That's not an exception, that's an entirely different use for a raised tank. And not a very big one either.
There are probably exceptions, where this isn't true, but raised tanks make modern society possible.
https://youtu.be/yZwfcMSDBHs more on water towers, which are raised tanks of water.
We also pump water into fake lakes to later extract electricity from it. (https://youtu.be/66YRCjkxIcg)
Another good thing with water towers is that we can keep running the pumps at a lower RPM where efficiency than if we were trying to build a system with pumps to keep pressure.
Great channel if you're curious about everything related to humans relationship with water.
I meant not a big tank is needed for one house. I wasn't talking about the size of the use case.
> We also pump water into fake lakes to later extract electricity from it.
We do, because lakes are much much bigger than tanks on a house.