I'm not saying that the current rate systems in Mexico, or California, or XYZ place are perfect -- far from it! But there's no reason they couldn't be changed to fit society's goals.
Edit: and they’re still drastically biased. Eg farmers getting preferential rates for wasteful crops like almonds.
And who owns the water? Anyone with a plot of land who can access the watertable? Anyone with a plot of land next to a river? What about those downriver from that plot?
"Deregulation" is as meaningless as "defund the police". If you scratch the surface it can mean anything between total anarchy and "keep only this specific set of laws that I believe are good".
What's needed is regulation which promotes a wanted outcome.
As far as who owns the water, well for mineral water sources, I’d say the citizens do, and the best way to handle that is probably still to charge Amazon the same amount and then use the proceeds as tax revenue for the general welfare so the people don’t have to be so poor in the first place.