Water conservancy in the Dongting lake region became a serious problem from the Ming onwards. Through research into a long-term dispute over water conservancy on the Baishui river, Yuanjiang county, the author discusses the complex social relations surrounding water conservancy. Because of differences in their respective interests, long-term conflict broke out between different landowners on the Baishui river over the issue of whether to dam the river. The repeated damming and excavation of the river was the result of negotiations over these interests rather than objective analysis. Thus water conservancy in the Dongting Lake region was not merely a hydraulic issue but also a social issue.