It arises close to the island's northwestern point, from which it is separated by a ridge, and flows southeastward through the Ruggedy Flat for 25 kilometres (16 mi) before reaching the Paterson Inlet on the island's central east coast.

[1] The Freshwater is the longest New Zealand river not to be located in either of the country's two main islands.

The river's catchment dominates much of the island's north, forming a wide swampy basin that covers some 150 square kilometres (58 sq mi) (almost a tenth of the island's total area).

A tramping track runs along the lower reach of the river.

This article about a river in Southland, New Zealand is a stub.