Ucayali river

The Ucayali River is one of the main rivers of Peru. Historically it has been considered that the Amazon River is born from its confluence with the Marañón River. The Ucayali River runs along the eastern slope of the Peruvian Andes, in the central part of the country. It has a length of 1,771 km, although considering its most distant sources (Tambo, Ene and Apurímac) it reaches 2,801 km.

The river gives its name to the Ucayali region.

Geography

Atalaya port, at the birth of Ucayali (Tambo and Urubamaba confluence).

Part of the Grau Square, in the port city of Pucallpa, the most important city on the banks of the Ucayali.

Cargo boat in the Ucayali River near the cities of Requena in the south and Nauta in the north.

The Ucayali River is born in the department of Ucayali, at the confluence of the Tambo River (159 km) and the Urubamba River (862 km), on the eastern Andean slope. It flows in a gentle slope towards the north of the country until it joins the Marañón River, both nominally giving rise to the Amazon River.

The Ucayali is currently considered the main headwaters of the Amazon River. It is 1,771 km long, of which 80% are navigable by vessels of up to 3,000 tons, but with its sources it reaches a total length of 2,801 km, from the source of the Apurímac, in the snow-capped Mismi, to the confluence of the Ucayali and Marañón:

• Apurímac river: 690 km;
• river Ene: 180.6 km;
• Tambo River: 158.5 km;
• Ucayali river: 1771 km, from the confluence of the Tambo to the confluence with the Marañón.

The most important tributaries are the Cohenga River, the Tahuania River, the Sheshea River, the Tamaya River (310 km), the Tapiche River (448 km), the Pachitea River (393 km) and the Aguaytía River (379 km).

Its main ports are in the cities of Puerto Atalaya, right at its source (Tambo and Urubamaba confluence, with more than 10,000 inhabitants in 2005), Pucallpa (the capital of the department of Ucayali and of the province of Coronel Portillo, which had more than 150,000 inhabitants in 2007), Contamana (17,000 inhabitants) and Requena, at the mouth of the Tapiche.

The current runs 5-6 km/h and you can always find a channel 20-50 m wide with a minimum depth of 1.5 m. There are five bad steps, due to the accumulation of trees and wooden rafts. Sometimes huge rocks fall from the mountains and are deposited in the riverbed, causing large eddies. Its width varies between 400-1200 m, due to the large number of islands.

The giant otter and the Amazon manatee are found in the Ucayali River, which are more abundant in the section of the Pacaya Samiria National Reserve (20,800 km²). It is a large area protected since 1982, upstream of Nauta, of a floodable area of the Amazon (ecosystem known as várzea), the largest in South America, and for this reason it was designated a RAMSAR site in 1986.

History

The Ucayali River was first called San Miguel and then Ucayali, Ucayare, Poro, Apu-Poro, Cocama and Cuzco River. Peru made many expensive and skillfully conducted reconnaissance expeditions to the Ucayali region. One of them (1867) claimed that it would have managed to reach a point about 380 kilometers from Lima, and the small steamer Napo managed to make its way through the violent currents up to 124 km upstream from the confluence with the river Pachitea, to the Tambo River, 1,240 km from the confluence of the Ucayali with the Amazon. The Napo then managed to climb the branch of the Urubamba 56 km upstream from its junction with the Tambo, to a point some 320 kilometers north of Cuzco.

The rest of the Urubamba, as shown by Bosquet in 1806 and Castelnau in 1846, was interrupted by waterfalls, reefs, and countless other obstacles to navigation. Torres, who explored the Alto Ucayali for the Peruvian government, gave a length of 299 km, counting from the mouth of the Pachitea to the crossing of the Tambo and Urubamba rivers.