Streamgaging Network

Flood-frequency analysis provides information about the magnitude and frequency of floods based on records of annual maximum instantaneous peak discharges. Accurate flood-frequency estimates, created using consistent and uniformly applied methods, are a key component of any effective flood risk and management program. This is a list of current USGS flood frequency reports published by state.

The USGS Hydrologic Instrumentation Facility (HIF) supports the water-resource monitoring efforts of USGS scientists and other Federal scientists by providing quality-assured hydrologic equipment and instrumentation support.

Powder River rises in the Bighorn Mountains of Wyoming and flows northward through a semi-arid landscape in Wyoming and Montana to the Yellowstone River. The river drains an area of 34,700 square kilometers and has an average discharge of about 500 million cubic meters per year. Cross-channel profile data were collected at 22 sites on the river and its tributaries from 1975 through 2014.

The USGS serves as the lead agency for the United States to measure and apportion natural flows of the St. Mary and Milk Rivers according to the Boundary Waters Treaty of 1909 and the International Joint Commission Order of 1921. The division of water between the United States and Canada is overseen by the Accredited Officers of the St. Mary and Milk Rivers, who are appointed by their respective...

Declining snow cover is playing a key role in decreasing the flow of the Colorado River, “the lifeblood of the Southwest,” by enabling increased evaporation. As the warming continues, increasingly severe water shortages are expected.

USGS water-related projects of international interest.

The USGS monitors stream water quality in Wyoming and Montana in cooperation with State, County, local, and other Federal agencies. Water-quality data for these sites are available from the USGS National Water Information System Web Mapper application in the form of an interactive map that can be accessed from the Data and Tools tab.

As the USGS Water Resources Mission Area looks to the future, we are updating our water programs to meet 21st century water-resource challenges. As part of these updates, we are integrating the National Water Quality Assessment Project's water-resource monitoring, assessment, trends, modeling, and forecasting activities into new WMA programs.

For 43 years, the Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) brought together scientists from the USGS along with students and professors from universities in Minnesota, North Dakota, Wisconsin, and California to study the physical, chemical, and biological processes of lakes, wetlands, and streams at local and watershed scales. In early 2022, The University of Minnesota and Bemidji...

The Urban Waters Federal Partnership reconnects urban communities with their waterways by improving coordination among federal agencies, particularly those communities that have been disproportionately impacted by pollution or economic distress. The UWFP draws upon Environmental Justice principles—the idea that all people, regardless of race, religion, national origin, or economic station, deserve...

Peak-flow frequency information is needed for flood-plain mapping, design of highway infrastructure, and many other purposes across Montana. The USGS Wyoming-Montana Water Science Center has an ongoing project working to update peak-flow frequency estimates at USGS streamgages across the state.

Rapid Deployment Gages (RDGs) are fully-functional streamgages designed to be deployed quickly and temporarily to measure and transmit stream stage data in emergency situations.