StackPath Ireland

Water · EPA annual reports

How much water do data centres in Ireland use?

Licensed data centres used 1.05 billion litres of public-supply water in 2025, about 0.17% of Uisce Éireann's supply, according to their EPA annual environmental reports (16 sites). Two sites, Meta Clonee and Equinix Blanchardstown, used 91% of it. The widely quoted 46 billion litres is a modelled power-station footprint, not water drawn on site.

Updated 3 October 2026 · data build 2026-10-10 · how we know · corrections

The scale, and where it goes

Figure 1

Data-centre water use, on one scale

Licensed data centres drew about 2.9 million litres a day of public water in 2025, about 0.17% of the 1,700 million Uisce Éireann treats daily; the much bigger "46 billion litres" figure is water used to generate their electricity, not water they draw.

Data-centre water use on one scaleAll public water treated: 1,700.0 million litres a day; Greater Dublin Area: 640.0 million litres a day; Water to make their electricity: 125.9 million litres a day; Data centres in summer 2026: 6.0 million litres a day; Data centres on the public network: 4.8 million litres a day; Licensed data centres, 2025: 2.9 million litres a day. 2.9 ML a day is the median daily use of about 10,997 households.MILLION LITRES A DAY · AREA = VOLUMEAll public water treated: 1,700.0 ML/dayGreater Dublin Area: 640.0 ML/dayWater to make their electricity: 125.9 ML/dayData centres in summer 2026: 6.0 ML/dayData centres on the public network: 4.8 ML/dayLicensed data centres, 2025: 2.9 ML/day1,700 ML · All public water treatedUisce Éireann, 2025640 ML · Greater Dublin Areaaverage day, 2026126 ML · Water to make their electricitymodelled, off-site, mostly at power stations6 ML · Data centres in summer 20264–6 ML/day, 57 sites (as reported)4.8 ML · Data centres on the public networkUisce Éireann, 57 sites, annualised2.9 ML · Licensed data centres, 2025metered, 16 sites, EPA reports2.9 ML a day ≈ 10,997 homes' median useat 261 L per household a day; 0.6% of Ireland's 1.84m households
Data-centre water use on one scaleAll public water treated: 1,700.0 million litres a day; Greater Dublin Area: 640.0 million litres a day; Water to make their electricity: 125.9 million litres a day; Data centres in summer 2026: 6.0 million litres a day; Data centres on the public network: 4.8 million litres a day; Licensed data centres, 2025: 2.9 million litres a day. 2.9 ML a day is the median daily use of about 10,997 households.MILLION LITRES A DAY · AREA = VOLUMEAll public water treated: 1,700.0 ML/dayGreater Dublin Area: 640.0 ML/dayWater to make their electricity: 125.9 ML/dayData centres in summer 2026: 6.0 ML/dayData centres on the public network: 4.8 ML/dayLicensed data centres, 2025: 2.9 ML/day1,700 ML · All public water treatedUisce Éireann, 2025640 ML · Greater Dublin Areaaverage day, 2026126 ML · Water to make their electricitymodelled, off-site, mostly at power stations6 ML · Data centres in summer 20264–6 ML/day, 57 sites (as reported)4.8 ML · Data centres on the public networkUisce Éireann, 57 sites, annualised2.9 ML · Licensed data centres, 2025metered, 16 sites, EPA reports2.9 ML a day ≈ 10,997 homes' median useat 261 L per household a day; 0.6% of Ireland's 1.84m households

Each square's area is proportional to litres per day, so the red square (data centres' metered public-supply water, 1.05 billion litres in 2025 from 16 EPA-licensed sites) can be compared directly with Dublin's and the country's supply. Uisce Éireann's own figure for the 57 data centres on its network, and reported summer peaks, are higher but on the same small scale. The dashed square is a modelled footprint: data centres' electricity multiplied by 6 litres per kWh used at power stations, which is a different quantity from water piped to the sites. National totals hide local pressure: most sites are in the Greater Dublin Area.

EstimateDaily figures are annual totals ÷ 365; household equivalents use the CSO 2022 median household use. The 57-site and summer figures were released to a TD and reported by The Journal; no primary document is public.

Sources: EPA annual environmental reports (Table 5, water used), 3 Oct 2026 · Uisce Éireann press release on 2024 annual report, 30 Jun 2025 · Irish Times (citing Uisce Éireann), 29 May 2026; UE press release 10 Jul 2026 (693 ML record), 29 May 2026 · The Journal, 24 Aug 2026, 24 Aug 2026 · Fearon, Bresnihan & Brodie, 'How we all pay for Big Tech', MUSSI Working Paper 31, Maynooth University, Sept 2026 · CSO, Domestic Metered Public Water Consumption 2022 - Key Findings, 20 Nov 2023

Figure 2

Two sites use most of the data-centre water

One Meta site and one Equinix site used 91.1% of licensed data centres' public water in 2025; most other sites use a few litres per MWh.

Where data-centre water goes2025: Runways Information Services (Meta) 556.5 million litres, Equinix Hyperscale 1 (DB5) 398.1 million litres, 14 other licensed sites 93.1 million litres. Litres per MWh: Meta 470.6, Equinix 2,453.3, 14 other sites 12.9 (others range 1–315.2).A · PUBLIC-SUPPLY WATER, 2025, LICENSED SITESRunways Information Services (Meta): 556.5 million litres (53.1%)Meta · 53%Equinix Hyperscale 1 (DB5): 398.1 million litres (38.0%)Equinix · 38%14 other licensed sites: 93.1 million litres (8.9%)14 other sites · 9% ↓Two sites used 91.1% of the 1,048 million litres; the other 14 together used 93 million.B · LITRES PER MWH OF ELECTRICITY (LOG SCALE)1101001,00010,00014 other sites: median 12.9 L/MWh14 other sites median 12.9Meta: 471 L/MWhMeta 471Equinix: 2,453 L/MWhEquinix 2,453Power stations 6,000, modelled
Where data-centre water goes2025: Runways Information Services (Meta) 556.5 million litres, Equinix Hyperscale 1 (DB5) 398.1 million litres, 14 other licensed sites 93.1 million litres. Litres per MWh: Meta 470.6, Equinix 2,453.3, 14 other sites 12.9 (others range 1–315.2).A · PUBLIC-SUPPLY WATER, 2025, LICENSED SITESRunways Information Services (Meta): 556.5 million litres (53.1%)Equinix Hyperscale 1 (DB5): 398.1 million litres (38.0%)14 other licensed sites: 93.1 million litres (8.9%)Meta: 53% · 557 MLEquinix: 38% · 398 ML14 other sites: 9% · 93 MLB · LITRES PER MWH OF ELECTRICITY (LOG SCALE)1101001,00010,00014 other sites: median 12.9 L/MWh14 other sites: median 12.9Meta: 471 L/MWhMeta: 471Equinix: 2,453 L/MWhEquinix: 2,453power stations (model): 6,000

Panel A splits the 1,048 million litres of public-supply water that EPA-licensed data centres reported for 2025 by site. Panel B divides each site's water by the electricity it drew, on a log scale, so each step is ten times the last: the median for the other 14 sites is 12.9 litres per MWh, while Equinix's site used 2,453. The reports do not say what the water is used for; a spread this wide is consistent with different cooling designs (our reading, not stated in the reports). The dashed line is the 6,000 litres per MWh a research paper assigns to generating Irish electricity, which happens at power stations, not data centres.

Sources: EPA annual environmental reports, Table 5 'Water used', 3 Oct 2026 · Fearon, Bresnihan & Brodie, 'How we all pay for Big Tech', MUSSI Working Paper 31, Maynooth University, Sept 2026

What's measured, site by site

1.05 bn L
Public water used by 16 licensed sites, 2025
≈ 419 Olympic pools · EPA reports
0.17%
Of Uisce Éireann's public supply
91%
Used by just two sites
Meta Clonee and Equinix Blanchardstown
46 bn L
The widely quoted 'footprint'
water used to generate their electricity, not drawn on site
Two different measures. The "over 999 million litres" in the press (The Journal, 2025) is, like our 1.05 bn above, a sum of what licensed sites report to the EPA; the totals differ by which sites are counted. The 46 billion litres from the Maynooth paper multiplies data-centre electricity by water used at power stations (6 L/kWh). Never add them. Ireland's climate lets most sites cool with outside air most of the year, which is why many use very little.

Litres per MWh of electricity, 2025

Meta · P1192471
Equinix Hyperscale 1 (DB5) · P11682,453
K2 Strategic Infrastructure · P1143315
Microsoft · P119040
Amazon Data Services · P117218
Microsoft · P11915
Amazon Data Services · P117714
Google · P118915
Microsoft · P118713
Amazon Data Services · P11713

Equinix Blanchardstown (evaporative cooling) uses ~2,450 L per MWh; most Amazon sites 1–26 L.

The 2026 summer, million litres a day

Jan-Apr 20262.3
May-Jul 20265.6
Jul 20266.5

Use rose with the hot summer from May, before the hosepipe bans (Dublin mid-July, national 24 July). About 0.6–0.9% of Dublin's supply at the peak.

EPA annual environmental reports (public-supply water) · Uisce Éireann via Dáil answers and The Journal · Maynooth MUSSI Working Paper 31 · as of 2026-10-03

What the Government has said

2026-06-11"most large data centres have improved efficiency and rely on closed loop systems with minimal ongoing consumption"
Dáil written answer, Minister for Climate, Energy and the Environment, PQ 150 [44886/26], 11 Jun 2026 (citing Uisce Éireann's previous analysis)
2026-07-28"data centres are not a major driver of demand on the public water supply network, accounting for less than 0.3%"
Dáil written answer, Minister for Climate, Energy and the Environment, PQ 225 [58369/26], 28 Jul 2026 (Uisce Éireann advice)
2026-07-28"not all data centres use water from the Uisce Éireann network, with a number of them having their own wells"
Dáil written answer, PQ 225 [58369/26], 28 Jul 2026
2023-02-02"There is currently no register held by a public body that includes the energy and water requirements of data centres."
Dáil written answer, PQ 200-201 [5313/23, 5314/23], 2 Feb 2023
2025-03-19"Uisce Éireann does not publish ongoing water consumption figures relating to particular businesses as the information may be commercially sensitive"
Dáil written answer, Minister for Housing, PQ 960 [12591/25], 19 Mar 2025
2026-04-14"data centres in Ireland are reporting this information to a confidential EU database on data centres"
Dáil written answer, PQ 449 [25230/26], 14 Apr 2026 (EED Article 12 / Reg. 2024/1364)
2026-09-17"ordinary people were asked to abide by a hosepipe ban this summer whereas data centres actually doubled their water consumption"
Dáil oral PQ 4 [65969/26], Deputy Ciarán Ahern (Labour), 17 Sep 2026

Questions people ask

Did data centres cause the 2026 hosepipe ban?
No single cause is published. Uisce Éireann told the Dáil data centres are under 0.3% of public supply (PQ 225, 28 July 2026), but metered use at the two biggest sites roughly doubled during the dry summer, in the stressed Dublin supply area.

Related