In Indian society, the main concern of the people living in urban areas is to store and minimize the wastage of municipal water supplies to households. This storage is regularized with the help of overhead tank attached with motor and submersible pumps.

Semi-Automatic Overflow Tank System (SOTS) is device that regulates this system of storing water in overhead tank by automatically switching off the pump when the tank is full. This device saves water as well as electricity and proves to be a step in sustainable development of consumer products.

SOTS device works on mechanical linkages combined together to form a complete electro-mechanical device capable of performing the given task. A MCB switch is used to power on and off the pump, a small 12V DC motor is used to trigger the MCB relay thus switching off the pump. The signal to start the motor to trigger MCB comes from connected float switch that is installed inside overhead tank at desired level. This trigger switches off the main supply thus pump, motor and buzzer (if installed) turns off after the tank is full.