Paraná River Source: The Pantanal Wetlands of Brazil

The Paraná River—South America's second-longest (4,880 km) and second-largest by discharge—begins not as a single spring but as a diffuse network of streams rising in the Pantanal, the world's largest tropical wetland (150,000–200,000 km² seasonal extent).

Headwater Geography

• Primary contributors: Paranaíba River (source: Serra da Mata da Corda, Minas Gerais) and Grande River (source: Serra da Mantiqueira, Minas Gerais/São Paulo border).
• Confluence: Paranaíba + Grande = Paraná River proper, near the Três Estados (Three States) marker: Minas Gerais, São Paulo, Mato Grosso do Sul.
• Pantanal connection: During wet season (Dec–Mar), the Paraguay River (Pantanal's main outlet) overtops into the Paranaíba basin via the Taquari River, linking the two systems hydrologically.

National Distribution of the Upper Basin

• Brazil: ~80 % of contributing area (Minas Gerais, São Paulo, Goiás, Mato Grosso do Sul, Paraná states).
• Paraguay: ~10 % (eastern Pantanal fringes).
• Bolivia: ~10 % (upper Paraguay headwaters feeding Pantanal).

Downstream Significance

From the confluence, the Paraná flows southwest, forming the Argentina–Paraguay border, receiving the Iguazú (Iguaçu) River, then the Paraguay River at Corrientes/Resistencia, before merging with the Uruguay River to form the Río de la Plata estuary. The basin supports 100+ million people, 50 GW hydro capacity (Itaipu, Yacyretá), and the Paraná–Paraguay Hidrovía commercial waterway.