How rehabilitated does conservation land have to be before a mining company gets its bond back from the Department of Conservation? Farah Hancock reports on one site that has conservationists concerned.

A mine on conservation land on the West Coast conditionally signed off as rehabilitated has been described as a desolate wasteland. 

The remaining condition for sign-off is one year of weeding.

There’s no topsoil, a gaping hole remains, and replanting, written as a concession condition, wasn’t done. The Department of Conservation (DoC), which signed off the rehabilitation, said conditions were changed after a discussion with the mining company. If rehabilitation is not completed, the company can lose the bond it paid when it gained the concession.

Drone footage shows the scale of the pit left behind. A person, just visible in orange at the start of the video, becomes ant-like as the drone rises.

The rehabilitated mining area on conservation land. Video: Neil Silverwood

DoC said the changes were documented and an experienced team was involved in the decisions which allowed them. Newsroom has requested this documentation.

The 22-hectare site in Mikonui Valley, 31 km south of Hokitika, was mined for gold by NZG Limited. The company’s four listed directors include: James Blackwell, Julia Jiyan Xu, Stone Shi, and David Wong-Tung. The first three of these directors are also directors of Oravida Limited. Wong-Tung, who is married to National MP Judith Collins, is a former director of Oravida Limited.

Conservationist and West Coast Conservation Board member Neil Silverwood visited the site in March and was met with what he describes as a moonscape. 

“It’s heartbreaking to see public conservation land treated that way.”

He is extremely surprised the rehabilitation work was ticked off by DoC.

“There’s no way it should be signed off in my view. The topsoil is not there, the contouring is very limited or non-existent.”

His understanding is large holes are usually filled in as part of a rehabilitation process.

“Normally the drainage landscape should be put back to how it was before the mining, or you muck up the hydrology.”

Photo: Neil Silverwood

As well as a hole left in the landscape it’s likely that, without topsoil, it will take plants a long time to grow back.

There are a number of methods miners in the area normally use to help plant over the large areas they scrape bare. One is called direct transfer. This is where clumps of plants are removed, with trees still standing, set to one side, and when mining is complete, put back. Around 50 percent of plants die, but it’s by far the fastest way to return some life to the landscape. 

The second way is to put topsoil and slash – chopped down trees – to one side. When mining is complete this is placed over the area. Silverwood said this normally grows a combination of gorse and seedlings, and in time recovers. 

“In this case, what happened [is] it’s just clay and rocks. Topsoil hasn’t been put back in place. It’s a really slow process.” 

He imagines it could take 15 to 30 years before plants are established.

The access document which is signed by the company and DoC spells out the conditions of rehabilitation.

For this mine, it included re-contouring of all areas, stripped topsoil and vegetation to be re-spread, revegetation of one area through spreading slash and planting indigenous vegetation at a rate of 5000 viable stems per hectare and replanting a second area at a rate of 2500 stems per hectare. What DoC have now agreed is acceptable is not what was in the document.

The site in 2017. Photo: Forest & Bird

The Hokitika district acting manager for DoC, Suvi Van Smit, answered Newsroom’s queries. 

She said re-contouring did take place and a “natural landform was achieved” but the hole, which she described as a ‘mine pond’ , was left because it was impractical to fill it in. A photo from 2017 shows the hole was initially far larger, although whether the current hole, with at least one steep, eroding side, can be described as a natural landform is subjective.

She said topsoil was spread.

“More than half of the site was covered in topsoil. There was not enough topsoil stockpiled to cover the whole site due to the area being previously mined, which reduced the available topsoil. The site was located on moraine terraces and these landforms characteristically have naturally sparse topsoil profiles. The rehabilitated area without topsoil has a cover of fine materials and sediments and will regenerate naturally through gorse.”

Moraines are the debris left by retreating glaciers. There is no retreating glacier in the area.

The need to replant the area with up to 5000 plants per hectare was also waived as Van Smit said it was agreed natural regeneration and weed control would be the best approach.

An Official Information Act request to DoC asking for details of West Coast mining on conservation land showed DoC has signed-off all rehabilitation efforts and returned bonds.

Bond amounts are calculated on the area of land and the amount of work and resources required to rehabilitate it.

“Our records show no mining companies have left sites that have not been rehabilitated to the satisfaction of the Department of Conservation on public conservation land in the West Coast area.”

It did point out there were a “couple of sites where the Department is working quite closely” with operators to ensure the site was rehabilitated. 

The sign off of the Mikonui Valley mine, conditional on a year’s worth of weeding, was based on a site inspection in October and from reviewing drone photographs after October.

No new mines on conservation land

In November 2017 it was announced there would be no new mines on conservation land. This promise has not come to fruition. A public discussion document on the proposed ban on mining on conservation land was supposed to be released in September 2018. 

The Otago Daily Times reported West Coast-Tasman MP Damien O’Connor saying the “no new mines” policy had been parked ahead of the September election as there was “a hell of a lot” of work to do and not enough time to complete it. 

The Minister of Conservation, Eugenie Sage, told Newsroom in March there was no due-date.

“There are three parties in Government and we’ve yet to reach agreement on the release of a discussion document.”

Until the policy is completed, applications to mine need to be processed under the current rules.

Forest & Bird’s regional advocacy manager for Canterbury/West Coast, Nicky Snoyink, said elsewhere the West Coast was losing native forest to mining.

In instances like this, where rehabilitation conditions were changed she asked “what certainty can Forest & Bird or the New Zealand public have that native species will be returned to public conservation land?”

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