In studies of contemporary changes to natural environments in China, ethnic groups in the nation's southwest are often used to demonstrate that earlier indigenous ideologies and institutions responsible for the harmonious relationships between human communities and their natural resources have now been swept away by government policies, market forces, new technologies, and most recently, climate change. In our study, we ask how a water system, in use for several centuries in a village of the Bai nationality, has been affected by these new factors. Our expectation was that the old water system would be disrupted or in decline as a result of the changes accompanying economic development and longterm drying trends in this part of China. We found, instead, that the old system is still structurally intact and the community continues to access it for farming and everyday household use. Based on an interdisciplinary approach combining ethnographic fieldwork and local geomorphological data, this article identifies some of the factors responsible for the longevity of the local water system. [water security, government policy, agricultural commercialization, labor migration, climate change] Ann Maxwell Hill is professor of anthropology and directed the Luce Initiative on Asian Studies and the Environment, a four-year grant concluded in October 2016, at Dickinson College. Kelin Zhuang is a geologist currently working on a climate change project in the