Catalan Water Research Institute research and innovation for the sustainable use of water

Conclusions of the World Water Day 2022 seminar: Groundwater: Making the invisible, visible

Monday, 04 April 2022

The activity, which had the participation of 83 attendees, was part of the celebration of World Water Day 2022 dedicated this year to underground water. For the session, the speakers Emilio Custodio (UPC, ULPGC), Mireia Iglesias (ACA), Lluís Sala and Agustí López-Fàbrega (CCB-Gi), Anna Menció (UdG), Albert Soler and Gil (UB), Ester Vilanova (Amphos 21), Viviana Re (University of Pisa), Damià Barceló (ICRA) and Josep Mas-Pla (ICRA, UdG). The most prominent messages from the experts were the following: • Groundwater constitutes a vital resource, often of good quality, and a long-term strategic reserve, there being a conflict between human and environmental uses that must be resolved through knowledge and research • This resource is intensively exploited in many places, generating both quantity and quality problems. The resulting problems must be solved through complex governance and appropriate planning. • At the level of Catalonia’s internal basins, 82% of underground water bodies have a good quantitative status, a percentage that is reduced to 43% of bodies in good qualitative status. The main quality problem is nitrate pollution. • The Internal Basin River Basin District Management Plan 2022-27 includes the needs, pressures and impacts and proposals for relevant measures. Together with the 2020 Drought Plan, the Management Plan values ​​groundwater as a strategic resource to guarantee supply and environmental preservation. • The local vision of resource management, as in the case of the Costa Brava, must be based on the Sustainable Development Goals of the United Nations. In addition, it will be necessary to give more importance to the hydrosocial aspects within the planning schemes and to tend towards a transversal, decentralized, integral and adaptive model of the water cycle. • Many aquatic ecosystems depend on groundwater flows to maintain their biodiversity. The underground flow provides the necessary volumes of water when precipitation is scarce and regulates the hydrogeochemical cycles, including denitrification, and allows the proper development of habitats. • Groundwater has been exposed to the entry of polluting substances for decades, so the accumulated mass of pollutants creates a serious problem with an inertia that can persist for decades, despite the natural attenuation processes that remove (slowly) various types of pollutants. In-situ or ex-situ decontamination are 2 specific solutions for improving the quality of underground water based on a great diversity of technological strategies. A paradigm shift is necessary with solutions that are based, whenever possible, on reproducing natural processes that increase the resilience of aquatic environments to loss of quality, and to integrate the concept of the circular economy into decontamination actions. • Research is the basis of knowledge and management. Artificial intelligence methods applied to hydrological management based on machine learning value databases and allow predicting results with a low cost and a high degree of confidence, complementing both the work of field and the information derived from it such as the conceptual and numerical models that describe the hydrogeological processes. It is a new approach to hydrogeological knowledge and, therefore, with great potential in the management of water resources. • The needs and perspectives of people, integrated into diverse social and economic groups interconnected with each other, are one of the most important aspects and at the same time least considered in approaches to hydrological management. Water, as a scarce resource, generates conflicts between users.

The socio-hydrogeological perspective provides a transdisciplinary perspective, based on the knowledge and analysis of hydrological and social data, which allows them to be focused on and resolved by overcoming the gap between science and society. • It is therefore necessary to make groundwater visible by linking science and society and promoting governance. In this context, it is necessary to recognize the user communities as examples of success where a day-to-day work is done by associating users and managers. Without this daily task of observation, data recording and planning, the abuse of groundwater, resulting from ignorance of the water cycle, can lead to consequences that are difficult to solve. Finally, during the seminar there was a memory for professor Dr. M. Ramón Llamas Madurga (1931-2022) who with his master’s degree developed Hydrogeology in the State and around the world and has been a scientific and personal reference for many people linked to underground water. The full video of the conference can be seen on ICRA’s YouTube channel: