Wiri Lava Cave, Auckland

Forest and Bird, Volume 20, Issue 3, 1 August 1989, Page 29

Wiri Lava Cave, Auckland

The 15-year campaign to save Wiri lava cave in South Auckland highlights the damage suffered by landforms of the young Auckland volcanic field since human colonisation. Much of Auckland City’s beauty and character is derived from its volcanic landscape centred on the 50 or so scoria and tuff cones formed by periodic eruptions over the last 100,000 years, yet in the last 150 years not one has escaped untouched by human vandalism. Many have their craters and peaks modified by reservoirs, playing fields and parking areas, their lower slopes pockmarked by abandoned quarries and covered in suburban housing and apartment blocks. Some, such as the Three Kings and in Manaukau City have been harder hit and are now remembered through the aggregate they provided to the city’s roads and concrete edifices. Basalt lava flows such as those erupted in the Auckland field, sometimes enclose unusual lava caves, formed when molten lava inside continues to flow out leaving an elongate cave. Lava caves still survive on Rangitoto and in the One Tree Hill, Onehunga and Mt Eden areas, but by far the best surviving example is at

Wiri, Manurewa. In the early 1970s, the Geological and Speleological Societies jointly approached the owners, NZ Railways, asking them to protect this cave from damage by blasting in the nearby railways’ quarry. NZR refused to negotiate formal protection, although Manukau City listed it on their District Scheme and invested thousands of dollars in its protection by strengthening the road that passes over it. On several occasions in the 1980s, vigilance by local speleologists has saved the cave from destruction by encroaching quarrying activites, as swift pleas to government ministers brought temporary reprieves. The case came to a head in 1987 as Railcorp prepared to realise its aggregate assets by sale or lease of the whole quarry, including the cave, to private enterprise. Lobbying by the Speleological and Geological Societies brought local media and television coverage and greater support than previously. This initiated a drawn-out period of negotiations between Manukau City, DoC, Railcorp and others, which recommended some form of permanent protection, but as yet no action has resulted.