Half of California water (period, not agricultural water, water) use is for growing alfalfa to feed to cattle. An industry where we have no comparative advantage, unlike almonds. But the water is cheap.
California almond production could also be a great deal more frugal, Israelis use about 1/20th the water per almond. Their big innovation is buried irrigation, California almond ranchers spray water on the ground and it mostly just evaporates. But water is cheap.
Abolish the water rights system and auction the water at a reasonable price. Almonds would stay, alfalfa would diminish or disappear.
But "conversion of water into money" aka farming is good. People like to eat.