California’s combination of climate, native ecosystems, and human uses makes water management inherently hard, unsatisfactory, and evolving.  California is doomed to have difficult and controversial water problems. No matter how successful we are.

California is one of the few parts of the world with a Mediterranean climate (Figure 1).  These climates tend to be dry (not much water), attractive places to live and farm (bringing high water demands), with mismatch between wetter winters and dry summer growing seasons.  The scarce water supply in the wrong season for human activities makes human management of water problematic for native ecosystems.