New gages for understanding surface water availability and spring Chinook salmon habitat in the Willamette Basin
Learn about our new streamgages in the Williamette River Basin.
The U.S. Geological Survey (USGS) is expanding the streamgaging network in the Willamette River Basin of northwestern Oregon by adding sites in remote, unregulated, and ungaged streams in the Clackamas, Santiam, Molalla, McKenzie, and Middle Fork Willamette River basins. The new sites are in stream reaches that are used by spring Chinook salmon (and in some cases, winter steelhead and bull trout) throughout the year. Experts from USGS and partner agencies carefully chose site locations to coincide approximately with the upstream extent of spawning by spring Chinook salmon. These new sites also capture major differences in the geologic and topographic conditions influencing surface water supply in the basin and can be used to explore water availability questions.
As of September 1, 2025, USGS is operating 14 new gages in unregulated spawning reaches. Monitoring includes:
- Continuous water temperature and water level data. Data are available online. Some sites transmit data in real-time, and for others, the data are downloaded during site visits.
- Streamflow. During site visits, scientists measure streamflow to document the range of flow pertinent to habitat conditions. Continuous and seasonal streamflow data are currently being generated and are available online.
- Air temperature. Monitored at nine locations, these data can be used to better identify which reaches could be susceptible to warming.
- Year-round photo documentation. Eight of the gages have specially designed, time-lapse cameras that allow the public to see year-round streamflow and habitat conditions near the gages. In some cases, cameras have captured fish and wildlife activity. The cameras are part of the USGS Flow Photo Explorer program.
These data can be easily accessed and plotted using the Data Grapher tool and selecting the “High-elevation Cascade Range sites.”
Data from the new gages will provide a basis for understanding current and future habitat conditions, water availability, and how some of these reaches may respond to extreme events like heat waves and droughts. In particular, the year-round water-level and temperature data will be used to describe habitat implications for spring Chinook salmon during the following conditions:
- Summer months when adult salmon are holding in rivers prior to spawning and when stressful warm water temperatures can contribute to pre-spawning mortality.
- Fall conditions when adult salmon spawn and eggs begin incubation. Stressful warm water conditions can be harmful to both adults and eggs.
- Winter months when embryos are incubating. During this period, direct mortality can occur due to high flows (causing redd scour) and heavy sedimentation (redd suffocation). Altered temperature regimes can affect emergence timing and synchronization with important biological windows (such as food availability and seasonal growth).
- Spring, summer, and fall months when juvenile salmon are rearing and migrating downstream and when stressful warm temperatures can affect behavior, health, disease, and predation potential by non-native fish.
In winter 2025-26, USGS will explore these data and how they can be used to better understand differences in surface water availability across the east side of the Willamette Basin.
This project is funded by USGS Water Mission Area’s Next Generation Water Observing Systems (NGWOS) to support the Willamette River Basin Integrated Water Science program.
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Click on the numbered map points to learn more about each monitoring station.
Integrated Water Science Basins: Willamette River