The Economist:

Agriculture accounts for 80% of water consumption in California, for example, but only 2% of economic activity.

James Hamblin:

Each almond requires 1.1 gallons of water to produce.

Alex Tabarrok:

In short, we are spending thousands of dollars worth of water to grow hundreds of dollars worth of almonds and that is truly nuts.

Eduardo Porter:

Despite California's distress, about half of the homes in the capital, Sacramento, still don't have water meters, paying a flat fee no matter how much water they consume.