River, southern Brazil.
It rises in the hills east of Passo Fundo and flows southward and eastward for 280 mi (450 km). At Pôrto Alegre it receives four other rivers and forms the Guaíba River, a shallow estuary that empties into the Atlantic Ocean. Navigable upstream as far as Cachoeira do Sul, it has one of the most heavily used river barge systems in Brazil.