A water supply system includes a first pipe, a water reservoir, and a Venturi pipe having a first Venturi nozzle terminal, a second Venturi nozzle terminal and a Venturi nozzle branch arranged between the first and second Venturi nozzle terminal. The first Venturi nozzle terminal is connected via the first pipe to the water reservoir. The first Venturi nozzle terminal is connectable to a second pipe to fill the water reservoir. The branch of the Venturi pipe is connectable to a third pipe to supply taps. Water flows through the Venturi pipe from the first Venturi nozzle terminal to the second Venturi nozzle terminal when the water reservoir is filled, and water flows through the Venturi pipe from the second Venturi nozzle terminal to the Venturi nozzle branch during the supply procedure, to provide a water supply system which requires less maintenance and is less temperamental.