Via Natural

The research activities carried out in each country by scientists coming from different disciplines and institutions allowed to define the main characteristics of this aquifer. This mega - aquifer is contained in aeolian and fluvial sands from the Triassic - Jurassic, usually covered by basalt formations from the Cretaceous, which provide a high confinement degree. The pattern of this sandy sediments is due to: the Paraná Sedimentary Basin boundaries, the faults, the structural features and the basalt deposits that cover the sandstones. Its thickness ranges from 50 up to 800 m. The deepness varies and reaches up to 1,800 m. Other distinctive characteristics are its high pressures and artesian yields at certain locations of the basin, the low salinity of its waters and its temperature.

Best estimates show that the Guarani contains enough water to supply 360 million people on a sustainable basis. Already, some 500 cities and towns across Brazil draw their water from the Guarani.

The Guarani Aquifer System is an underground water reservoir. It is a group of sandy rocks below the soils' level with water in its pores and fissures. These rocks were deposited there between 245 and 144 million years ago.

It is named Guarani because its extension is approximately the same as the Great Guarani Nation, native population that inhabited the region

Part of the rainwater that falls in the region gets directly into the aquifer infiltrating in the soil or by rivers, streams and lakes that by their beds allow the water to pass to deeper layers. The water that gets in is called “recharge“ and it is quantified in an annual volume. For the GAS, the recharge is estimated in 166 km³/year. The permanent GAS water reserves --the water deposited in rocks pores and fissures-- are approximately 45.000 km³.