Meeting Temperature Requirements for Fisheries Downstream of Folsom Reservoir, California

摘要

Folsom lake, located near Sacramento California USA, is a deep-storage reservoir that provides municipal water, power generation and cold water for salmonid fish in the lower American River. The reservoir has discrete temperature control shutters on the three powerhouse intakes that allow the operator to choose different water levels at each intake to accommodate downstream temperature requirements. A complex model of the reservoir was developed using the CE-QUAL-W2 model (Cole and Wells, 2013) and was calibrated to historical operations over a 10-year time period. Absolute mean temperature errors in model profiles and in downstream temperature were 0.57°C and 0.59°C, respectively, well less than the goal of ＜1°C. Variability in meteorological data sources and leakage through the temperature control shutters at the dam were challenges during model calibration. A complex operational model tool was developed using the CE-QUAL-W2 model to automatically determine how best to select outlet shutter position in order to reach the downstream temperature goals for fish. The goal was to develop an operational tool that best allows for meeting overall goals of using the limited stored cold water pool to meet downstream temperature objectives. The model proved successful running long-term simulations that can be used to evaluate operations based on modified or forecasted hydrological and meteorological inputs.