• Project: Tungkillo Compute and Energy Hub
• Address: 312 Collins Road, Tungkillo SA, in the eastern Mount Lofty Ranges within the Mid Murray Council area
• Site: 220 hectares over five parcels, with about 120 hectares to be developed and about 100 hectares kept for grazing
• Capacity: about 1,200MW of hyperscale data centre capacity
• Power: two new substations tapping the ElectraNet 275kV line that already crosses the site, with about 80 per cent wind and solar contracted from elsewhere in SA and about 20 per cent from on-site gas turbines
• Cooling: closed-loop direct-to-chip liquid cooling with dry air-cooled heat rejection
• Water: about 20 megalitres a year in operation, mostly harvested roof rainwater, with no SA Water mains connection and no River Murray take
• Timeline: three stages, first operations 2028, full build-out 2031
• Approval path: Essential Infrastructure/Crown assessment, with the State Commission Assessment Panel advising the Minister for Planning
• Proponent: Quantum DC Pty Ltd, part of the Quantum Group, chief executive Alby Tomassi
• Investment and jobs: no dollar figure or job count has been published

For a data centre developer the attraction of the Tungkillo site is simple: the grid is already there. An ElectraNet 275kV transmission line runs across the land, which means the project can connect through two new substations without building long new transmission lines. Quantum DC has told ABC Riverland it picked the area for its closeness to existing energy infrastructure and to renewable projects under construction nearby.

One of those neighbours is the Tungkillo battery energy storage system, a 270MW/1,080MWh project approved in December 2024 and bought by Iberdrola from RES Australia in 2025, with construction expected to start late this year. Quantum DC says that battery is a separate project and not part of its application. Industry press has asked whether any supply arrangement exists between the two.

The design leans heavily on avoiding the two issues that sink data centres in dry country: water and grid strain. The hub would use closed-loop liquid cooling that rejects heat through dry equipment rather than evaporation. Operational water would come mainly from rainwater captured off building roofs, topped up by commercial water carts. Construction is a bigger drink, at a preliminary 150 to 250 megalitres across all stages, excluding concrete.

On power, the company says wind and solar would supply most of the load, with on-site gas turbines firming supply only when renewables drop away. It says there would be no diesel generator fleet for backup, apart from a small black-start unit for the turbines. Local reporting has put the gas plant at around 400MW, although Quantum DC's own published project description does not give a figure. The company has commissioned independent modelling of the effect on power prices but has not released it.

Tungkillo sits in the River Murray International Dark Sky Reserve, which was Australia's first accredited dark sky reserve. That fact has become the centre of local opposition. Residents told the ABC they fear light spill, constant generator noise carrying across the hills and the effect on animals. Others have raised fire risk, bees, water, power use and years of construction trucks on country roads. Quantum DC says the site itself is more than 5km outside the reserve.

The numbers have grown quickly. A Facebook group opposing the hyperscale data centre went from launch to about 2,800 members within days and local press now puts it close to 5,000. An online petition passed 1,000 signatures in two days and has since topped 4,000. On Thursday night about 600 people gathered outside the Tungkillo Soldiers Memorial Hall and voted unanimously against the project.

That Thursday drop-in session never ran. Quantum DC cancelled it after what it described as a credible bomb threat and said the matter had been reported to police. The Saturday session at Mannum was then pulled as well. Mr Tomassi said the call was about public safety and making sure the full range of views could be heard. Three replacement sessions are now set for the Mannum Leisure Centre on 20 and 21 November and the company has promised to post answers to frequently asked questions on its website.

State Member for Hammond Robert Roylance has come out against the development after hundreds of constituents contacted his office. Federal MP Tony Pasin has met the proponents and set out five conditions: explain the impacts, supply their own power, pay for road and water upgrades, deal with community concerns and meet any national data centre standard if one is introduced. He has also questioned whether communities get the same consultation protections for data centres as they would for a factory or abattoir.

Mid Murray Mayor Simone Bailey says she learned of the plan on 16 October and met the proponents privately four days later. She has concerns, particularly about the location, but is holding off on a formal view until she has the facts. Council has raised questions about traffic, fire risk, environmental impacts and light pollution.

The State Government says it has not received a formal application. Any application will need to show how the project handles energy, water, cooling and impacts on surrounding land.

Quantum DC describes itself as an originator and developer of digital infrastructure, with a team drawn from institutional real estate, energy markets, engineering and environmental approvals. It is part of the Quantum Group alongside Quantum Developments Australia and Quantum Energy Trading, with an office in South Melbourne. Local reporting names Melbourne property developer Mr Tomassi and environmental consultant Anthony Caruana as the people behind it. Tungkillo would be the group's first major project.

Mr Tomassi has said the company wants to understand community concerns, deliver benefits and coexist with residents for the next 30 years and beyond. The pitch to the region is local supplier and contractor work, construction and operational jobs and a large new rate base for council. Specialist studies on traffic, noise and vibration, air quality, water, biodiversity, Aboriginal cultural heritage, bushfire risk and visual impact are under way and will be published with the application.

Tungkillo is not the only gigawatt-scale bet on South Australia. Earlier this month Firmus put forward Tailem Bend and Stirling North AI factory sites totalling about 2.7GW, after CDC stepped back from its own SA project. The state's mix of high renewable penetration, strong transmission and available land is drawing developers who cannot get power quickly enough in Sydney or Melbourne.

Elsewhere the friction is just as visible. In Perth, CDC's Hazelmere proposal on Bushmead Road is out for comment. In Melbourne, NextDC's M3 West Footscray campus was hit by a grid connection delay that cut its guidance and its share price. In Darwin, the proposed Weddell campus survived a moratorium vote. Nationally, the Australian Financial Review reported this week that the Federal Government is looking at banning new data centres in suburban areas as part of broader AI reforms.

Put together, the pattern is clear. Data centres are being pushed out of the suburbs by power, planning and politics. That sends them toward rural sites with big transmission lines, where the planning fight shifts from neighbours over the back fence to whole farming districts.

For rural and industrial landholders near major transmission corridors, Tungkillo shows how fast land values can be re-rated once a hyperscale user arrives. A grazing block with a 275kV line through it suddenly becomes energy infrastructure land. For neighbouring owners it can cut the other way, with uncertainty about noise, traffic and views.

For developers, the bigger lesson is about sequence. Quantum DC has gone public before lodging, which is the right instinct under a Crown pathway that limits local input. But the first formal community contact has arrived after a social media campaign had already defined the project. Once residents have framed a proposal as a threat to a dark sky reserve, every later document is read through that lens.

• Show it before someone else describes it. Clear site plans, massing images and night-time views answer the light and visual questions before rumour does.
• Publish the hard numbers early. Gas capacity, water sources, truck movements and jobs are the questions people ask first. Gaps get filled by the loudest voice.
• Plan for a crowd. A 200-person hall for a 5,000-member opposition group sends the wrong message on its own.
• Keep one source of truth. A simple project website with a live FAQ, maps and dates stops conflicting versions of the story spreading.
• Explain the approval path plainly. When people learn the decision sits with the Minister, they want to know exactly how their submissions will be weighed.

The next markers are the FAQ Quantum DC has promised, the three Mannum sessions on 20 and 21 November and the lodgement of the development application itself. Once lodged, public notification runs for at least 15 business days before SCAP reviews it and advises the Minister. Watch too for the gas capacity figure, the price modelling and whether any link to the Iberdrola battery next door is confirmed.

Beyond Tungkillo, the outcome will matter for every gigawatt-scale data centre being scoped in regional South Australia. If 312 Collins Road can win approval with this level of opposition, more developers will follow the transmission lines into the hills. If it stalls, the state's data centre pipeline may have to look harder at already industrial land.