Projects & Programs
Temperature Modeling of Box Canyon Reservoir, Washington
PNNL staff developed a predictive temperature model to analyze the potential effects of Box Canyon Hydroelectric Project operations on water temperature within the Box Canyon Reservoir. Box Canyon Reservoir is located in northeast Washington on the Pend Oreille River and extends from the tailwater of Albeni Falls Dam at river mile (RM) 90.34 to the forebay of Box Canyon Dam at RM 34.6. Pend Oreille PUD operates the Box Canyon Hydroelectric Project (FERC No. 2042). Box Canyon Reservoir is on the 303(d) list of waters impaired for temperature. As part of the re-licensing process, a Section 401 Water Quality Certificate is required. PNNL conducted a temperature assessment of the Box Canyon Reservoir using the U.S. Army Corps of Engineers' CE-QUAL-W2 reservoir temperature and water quality model to demonstrate that the project does not adversely impact the temperatures in the reservoir and in the discharge waters. The model was calibrated to observed temperature data collected in 1997 and 1998. The model successfully reproduced the seasonal temperature variations as well as daily variations in the reservoir. Model results showed excellent agreement with the observed data. The calibrated model was applied to simulate the temperature distributions without project operation (natural condition). Model results indicated that the construction of the project has negligible effect on the reservoir and discharge temperatures.
Project Highlights:
- PNNL developed a vertical two-dimensional dynamic temperature model of the Box Canyon Reservoir using CE-QUAL-W2 model
- The model demonstrated that the effect of the project on the reservoir and temperatures is negligible
- PNNL provided a modeling-based assessment of impacts on natural temperatures that helped secure the 401 water quality certificate in support of FERC re-licensing effort for the project.