Between April and September 2025, the UPWATER project conducted a participatory multi-criteria decision analysis (MCDA) to identify and prioritize effective measures for preventing and mitigating groundwater contamination in the Besòs Delta aquifer (Spain) and the Athens Region aquifer (Greece).
The process unfolded in two stages. During the first phase, local, regional, and national stakeholders assessed and assigned weights to a series of technical, economic, social, and environmental criteria through a structured workshop. In the second phase, these weighted criteria were used to evaluate and rank specific management measures, while also examining their practical implementation challenges and governance requirements.
In the Besòs Delta, the top-priority actions identified include the treatment and infiltration of wetlands and wells, alongside restrictions on groundwater extraction. In the Athens Region, nature-based solutions for wastewater treatment were ranked as the most effective and sustainable option.
The participatory process engaged a broad range of institutions, including the Catalan Water Agency (ACA), the Barcelona Metropolitan Area (AMB), the Consorci Besòs Tordera (CBT), Barcelona Cicle de l’Aigua (BCASA), and the Greek Ministry of Environment and Energy. Technical and research partners such as Metrica, the Athens Water Supply and Sewerage Company (EYDAP), IWW, INERIS, TARH, NTUA, IDAEA-CSIC, and FNCA also contributed to the analysis.
The results of this collaborative process will serve as a foundation for policy recommendations on groundwater protection, to be presented in early 2026.
