RESUMEN INGLÉS

The interdisciplinary nature of water problems requires methods to integrate the technical, economic, environmental, social and legal aspects into a comprehensive framework that allows the development of efficient and sustainable water management strategies.
The research presents a methodology for allocating costs among water uses with a cooperative game theory approach based on the integral river basin modelling at monthly time detail. Cooperative game theory provides the tools to consider cost allocation problems by means of the analysis of incentives to cooperation. The game theoretic approach relies on considering the principles of rationality, equity and efficiency in an axiomatic perspective to achieve a fair and just cost allocation process on a strategic basis, where the decisions of a subject are relevant on the behavior of the other actors.
The proposed approach starts from the hydrologic and economic characterization of the system to be modelled and is based on the concept of the users’ responsibility on the water services, in other words, the minimal set of investments to achieve a certain service level for each water use. Decision support systems for water resources management (SIMGES, Andreu et al. 1996; WARGI, Sechi G.M. and Zuddas P., 2002) have been applied to retrieve water system performances and to calculate the characteristic function of each one of the user coalitions that may arise in the water resources system.
The solution of a cooperative game is the amount of money each player should pay as a fair and efficient cost allocation of the water services.
As a case of study, has been analyzed the Turia river basin (Spain).