National Water and Sewerage Corporation (NWSC) has some tip for you that will help you control water theft. Here it is;
A lockable ball valve can be installed on the water line, but this also requires a key which can be conveniently hanged onto a key ring.
Depending on how the water lines run into the house, the lockable ball valve can be installed on the hose tap lines only which means you can stop water going to the hose tap, but still allow water feed the rest of the fixtures and appliances in the house.
