A study in which IHCantabria has participated warns about the growing water insecurity in the Mediterranean basin

90% of the water available in some Mediterranean basins is destined for human uses, leaving ecosystems on the verge of collapse

The Mediterranean basin is facing a silent crisis that threatens its biodiversity, economy and public health: water scarcity is jeopardizing water security and freshwater ecosystems. This is the warning of a study recently published in the journal Environmental Research Letters, in which the Environmental Hydraulics Institute of the Universidad de Cantabria (IHCantabria), together with other Spanish scientific institutions, participates.

The scientific article, entitled “Water scarcity challenges water security: a case for Spain’s freshwater ecosystems“, points out that intensive water use – concentrated in agriculture, tourism and certain industrial sectors – is pushing rivers, aquifers and wetlands towards a point of no return.

Ecosystems under pressure

The researchers who participated in this study emphasize that in several Mediterranean basins, up to 90% of the available water resources are used for human activities, leaving insufficient reserves for the maintenance of ecosystems. “This overexploitation, together with the increasing frequency of droughts and the effects of climate change, is degrading emblematic sites such as Doñana, the Tablas de Daimiel or the Ebro delta,” explains José (Pepe) Barquín Ortiz, one of the co-authors of the article, full professor at the University of Cantabria and head of the Continental Ecosystems Group at IHCantabria.

Biodiversity loss, saline intrusion in coastal aquifers, and the proliferation of invasive species are some of the consequences of this pressure. In addition, the disconnection of rivers from their floodplains and pollution from urban and industrial discharges increase health risks and reduce the capacity of ecosystems to provide essential services, such as flood protection and natural water purification, respectively.

Transforming water management

The study warns that policies focused on increasing water supply – such as the construction of reservoirs or the promotion of desalination – are no longer sustainable solutions on their own. In fact, investments aimed at improving irrigation efficiency have led to an increase in irrigated area, without achieving real water savings.

The authors propose a paradigm shift: prioritizing the protection and restoration of ecosystems, promoting conservation agriculture, controlling illegal extractions, and avoiding the establishment of industries or tourist complexes in areas subject to water stress. They also stress the importance of institutional coordination and of implementing climate change adaptation measures in an integrated manner.

A mirror for other semi-arid regions

Having developed a highly water-dependent economy in a semi-arid territory, Spain is a relevant case study for other regions of the world with Mediterranean climates. The Spanish experience shows the risks of relegating ecosystem needs to human demand and offers lessons for moving towards a balance that ensures water security, biodiversity preservation and economic resilience.

The paradigm of the Cantabrian Sea

In the case of the Cantabrian basins, the water stress index is much lower compared to the Spanish Mediterranean basins. Used for comparison on a national scale, this index only reflects the annual water balance. However, on a seasonal scale, many of the Cantabrian basins present the same problems as the Mediterranean basins during the dry months. This problem is being accentuated by the effects of climate change and by the increase in water demand, due to the increase in tourism during the summer period. This cocktail threatens the conservation of biodiversity and water security in the Cantabrian basins.

To address this problem, a new research project ─funded by the FBBVA─ will analyze in detail the water security of Santander, as a representative of a Cantabrian city, together with 2 Mediterranean cities: Barcelona and Valencia. The new project, entitled “Challenges in the face of scarcity to achieve water security in Spain” (H2OSEG), aims to investigate the strategies needed to ensure water security in Spain, taking these case studies as an example to identify water scarcity issues arising throughout the country.

The full content of the article entitled “Water scarcity challenges water security: a case for Spain’s freshwater ecosystems“, can be accessed through the following link: https://iopscience.iop.org/article/10.1088/1748-9326/adfbfc