The Pahau River or Pahu River is a river of the north Canterbury Region 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...

's South Island

South Island

The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...

. It has its origins in the Tekoa Range, 25 kilometres northwest of Culverden

Culverden

Culverden is a small town in the Canterbury region of New Zealand's South Island. The 2006 New Zealand Census of Population and Dwellings had a usually-resident population of 420. This represented an increase of 7% or 27 people from the previous census in 2001.Culverden is located on State Highway...

, and flows initially north before turning south to flow down a long valley between two ridges. At the northern edge of the Canterbury Plains

Canterbury Plains

The Canterbury Plains are an area in New Zealand centred to the south of the city of Christchurch in the Canterbury Region. Their northern extremes are at the foot of the Hundalee Hills in the Hurunui District, and in the south they merge into the plains of North Otago beyond the Waitaki...

 it turns southeast, flowing past the southern outskirts of Culverden to reach the Hurunui River

Hurunui River

The Hurunui River is the fourth largest of the four principal rivers in north Canterbury, New Zealand, with a catchment area of 2,670 square kilometres. The river flows from the eastern side of the Southern Alps, to the Pacific Ocean....

eight kilometres to the southeast of the town.