This project expands upon project 4773, which examined the impact of integrating seawater desalinated via reverse osmosis (SWRO) water into existing regional supplies of disparate quality. This new research will evaluate the influence of an increased percent of State Project Water in imported water supplies on treated water blends with SWRO water. Complimentary modeling will evaluate the reduction in regional salinity loading due to the introduction of desalinated water from the Claude “Bud” Lewis Carlsbad Desalination Plant and planned potable reuse projects in the service area. The results of the study will be incorporated into an economic model to quantify the associated benefit of reduced salinity. Research partners: San Diego County Water Authority and Southern California Salinity Coalition.