THE PAPER PRESENTS the experiences gained and the lessons learned by the National Irrigation Administration (NIA), the Philippines, during the installation in the mid-1970s of some 35 groundwater pump systems; and in the conceptualization of feasible and affordable arrangements for the subsequent turnover of the operation and maintenance (O&M) of the schemes to Irrigators' Associations (!As). It will also discuss the policies of the irrigation agency on pump irrigation systems, as well as the activities and programs undertaken to assist the !As, in developing their capacities in managing the pump schemes and improving their water delivery systems, cropping pattern and schedules to overcome the high cost of electric power while still improving their productiV'ity. The success and failure in operating the pumps will also be presented including the strategies adopted by both the NIA and !As to overcome the problems and constraints. Specific topics will also be included to present the various arrangements forged by the NIA and the !As relative to the O&M of the pump systems which will embrace rental arrangements, full management takeover by the !As and eventual ownership of the pump system. Some critical issues and problems encountered such as drawdown effects on the shallow wells used as domestic water supplies in the nearby communities, collection of water charges, shutting down of pump operations, etc., will also be discussed. Highlights of the paper will likewise include the stringent rules and regulations as well as the strategies adopted by some !As in their quest to instill discipline among the water users particularly in implementing the planned water delivery and cropping schedules and thereby reducing O&M costs, and in their incessant desire to transform from government-dependent organizations into self-reliant and financially viable associations of formerly rain-fed farmers. Last, the paper will provide insights into the plans of the NIA and the !As to initiate programs toward sustaining the operation of the groundwater pump systems and in further improving the productivity of the farmlands served by the pumps. This is in line with the renewed five-year vision of the agency for a dynamic and functioning NIA and !As working in partnership toward accelerating irrigation development and providing an efficient level of service.