China has the largest electricity generation capacity in the world today. Its number of large dams is second to none. Xiangli Ding provides a historical understanding of China’s ever-growing energy demands and how they have affected its rivers, wild species, and millions of residents. River management has been an essential state responsibility throughout Chinese history. In the industrial age, with the global proliferation of concrete dam technology, people started to demand more from rivers, particularly when required for electricity production. Yet hydropower projects are always more than a technological engineering enterprise, layered with political, social, and environmental meaning. Through an examination of specific hydroelectric power projects, the activities of engineers, and the experience of local communities and species, Ding offers a fresh perspective on twentieth-century China from environmental and technological perspectives.