North Santiam River Basin Study

The North Santiam River is the primary source of drinking water for more than 177,000 people in Salem, Oregon and the surrounding communities. The USGS, in cooperation with the City of Salem, the U.S. Army Corps of Engineers, and the U.S. Forest Service monitors streamflow and water quality in the North Santiam River basin. The information obtained from this monitoring network is used by the City of Salem to determine when conditions might impact its drinking water treatment facility and to inform operational decisions at the Army Corps of Engineers’ Detroit and Big Cliff Dams.

These data provide a detailed picture of hydrologic and water quality conditions in Detroit Lake and the North Santiam River at important temporal scales, which allows us to better understand how the reservoir-river system responds to key drivers such as precipitation, temperature, harmful algal bloom (HAB) events, and other factors. For example, these data provide insights into the evolution, behavior, and decay of the seasonal algal blooms in Detroit Lake. The data collected by the USGS can be used to inform modeling and management strategies in the North Santiam River basin, warn downstream drinking water providers of HAB events, and perhaps to predict harmful algal blooms in the future.