"Climate change is expected to affect the quantity and timing of water flow in the state," explained Kaveh Madani, a former postdoctoral research scholar in UC Riverside's Water Science and Policy Center (WSPC), who led a research project on climate change effects on hydropower production, demand, and pricing in California. "Under dry climate warming, the state will receive less precipitation, with most of it as rain instead of snow, impacting hydropower supply and operations."
http://www.sciencedaily.com/releases/2012/08/120807132306.htm