Lack of water, an essential life resource, is expected to affect one-third of the population worldwide by 2025. Today, 1.2 billion people live in areas of scarcity, while 1.6 billion face water shortages due to economic problems. The more society grows, both in terms of population and urbanisation, the greater the need for water, causing ever-growing problems in daily life. Indeed water use has been growing at more than twice the rate of population increase over the last century. Water scarcity is not only related to the amount of precipitation and fresh water, it also depends on water conservation, distribution, quality and demand. The issue is particularly worrying in least developed countries (LDCs), where water is scarce or there is little or no infrastructure to extract, distribute or conserve water. Water scarcity also means that, apart from drinking problems, people face problems in hygiene or the environment they live in. It increases the chances of disease and infection, while water conservation in unsafe conditions often provokes the risk of contamination. The international community is trying to tackle this problem and aims to halve the proportion of people without access to safe drinking water or basic sanitation.