Paraguay is a landlocked country located in the southern hemisphere of the Americas. It shares borders with Bolivia, Brazil and Argentina.

The Paraguay river splits the country into two natural regions, the eastern part or humid region, and the western part or Chaco, with drier alluvial plains. There are great differences between these two regions not only from the water resources standpoint but also as regards nature. Furthermore, the Paraguay river is the main drainage system of the country, and also collects surface water from Brazil and Bolivia, adding to the water that flows towards Argentina.