Water resources management in arid and semiarid region is a complex, multifaceted task due to the many hydrological, environmental, and management factors that need to be integrated in order to provide to all users from different sectors sufficient supplies of adequate quality while ensuring the necessary level of environmental protection.

Specifically, scarcity of conventional water resources in arid and semi-arid regions promotes the search for additional sources (i.e., unconventional or marginal waters) such as deep groundwater, treated wastewater, saline or brackish water, and for practices, such as advanced irrigation technologies and water harvesting, for reducing demands and satisfying water requirements. Furthermore, drought events, that often occur in Mediterranean countries, amplify water management problems and require long-term measures to reduce the water systems vulnerability, and short-term measures to mitigate drought impacts.

This paper presents the main objectives and the preliminary results obtained during the first year of the WAM-ME project, which is carried out by seven partners from six Mediterranean countries with the overall goal of increasing the scientific background and developing technological tools for improving water resources management and environmental control in drought-prone Mediterranean regions, addressing the exigency of integrated water management and environmental protection, as already highlighted in the European Commission water policies and directives.

Particular attention will be devoted to the definition of criteria for an efficient use of marginal water resources (in particular the reuse of treated waste water for irrigation and the withdrawal of deep groundwater considered as emergency resource) and the development of modeling tools and Decision Support System (DSS). These criteria and tools could support the choice of the preferable mix of long-term and short-term measures for water management under normal and drought emergency conditions.

The specific objectives of the project are as follows:

Identify the most significant problems occurred in the countries participating to the project during recent drought events and the institutional, legal, and technical features of the water management systems in operation;

Develop adequate recommendations for the most efficient water application methods, diminishing risks for environment and human health while utilization low qualities waters, by using the results of specific field experiments with waste water treated effluent and with different kinds of modern application technologies;

Define potential applications and limits of the use under drought conditions of water resources marginal for quality (waste water, saline and brackish water) or marginal for exploitation costs (deep groundwater), taking into account the minimum water quality requisites, the level of treatment and the hygienic constraints as a function of the final uses and utilization schemes, and to provide recommendations for treated wastewater disposal and reuse incorporating criteria developed by various countries and international authorities.

Develop a set of strategies identifying the role of groundwater in mitigating drought impacts in complex water systems which include the conjunctive use of surface and groundwater;

Develop an optimization model for the conjunctive use of conventional and marginal waters incorporating significant water quality indices;

Develop a Decision Support System (DSS) for the management of integrated water resources systems focused to drought prevention and mitigation which could help the decision makers to face drought risk in the Mediterranean regions;

Verify the usefulness of the developed optimization model and DSS tools to identify, in selected Mediterranean regions, the preferable mix of long-term and short-term measures for drought impacts mitigation.