> "Eighty percent of California's water goes to agriculture" is very literally saying "Eighty percent of California's water feeds people"
Alfalfa doesn't feed people [1]. It feeds cows that feed people. And nobody is going to starve because almonds and pistachios are pricier.
Moreover, California's agriculture is notoriously water inefficient [2]. Why wouldn't it be? What other behavior would you expect from agricultural multinationals for whom we've effectively zero rated a commodity input?