A distributary is a river that branches off from a major river before it reaches the sea, particularly in a river delta. The phenomenon is known as river bifurcation. The opposite of a distributary is a tributary.

In Louisiana, for example, the Atchafalaya River splits from the Mississippi River. In some cases, a distributary can "steal" so much water from its parent that it can become the main route. This is actually a serious problem for New Orleans, because the Atchafalaya takes a steeper route to the Gulf of Mexico, and therefore takes more and more water from the Mississippi. This was recently stopped by the construction of the Old River Control Structure, a dam to control the outflow from the Mississippi into the Atchafalaya.

The IJssel, the Waal and the Nederrijn (Lower Rhine) are the three principal distributaries of the Rhine. Other notable distributaries are the Kollidam, a distributary of the Kaveri River, and the Hoogli River, a distributary of the Ganges River, both in India.

Rivers

Bifurkation (Gewässer) | Bifurcación de un río | Forkiĝo (rivera) | Árkvísl | Bifurkacija | Bifurcatie (geografie) | Bifurkacja (geografia) | Бифуркация рек | Bifurkacija | Bifurkaatio