A conservation covenant was agreed between Bendigo landowners and the Minister of Conservation in August 2000, under section 77 of the Reserves Act, 1977.
The covenant requires protection and enhancement of the land for "natural functioning of ecosystems and native floral and fauna in their diverse communities and dynamic inter-relationships with their earth substrate and water courses and the atmosphere".
Sustainable Tarras’ chairwoman Suze Keith, who unearthed the covenant and other documents through an Official Information Act request to the Department of Conservation, said the mine could lead to biodiversity loss.
"What’s the point of a covenant if legislation can ride over the top of it and permanently destroy values previously agreed by landowners and Doc?" she asked.
"Blasting a massive hole in a conservation area is not the done thing and that is why we oppose the mine."
Areas protected by the covenant — and being prospected by Santana Minerals, which hopes to dig the mine — have been put up for sale by Bendigo Station.
A spokesperson for Santana said the company would "imminently" be seeking permission to mine Bendigo using the fast-track process. It wants four open pits including one 1000m long and 800m wide, plus underground mines.
It is a matter of speculation whether Santana is buying the 798ha land for sale, but it includes an area named Rise and Shine where Santana exploration drilling has found gold.
An anti-mine campaign called Ours Not Mine is backed by groups including Sustainable Tarras and the Central Otago Environmental Society (COES).
COES secretary Matthew Sole said "the economy should be predicated on the sustainability of our natural environment, but this gets externalised, ignored in the name of short-term economic gain, but for what?".
"If you fly over the area you would see gaping pits in one of the most impressive landscapes. It would be desecration, like shooting yourself in the foot."
The covenant has been altered since exploration drilling started, another released document reveals.
Three weeks after the change of government in 2023, a covenant "variation" was agreed with Bendigo Station allowing "temporary" tracks providing access to Rise and Shine Creek.
The move came a year after Doc allowed access tracks and more exploration drilling at 50 sites within the covenant area, including at Rise and Shine Creek, but said further requests for tracks "would be declined".
There were "accumulating effects ... greater than previously assessed".
The covenant described Rise and Shine Creek as having "historic mining sites" where "interpretation signs" could be placed.
The October 2022 exploration approval was one of five issued by Doc since October 2017 allowing prospecting by Matakanui Gold Ltd (MGL), which was bought in 2020 by Santana. The four latest approvals allowed 60m-deep drill holes at 50 sites and various access tracks.
The released documents show that in July this year an application for more exploration was withdrawn by Santana after a Doc report recommended it be declined.
The protected land is described in the covenant as a "significant" part of the ecological character of the Dunstan ecological district, studied in a 1987 survey.
The area could be grazed, but only to an extent that protected the purpose of the covenant, and must be kept free from weeds, pests and "rubbish and other unsightly or offensive material".
The public should have public access to historic mining sites, including in the Rise and Shine Creek area. Conservation Minister Tama Potaka had the right to monitor native plants and historic sites and a plan for the land’s management should be followed.
However, the covenant has caveats. Prospecting or mining could not be carried out "without the minister’s prior approval" and the conditions of the covenant could only be changed by agreement.
Grant Porter, spokesman for Bendigo Station owner John Perriam, said the sale would leave Mr Perriam with 7500ha and, if a sale was made, it would be with "consideration to the local community, environment and the farming and viticultural interests at Bendigo".
The Santana spokesperson said the company intended to show "how mining can coexist with responsible environmental stewardship".
