People from out of state. The native Californians would not have to pay, since they already live there.
I think it's important to remember that California's wealth comes not from internally, but from externally. By exporting the goods from labor in the state, labor that is largely the result of immigrants into the state, California is leading the way to a more environmentally friendly path, with greater wealth, for all of humanity.
Wishing to cut that off because of a few conservative "native born" Californians don't want to see apartment buildings is the height of foolishness and greed.
Water supply issues notwithstanding, which could easily change California’s intrinsic desirability.