Annett B. Sullivan

Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon, for downstream temperature management

A hydrodynamic and water temperature model was developed for Big Cliff Reservoir on the North Santiam River in western Oregon for calendar years 2002 and 2003. This model allows the connection of an existing model of Detroit Lake upstream to an existing model of the North Santiam River downstream. The Big Cliff Reservoir model was able to reproduce the daily as well as hourly fluctuations in water surface elevation well. Initial runs showed that the magnitude and seasonal patterns in modeled water temperature released from Big Cliff Dam matched measured temperature just downstream in the North Santiam River generally well; however, model temperatures were 2 to 3°C too warm in late October to early November. Sensitivity testing and other investigations into this issue led to modifications in the setup of the modeled Detroit Lake model releases, which formed the upstream boundary of the Big Cliff Reservoir model. These changes led to somewhat higher water temperature errors within the Detroit Lake model, but improved the measuredto-modeled fit for the Big Cliff release in late October to early November in both 2002 and 2003.

Modeling water quality, temperature, and flow in Link River, south-central Oregon

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