1 – INTRODUCTIONWater availability crucially influences human well-being and directly affects ecosystems and the environment. Water supply and demand issues are particularly more complex in areas of rapid urban and population growth. Projections indicate that 46 to 52 countries and a total population of 3 billion people will face water stress by 2025 (Rosegrant, 1997). And to further increase the complexity, there is the fact that water availability is not uniform. Water is distributed irregularly and, therefore, water-related problems are specific to each region. Water supply and demand problems generally fall into the category of serious problems. Their complexity lies in the fact that they have many interdependencies, are multi-causal and have no clear solution. Furthermore, water issues involve behavioral change and are generally associated with policy decisions and planning effectiveness. There is usually a problem of conflicting interests, meaning that the “solution” for one party may be a “problem” for others (Freeman, 2000). The aim of this study is to understand the social, economic and biophysical aspects of this issue and the interactions between them. Water scarcity can be considered physical or economic (Ricci et al, 2000). Physical scarcity is linked to the biophysical aspects of the problem and is beyond human control. Economic scarcity is associated with the available technology and costs associated with the process of water exploitation, treatment, distribution and reuse. The analysis will take into account both the economic and physical demand for water and their interactions.2 – BIOPHYSICAL ASPECTS Water resources are essentially extracted from two sources: surface water and groundwater. The main source that provides your...... middle of paper ......s. BioScience, 54, 909-918.RICCI, PF, RAGAINI, RC, GOLDSTEIN, R. & SMITH, W. 2000. Global water quality, supply and demand: implications for megacities. Available: http://www.federationofscientists.org/PMPanels/Pollution/Water_Quality.pdf [Accessed 03/31/2014]. ROSEGRANT, MW 1997. Water resources in the 21st century: challenges and implications for action. Discussion Papers on IFPRI Vision 2020. WAKODE, H. 2011. Urban growth and its effects on water supply and demand in Hyderabad. Urbanization and water [Online]. Available: http://www.waterandmegacities.org/urban-growth-and-its-effect-on-water-supply-demand-in-hyderabad/ [Accessed 03/31/2014].WANG, J., DA , L., SONG, K. & LI, B.-L. 2008. Temporal variations of surface water quality in urban, suburban and rural areas during rapid urbanization in Shanghai, China. Environmental pollution, 152, 387-393.