The headwaters are found in the valleys of the Frederick Hills in Arnhem Land and flow in a northerly direction through uninhabited country for a distance of 30 kilometres (19 mi) until discharging into Arnhem Bay and eventually the Arafura Sea.

The catchment area of the river is 1,026 square kilometres (396 sq mi).

[2] The estuary formed at the river mouth is tidal in nature and in near pristine condition.

[3] The estuary occupies an area of 53.5 hectares (132 acres) of open water.

It is tide dominated in nature having a single channel and is surrounded by an area of 10.5 square kilometres (4 sq mi) covered with mangroves.