The Guaíba River is a waterway in Rio Grande do Sul

Rio Grande do Sul

Rio Grande do Sul is the southernmost state in Brazil, and the state with the fifth highest Human Development Index in the country. In this state is located the southernmost city in the country, Chuí, on the border with Uruguay. In the region of Bento Gonçalves and Caxias do Sul, the largest wine...

, a state of southern Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

. It is famous for its beautiful reflection at sunset. The Guaíba is an extension of the Lagoa dos Patos

Lagoa dos Patos

Lagoa dos Patos is the second largest lagoon in Latin America and the biggest in Brazil. It is located in the state of Rio Grande do Sul, southern Brazil. It is 174 miles long, has a maximum width of 44 miles , and a total area of 3,803 sq. mi....

, a huge coastal lagoon to the south, and although commonly referred to as a river, the Guaíba is a brackish water

Brackish water

Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...

 estuary

Estuary

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

, and is also referred to as a bay, lake, or lagoon. The Jacuí River

Jacuí River

The Jacuí River is a river in Rio Grande do Sul state of southern Brazil. The Jacuí empties into the Guaíba River, an estuarine arm of the Lagoa dos Patos, a large coastal lagoon connected to the Atlantic Ocean....

 empties into the Guaíba from the north.

The city of Porto Alegre

Porto Alegre

Porto Alegre is the tenth most populous municipality in Brazil, with 1,409,939 inhabitants, and the centre of Brazil's fourth largest metropolitan area . It is also the capital city of the southernmost Brazilian state of Rio Grande do Sul. The city is the southernmost capital city of a Brazilian...

, which is the capital of the state of Rio Grande do Sul, lies on the eastern shore of the Guaíba River, and the city of Guaíba

Guaíba

Guaíba is a Brazilian city that lies on the opposite side of the Guaíba River from Porto Alegre in Rio Grande do Sul state. It is a small and calm industrial town with a large cellulose and elevator factory....

 lies opposite Porto Alegre on the western shore. The Guaíba is navigable, and is connected to the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 via the Lagoa dos Patos

Lagoa dos Patos

Lagoa dos Patos is the second largest lagoon in Latin America and the biggest in Brazil. It is located in the state of Rio Grande do Sul, southern Brazil. It is 174 miles long, has a maximum width of 44 miles , and a total area of 3,803 sq. mi....

 and its outlet channel, located farther south at Rio Grande

Rio Grande, Rio Grande do Sul

Rio Grande is the oldest city in the Brazilian state of Rio Grande do Sul and also the former state capital from 1835 to 1845...

.