DATA CENTRE WATER use has almost doubled during the summer months compared to the start of the year, according to new figures from Uisce Éireann.

In a summer which has led to widespread water restrictions for households, close to 17 million litres of water per day were used by data centres connected to the public water supply during May, June and July this year.

This compares to nine million litres of water per day used by the same data centres during the first four months of this year.

Converting these figures to monthly use, approximately 514 million litres of water was used between May and July, compared to 276 million litres between January and April.

July saw the highest water use this year to date among data centres, during which Uisce Éireann introduced a nationwide hosepipe ban due to a lack of rainfall.

During this month, data centres used over 200 million litres of water, according to the figures, or the same amount as roughly 50,000 people.

Commercial users, such as data centres, but also golf courses, car washes and launderettes, are exempt from the hosepipe ban.

The figures were provided to Labour TD Ciarán Ahern following a desktop review of known data centres in Ireland by Uisce Éireann. It found 57 data centres connected to the public water supply.

As water is used in data centres for cooling, it is normal for more water to be used during the summer months, and Ireland’s exceptionally hot summer has undoubtedly contributed to the rise in water use.

The hot weather began in May when temperatures reached 31 degrees in parts of the country, and it has largely continued since. 

Last month was Ireland’s driest July on record and saw Uisce Éireann impose a nationwide hosepipe ban until the last week of August. 

But Ahern told The Journal that while households were being told to ration their water use, “data centres connected to Uisce Éireann’s supply more than doubled their consumption over the summer months.” He added:

This is yet another example of the preferential treatment given to big businesses and tech oligarchs by the State.

“Water is a precious commodity,” Ahern said, adding that during dry periods everyone should do their part to conserve it, “but that message obviously isn’t being heard nor enforced by data centre operators”.

The Journal Investigates has previously reported that Ireland’s largest data centres used almost one billion litres of water last year – enough water to fill 400 Olympic-sized swimming pools, or the equivalent of approximately 20,500 people’s annual water use.

And while other industries like pharmaceuticals use a lot more water, the concentration of data centres in the Greater Dublin area has raised concerns about the pressure placed on water supplies in the capital.

Just two of Ireland’s largest data centres are located outside Dublin: Meta’s campus in Meath and an Amazon data centre on the border of Meath and Louth in Drogheda.

Uisce Éireann has said that data centre water use accounts for just a fraction of the total production, and they told Ahern that the fluctuation during the hotter summer months “is not a risk to the public water supply”.

They added that “the development of data centres is a matter of government policy” but that in planning future water supplies “data centres are not a concern for Uisce Éireann”.

The Journal has also previously reported that the government’s data centre report cut recommendations for introducing “measurable and comprehensible targets for water use” as a means of addressing local community “perceptions”.

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Instead, the final version calls for “transparent reporting on energy and water use” even though the European Commission has collected key metrics like energy efficiency and water consumption from data centres since 2024.

But much of this information is hidden from public view, after the tech industry successfully lobbied to classify it as confidential and commercially sensitive.

Some of this information is supposed to be made available at the national level, but Ireland has missed the first three reporting deadlines due to delays at the Department of the Environment in transposing the legislation.

This has meant that the impact of data centres has remained largely opaque.

Ahern criticised the government’s data centre report, saying that it “deliberately omitted the negative impacts” and that “workers and families are paying the price for insatiable growth in data centres’ energy and water demand.”

He called for a “full and honest cost-benefit analysis that examines whether unfettered growth in the number of data centres in Ireland is a good thing”, adding that the government should make the case for their data centre policy “and show that these prices are worth paying”.

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Conor O’Carroll is an investigative reporter with The Journal Investigates.

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