Mobilization of the resources of low opportunity cost, especially labor in the rural sector, for the construction of social overhead capital has long been identified as a key to the development of low-income countries.1 Local-resource mobilization depends critically on the organization of community work programs at the village level. Yet few empirical explorations have been made to identify the economic and social conditions by which labor and other local resources can be effectively mobilized by village communities. In order to fill this gap, we attempt a case study of a communal irrigation project organized by a village in Central Luzon of the Philippines. Economic incentives for the organization of the community work program for irrigation development are analyzed in terms of the profitability of the project and the rate of return to labor mobilized. The social conditions under which such economic incentives lead to the effective organization of communal labor are explored in terms of the structure of community leadership as well as the distribution of benefits among different classes in the community.