Meeting of the Waters

The Meeting of Waters, Encontro das Águas in Portuguese, is the confluence of the dark blackwater Rio Negro and the pale, sandy whitewater Solimões, as the Amazon is called in Brazil above this point, about 8 km (5 mi) downstream of Manaus; from here on the river takes the name Amazon. Each river is nearly 3 km (2 mi) wide at the meeting, and the water is up to 60 m (200 ft) deep in places. For about 6 km (3.7 mi) the two run side by side without mixing, or for tens of kilometres by another account, and they blend fully only after another 60 km (37 mi), or some 150 km (93 mi) downstream at the mouth of the Madeira by another. The Rio Negro flows at about 2 km/h (1.2 mph) at 28 °C (82 °F), its acidic water, of pH 5.5, nearly free of sediment and stained black by decayed leaves from the Colombian hills, the stagnant forest plains and humus-rich swamps; the Solimões flows at 4 to 6 km/h (2.5-3.7 mph) at 22 °C (72 °F), neutral and laden with silt eroded from the Andes, and with a discharge of about 103,000 m³ a second against the Negro's 29,300, its denser water runs deeper and faster. Local fishermen on the Negro side drop their nets deep to reach the Solimões water beneath, richer in suspended matter and so in fish. Spanish conquerors described the meeting in the 16th century, it is one of the main sights of Manaus, and Oscar Niemeyer designed a monument to it, one of his last works, still unbuilt. Smaller meetings of waters occur at Santarém, where the Tapajós joins the Amazon, and at Tefé, Coari, Iquitos and Puerto Maldonado.

Background

The Meeting of Waters, Encontro das Águas in Portuguese, is where the blackwater Rio Negro meets the sandy whitewater Amazon, known in Brazil as the Solimões above this point. The two run side by side without mixing for 6 km, one of the main sights of Manaus, and take another 60 km to blend fully. The difference comes from temperature, speed and sediment: the Rio Negro moves at about 2 km/h at 28 °C, the Solimões at 4 to 6 km/h at 22 °C, carrying silt from the Andes, while the black water, from the Colombian hills and the forest, holds almost no sediment and is stained by rotting leaves.

Source: Wikipedia, "Meeting of Waters"

The landscape

• Two waters side by side - black and sandy water running together unmixed for about 6 km.
• A temperature step - about 28 °C in the Negro against 22 °C in the Solimões.
• The reason they resist mixing - different speed, temperature and density.
• The fishermen's trick - nets dropped deep on the Negro side to reach the richer Solimões water below.

When to go

All year.

Before you go

The meeting lies about 8 km downstream of Manaus, where each river is nearly 3 km wide, and the two waters stay apart for about 6 km before blending slowly further downstream.

Nearby

Careiro da Várzea is about 13 km to the south-east, central Manaus and the Teatro Amazonas about 13 km to the west, Iranduba about 36 km to the west-south-west and Anavilhanas National Park about 140 km to the north-west, in a straight line.

Key facts