The amount of water it takes to grow almonds in California is just bananas
And there's some question as to whether California is misallocating the water that it does have.
Here's a tidbit, from Mother Jones via Marginal Revolution's Alex Tabarrok:
...agriculture uses 80% of the water in California but accounts for less than 2% of the economy. So how much water does almond production alone use? More water is used in almond production than is used by all the residents and businesses of San Francisco and Los Angeles combined.
It's important to note that California produces a huge chunk of the produce consumed in the United States. Presumably having food on the table is vastly more important to society than it would seem if you just look at it from a percentage-of-the-economy perspective.
But what about the almonds in particular? It takes a disproportionate amount of water to grow them versus other crops.
FT Alphaville's Matthew C. Klein pointed out this is just a comparison of direct consumption. It doesn't account for other ways that people in LA and San Francisco use water, like, say, the irrigation used to grow the food that they eat.
In my mind, though, this doesn't matter much. It would matter, if Californians relied on almonds as a staple of their diet. A few might. But by and large almonds are a luxury food in the United States. If California stopped growing so many almonds, prices would go up, but few people would see their daily life profoundly affected.
But then there's another problem. Almonds are one of California's largest agriculture exports. According to Orcam Financial Group's Cullen Roche, 62% of California's almond production is exported. The US produces about half of the world's almonds. Ceasing production would be a big deal.
But would it be a bigger deal than some of the other consequences of not having enough water in California?