The Haupiri River is a river of New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

. It starts near Mount Dixon

Mount Dixon

There are several places called Mount Dixon:*Mount Dixon , in the United States*Mount Dixon , in Australia's subantarctic islands*Mount Dixon, Mid Canterbury, in Aoraki/Mount Cook National Park, New Zealand...

 in the Kaimata Range of the Southern Alps

Southern Alps

The Southern Alps is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the island's western side...

 and flows north-west near to Lake Haupiri, then north-east to join the Ahaura River

Ahaura River

The Ahaura River is in the South Island of New Zealand. This river drains the western flanks of the Southern Alps and flows into the Grey River....

. The Ahaura joins the Grey River which flows into the Tasman Sea

Tasman Sea

The Tasman Sea is the large body of water between Australia and New Zealand, approximately across. It extends 2,800 km from north to south. It is a south-western segment of the South Pacific Ocean. The sea was named after the Dutch explorer Abel Janszoon Tasman, the first recorded European...

 at Greymouth

Greymouth

Greymouth is the largest town in the West Coast region in the South Island of New Zealand, and the seat of the Grey District Council. The population of the whole Grey District is , which accounts for % of the West Coast's inhabitants...

.

Hot water springs on the upper reaches of the river, near Mount Elizabeth

Mount Elizabeth

Mount Elizabeth is a massive ice-free mountain, 4,480 m, standing 6 nautical miles south of Mount Anne in Queen Alexandra Range. Discovered by the British Antarctic Expedition and named for Elizabeth Dawson-Lambton, a supporter of the expedition....

, were developed in the early 20th century by the Tourism Department. Although the structures have been damaged, swimming is still possible. The springs are reached by a tramping track. The springs are now on private land.

Trout fishing is popular in the upper reaches.