Evaluating Effects of Climate Change on Source Water Quality of Lake Cachuma, California

Climate change is an important and well-studied phenomenon and historical data tracking changes in weather and climate are readily available. Climate change could induce shifts in mean values for weather variables and/or cause new patterns in climate variability, both of which could cause impacts on water demands, supplies, and source water quality. Water suppliers are beginning to consider the potential impacts of climate change on future water supplies. However, the focus of past work has been on water quantity impacts (e.g., flooding and droughts) rather than on changes in water quality. This paper focuses on an assessment of how various climate change scenarios would affect lake hydrology and selected source water quality parameters for Lake Cachuma, which provides water supply to the Goleta Water District and several other water agencies in Santa Barbara County, California. The climate change assessment indicates that under a variety of scenarios of a warming climate, the likelihood of taste and odor events during the dry season would increase and turbidity and apparent color events would be more likely if precipitation rates increase.