The Waikawa River flows east then south through the Catlins

The Catlins

The Catlins comprises an area in the southeastern corner of the South Island of New Zealand. The area lies between Balclutha and Invercargill, straddling the boundary between the Otago and Southland regions...

, an area of the southern 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...

 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...

. Its total length is 23 kilometres (14.3 mi), and it flows into the Pacific Ocean

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 at Waikawa

Waikawa, Southland

Waikawa is the name of a small settlement in Southland, New Zealand, at the southwestern edge of The Catlins.The township is now a small fishing settlement, but at one time in the late 19th century was a major port, shipping timber from the sawmills of the Catlins north to help build the new town...

. Close to its mouth, it cascades over a small series of cataracts, ironically named Niagara Falls.

The river's source is located 15 kilometres (9.3 mi) east of Fortrose

Fortrose, New Zealand

Fortrose is a locality on the southernmost coast of the South Island of New Zealand in the Southland region. It is situated on Toetoes Bay at the mouth of the Mataura River, and is on the far western edge of the Catlins...

.