Water Lock is both a water meter and a locking device for use on bathtub taps. It allows the user to set the desired volume of water for their bath, and leave the flow of water unmonitored. The flow will be automatically stopped when the set volume has run through the tap. The purpose is to avoid the wastage of water through the over-filling of the bathtub.

Water Lock simultaneously records and displays the water volume. When the water is flowing, it is ‘on’. When the flow is terminated, Water Lock is ‘off’. It uses the principle of a combination padlock for its operation. It is expected that the device would increase users’ awareness of their water consumption while helping them to avoid wastage.