Watershed/Basin Studies

Learn about our new streamgages in the Williamette River Basin.

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.

The USGS has been studying the Klamath Basin for decades. The USGS provides unbiased data to Tribal partners and resource managers to aid with complex management and conservation efforts.

The USGS is monitoring water-quality above, within, and below Middle Fork Willamette and the South Santiam River dams to understand how reservoir drawdowns influence downstream water-quality conditions.

In response to increasing groundwater demand and declining groundwater levels in the Harney Basin of southeastern Oregon, the U.S. Geological Survey and Oregon Water Resources Department conducted a groundwater-availability study during 2016–22. Read to learn about the key findings

In this study, USGS scientists from multiple centers used advanced hyperspectral imaging techniques to advance monitoring of attached benthic algae (periphyton) in Cascade Range rivers used for municipal water supply. Periphyton are naturally occurring, but excess growth can harm ecosystems and degrade raw and treated drinking water quality. In these rivers, periphyton contain cyanobacteria that...

Scientists Stephen Gingerich and Adel Haj, Jr. are leading efforts to estimate groundwater budgets across the state. Water hidden beneath the earth’s surface is a vital resource and quantifying its availability is crucial for long-term management. USGS scientists are collaborating with scientists at the Oregon Water Resources Department to gain a better understanding of this valuable resource.

The goal of this project is to develop an effectiveness monitoring framework that can be used to inform monitoring and data collection for the Willamette River Focused Investment Partnership (WFIP) Effectiveness Monitoring Program. The USGS is developing this monitoring framework in collaboration with the Benton Soil and Water Conservation District (BSWCD), Bonneville Environmental Foundation (BEF...

The amount and type of algae in the Tualatin River affect the river’s water quality and ecological health, as well as its value as a recreational resource. As a relatively new source of summertime flow to the upper Tualatin River, discharges from the Fernhill Natural Treatment System (NTS) have the potential to enhance or degrade downstream water quality. Discharges of low nutrient concentrations...

Many regulatory, management, and conservation organizations are interested in protecting and increasing coldwater refuges and thermal diversity for Chinook salmon, steelhead, and other natives fishes in the Willamette River basin. This study synthesizes current and emerging science related to coldwater refuges and thermal diversity. It is also develops conceptual frameworks for understanding the...

Native lampreys are culturally significant fishes for tribal communities in Oregon. As such, the USGS has begun working with the Cow Creek Band of Umpqua Tribe of Indians to study changes that may be affecting habitat for native Pacific and western brook lampreys in the Umpqua River basin.

When streamflow fluctuates in the Willamette River so does the amount of available rearing habitat used by Threatened Upper Willamette River spring Chinook salmon and winter steelhead trout. The USGS investigates how flow conditions and dam operations affect rearing habitat availability so that flow managers can maintain suitable flows for these species.