I live right in the heart of California Farm Land (Madera County). A person can only eat so many pistachios and almonds (Cash Crops), which are earmarked mostly for export anyway. These orchards are pumping water from deep wells (2000 feet+) 24 hours a day, 7 days a week.
Your exactly right 10% of ALL water in California is used to grow one single crop almonds.
Why ? because it is so profitable. Vegetables, not so much and so these crops will lie fallow this year.