The project builds on the achievements of RER7013, "Evaluating Groundwater Resources and Groundwater-Surface-Water Interactions in the Context of Adapting to Climate Change", which provided a first overview of groundwater and surface water resources, including transboundary water resources, in 27 participating Member States and sought to improve the capacity and self-reliance of participating Member States to introduce isotope hydrology in water resources planning, management, and development at national and transboundary levels. The phase two project seeks to increase coverage and capacity of the regional network in the European TC (TCEU) region, which was consolidated during RER7013, for the monitoring and evaluation of water resource quality and quantity using isotope techniques. In order to promote greater regional cooperation, the project continues to encourage participating countries to work together to improve the characterization of shared aquifers, address identified data gaps, and facilitate the use of isotope hydrology for the formulation of water-related policies. This third aspect is outlined as a new component of the project, given the need and interest of several participating countries. Ultimately, the project aims to enhance evidence-based decision-making for integrated water management to improve water security in Member States of Europe and Central Asia.

The phase two project will address issues identified under RER7013, such as: (i) sampling in areas where important data gaps have been identified and under-investigated sites; (ii) the development of common regional studies and a set of new case studies, including assessments of water balance in the catchments, the impact of glacier melt on transboundary rivers, the evaluation of river damming on surface and groundwater, the contribution of tributaries to main rivers, the effect of hydrotechnical facilities on river flow and groundwater surface water interactions; (iii) the setting up of additional stations to sample rainfall, groundwater and surface waters for isotope analysis; (iv) encouraging the translation of findings already made during the RER7013 project, and planned activities within the new project, into policies; and (v) the strengthening of collaboration between the national authorities involved in the management of shared water resources and the participating institutions and organizations. This regional project thus aims to address a cross-cutting issue of water security, grounded in climate change impacts, and exacerbated by insufficient knowledge and technical capacity to sustainably manage water resources, particularly transboundary water resources, at regional and national levels. The main project output will be the development of best practices guidelines on isotope hydrology applications in transboundary rivers impacted by climate change, and anthropogenic activities that are grounded in knowledge obtained during the project implementation. The proposed project will strengthen national and regional capacities on isotope hydrology applications and will add value towards the translation of science into action and policy.