The operation of the Mulino di Bienno (having been designed to be water-powered) is given by the driving force of the Vaso Rè.

The water flowing along the artificial canal crosses the historic center until it reaches just above the Mill where it is channeled into a secondary wooden watercourse and through a steep descent it breaks against the "cassette wheel", the pressure of the water against the "blades" activates the rotational movement of the wheel thus starting the internal gears.