Tensions and Cooperation Challenges
During droughts, most of the tensions occur among water users, whose water rights are regulated by a complex water rights system that establishes prioritization of uses in case of drought and is framed within river basin management plans. Tensions among users can spill over into interregional relations when regional government advocates for the interests of its constituency (e.g., to avoid water restrictions or to support the need for investments in new water infrastructure). Most of the interregional tensions, however, occur over competences over water resources and water allocation. In particular, water allocation as defined in the river basin management plans (revised and approved every 6 years), the construction and operating of water infrastructure, and water transfers are significant sources of tensions and disputes between regions and between regions and the central government. This can be explained by the fact that Spain has a strong regulatory framework for water management, and those issues and instruments create the foundation for any decision taken to manage drought. Thus, regions engaged in bitter disputes over the approval of the National Hydrological Plan in 2001, as it included the construction of a long list of new water infrastructure and a major water transfer from the Ebro basin in the northeastern part of the country to several regions along the Mediterranean coast. Moreover, since the 2000s there have been several judicial cases in the Supreme and Constitutional Courts where regions have sued one another in order to gain greater control over water resources development in their territories and to increase their competences over water resources planning and management (for an overview, see Lopez-Gunn and De Stefano 2014; Moral Ituarte and Hernandez-Mora Zapata 2016).