Measuring and Monitoring Water

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...

Since 1969, the U.S. Geological Survey has maintained a research project in the San Francisco Bay-Delta system to measure and understand how estuarine systems and tidal river deltas function and change in response to hydro-climatic variability and human activities.

In 2019, the USGS began studying the baseline water-quality of selected transboundary rivers in the Pacific Northwest. These studies are designed to characterize current water-quality conditions so as to facilitate future assessments of potential impacts related to upstream mining activities.

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.

The USGS National Hydrologic Model (NHM) infrastructure supports the efficient construction of local-, regional-, and national-scale hydrologic models. The NHM infrastructure consists of: 1) an underlying geospatial fabric of modeling units with an associated parameter database, 2) a model input data archive, and 3) a repository of the physical model simulation code bases.

The Intergovernmental (formerly International) Hydrological Programme (IHP) is the United Nations Educational, Scientific and Cultural Organization's (UNESCO) international scientific cooperative program in water research, water resources management, education, and capacity building.

USGS water-related projects of international interest.

SPARROW mappers are interactive tools that allow the user to explore river streamflow and nutrient and sediment loads and yields and the importance of different sources of contaminants in a particular river basin. Data can be visualized using maps and interactive graphs and tables, and rankings can be shown by state, major watershed, hydrologic unit (HUC), and catchment.

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.

Water data visualizations are provocative visuals and captivating stories that inform, inspire, and empower people to address our Nation's most pressing water issues. USGS data science and visualization experts use visualizations to communicate water data in compelling and often interactive ways when static images or written narrative can’t effectively communicate the interconnectivity and...

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...