The Rotokakahi River flows in a broad, sweeping south-westerly arc from the township of Broadwood into the southern arm of the Whangape Harbour in Northland, New Zealand. The river runs approximately 30 kilometres in length with an average gradient of 1:395 (2.5m/km), making it an essentially flat waterway throughout its course.

The river is tidal for a considerable portion of its lower reaches, and the character of the water is flat and muddy with snags present. Motor launches can navigate approximately 6 kilometres to the road bridge, while jet boats can travel around 10 kilometres to the edge of Warawara State Forest. The river is rated Grade 1. Drift boats and rafts are considered unsuitable due to insufficient current.

For canoeists and kayakers, the tidal and flat nature of the river means paddling conditions are heavily dependent on tidal state. The presence of snags throughout the river is a notable hazard to be aware of when planning a trip. The overall aesthetic character of the river has been described as uninspiring, and its recreational value is considered insignificant for paddling purposes.

The Mangonuiowae River, a south-flowing tributary approximately 27 kilometres long with a similar gradient of 2.5m/km, joins the Rotokakahi near Broadwood. The confluence is located in the Hokianga/North Cape map sheet area.

Given the flat gradient, tidal influence, muddy conditions, and presence of snags, the Rotokakahi River offers very limited appeal for recreational paddling. Those considering a trip should account for tidal timing when planning access and egress, and exercise caution regarding submerged snags throughout the navigable reaches.