In its inauguration in 1979, the Tagus-Segura Interbasin Transfer was designed to transfer up to 650 hm3/year of water from the head of the Tagus river along 286 km of canals, pipes, and the Jucar river, to the Segura river basin. From there it is distributed for human consumption and to a large swathe of irrigated territory across the region of Murcia and the provinces of Alicante (Valencian Community) and Almeria (Andalusia). It is the subject of intense contestations across geographies, territories, and political scales, with economic groups and political movements on either side claiming the Tagus headwaters as their basin’s own. Environmental movements increasingly claim the need for larger quantities of minimum environmental flows, water-related ecological issues are increasing in size and scope in both basins, and low rainfall has decreased the amount of Tagus headwaters transferred, instigating contestations further. In this context, this research collaborates with irrigation associations in both the Tagus and Segura basins, where it aims to understand irrigators’ perceptions of their territory, what the local problems related to water and agriculture are, how the transfer has impacted them, and what their perceptions of other irrigator associations in different territories and basins are. Similarly, this research explores their hopes and doubts for the water future of their territories, their perceptions of sustainability, and how this sustainability is perceived in their territories and across their own and other basins.

Actual and projected water scarcity has accelerated the development, both in number and in scale, of hydrological infrastructure, particularly of mega-projects in the form of Inter-Basin Water Transfers (IBWTs). These are unique since IBWTs transfer freshwater from one geographically distinct river catchment or basin to another. In the most ambitious cases, planned IBWTs would make up multi-IBWT hydro-networks. Despite increased implementation of demand-side policies with the IWRM water governance paradigm shift, supply-side options in the form of IBWTs are going to increase. IBWTs are a powerful empirical case to deploy and examine hydrosocial territories, since they shift and change socionatural relations across scales, temporalities, and territories, (re)casting the relationships between individuals, society, the State, and nature, as well as with and beyond water. Using IBWTs as the empirical case, this research sits at the intersection of the political ecology of water, socionatural relations, science and technology studies, subjectivities, and feminist futures scholarship. It argues that IBWTs craft new and contradictory hydrosocial relations, inserting specific territories, populations, and ecologies into intensifying processes of globalization and accumulation, and others into hinterlands, along specific sociopolitical narratives that fashion hegemonic, counterhegemonic, ambiguous, and contested socionatural subjects and territories. Using a mixed methods approach, this research analyzes IBWTs both from above – reviewing the literature on IBWTs from across the world to provide broad perspectives, and from below – taking the Tajo-Segura IBWT in Spain and irrigation farmers on either side of the transfer – to explore this argument.