Argentina, Brazil, Paraguay and Uruguay are to present a joint proposal before the Global Environment Fund for the management, protection and sustainable use of the Guaraní Aquifer. The project involves a subterranean reservoir that spreads over 1.2 million square km in the four countries that make up Mercosur (Southern Common Market) and which could meet the water needs of a population several times larger than the 15 million people currently living in the area.

Hundreds of Brazilian towns and cities utilize the Guaraní Aquifer, but data is still scarce about its potential and its current levels of contamination. An in-depth study is to be carried out over four years at a cost of 15 to 25 million dollars.