I thought the solution to this would be simple. Shouldn't we just price water on an exponential scale. I.e. normally water costs $X/gallon, and under some thres

I thought the solution to this would be simple. Shouldn't we just price water on an exponential scale. I.e. normally water costs $X/gallon, and under some threshold, that price is constant. However, once you exceed that threshold, the price PER GALLON increases at an exponential rate. If the wealthy want 5 pools + water slide, great! They pay a hefty sum and that money gets plowed into better water infrastructure. It would have 1 of 2 effects, the super rich end up using less water (which we want) or they pay HUGE amounts of money that get plowed back into the community. If water is that scarce, this seems reasonable. Why wouldn't this work? We'd have to get some laws passed or we need the 411 different water districts would have to enforce this uniformly?