On a far-flung tip of Australia, this ageing hulk of an alumina refinery is slowly being dismantled.

Its rusting remains torn down, scrapped and shipped out.

It's part of an expansive mining operation in north-east Arnhem Land in the Northern Territory, run by multinational firm Rio Tinto, that's preparing to stop digging out bauxite by 2030.

Over its five decades, Gove Operations has generated thousands of jobs for the territory.

It has also produced hundreds of millions of dollars in mining royalties for surrounding Yolŋu communities on whose land these haul trucks and conveyor belts run.

When the mining operations end, so too will the royalties.

With just a few short years remaining, clan elders are acutely aware of the risks ahead – wary their people may soon be facing one of the greatest challenges of their generation.

Rio Tinto's mine brought millions of dollars and deep divisions to north-east Arnhem Land. What happens when the company's money flow suddenly stops?

Djawa Yunupiŋu was just a boy when the bulldozers rolled into Arnhem Land in the 1960s.

Back then, Swiss consortium Nabalco had struck an agreement with the Commonwealth to mine the area for bauxite – the raw material of aluminium, to help produce the world's trains, cars and cans.

The problem was, it was Yolŋu land — and according to elders — Nabalco wasn't paying its due rent.

"It still hurts me," says Yunupiŋu, now aged 64, staring out to the mining company's export wharf from his home community of Gunyaŋara. 

"Because in those days, we tried hard to reach an agreement with Nabalco – all they said was no.

"And that hurt our people."

The Gumatj clan leader has watched the world change since those early days.

Over the ensuing decades, the tides – like those of his coastal waters – began to turn.

Arrears were owed to the land's original occupants, and the mining industry accepted the cost.

By 2011, Rio Tinto had taken over the Gove Operations mining lease, and was ready to sign a landmark agreement with the Yolŋu landowners of the Gumatj, Rirratjiŋu and Galpu clans.

At the time, both the ABC and News Corp reported the confidential Gove Agreement was worth around $700 million to the Yolŋu over the duration of the company's 42-year lease.

While it's difficult to calculate exactly, analysis of annual reports by the Gumatj and Rirratjiŋu clans show both have attracted tens of millions in royalties over the past five years alone.

But the edge of the royalties cliff is looming.

"I'd just hate to see my people from this community lining up at Centrelink," Yunupiŋu says.

"Get back to welfare. I just don't want to see that.

"Whatever royalties we're getting now, we have to save 'em, for the future of our kids."

Clan leaders acknowledge there's long been a critical stereotype that the millions paid to Aboriginal clans in statutory royalties are often squandered – spent on flash cars and at the pub.

But Yunupiŋu believes his Gumatj clan has invested its majority share of the Gove Agreement royalties, more than 70 per cent, wisely enough to stop a flood of people from sitting at home on the dole.

"The thought there was to get [my people] away from welfare, join the workforce," he says.

"The Gumatj has started like 10 businesses here — woodworks, work at our own mining company, we've got a sawmill to cut trees, a coffee shop and retail [business]."

The Gumatj sawmill continues to prosper.

Its stringybark timber lines some of the Northern Territory's prestige builds, from Darwin's botanic gardens visitors centre to shade structures and a car park outside parliament house.

However, on the day the ABC visits, just one Yolŋu worker has turned up for the day's labour. The other employees are out bush for bäpurru (Yolŋu funeral ceremonies).

Long-time employee Jeffrey Dhurrkay says he's constantly trying to convince family to go to work.

"When the mine closes, this will be running, but we do need workers to come, especially Yolŋu, to come in and work here to run this company," Dhurrkay says.

"We need to just keep it going … for our children, and our children's children."

Others are also making moves to ensure the Yolŋu are ready for the precarious future post-mining.

Charles Darwin University (CDU) is opening a campus in East Arnhem Land for the first time in a decade in a bid to train Yolŋu, on their own country and communities, for jobs that will still exist such as weed controllers and housing inspectors. 

CDU's associate vice-chancellor for the East Arnhem region, Alice Doyle, says the new campus is being opened in part as a response to calls for help from royalty-reliant families.

"We've got a couple of generations of families now that have lived off royalties, or relied on royalties or been accepting of royalties, which means they haven't needed to skill themselves for employment, or employment opportunities," Doyle says.

"Those families are seeing the need for that training to occur now, and are asking of us to be able to support them, so we're here to try and do that, we're here to respond to the region."

The Rirratjiŋu clan, too, says it's making the most of its 27 per cent share of the Gove Agreement.

They also have a mining operation, a quarry, and are currently constructing a new business centre in the township of Nhulunbuy, to attract corporate renters and visitors to help stabilise the economy.

The arrival of Rio Tinto's royalties created deep divisions between the Gumatj and Rirratjiŋu clans over who gets what share, and why.

Recent years have seen a seemingly endless flow of lawyers and anthropologists into Arnhem Land to try to resolve bitter, long-lasting legal disputes over parcels of land that attract royalty payments.

Looking out over his father's clan land, Rirratjiŋu elder Witiyana Marika says he hopes the end of mining royalties can also bring a renewed sense of peace to the Gove Peninsula.

"I want unity, we want unity," Marika says. 

"As traditional owners of this land, Rirratjiŋu and Gumatj, we can both work together towards our next generation, and stop that sit-down money. Get people working. 

"Because we can’t face [the post-mining future] alone."

As well as Gove Operations, other major mines have either ceased or are set to finish up in Jabiru and Groote Eylandt, which will see millions evaporate from regional economies across the NT. 

Author Richard Trudgen, who has been living and working with Yolŋu in north-east Arnhem Land for half a century, says many people aren't even aware the royalties are coming to an end. 

"Even though it's been said at public meetings in English, not many people know about it."

In spite of the millions spent in mining royalties, Census data reveals East Arnhem Land is still statistically one of the 10 most disadvantaged local government areas in Australia. 

"The legacy from mining here looks pretty poor at the moment," Trudgen says.

He points to the region's high rates of unemployment, incarceration and death, and low levels of school attendance.

"So when it comes to the legacy and development from mining, there's going to be a big hole in the ground, but I'm not sure what else."

In Trudgen's view, while a percentage of the mining payments are being used to good effect, "royalties, in total, are being used as almost a backup welfare system".

Rio Tinto declined multiple requests to be interviewed for this story but said in a statement it was working with traditional owners on a post-mining future.

"By providing benefits like employment, training, and supporting regional economic development, we can provide lasting value and positive outcomes to communities," the statement read.

On the tip of the peninsula, the former alumina refinery has just a few more years until it's completely pulled down, and the work begins on the land's rehabilitation.

After that, it's a waiting game to see if the land, or its people, will ever be the same again. 

Reporter: Matt Garrick

Images: Hamish Harty

Digital production: Sarah Spina-Matthews

Video editing: Jayden O'Neill