Caño Casiquiare

An anomalous river that allows to navigate between two large basins in South America, the Orinoco and the Amazon hydrographic systems

The Caño Casiquiare is a watercourse that is at the same time drainage and occasionally tributary of the Orinoco River in its upper basin.

It has a length of about 326 km and serves as a connection between the Orinoco system with the Amazon-Negro River basin. Such a connection makes it the largest connecting river of two major river systems in the world.

For that reason it is possible to navigate with medium draft vessels between both basins.

Normally the Casiquiare takes waters from the Orinoco River to the southwest of the Duida plateau, transporting them, through its extensive flat plains of little slope in which it receives several tributaries and making great meanders to the Negro River, which in turn flows into the Amazon River .

The point of origin (on the Orinoco River) is at a height of about 123 meters above sea level while its confluence with the Black River is about 91 meters above sea level. The communication between the Orinoco and the Amazon through the Casiquiare, which was used to trade by local Indians (Yanomanis, Yekwanas, Piaroas and others).

It is a situation that may end up in the capture of the Orinoco River, diverting it to the Amazon basin. When this happens, the Orinoco River will lose its upper basin,

Geologically it is a kind of spill on a rocky bottom whose erosion is very difficult due to the resistance of the granitic rocks of the substrate.

The very nature of the rocky bottom of the channel of both the Orinoco and the Casiquiare, has stabilized the situation over a very long time: being the Casiquiare of lower flow than the Orinoco itself, the depth is less than that of this last river , which has given rise to the absence of a complete spill yet. The Casiquiare River is a large and quite wide river (200 to 500 meters) although with little flow. Because of this it is easily navigable with boats that are used to communicate various points of its banks.

On some of my trips to the upper Orinoco river basin, I had the opportunity to travel it on a motor boat (which are locally called “flying”) and this strange hydrological phenomenon, which, due to its magnitude, is unique in the area world. There I could observe the presence of several indigenous villages that use the rivers to stock up on water and food and trade.

The native peoples that inhabit the area of ​​the confluence of the Casiquiare with the Orinoco with the Casiquiare are the Yanomani, a relatively large ethnic group (approximately 35,000 in some 300 villages), which has retained much of its traditions despite the incursion of religious missions

The most important of these missions was (they have already withdrawn thanks to measures taken by President Hugo Chavez) the so-called "New Tribes" of American origin that has invested resources and efforts to convert the Yanomami to their beliefs trying to get them out of "paganism."

From the seizure of the Bolivarian government, these religious groups were expelled and therefore the yanomami nation has been able to recover its threatened cultural legacy.

In recent years, due to the difficult economic and social conditions that the Venezuelan government is facing, due to the blockade and other political and social circumstances, the region inhabited by the Yanomami, which is located on the border between Venezuela and Brazil, has experienced the irruption of people from outside their territory who have disturbed the tranquility of their villages.

On the other hand, since the inauguration of the new Brazilian government, Jair Bolsonaro, its reserve protected by the National Indian Foundation (FUNAI) has been threatened because it is no longer the FUNAI that is responsible for identification and demarcation of indigenous lands, but the Ministry of Agriculture that is much more likely to be influenced by landowners and agricultural and agroforestry corporations. On the other hand, there has been a manifest indifference to the invasion of more than 20,000 garimpeiros (small miners) in the Yanomami reserve in Brazil whose surface area of ​​37,300 km2 appears to be highly vulnerable.