The Rongahere Gorge is the only section of the Clutha River that still retains its rare mixed beech forest, virtually unchanged in 12,000 years. Obviously, it has significant conservation value, with unique stands of mature red beech, mixed with rare mountain and black beech. The red beech are in their southern most location. The rongahere mixed beech forest provides a nationally important refuge for threatened native species.
Birch Island / Moa Nui is an ecological 'Noah's Ark'. This 1km long island, covering seven hectares, has remained predator free, isolated in the Upper Rongahere Gorge. In 1995, scientists investigating the invertebrate fauna on the island discovered several new species, and in 2001 the island became a protected area under the Conservation Act. Birch Island has what is considered to be the most intact ecosystem of its kind in New Zealand.
The Rongahere native river corridor is home to some of our rarest and most endangered species, including important populations of Karearea / NZ Falcon, Mohua / Yellowhead (Mohoua ochrocephala), Yellow-Crested Parakeet / Karariki, South Island Robin, and various invertebrates.
Sightings of Karearea in the Rongahere confirm that the gorge is a favoured habitat for this highly endangered bird. There are no comprehensive figures for the number of Karearea surviving today, though Wingspan estimates no more than 1500 pairs in total. Although they have been fully protected for over 30 years their numbers are still so critically low that they are classified as a 'threatened' species - the second highest conservation priority. Karearea appear on the NZ Twenty Dollar note, but are disappearing from our environment.
The Mohua / Yellowhead is also known as the bush canary because it has a delightful song of rich flute notes. A hole nester, they are especially vulnerable to rats and stoats. There are a very few places where Mohua persist on the mainland. Many people believe that Contact Energy should be sponsoring the protection of endangered species like the Mohua, not threatening their habitat.
If a dam was built near Tuapeka Mouth, the entire Rongahere Gorge would be inundated, and the reservoir would extend as far as Miller's Flat, also destroying the entire Beaumont Gorge. The unique biodiversity of the Rongahere Gorge would be lost forever, along with 3,400 hectares of land, including fertile farmland and orchards, and hundreds of homes.