Mineral and thermal waters have great economic importance and are widely used for therapeutic, balneological, water bottling and energetic purposes, even though they represent a small percentage on the total yield of groundwater systems. The hydrogeological environment where mineral and thermal waters originated is complicated by specific hydrostratigraphical and structural conditions that permit the occurrence of different hydrochemical facies, including more flow paths and interactions among waters with different qualities. Geological uncertainties affect the hydrogeological model and make the interpretation of the hydrochemical facies often difficult. On the other side, the understanding of the recharge area, flow paths and processes of water–rock interaction is indispensable for the determination of available resources and their proper management. Often the legislation on mineral and thermal waters is focused on the definition of quality of the resources rather than the best practices of abstraction and management.

This gives rise to the need to improve knowledge on the physical and chemical processes that contribute to the formation of mineral and thermal waters for the maintenance of quantity and chemical characteristics of these valuable economic and environmental resources.

This is the context of this special issue of Sustainable Water Resources Management which reflects contributions made as parts of two events held in Europe co-sponsored by the IAH Commission on Mineral and Thermal Waters:

  • Session “Mineral and thermal waters: hydrogeology, hydrogeochemistry and sustainable management” at the 42nd IAH Congress Aqua, Rome (Italy) 13–18 September 2015,

  • MinWat2017, 2nd International Multidisciplinary Conference on Mineral Waters: Genesis, Exploitation, Protection and Valorisation, Luso (Portugal) 26–31 March 2017.

The issue contains seven articles on different topics related to the fields of research, investigation and sustainable use of mineral and thermal waters in some European countries.

The topics addressed in the articles represent a contribution on a subject that has been poorly treated from a purely hydrogeological point of view. The proposed cases have as their main theme the complexity of the physical system in which mineral and thermal waters originate, selecting case studies related to very different geological and hydrogeological contexts.

The road ahead to reach a sustainable use of mineral and thermal waters is still long and must necessarily provide for greater interaction and exchange of views between scientists and managers. The purpose of this special issue is to further stimulate the discussion on the contribution that hydrogeology can provide to help managers in questions related to the research, use and protection of mineral and thermal waters.

The guest editors are grateful for the support of the editor-in-chief Dr. James W. LaMoreaux and assistant editor Nancy Green at all the stages of the preparation of this thematic issue. The editors would like also to recognize the work performed by the numerous reviewers for their insightful input during the peer-reviewing process to improve the quality of the manuscripts. Finally, we are thankful to the Organizing Committees of Aqua2015 and MinWat2017 for allowing a selection of potential manuscripts to be substantially extended into this special issue.

Paula M. Carreira

José M. Marques

Vincenzo Piscopo