The world’s largest data centres can consume up to five million gallons of water a day, about 1.8 billion gallons annually just to keep their computers from overheating.

It is a surprising reality behind the digital services millions rely on daily.

From writing emails and essays with ChatGPT to generating images with DALL·E or Midjourney, artificial intelligence may appear invisible and weightless.

But behind the scenes, these technologies depend on vast physical infrastructure, data centres packed with powerful servers that require constant cooling.

And that cooling often requires significant amounts of water.

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As Rwanda accelerates its digital transformation and positions itself as a regional technology hub, experts say the country should start planning early for the environmental impact of the infrastructure powering artificial intelligence.

AI systems operate in large facilities where thousands of servers run complex calculations around the clock, generating intense heat. Without effective cooling, the hardware would quickly fail.

To manage this, many data centres rely on water-based cooling systems that absorb heat from servers and release it outside the building. The scale of water use can be substantial.

Researchers estimate that every 20 to 50 prompts to an AI chatbot can indirectly consume about half a litre of water, largely due to cooling in the data centres processing those requests.

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Individually, this seems minimal. But with millions of users globally, the cumulative impact is significant. By some projections, AI-related infrastructure could consume between 4.2 and 6.6 billion cubic metres of water annually by 2027.

Why Rwanda should start planning

Although Rwanda does not yet host hyperscale data centres seen in major global hubs, its digital infrastructure is expanding steadily as part of efforts to become a regional tech leader.

With rising demand for cloud computing, AI applications, and digital services, data centre capacity is expected to grow.

The country is also exploring advanced computing infrastructure in major projects, including developments around Kigali International Airport, according to sources.

Ivan Kalisa, Director of Network and Security Operations at AOS, a data centre in Kigali, says cooling systems account for a notable share of energy use.

"In highly efficient hyperscale data centres, cooling may account for about seven percent of total electricity use,” he said.

"But in less efficient facilities, it can exceed 30 percent, and in older designs, estimates reach around 40 percent.”

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Beyond electricity demand, traditional cooling systems can pose environmental concerns, including heat discharge into surrounding areas and potential climate impacts from refrigerant leaks.

As AI workloads grow, companies are increasingly adopting liquid cooling systems, which circulate liquid directly through server components to absorb heat more efficiently.

Kalisa notes that liquid cooling can reduce energy consumption, lower noise levels, and minimise reliance on refrigerants. It can also produce warm water that may be reused, making waste-heat recovery more feasible.

However, these systems require specialised infrastructure and expertise, and their water use varies depending on design—highlighting the need for careful planning.

Water use already regulated, new pressures emerging

Even before large-scale data centres take hold, Rwanda already regulates water use through a permitting system.

Vital Munyandida, Water Permit Division Manager at the Rwanda Water Resources Board, says water abstraction is controlled across sectors.

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"Any facility intending to abstract significant amounts of water must obtain a water use permit and comply with conditions related to sustainable abstraction, efficiency, and protection of water resources,” he said.

The board assesses the potential impact of proposed water use before granting approval.

As demand grows, the institution is strengthening long-term planning tools, including catchment management plans and improved water-use databases, to ensure sustainability.

Public awareness still low

For many Rwandans, the issue remains largely unfamiliar.

However, some are beginning to consider the long-term implications of the country’s digital ambitions.

Elvis Kwizera, a Kigali resident, says awareness is still limited.

"Many people in Rwanda may not know about this because it hasn’t been a visible issue here,” he said.

"As our country embraces rapid digital growth, we could face serious challenges if stakeholders don’t start planning now.”

He believes early discussion is critical.

"Where will the water come from? How efficiently will it be used? These are questions we should start asking as technology grows.”

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Regulations on the way

Authorities are working to establish clearer rules for the sector.

Charles Gahungu, Head of ICT Regulation at the Rwanda Utilities Regulatory Authority, said a specific regulatory framework for data centres is being developed.

"At the moment, when licensing a data centre, we do not enforce a specific cooling technology,” he said.

However, new regulations expected before July will provide clearer guidance, with stakeholder consultations planned.