The objective of an efficient operation and maintenance of a water supply system is to provide safe drinking water as per designed quality and quantity, with adequate pressure at convenient location and time at competitive cost on a sustainable manner. The manual was drafted keeping in account all the features of water supply system and the required critical aspects of operation and maintenance. Facets of design, manpower, monitoring, training and finance has been extensively covered by the authors. The Document is designed with a vision to sustain the water supply schemes in the rural districts of West Bengal.