The environmental program that protects the supply of groundwater is the South American Guarani Aquifer System.
South American Guarani Aquifer System is located beneath the surface of Argentina, Brasil, Uruguay and Paraguay. It is considered the largest aquifer system in the world and is an important source of fresh water. It is estimated to contain nearly 37,000 cubic kilometres of water, with an overall recharge rate of about 166 km³/year from precipitation.
