The Waitangitāhuna River is a unique and historically significant waterway on New Zealand's South Island West Coast. Originally a single river, a major avulsion event in March 1967 permanently altered its course, resulting in what are now considered two distinct rivers sharing the same name. This event fundamentally changed the river's geography and hydrology, creating a dynamic system that flows through a corridor linking several high-value wetland habitats. The river provides important habitat for a diversity of freshwater fish species and common forest avifauna, set within a region characterized by its remote and rugged natural beauty.