A proposal that a 2-kilometre (1.2 mi) stretch of river below the area known as Balloon Loop be named the Anduin Reach to honour New Zealand film maker Peter Jackson for his use of the area as the River Anduin was rejected by the New Zealand Geographic Board in April 2009.

The Waiau flows out of the lake in the southeast, close to the small town of Manapouri, and shortly thereafter is joined by the waters of the Mararoa River.

[4] Several species of endangered birds live around the shores of Lake Te Anau, and the upper Waiau River, notably the Takahē (Notornis hochstetteri).

Toxic levels of the algae benthic cyanobacteria were found in December 2018 where the Waiau River runs by Tuatapere.

It is the largest of several wetland areas developed by the trust to increase the diversity and habitat of Waiau native species and improve the water quality of the river.

[9] The Waiau Fisheries and Wildlife Habitat Enhancement Trust was established in 1996 to mitigate the effects of the Manapōuri Hydro Electric Power Scheme.

[10] By filtering agricultural run-off in smaller streams and ponds and fencing stock off from waterways, the overall health of the Waiau River is able to improve.

[14] A survey of the “Anduin Reach” was conducted in 2007, and landmark names were proposed based on the Lord of the Rings film trilogy.

It was decided that Anduin Reach should be the place name to help promote the future prospects of the Cycle Trail Project.