California was a desert before settlers came. Vast irrigation projects over a hundred years brought life sustaining water to the region and the region bloomed into vast, fertile farmland.
California's Idiots shut off the valley from vast water reserves to save non-indigenous smelt in the reservoirs and the valley returns to desert.... because global warming.
Also, Pro Tip: Natural or Man made, drought by definition is climate change. You sound stupid using the phrase in this case. Like saying that the cause of the flooding in New Orleans was moisture change.