The Casiquiare river is a distributary of the upper Orinoco flowing southward into the Rio Negro, in Venezuela, South America. As such, it forms a unique natural canal between the Orinoco and Amazon river systems. It is the world's largest river of the kind that links two major river systems, a so-called bifurcation. The area forms a water divide, more dramatically at regional flood stage.
The Casiquiare (bottom left) is separated from the Orinoco
Sunset on the Casiquiare River, in the State of Amazonas (Venezuela)
A distributary, or a distributary channel, is a stream that branches off and flows away from a main stream channel, a phenomenon known as river bifurcation. A distributary is effectively the opposite of a tributary, which is a stream that flows towards and into another stream or river. Distributaries are often found where a stream approaches a lake or an ocean; as such, they are a common feature of river deltas. They can also occur inland, on alluvial fans, or where a tributary stream bifurcates as it nears its confluence with a larger stream. In some cases, a minor distributary can divert so much water from the main channel that it can later become the main route.
Rhine–Meuse–Scheldt delta, with the flow from right to left, showing several streams branching off from their main streams
Satellite image of part of the Rhine–Meuse–Scheldt delta
A seasonal distributary of the Kaveri River on the Kaveri delta, near Nannilam, India
Delta of Papua New Guinea's Fly River