Case Studies

Environmental management is core business to the NZ mining industry.

We borrow the land, mine it, and return it - to the standards expected in NZ legislation, and consistent with the Straterra Charter

Environmental management in the mining industry may take many forms. The governing criterion for this work is “sustainable management”, as defined in the Resource Management Act 1991. On conservation land, additional tests apply under the Conservation Act 1987, and related legislation.

At the high end of ecological restoration, live vegetation may be removed in chunks before mining, stored during mining, and returned live on sites that have been re-contoured, and prepared to receive vegetation. This technique is termed “direct vegetation transfer”, and is best suited to boutique ecological restoration at critical sites because of the expense. An example is Mt Frederick at the Stockton mine. 

REGULATORY AND SOCIAL RESPONSIBILITY

Environmental management work, as outlined above, will be specified in the conditions for the mining company’s environmental and heritage approvals. These include resource consents (RMA), access arrangements (Crown Minerals Act 1991), concessions (Conservation Act 1987), permits to move wildlife (Wildlife Act 1953), and authorities to modify archaeological sites and heritage (Historic Places Act 1993).

Environmental management is also often carried out voluntarily as part of the mining company’s gaining a “social licence to operate" in a community or rohe (traditional area of a Maori tribe (iwi) or sub-tribe (hapu)).

After a mining operation, the land can never be put back exactly as it was. That would be an unrealistic expectation and is not required in law. The approach taken is variously described as compensation (to counter-balance adverse effects), mitigation (to make these effects less severe), and/or remediation (to repair damage caused by adverse effects).

Biodiversity offsets have been proposed as an approach to managing the effects of development on biodiversity at a site by creating of enhancing biodiversity at another site, to a standard of “no net loss”, or “net gain”. Straterra is actively pursuing the development of a workable framework for this tool, with technical, non-statutory guidance produced by the Department of Conservation as a valuable starting point.

SITE REHABILITATION

Site rehabilitation will more usually entail rec-ontouring of the landscape, application of topsoil, and planting of native seedlings, and/or pasture, in the case of land that was once farmland. Examples of such work include: Golden Cross gold mine, Martha and nearby underground gold mines at Waihi, Cascade coal mine, and the Macraes gold mine.

Mining companies will typically work with councils, the Department of Conservation, and sometimes communities and environmental NGOs, on biodiversity conservation, within the mine footprint and elsewhere.

Examples of such work include: animal and plant pest control; translocation of native species; riparian planting; water treatment; wetland restoration; and legal protection of land.

Golden Cross

The Golden Cross gold and silver mine is one of few examples in New Zealand of a mine proceeding through development, operation, and closure since 1990.

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