We break down how much water AI data centres use.
Image: File
Concerns and questions mount after the City of Cape Town’s Municipal Planning Tribunal (MPT) supported an application for the rezoning of a hyperscale data centre development at King Air Industria.
But how much water do these hyperscale data centres use, and should we be concerned?
As we all know, the use of artificial intelligence is skyrocketing globally, and its environmental cost is alarming.
A single 100-word AI prompt or your venting into ChatGPT consumes roughly 519 millilitres of water, about the size of a standard water bottle.
On the surface, this might not sound like a lot. But with billions of queries processed worldwide every minute, we are talking about billions of litres every minute.
The Global Scale of the Problem Data centres accounted for roughly 1% to 2% of total global electricity demand in 2020.
Because advanced processing chips generate immense amounts of heat, facilities must employ heavy-duty cooling systems to prevent hardware damage.
According to the Uptime Institute, a relatively small 1-megawatt data centre can consume 26 million litres of water annually just for cooling.
On the other hand, the number of massive "hyperscale" data centres is rapidly expanding.
As of 2020, there were nearly 600 of these massive facilities worldwide, with hubs located across the globe, including in China (10% of the global total) and Japan (6%).
The true water cost of data centres extends far beyond the water pumped into their on-site cooling towers. A facility's total water footprint also includes the "indirect" water consumed by the power plants that generate its electricity, as well as the water required to manufacture its hardware.
Fossil fuel and nuclear power plants rely on large boilers of water superheated into steam to turn turbines. This means immense amounts of water is evaporated simply to keep the servers powered.
While many are aware of the cooling towers and manfacturing, you might not know about the microchips. The microchips inside the servers require heavily treated "ultrapure" water during their manufacturing process to rinse off silicon residue. According to the World Economic Forum, an average chip factory consumes approximately 37.8 million litres of ultrapure water every day.
The immense strain on local resources is causing backlash and infrastructure crises in several countries. In Ireland, data centres consumed roughly as much electricity as the entire nation in 2023. Because the national power grid is nearly maxed out, some facilities in Ireland have resorted to using highly polluting off-grid generators to maintain operations.
In the United Kingdom, Thames Water has noted that 80% of the UK's data centres are concentrated in the London area, a region that receives surprisingly low annual rainfall. As data centre water usage peaks during the hottest, driest times of the year, the utility has had to restrict or object to new data centre developments to protect the region's water supply.
Similar concerns over resource scarcity have led to a temporary ban on new data centres in the Netherlands, while France is in the process of passing new laws requiring greater transparency regarding water usage.
As freshwater makes up only 3% of Earth's water, the tech industry is actively exploring ways to mitigate this crisis. On the hardware side, Microsoft has experimented with sinking data centres into the cold waters off the coast of Scotland to naturally reduce cooling demands.
Other facilities are moving toward "immersion cooling," which submerges servers in specialised synthetic, non-conductive fluids rather than relying on evaporative water cooling.
Tech companies are also investing heavily in international water stewardship projects to replenish the basins they draw from. For instance, Google is funding wetland restorations in the Andes Mountains of Chile, supporting rainwater harvesting and double-dike construction in the Netherlands, and improving water quality at the Singapore Botanic Gardens.
However, experts warn that technological fixes alone won't be enough. Communities worldwide will need to adopt integrated land and water planning to carefully weigh the economic benefits of the AI boom against its profound impacts on our most precious, finite resource.
In a statement released on Thursday, the City of Cape said the MPT approved the application, but it is subject to several conditions. It added that it will issue a formal notice of the decision once it is possible.
The City stated that anyone who submitted a valid objection during the statutory public participation process will receive the decision and information on how to lodge an appeal.
Once an appeal is submitted, it will be considered through the City's prescribed appeal process before a final decision is made. If the approval is not appealed, the development cannot proceed immediately.
"The applicant must still obtain additional approvals, including the submission and approval of a Site Development Plan. As part of that process, detailed technical matters, including the provision of engineering services and infrastructure, must be assessed by the relevant City departments before any further approvals are granted.
The City noted concerns over water use, electricity demand and environmental impacts, saying that these all "form part of the planning and regulatory processes and are considered in accordance with the applicable legislation and technical requirements."
The City of Cape Town added that because the statutory planning process has not yet been concluded, it would not be appropriate for the City to comment further on the merits of the application or on issues that may form part of any appeal or future approval processes.
IOL