Hazards (Floods, Droughts, Hurricanes, etc.)

To manage our water resources effectively, we need to understand how much water is available and its usefulness. The USGS monitors the nation’s water resources through various national observing networks that use a range of technologies and methods to assess real-time water conditions and predict future changes in water availability for human and ecological uses.

The USGS National Water Availability Assessment consists of reports, which provide a scientific summary and interpretation of water quantity, quality and use, and the data companion, which delivers model-based estimates of water supply and demand.

Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. They are designed to capture a range of conditions in major drivers of water availability.

The USGS Water Resources Mission Area is assessing how much water is available for human and ecological needs in the United States and identifying where and when the Nation may have challenges meeting its demand for water.

As of October 2024, the USGS Groundwater and Streamflow Information Program supports the collection and (or) delivery of both streamflow and water-level information at 8,705 sites and water-level information alone at 3,460 additional sites. The data are served online—most in near real-time—to meet many diverse needs including the protection of life, property, the environment, and our economy.

Centennial Streamgages are USGS streamgages that have been in operation for more than 100 years.

The Willamette River Basin reflects the conflicting water demands between humans and ecosystems—particularly salmon— and the challenge resource managers face throughout the Pacific Northwest.

Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. In the Upper Colorado River Basin, the USGS will conduct a focused assessment of how snowpack and snowmelt influence hydrology and water quality, and an integrated and comprehensive assessment of multiple water quantity, quality and use factors.

The Delta of the Sacramento and San Joaquin rivers provides drinking water supplies to two-thirds of Californians, and is a fragile ecosystem home to threatened and endangered species. The CASCaDE project builds on several decades of USGS science to address the goals of achieving water supply reliability and restoring the ecosystems in the Bay-Delta system.

Did you know that earthquakes can cause changes in groundwater levels? Very large earthquakes can even cause water-level fluctuations in some wells thousands of miles away, depending on the local geological conditions around the well.

The U.S. Geological Survey is integrating its water science programs to better address the Nation’s greatest water resource challenges. At the heart of this effort are plans to intensively study at least 10 Integrated Water Science (IWS) basins — medium-sized watersheds (10,000-20,000 square miles) and underlying aquifers — over the next decade. The IWS basins will represent a wide range of...

The Next Generation Water Observing System (NGWOS) supports water availability assessments, management, and prediction by enhancing water observations in basins that represent major U.S. hydrologic regions. NGWOS provides high-resolution, real-time data on water quantity, quality, and use, as well as advance the development and application of new sensor technologies and remote sensing methods.