The Waipā River is in the Waikato region of the North Island of New Zealand. The headwaters are in the Rangitoto Range east of Te Kuiti. It flows north for 115 kilometres (71 mi), passing through Otorohanga and Pirongia, before flowing into the Waikato River at Ngāruawāhia. It is the Waikato's largest tributary. The Waipā's main tributary is the Puniu River. The Waipā is prone to flooding in its lower reaches as flood flows can be over 100 times—20 to 560 m3/s (710 to 19,780 cu ft/s)—those of dry flows and the river can rise up to 11 m (36 ft).