The Otaki River is located in 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...

. It originates in the Tararua Range

Tararua Range

The Tararua 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....

 and flows for 45 km, firstly heading southwest through a valley in the Tararua Ranges. It turns northwest in the area of Otaki Forks, where it is joined by the Waiotauru River. After continuing through Otaki Gorge towards Kapiti Coast

Kapiti Coast

The Kapiti Coast is the name of the section of the coast of the south-western North Island of New Zealand that is north of Wellington and opposite Kapiti Island. It falls under the jurisdiction of the Wellington Regional Council...

, it crosses State Highway 1 (SH1) south of Otaki

Otaki

Otaki may refer to:*Ōtaki , a parliamentary electorate in New Zealand*Otaki, New Zealand, a town in New Zealand*Otaki River, a river in New Zealand*Ōtaki, Chiba, a town in Japan*Ōtaki, Saitama, a former village in Japan...

 and reaches 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...

south of the settlement of Otaki Beach.

The Otaki River is one of the major rivers that formed the fertile floodplains of the Kapiti Coast. The Otaki Forks area, accessible via Otaki Gorge Road, is a popular recreational area and the start of several tramping tracks into the Tararua Range. The Otaki River also offers fishing of brown trout.