California residents use a very small amount of California's water, most is Ag, which is exported to the rest of the world. [0]
So the idea that California is somehow shooting themselves in the foot (rather than refusing to further subsidize the Ag. industry which has done insane damage to the state's ecology) is severely misinformed.
[0]https://cwc.ca.gov/-/media/CWC-Website/Files/Documents/2019/...