In this book, Erik Swyngedouw explores how water becomes part of the tumultuous processes of modernization and development. Using the experience of Spain as a lens to view the interplay of modernity and environmental transformation, Swyngedouw shows that every political project is also an environmental project. In 1898, Spain lost its last overseas colony, triggering a period of post-imperialist turmoil still referred to as El Disastre. Turning inward, the nation embarked on "regeneration" and modernization. Water played a central role in this; during a turbulent period from the twentieth century into the twenty-first -- through the Franco years and into the new era of liberal democracy -- Spain's waterscapes were completely transformed, with large-scale projects that ranged from dam construction to irrigation to desalinization. Swyngedouw describes the contested political-ecological process that marked this transformation, showing that the Spain's diverse and contested paths to modernization were predicated on particular trajectories of environmental transformation. After laying out his theoretical perspectives, Swyngedouw analyzes three periods of Spain's political-ecological modernization: the aspirations and stalled modernization of the early twentieth century; the accelerated efforts under the authoritarian Franco regime -- which included six hundred dams, expanded hydroelectricity, and massive irrigation; and the changing hydro-social landscape under social democracy. Offering an innovative perspective on the relationship of nature and society, Liquid Power illuminates the political nature of nature.