The Waiau River is the largest river in the Southland region of New Zealand. 'Waiau' translates to 'River of Swirling Currents'. It is the outflow of Lake Te Anau, flowing from it into Lake Manapouri 10 kilometres (6 miles) to the south, and from there flows south for 70 kilometres (43 miles) before reaching the Foveaux Strait 8 kilometres (5 miles) south of Tuatapere. It also takes water from Lake Monowai.
https://en.wikipedia.org/wiki/Waiau_River_(Southland)