Willamette River Studies

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...

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.

USGS research directly helps local public agencies that are responsible for the design and maintenance of the levees that surround the northern Portland metropolitan area with the goal of protecting life and property in the event of flooding from the Columbia and Willamette Rivers that surround the city.

USGS total dissolved gas (TDG) data help guide spill and discharge management from dams operated along tributaries of the Willamette River.

Hills Creek, Lookout Point, and Dexter Dams are located on the Middle Fork Willamette River upstream of Eugene in western Oregon, and are important resources managed by the U.S. Army Corps of Engineers (USACE) for flood control, hydroelectric power, recreation, navigation, and irrigation. On the South Santiam River east of Albany in western Oregon, Green Peter and Foster Dams provide functions and...

The U.S. Army Corps of Engineers operates 12 dams in the Willamette River Basin. The dams alter natural temperature and hydrologic regimes. Unnatural water temperatures can negatively impact all life stages of salmonid fish species. Water temperature in the mainstem Willamette River regularly exceeds the standard of 18.0 °C (64.4 °F) designated for salmon and trout rearing and migration for mid...

Each autumn Fall Creek Lake is drawn down to allow endangered juvenile salmonids to pass freely through the dam. The drawdowns involve lowering the lake water level to the lake bed, creating a fluvial environment characterized by large amounts of sediment being transported through the dam and into Fall Creek and the Middle Fork Willamette River.

Cottage Grove Reservoir is an impoundment of the Coast Fork of the Willamette River and is managed by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Valley Flood Control Plan. The reservoir is currently under a fish consumption advisory because of elevated levels of mercury in fish tissue observed in an Oregon Department of Environmental Quality sampling survey in 2003 (Oregon...

Environmental flows are defined as "streamflow needed to sustain ecosystems while continuing to meet human needs."

The U.S. Geological Survey (USGS) studies the water resources of the Willamette River Basin. Here you will find a description of the study, as well as information and data resulting from this work.