The Wairoa River, also known as Wairoa South, is the second longest river in the Auckland Region of New Zealand's North Island. It flows south from its sources in the Hunua Ranges, then northwards into the Hauraki Gulf. The Wairoa Reservoir and Hūnua Falls form sections of the river, and the Wairoa River flows adjacent to the township of Clevedon.

The Hunua Ranges is a mountain range and regional park to the southeast of Auckland city, in the Auckland and Waikato regions of New Zealand's North Island. The ranges cover some 250 square kilometres (97 sq mi) and rise to 688 metres (2255 ft) at Kohukohunui.