If water were priced by auction, which I support, almond growers would invest in less wasteful irrigation methods, mostly subsurface drip: https://wcngg.com/2018/08/02/subsurface-drip-irrigation-has-...
More to the point, if water had a market-clearing price, California would stop growing so much alfalfa. Alfalfa uses half, half, of California's water, and California has no unique advantages at all in growing alfalfa.
But to reiterate, your first paragraph is absurd and very silly indeed. Lots of places have super cheap water but California still grows four out of five almonds on Earth. It baffles me that you thought cheap water was a plausible explanation for this.