the Yellowstone River Conservation District Council was formed to address conservation issues on the river. The Yellowstone River Conservation District Council partnered with the U.S. Army Corps of Engineers to carry out a cumulative effects study on the main stem of the Yellowstone River. The cumulative effects study is intended to provide a basis for future management decisions within the watershed. Streamflow statistics, such as flow-frequency data calculated for unregulated and regulated streamflow conditions, are a necessary component of the cumulative effects study. Calculations included in the report are low-flow frequency data and general monthly and annual statistics for unregulated and regulated streamflow conditions for the Upper Yellowstone and Bighorn Rivers for the 1928–2002 study period. Unregulated streamflow represents flow conditions during the 1928–2002 study period if there had been no water-resources development in the Yellowstone River Basin. Regulated streamflow represents estimates of flow conditions during the 1928–2002 study period if the level of water-resources development existing in 2002 was in place during the entire study period.
Find out more about the project