> Given that there's numerous cities and countries that are suffering from water shortages, you'd think that the price of water would go up already. But it hasn't, because there's interests at play to keep the price of water relatively low.

That just means the shortage is not sufficiently severe to cause prices to move.

> Anyway you'd need different prices for different types of consumers, because it's a basic need for humans; you can't make water unaffordable for poorer people.

The simpler way is to give poorer people money.