In the Mediterranean basin, wide differences in water supply and demand characteristics exist and no individual case study may be a representative of the entire region. Some countries suffer problems of overexploitation of groundwater while others suffer from water quality degradation. On the other hand, some have enough or plentiful water but lack institutional structures to manage water efficiently, while others have scarce and limited water and seek non-conventional water like desalination or importation of water. Managing water scarcity Integrated water resource management is a cross-sectoral policy approach that requires coordination among the different water uses and institutional sectors to respond to the growing demands for water in the context of finite supplies. This process aims at ensuring the coordinated development of water, land and related resources to optimise economic and social welfare without compromising the sustainability of environmental systems. Therefore, it is a complex and multi-dimensional process that must be customised to the specific geographical, environmental, social, cultural, political and economic conditions of each region and catchments (GWP, 2000). It involves understanding the interactions of the various social, political, economic and ecological processes that influence choices and strategies within the ecosystem, and addressing issues through the involvement of various stakeholder groups. This ecosystem approach has been developed, through the concept of integrated watershed management, as a strategy to rebuild agriculture and promote participatory development. (Noronha, 2004). It is a great tool for an adequate decision-making process, providing stakeholders, decision-makers and policy makers with integrated environmental and socio-economic information to deal with the needs of local populations, and to assess different development options and water management strategies (White et al., 2002). Managing water resources was traditionally approached by the supply sector, building reservoirs and distribution network systems, finding new water sources. It was considered that the major strategies should comply with the needs of humans in terms of drinking water, food, etc. Although this continues to be a major obligation for human societies, it is also clear that water is necessary for more than domestic use or production of food (Lundqvist, 2000). Water is also crucial for the functioning of ecosystems, and for the goods and services these ecosystems produce to society, therefore to the sustainability of societies' development. Nowadays water management must be dealt in terms of change and adaptation: both in society itself and in society's interactions with nature. Lundqvist (2000) approaches the changes in water management as different turns of a screw. In a first moment, scarcity is recognised as a pure natural resource scarcity and the remedy is to "get more water", which is accomplished by large-scale engineering efforts. On a second moment, it is recognised that it may no longer be possible to develop additional large volumes of water. The effort at this stage is re-directed towards efficiency measures, predominantly to get "more use per drop". This often induces significant changes in national policies, through the adoption of demand management strategies aiming at producing more with less water or to produce higher economic values from available water resources.