The Waiau River is the largest river system in the southwestern corner of the South Island. It has its sources in the Eglinton and Clinton Rivers, both of which are major inflows to Lake Te Anau, one of the two large lakes formed from glaciation which are part of the Waiau's system. Other rivers to flow into Te Anau include the Glaisnock River, Wapiti, Doon, and Upukerora Rivers, as well as numerous burns, of which the largest are the Junction, Woodrow, Ettrick, Snag, and Mackenzie Burns.