The Pohangina River is a river of the southwestern North Island

North Island

The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...

 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...

. A tributary of the Manawatu River

Manawatu River

The Manawatu River is a major river of the southern North Island of New Zealand.The river has its headwaters to the northwest of Norsewood in the Ruahine Ranges of southern Hawke's Bay. It flows initially eastward before turning south-west near Ormondville, flowing 40 km before turning...

, it flows generally southward from its source in the Ruahine Range

Ruahine Range

The Ruahine Range is one of several mountain ranges in the North Island of New Zealand which form a ridge running parallel with the east coast of the island between East Cape and Wellington....

, joining the Manawatu River about 15 km northeast of Palmerston North

Palmerston North

Palmerston North is the main city of the Manawatu-Wanganui region of the North Island of New Zealand. It is an inland city with a population of and is the country's seventh largest city and eighth largest urban area. Palmerston North is located in the eastern Manawatu Plains near the north bank...

at Ashhurst. Brown and (rarely) rainbow trout live in the river but are rare above the Centre Creek confluence. The headwaters of the river above the Cattle Creek confluence are home to small numbers of whio (blue duck; Hymenolaimus malacorhynchus).