As usual, Wikipedia has some interesting numbers[1]. Relevant to your particular question, alfalfa uses ~20% of the irrigation water in the state. The amount of

As usual, Wikipedia has some interesting numbers[1]. Relevant to your particular question, alfalfa uses ~20% of the irrigation water in the state. The amount of alfalfa eaten just by horses requires ~1.9M acre-feet, which is ~620 billion gallons. [1] - https://en.wikipedia.org/wiki/Water_in_California#Uses_of_water https://en.wikipedia.org/wiki/Water_in_California#Uses_of_wa...