Drought

The Smith River watershed is an important recreational and agricultural area in Meagher and Cascade counties in west-central Montana. Thousands of visitors travel to the area annually to float and fish the Smith River. Additionally, most of the water used to irrigate 36,000 acres of the upper Smith River watershed is withdrawn from the Smith River or its tributaries. During a recent drought...

The USGS monitors drought conditions at more than 300 streamgages across Wyoming and Montana. Low-flow conditions are expressed as percentiles comparing current (within the past few hours) instantaneous flow to historical daily mean flow for all days of the year.

Rivers and streams are constantly changing. Streamflows can change throughout the year and between years due to snowmelt, precipitation, diversions, and return flows. For many streams, these fluctuations determine whether a stream has year-round flow or not. PRObability of Streamflow PERmanence (PROSPER) is a project initiated to better understand what causes these fluctuations in different...