The models 20 and 40 of RAINMASTER Favorite are designed with self regulating mechanism and monitoring stations that include in built main water supply system, pump and controller. The entire unit can be installed in limited space. The operating system of this system involve conveying of stored water by its pump from storage tank by utilizing an intake suction hose. The state of the art technology used in this system is effective in supplying water both for internal and external utilization purpose that include drainage of human waste materials, for washing clothes in washing machine, for cleaning work, irrigation work, in cooling equipment and so on. The RAINMASTER Favorite 20 and 40 units come in handy for automatic functioning of main water supply system during the scarcity of greywater or rainwater.