Branching channel flow refers to any side water withdrawals from rivers or main channels.
Branching channels have wide application in many practical projects, such as irrigation and drainage
network systems, water and waste water treatment plants, and many water resources projects. In the
last decades, extensive theoretical and experimental investigations of the branching open channels
have been carried out to understand the characteristics of this branching flow, varying from case
studies to theoretical and experimental investigations. The objectives of this paper are to review and
summarise the relevant literatures regarding branching channel flow. These literatures were reviewed
based on flow characteristics, physical characteristics, and modeling of the branching flow.
Investigations of the flow into branching channel show that the branching discharge depends on many
interlinked parameters. It increases with the decreasing of the main channel flow velocity and Froude
number at the upstream of the branch channel junction. Also it increases with the increasing of the
branch channel bed slope. In subcritical flow, water depth in the branch channel is always lower than
the main channel water depth. The flow diversion to the branch channel leads to an increase of water
depth at the downstream of the main channel. From the review, it is important to highlight that most
of the study concentrated on flow characteristics in a right angle branch channel with a rigid boundary.
Investigations on different branching angles with movable bed have still to be explored.