At a glance
Data centres use 0.04% of Australia's distributed water and about 2% of its electricity, on CSIRO and AEMO figures.
Victoria's regulator now has networks recover a share of shared costs from new connections, and expects household distribution bills to fall A$6 to A$38 a year.
Sydney's data centres are forecast to use 10.5 gigalitres of water a year by 2030, about 1.9% of the city's supply.
A higher Sydney figure of 90 gigalitres by 2035 counts servicing enquiries, which run well ahead of what gets built and connected.
Who pays above the distribution network is still unsettled, with two rule change requests lodged in July.
Both sides of the data centre moratorium debate have their numbers right
Greens senator Sarah Hanson-Young renewed her party's call for a moratorium on new data centres on ABC's Insiders on Sunday, naming four conditions before the sector builds further: power bills that do not rise, protected water, protected jobs and community benefit. She framed the four as the test of the sector's social licence. Data Centres Australia chief executive Belinda Dennett set out the industry's answer on water, energy and grid investment, the same figures the sector has argued since it commissioned its economic modelling last November.
Both sets of figures check out against their sources, and they measure different things. The industry's 0.04% of water and 2% of electricity are national shares, and the objection Hanson-Young put on Insiders was local. Sydney is the exception, where two published forecasts for data centre water use differ by a factor of almost nine depending on whether the count starts from what developers have asked for or what has been built. On who pays for the grid, the Australian Energy Regulator settled the distribution question for Victoria on 30 April and left transmission open, where the largest campuses connect.
CSIRO puts data centres at 0.04% of Australia's distributed water
CSIRO's submission to the NSW Legislative Council inquiry puts data centres at 5.5 gigalitres of Australia's distributed water, against 132 gigalitres for mining and 235 gigalitres for manufacturing. Dennett's 0.04% share is correct and her 2.3% of manufacturing's draw is exact. The denominator covers water distributed through the mains, including supply to agriculture, so neither figure describes drinking water.
Data centres used 3.9 terawatt hours in 2025, close to 2% of national consumption, and research Mandala prepared for Data Centres Australia, AirTrunk, Amazon Web Services, CDC and NEXTDC forecasts 12 terawatt hours by 2030. The objection raised on Insiders was local. Both figures are national.
Figure | What it measures | Verdict |
|---|---|---|
0.04% of water | 5.5GL against distributed water, agriculture included | Holds, per CSIRO citing ABS |
2% of electricity | 3.9TWh against national consumption in 2025 | Holds, per AEMO via Mandala |
A$10.3bn to the grid | The Australian government's commitment to 2030 | Not an industry figure |
Two Sydney water forecasts differ by a factor of almost nine
The Water Services Association of Australia published both Sydney forecasts in December, side by side, without reconciling them. The industry estimate runs to 10.5 gigalitres a year by 2030, about 1.9% of supply, modelled from energy forecasts holding water intensity flat. Sydney Water's own estimate reaches 90 gigalitres a year by 2035, between 15% and 20% of supply, built from market applications and servicing enquiries.
The two run to different years, 2030 against 2035, and start from different inputs. A servicing enquiry records what a developer asked for, and a connection records what got built. Powercor told the AER in December that Mandala had assessed expected capacity at 45% below its 5,311MW connection pipeline, a gap the electricity side can measure because the connection data exists.
Operators moved on cooling ahead of any rule. Mandala forecasts A$500m to A$1.1bn of recycled water pipeline and treatment investment to 2030, and NEXTDC has taken S7 off potable supply, as has AWS in Melbourne, which also publishes its Australian water figures.
Victoria's regulator settled distribution cost recovery in April
The Australian Energy Regulator published final revenue decisions for five Victorian distributors on 30 April. Board member Lynne Gallagher said the decisions "help ensure data centres are paying their own way when connecting to the distribution network", covering the direct cost of connection and "a fair portion of the shared distribution network costs". They took effect on 1 July.
The regulator's estimates indicate an average annual decrease of A$6 to A$38 in the distribution component of Victorian residential bills across 2026-31, because approved revenue gets shared among more customers as demand grows. Whether bills keep falling in the later years depends on whether that demand arrives. That is the network component of a bill, not the wholesale or retail parts.
The decisions cover one state and one layer of the network, where a connection costs between A$20.5m and A$86.8m. Climate Change and Energy Minister Chris Bowen lodged two rule change requests with the Australian Energy Market Commission on 22 July, covering how upstream transmission augmentations are priced into distribution connections and who carries the risk if an asset strands.
One grid figure belongs to the government
Mandala records A$3.1bn of industry investment in grid infrastructure between 2020 and 2025, rising to a cumulative A$7.2bn by 2030, of which A$1.1bn is capacity above data centre needs and available for public use. The same report names A$10.3bn as the Australian government's commitment to grid electricity infrastructure to 2030, offered as a comparison. The A$10.3bn now circulating as a data centre contribution is the government's own number. The national AI plan proposes an obligation to underwrite new power supply, in a bill due in Parliament in early 2027.
What to watch
The Senate inquiry. The Environment and Communications References Committee took the AI data centre reference on 13 May and reports by 16 November, covering regulatory frameworks and the environmental impacts. It is where Sydney Water's 90 gigalitres and the industry's 10.5 meet on the record.
The augmentation rules. Bowen's two requests sit on the AEMC register as ERC0448 and ERC0456. Consultation has not yet opened, and the second package carries the harder question of cost recovery from transmission-connected customers.
The bill. The national expectations for data centres remain voluntary, and the bill due in early 2027 is the instrument that would convert any of them into obligations.