The Waiapu River is a river in the Gisborne District of the North Island of New Zealand, with a total length of approximately . Found in the north-east of the Waiapu Valley, it flows north-east from the joining of the Mata River and the Tapuaeroa River (both of which flow from the Raukumara Ranges), then passes by Ruatoria before reaching the Pacific Ocean at Rangitukia. Other tributaries of the Waiapu River include the Mangaoporo, Poroporo, Wairoa, Maraehara rivers, and the Paoaruku stream. It …