Since 21 June 2019 the official name has been Waikōau River.
[1] Waikōau River North Branch has been the official name of a tributary, which joins the river about a kilometre from the sea, since 19 December 2019.
[2] Rising north of the Hump Ridge, it flows south-eastward into Te Waewae Bay.
The New Zealand Ministry for Culture and Heritage gives a translation of "waters of the shag" for Waikōau.
[4] "Place name detail: Waikoau River".