Mangakahia River  The Mangakahia River is a river of the Northland Region of New Zealand's North Island. It flows east from its sources in the Mataraua Forest, turning southeastward after about on joining with the small Awarua River. It is joined by the Opouteke River near Pakotai, then turns east, until it is joined by the Hikurangi River. It then turns south again, passing Titoki and then joining with the Wairua River to form the Wairoa River approximately halfway between Whangarei and Dargaville. The New Zealand Ministry for Culture and Heritage gives a translation of "stream of the New Zealand passionfruit vine" for "Mangakāhia".