The Waimakariri River is one of the largest rivers in Canterbury, New Zealand. It is on the eastern coast of New Zealand's South Island. It flows for 151 kilometres (94 mi) southeast from the Southern Alps across the Canterbury Plains to the Pacific Ocean.
|Source||Southern Alps, near Mount Rolleston|
|- location||Southern Alps, Canterbury|
|- elevation||1,535 m (5,036 ft)|
|Mouth||Brooklands Lagoon, Pacific Ocean|
|- location||near Kaiapoi|
|- elevation||0 m (0 ft)|
|Length||151 km (94 mi)|
|- average||76 m3/s (2,700 cu ft/s)|
|- left||Bealey River, Poulter River, Esk River, Eyre River, Kaiapoi River|
|- right||White River, Broken River, Kowai River, Styx River|
The river is a fine example of a braided river. As the photograph shows, for much of its upper reaches, the river is braided. It runs across wide shingle beds. As the river approaches the Canterbury Plains, it passes through a belt of mountains. There it is forced into a narrow canyon (the Waimakariri Gorge). Then it goes back to its braided form across the plains. It enters the Pacific north of Christchurch, near the town of Kaiapoi.
- Waimakariri River Improvement Act 1922, Section 17(1) - Parliament of New Zealand.