This project, led by the International Atomic Energy Agency, aims to bridge gaps in isotope hydrology knowledge and technical capacity among countries in Europe and Central Asia. It focuses on raising awareness about isotope-based methods used in water resource analysis. A key objective is to promote knowledge exchange and capacity building through training courses and fellowships. The project also addresses regional and transboundary water issues, including the impacts of climate change and human activities on groundwater. Additionally, it seeks to strengthen a network of professionals working on isotope-based water monitoring and assessment. Groundwater makes up 98% of the world’s unfrozen freshwater, yet its sustainable management remains complex. Challenges include over-extraction, pollution, and declining water quality, which are intensified by climate change and increased human activity. These pressures threaten communities and ecosystems that depend on groundwater resources. Understanding aquifer systems and interactions between groundwater and surface water is essential for effective water management. Isotope analysis provides a powerful tool for studying these systems, although expertise and technical capacity vary widely across the 27 participating countries in Europe and Central Asia.