Using the ＂Registers of Huapi Weir＂, the records of a civilian water conservancy, as well as lineage genealogies and local gazetteers, this paper explores the history of the Huapi weir, Chongyang county. It discusses the role of water conservancy organizations in maintaining social order in rural southern Hubei in Ming and Qing. It considers such factors as local irrigation, the management of water conservancy organizations, and the rituals associated with such organizations. The basic argument is that when the authority of local government weakened due to diminished fiscal capacity, water conservancy gradually shifted from official into private hands. Local society organized itself to deal with such issues as rights and responsibilities associated with access to water, maintenance and repair of water conservancy facilities and distribution of water. But when disputes over water broke out, especially conflicts of interest that transcended the area irrigated by the weir, state authority was needed to resolve the conflict. In other words, even when the state lacked the capacity to provide public goods, a complex mutual inter-dependence between local state power authority and popular organizations developed in response to problems at different levels.