Temperature Effects of Point Sources, Riparian Shading, and Dam Operations on the Willamette River
Objectives and Approach
Through these objectives, this investigation was designed to develop a better overall understanding of anthropogenic influences on water temperature in the main-stem Willamette River, and provide information and tools that might be used in the development of a heat-trading system that operates within the limits set by the Willamette temperature TMDL.
Both the spatial and temporal scopes of this investigation were aligned with those used in the development of the TMDL. The Willamette flow and temperature models, developed previously to form the basis for the temperature TMDL, were used to simulate the time periods from June 1 through October 31 of 2001 and from April 1 through October 31 of 2002. The models include the entire main-stem Willamette River as well as the lower reaches of selected tributaries (Clackamas, Santiam, North Santiam, South Santiam, Long Tom, McKenzie, South Fork McKenzie, Middle and Coast Fork Willamette, and Row Rivers, as well as Fall Creek) up to their first major dams (map); the McKenzie River was modeled only up to the point where it is joined by the South Fork McKenzie River. By keeping the same spatial and temporal domains as those used in the Willamette temperature TMDL, the results of this investigation can be directly compared to and augment the information and results created during the TMDL process.