San Vicente Reservoir Expansion Modeling

San Diego County Water Authority

San Diego, CA 

Flow Science developed a calibrated model of temperature, salinity, and dissolved oxygen for San Vicente using the one-dimensional DYRESM model. The resulting model was used to evaluate water quality conditions for an expanded reservoir due to a planned increase in the height of the dam. The reservoir was evaluated for a variety of aqueduct inflow and runoff conditions. Statistical techniques were applied to the model output to enable probabilistic interpretations of model results, including Monte Carlo simulations to determine optimal outlet elevations in an expanded reservoir. Subsequently, Flow Science recalibrated the DYRESM model for dissolved oxygen, nutrients, and chlorophyll (as a surrogate for algae) based on more recent data. The model was used to evaluate water quality impacts on San Vicente Reservoir resulting from construction drawdown conditions that will persist for four years. A variety of Aqueduct inflow and runoff conditions were being considered. The results of the modeling were used to identify potential water quality problems that may require mitigation and make recommendations for physical and operational improvements.