Although Paraguay produces (and exports) more hydroelectric energy per capita than any other country in the region, these resources are situated on the border with Argentina and Brazil, inflecting national energy matters with transnational complexities. Popular sectors framed Itaipú (with Brazil) and Yacyretá (with Argentina) dams as imperialistic predation. In the last decade, the Paraguayan nation became the possessor of "hydroelectric sovereignty," which is always threatened. Energy experts from the left conceptualized hydroelectric sovereignty as the proper relationship of "nation" to "territory" mediated by the "state," through grassroots struggles to regain control of the country's hydroelectric resources. As part of an ethic of renewable energy, "hydroelectric sovereignty" results in a new kind of territoriality. Through the discursive and civic creation of hydroelectric sovereignty in an electoral campaign to "recover hydroelectric sovereignty," I show how "nature" and "nation" are altered by hydroelectric statecraft, political-economic and symbolic structures that emanate from hydroelectricity.