An overhanging water tower is an elevated water tank which overhangs a wide central shaft by less than half of the tank's radius. It is constructed for storing water and increasing pressure in a water system.

The supporting central shaft is wide relative to the tank. The tank projects beyond it by less than half of the tank's radius, retaining the stated proportional limit.

The elevated tank stores water and contributes pressure to the supply system. The overhang describes its support geometry rather than a different storage use.