Streams and Rivers

Throughout the world, irrigation (water for agriculture) is essential for keeping fruits, vegetables, and grains growing to feed the world's population. In addition, irrigation can alleviate crop stress from droughts, decrease soil erosion, and can reduce water pollution. USGS scientists provide estimates of irrigation water use to help water managers make informed decisions.

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.

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

SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources. Interactive, online SPARROW mapping tools allow for easy access to explore relations between human activities, natural processes, and...

The USGS collects real-time flood data and conducts flood science to help keep communities safe before, during, and after a flood.

When planning for a flood, there are three key questions that must be answered:  What areas will be flooded? How deep will the floodwaters get? When will the flood arrive? A flood inundation map library is a set of maps that together show where flooding may occur – and how deep it may be - over a range of potential flooding scenarios in a stream or river.

The USGS Flood Inundation Mapping (FIM) Program helps communities protect lives and property by providing tools and information to help them understand their local flood risks and make cost-effective mitigation decisions.

High-water marks are like footprints left behind by a flood — they show how high the water reached during a flood event. High-water marks serve as valuable data points for both educational purposes and scientific research, helping us understand past and recent flood events. Collecting this information is an essential and time-sensitive task for understanding flood risk and improving public safety.

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.

FORT aquatic scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. They then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. They have pioneered the use of cottonwood, a...

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.