A water tower is used to store drinking water, which is pumped up to the holding tank at the top of the structure. The tank must be higher than the end-users so that enough pressure is exerted to allow the water to reach them via the distribution network, thereby obeying the laws of communicating vessels.
This animation shows how water is distributed by gravity throughout a community. You can change the height of the water tower by clicking on and dragging its tank.
Click and drag (vertically) the tank of the tower.