San Luis Reservoir, California (IMAGE) University of California - Irvine Caption The water level of the San Luis Reservoir in California's Merced County fluctuates in wet and dry years. UCI research gives resource managers a new tool for predicting winter rainfall months in advance. Credit Amir AghaKouchak, UCI Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.