California (CALFED) Daily Environmental Water Management Modeling for Fish Protection and Water Supply Evaluation

CALFED is a cooperative venture of Federal and State water and environmental resource management agencies. CALFED's objectives are to provide improved fish protection and increased water supply reliability using the existing storage and pumping facilities. The water supply targets require considerable Delta export pumping. Efforts to reduce fish entrainment would restrict export pumping. The basic strategy is to allow the greatest possible pumping in periods with low risk of entrainment and reduce pumping when entrainment risk is high. One necessary component will be real-time fish monitoring to detect high fish densities. The second component is an Environmental Water Account (EWA) that will allow direct control over pumping restrictions necessary to reduce entrainment. A gaming approach has been used to interactively simulate the effects of fish protection measures on Delta flows and water supply conditions. A combination of a monthly planning model run in a year-by-year mode and daily operations models were used in the interactive gaming sessions. The monthly DWRSIM results for a year were used to approximate the baseline conditions that might include different facilities or operating constraints. The daily models were used to show the daily patterns of reservoir releases and Delta inflows and the effects of various Delta objectives on required Delta outflow and allowable export pumping. The daily Delta model included the historic Central Valley Project (CVP) and State Water Project (SWP) fish salvage density data, which were used to guide the EWA adjustments to export pumping in a month-by-month gaming exercise, and to calculate the fish entrainment protection achieved.