AWWA WQTC62510

Past work on climate variability and water resources has focused on water quantity impacts (e.g., flooding and droughts) rather than on changes in water quality. This paper addresses two aspects of climate variability impacts on selected water quality parameters: assessment of projecting seasonal water using various prior season hydroclimate parameters; and, assessment of the feasibility of projecting seasonal to annual lake water quality changes using El Nino/Southern Oscillation (ENSO) indicators observed in prior seasons. Work with Lake Cachuma, near Goleta, California, found that dry season water quality, when taste and odor complaints could be forecast from wet season hydroclimate (air temperature related) using probability relationships. The assessment of ENSO patterns suggests that dry season ENSO is a strong predictor of regional wet season precipitation, and thus provides opportunities to forecast increases in turbidity and color. In addition, prior season hydroclimate parameters may provide insight on water quality related to spring runoff and to summer taste and odor concerns. Water quality forecasting models using prior hydroclimate parameter or climate variability indices to forecast future water quality has the potential to assist water suppliers in managing their source waters on a seasonal basis. Includes 18 references, tables, figures.