Why are there water tanks on roof?

Hi, I’m kinda new to taiwan so i have loads of questions about this place. I come from Australia and one thing i noticed here is water tanks ontop of every building. Why on earth is this so?
To my knowledge water here is safe to drink through the pipes under ground (except kaohsiung)?? Is this true especially in taipei?

Also why are there water tanks on the roof and what is there purpose? From what i can see is water makes its way up to the tanks from the pipes underground (from tap water treatment plant) and then a pump then pumps the water into the building. Seems the pump creates the pressure.
Why cant the pipes go directly into the building like in the west instead of into a tank whats the reason for this?


The water pressure in the system is insufficient for it.

Thanks, also my landlord said there is an Aqua Sterilizer in the tank, im in Kaohsiung. The water has a chlorine/bleach smell and sometimes a fish gut smell to it. Im concerned about this. What exactly would this sterilizer be? Tablets?

Some home owners also want their own separate water tank for their house. My old apartment had a large shared water tank (made from cement as part of original building structure). One of the ten home owners decided to add his own water tank which only is useful if there is a water outage.
However, this became a problem in that the roof leaked (we were on top floor) so we wanted to redo the roof and suddenly a water tank was there. The guy who installed the tank was embarrassed in that he did not inform us and screwing that water tank onto our roof could also cause problems. We also could not conveniently redo the roof with the water tank there. He removed the tank.

On roof because if sunny you can save a lot for heating it

to add more noise.

what district in Kaohsiung?


It’s more convenient to put them on the roof, would be quite messy if they were at street level. You’ll find most buildings in the west also have a water tank somewhere.

They were looking at the buildings one day, and thought, how can we make these even fuglier?


They have water tanks in the West too. They are just far more centralized.

Don’t you ever notice tall water towers in almost every town or city? They are pretty tall too, I think higher than nearly all buildings in the city. They do this to create sufficient pressure. They don’t have to have pumps running 24/7 in order to have pressure.

It’s just that in Taiwan the tanks are decentralized since it would not be practical to have a central tank for the entire city. You would need tanks taller than Taipei 101.

You see this in densely populated American cities like New York City too, buildings all have water tanks on top.

@KHHville Formosa boulevard area. I think its xinxing district

Thanks for replies. I’ve never seen them in Sydney or Newcastle where im from so maybe Aus doesnt have this idk. Does japan have them on the roofs of the smaller 5 story and above buildings like in Tokyo and the smaller cities? I dont remember seeing any when i was there last.

If the water head (almost the same thing as pressure in this context), is not enough to get to higher floors in won’t reach the tank anyway. A lot of buildings actually have pumps for that.
The water in tanks are used during water shortages, which is quite obvious.
The main they are on the roof is to ensure adequate hydraulic head so that water can reach all outlets without a pump (in case of an electricity shortage).