Cardrona River

Template:Short description Template:Use New Zealand English Template:Use dmy dates Template:Template other The Cardrona River is in Otago in the South Island of New Zealand. It is one of the first tributaries of the Clutha River / Mata-Au, which it meets only from the latter's origin at the outflow of Lake Wānaka.

The Cardrona flows north for down the steep narrow Cardrona Valley. Its headwaters are near New Zealand's highest main road, the Crown Range route. The river runs past the settlement of Cardona and the Cardrona skifield, then south of Wānaka township.

The original name of the river is the . It was a traditional Māori route linking Whakatipu Waimāori (Lake Wakatipu) with lakes Wānaka and Hāwea. Ngāi Tahu recorded Ōrau as a kāinga mahinga kai (food-gathering place) where tuna (eels), pora ('Māori turnip') and weka were gathered.

In 2017, a toxic cyanobacteria phormidium was found in the river after a period of warm temperatures. The public were warned that people and dogs should avoid contact with the water while the algae was present. The Cardrona River is one of several rivers in the Otago region that are known as vulnerable to outbreaks of cyanobacteria.

An environmental DNA analysis in 2023 revealed a previously unknown population of galaxid fish are present in the Cardrona River. The species identified is the Clutha flathead galaxid, which is critically threatened and close to extinction.

In 2024, a group of 50 volunteers removed around of rubbish from a section of the river. Further cleanups were planned for other sections of the river.