Stream Water Quality Modeling and Methods Report. Windy Gap Firming Project.

摘要

This report describes the methods used to simulate the water quality of the Colorado River, Willow Creek, and East Slope streams within the South Platte River basin for the direct and cumulative effect simulations for the Windy Gap Firming Project (WGFP). The Windy Gap Water Resources Technical Report (ERO and Boyle 2007) provided hydrologic data. The QUAL2K modeling software was used to develop a water-quality model for the Colorado River between Lake Granby and Gore Canyon, just downstream of the town of Kremmling, Colorado. The model application was developed and calibrated using hydrologic and water-quality data from the reach. Data used for calibration and the modeling results for the calibration period are discussed and the model performance is quantified. The model is described in Section 2. A nutrient loading model was developed for the Fraser River Basin for cumulative effects simulations. The details of the modeling methods used by this model are included in Section 3. The Stream Segment Temperature Model (SSTEMP) was used to determine the impacts of reduced streamflows below Willow Creek Reservoir to the temperature of the approximately 3-mile segment of Willow Creek between Willow Creek Reservoir and the Colorado River. SSTEMP handles only single stream segments for a single time period, such as a day, week, or month. Model operation and calibration is described in Section 4, as well as model results for two simulated dates.