Water for the machines: data centres in the desert

Gigawatt-scale AI campuses are being announced across the Gulf. Stargate UAE is planned as a 1 GW cluster in Abu Dhabi, with 200 MW expected live in 2026.³ HUMAIN plans AI factories of up to 500 MW in Saudi Arabia, and DataVolt a 1.5 GW campus at Oxagon.^4 5 None of these announcements says how the machines will be cooled, or what water they will draw.

The cooling fork

Operators state the trade-off plainly. Microsoft notes that water has traditionally been evaporated on site to cut the power demand of cooling. Replacing evaporative systems with mechanical cooling, it says, raises power usage effectiveness.² Google puts the other side in numbers: water-cooled data centres use about 10% less energy than many air-cooled ones.⁶ Water and electricity substitute for each other, and in the Gulf both are manufactured.

The newest answer moves cooling to the chip. Microsoft’s design, launched in August 2024 for AI workloads, circulates water in a closed loop between servers and chillers, filled once during construction. The company says the design will avoid more than 125 million litres a year per data centre.² Across its fleet, Microsoft’s water usage effectiveness fell from 0.49 litres per kWh in 2021 to 0.27 in fiscal 2025.^2 7

Heat is the variable

AWS’s regional table shows what climate does. Its Stockholm region withdrew 0.02 litres per kWh in 2025, Singapore 1.57 and Jakarta 2.85.¹ The same company draws more than a hundred times as much water where the air is hot and humid. For its two Gulf regions AWS publishes power effectiveness, 1.33 in Bahrain and 1.25 in the UAE for 2025, and leaves the water column blank.¹ The regions where the number matters most are the ones without it.

The arithmetic at gigawatt scale

A 1 GW campus at full IT load uses 24 million kWh a day. At the 0.84 litres per kWh that AWS cites as the industry average, that is about 20,000 cubic metres of water a day; at AWS’s 2025 fleet figure of 0.12, about 2,900.¹ Both are illustrations on published ratios, not disclosures. For scale, Taweelah, which its contractor calls the largest reverse-osmosis plant in operation, produces 909,218 cubic metres a day.¹⁰ Even at that industry average, a gigawatt of computing draws about 2% of that.

Absolute totals are rising anyway. Google’s data centres and offices consumed about 41 million cubic metres of water in 2025, compared with about 31 million in 2024. The company reports that in 2025, as in 2024, 72% of its freshwater withdrawals came from sources at low risk of depletion or scarcity.^9 11 Meta’s data centres ran at 0.19 litres per kWh in 2024, down from 0.30 in 2020.⁸

What to ask for

In our view, water should be a named line in these deals, and disclosure should be regional. Three questions separate a considered campus from an announcement. Which cooling design is specified, and what power penalty was accepted for it? Where does make-up water come from: potable supply, treated effluent or desalination built for the site? And will the operator publish water usage effectiveness for the region, as it already does for power?

Treated effluent is the obvious answer, and district cooling shows its limits. Qatar Cool switched its two West Bay plants entirely from potable water to treated sewage effluent, and Qatar Foundation converted its cooling plants by 2023.^12 13 In Dubai, Empower’s recycled water share fell from 13.1% in 2023 to 8.3% in 2024, after reduced and poorer supply following the April 2024 rains. It recovered to 9.22% in 2025.^14 15 Tabreed reported buying more potable water in 2025 because less effluent was available.¹⁶ A campus that plans on effluent needs a contract for it, and a fallback.

In the region

The announcements so far are about power and chips. Stargate UAE names G42, Oracle, NVIDIA, Cisco and SoftBank as partners.³ HUMAIN describes its first deployment as an 18,000 NVIDIA GB300 Grace Blackwell AI supercomputer.⁴ DataVolt says its Oxagon campus will use advanced cooling technologies and run on renewable power.⁵ None of the three announcements gives a water figure.

The operators that have said anything are cautious. Khazna told Rest of World it is exploring treated sewage effluent at some of its UAE facilities, and its Ajman site is designed for closed-loop liquid cooling.^17 18 Google told Arab News it might consider seawater for its planned hub in Dammam.¹⁹ One regional policy analysis found no overarching strategy to leverage treated sewage effluent for data-centre growth, while purple-pipe networks for its distribution remain limited.²⁰

What to watch

• 2026Stargate UAE’s first 200 MW is expected to go live in Abu Dhabi.³
• 2028DataVolt’s first phase at Oxagon, funded with US$5 billion, is expected to be operational.⁵

Further reading

• Microsoft, “Sustainable by design: next-generation datacenters consume zero water for cooling” (2024). The clearest operator statement of the water and power trade-off. microsoft.com
• AWS Cloud sustainability page. The only hyperscaler table of water use for individual cloud regions, blanks included. sustainability.aboutamazon.com
• Meta, 2025 Environmental Data Index. A five-year WUE series with its definition stated. sustainability.atmeta.com
• Google, 2026 Environmental Report. Absolute water totals, without a fleet WUE ratio. sustainability.google