Volcanic aquifers appear to exhibit greater resilience to global change compared to other available resources in Auvergne (France). Nevertheless, declining piezometric levels in these aquifers are prompting resource managers to question the quantity of available water and the sustainability of this resource type. The Clermont Auvergne Metropole agglomeration (300,000 inhabitants) relies on two types of resources: an alluvial resource (70%) whose productivity is expected to be significantly impacted in the future by climate changes, and a volcanic resource (30%) where the availability of which is not yet in question due to limited knowledge. To evaluate the potential of this volcanic aquifer in crystalline context, a multidisciplinary study, using existing data and providing new ones, has been projected. Update the geological model of the Tiretaine watershed has enabled to estimate the volume of volcanic formations on this watershed, as well as the distribution between scoriaceous and massive volcanic materials. The use of several hydrochemical tracers and dissolved gases, both natural and anthropogenic, provides insights into water mixing (major and trace elements), recharge altitude zone (18O and 2H), recharge conditions (Ne, Ar, N2) and groundwater ages (CFC, Tritium). Groundwater dating methods brings constraints on the water residence time within the volcanic aquifer and also enable estimation of stored water. Based on these new data, a hydrogeological conceptual model is proposed for this volcanic watershed. To convert these data into an effective management tool for resource managers, long-term observations have begun during this project. The aim for the future of this collaboration between academic researchers and water managers is to upgrade this conceptual model into a numerical model able to simulate the hydrogeological functioning of this watershed and making projections for drinking water supply in the future.