One in five of the inhabitants of our planet have no drinking water. 97.5% of the available water is salty. 2.5 % is constituted by fresh water, and it is on the way to running out. But in South America, there lies the silent Guarani Aquifer (El Acuífero Guaraní), an underground freshwater reserve that covers Argentina, Brazil, Uruguay and Paraguay, which is able to supply drinking water for the whole planet for the next 200 years. The intervention of supranational organizations such as the World Bank and multinational corporations that commercialize water in the design of future national strategies to preserve and use these natural resources has caused much controversy and aroused suspicion in the nations involved.