If you try to raise the price of water beyond that which farmers could work around, they'd likely just pack up and leave, like ChristianKI says. And nobody wants that, either.

I am entirely fine with that. There is no right to grow water-thirsty crops in the desert.

Look at one of the documents linked in the OP. If the farmers stop growing alfalfa hay which is one of the thirstiest crops and replace it with almost anything else, California will save a lot of water.