The installation for the automatic regulation of the level of water 1b in a drinking trough 1 has a feed pipe 2 leading into the bottom 1a of the trough 1 at its centre, and the said pipe possesses a valve member 4 situated on the level 1b, its member for closing or for opening the pipe being caused to close by the hydrostatic pressure generated by the difference H in height between the level 1b and the device 4, in opposition to a return member bringing the said member back to its open position, the force of whose action is adjustable as a function of the desired level. <IMAGE>
