Ignacio Garriga, Vox candidate for the presidency of the Generalitat, has put on the table in an interview with Els Matins on TV3 the interconnection of the internal basins of Catalonia as a priority option to prevent and solve droughts. It is something similar to what Alejandro Fernández, PP presidential candidate, said on Monday in the same program, where he stated that the Ebro River sends to the sea “an amount of water that would be much more than enough to guarantee the supply to the Metropolitan Area of Barcelona (AMB)”.
It is true that the amount of water that reaches the sea from the Ebro River would be enough to cover the needs of the AMB. The region consumes about 0.65 hm3 of drinking water per day, according to estimates by the Generalitat, while the flow of the Ebro in Tortosa, the last measurement point before reaching the sea, has been on average about 15 hm3 per day in the three days we have in May. Now, the interconnection - the union between the Ter-Llobregat system that supplies the AMB and the Consorci d'Aigües de Tarragona, which manages the Ebro water in southern Catalonia - is a controversial issue due to its environmental and social impacts, and there are different scientific voices facing each other regarding its suitability. We explain it to you!
An idea that emerges from Fernández's speech is that the water from the rivers that reaches the sea is lost water. It is a perception that is also widespread among the population: practically half of the citizens think in these terms, according to a survey by the Citizen Drought Observatory, published in October 2023 (page 28).
This notion is erroneous, as stated by the various experts contacted by Verificat. The water from the rivers that reaches the sea is key to keeping ecosystems in good condition. If the flow is stopped (or reduced), the beaches and deltas would deteriorate until they disappear due to the lack of sediments, different species of fish would be threatened by the lack of nutrients transported by the rivers, the temperature and salinity conditions of the sea would change and The biodiversity of the river would be threatened.
These are some of the consequences cited by the Center for Ecological Research and Forest Applications (CREAF) on its website and replicated by other independent experts of the institution. In fact, the Ebro Delta has been eroding for years due to its reduced flow, due to the numerous reservoirs that store water in its course.
On December 15, 2023, the Intercol·legial Observatori de l'Aigua (created just a few months before), formed by the colleges of economists and civil engineers, industrialists and agronomists, proposed the interconnection of all Catalan supply networks to improve “resilience and guarantee of supply” throughout the territory. The entity proposed to begin by uniting the Ter-Llobregat system (which supplies the AMB) and the Tarragona Water Consortium, which captures and distributes water from the Ebro.
Almost a month later, the Intercol·legial de les Terres de l'Ebre, made up of seven professional associations in the area, rejected the proposal, calling it an "error." The Government has rejected the measure for now.
For Vicenç Acuña, director of the Catalan Water Research Institute (ICRA), interconnection “is not a crazy option and does not have too great an economic cost.” The expert welcomes “having these connections to be able to respond to emergencies, as for example is already done in electrical or internet communication networks.” He rules out, however, that it is a priority intervention. For him, the regeneration and reuse of water, forest management to have more resources in the rivers and desalination are measures to prioritize.
Narcís Prat, emeritus professor of Ecology at the University of Barcelona (UB), catalogs this vision of commercialization of water, which forgets that it is an environmental and social asset for the region. The expert is committed to local management and savings measures to overcome the crisis, and then to commit to the regeneration and reuse of water, desalination and rainwater harvesting to deal with emergency situations.
It is a vision similar to that shared by Emili García-Berthou, professor of Aquatic Ecology at the University of Girona. “What seems logical is to reduce the demand for water from internal basins and from everywhere (better regulate uses), and not increase the problems of other basins,” he points out.
