With record-setting temperatures and the first ever mandatory state-wide water restriction, it's not as if Californians need another reminder of just how serious the current drought is. Unfortunately, a study published today in Nature Climate Change does just that. And the news is ominous. As of April 1st, 2015, the snowpack in the Sierra Nevada mountains--which provides 30 percent of the state's spring and summer water--is at its lowest level in 500 years. This has grave implications for both human and natural water systems in the state.