Data centres & Greek water

Why data-centre water doesn't go through the water-permit process

Greek water permits regulate abstraction from the environment — a borehole, a spring, a river — not consumption. Which rules a facility meets therefore depends on where its water comes from and which environmental instrument covers it, not on what sector it is in. A data centre on the public mains and a farm with its own borehole are treated differently for the same reason a hospital and an irrigator are. The table sets out the routes; the mechanisms below cite the acts.

1. 1
   Water permits license the taking of water, and the utility has already taken it. ΚΥΑ 146896/2014requires a water-use permit for abstraction from a water body. A facility supplied by ΕΥΔΑΠ or a ΔΕΥΑ abstracts nothing itself: the utility holds the permits for its sources and sells treated water to customers, large or small. Microsoft's ATH04 is the worked example — its siting decision specifies supply from a Φ160 municipal main (Ψ5ΚΒ46ΝΛΣΞ-ΡΓΓ, §1.1.4) and the Spata council approved two Φ63 mm connections (ΑΔΣ 107/2025). No Directorate of Waters was involved because no borehole was. The utilities publish no split by customer, so that water is recorded as public supply.
2. 2
   When a data centre does abstract, it meets the same rule as a farm. The one data-centre entry in this site's 76,000-act record is a water-use licence for 2,220 m³/yr of landscaping water at Digital Realty's Koropi campus (ΨΟΟ2ΟΡ1Κ-ΟΞΞ). DATA4's Paiania ΑΕΠΟ lists on-site abstraction points and makes them conditional on a Directorate of Waters use licence (9ΚΧΧΟΡ1Κ-02Α, term 22). The asymmetry is about the pipe, not the sector.
3. 3
   Environmental licensing is where a water figure gets stated — and a 20 MW threshold decides how much. Above it, a full ΑΕΠΟ follows an impact study and municipal consultation, and may set water terms (Olive, 80 MW: 6ΜΣΡΟΡ1Κ-Ν1Θ; DATA4: 9ΚΧΧΟΡ1Κ-02Α). From 29 July 2025, data centres of 2–20 MW instead fall under standard environmental terms (ΠΠΔ) — ΚΥΑ ΥΠΕΝ/ΔΙΠΑ/82255/5190 (Β' 4095): a regional decision within 20 working days, without a study or public consultation. The regulator's rationale is the usual one for standard terms — proportionate handling of smaller, lower-impact projects. Six registry sites have taken that route so far: Amyntaio (9ΝΡΓ7ΛΨ-ΓΚ7), Amyntaio (ΡΤΓΘ7ΛΨ-ΘΣΩ), Ioannina (9ΟΑ37Λ9-2Ι5), Ioannina (ΡΠ9Ε7Λ9-89Ο), Thermopyles–Molos (ΡΚΨΑ7ΛΗ-5ΨΜ), Evros (Ψ7ΨΥ7ΛΒ-ΣΘΔ). None states an annual water figure, because the route does not call for one. The rule has been appealed to the Council of State by a Spata residents' committee (Nov 2025); the case is pending.
4. 4
   Strategic investments use a consolidated instrument. Microsoft's three Attica sites were designated a strategic investment: a strategic environmental assessment was approved first (ΩΧΕΗ4653Π4-ΗΛΑ, 2023), then a Presidential Decree fixed the special spatial plan (ΕΣΧΑΣΕ, Π.Δ. 15-01-2024, ΦΕΚ Δ' 5/2024), and a single ministerial decision issued siting and environmental terms together (ΚΥΑ 69748/2024). The water figure exists — 8,856 m³/yr — but it sits inside that instrument rather than in a water permit, which is why it is the one operator-stated figure on this page.

What this does to the numbers.Data-centre water is real but is booked where the utility abstracts it, so the national stress index (WEI+) and this site's permit ledger see it as urban supply, not as a sector. The only facility-level figures are the ones an environmental decision happens to state — 4 of the 50 facilities tracked. The Ministry's own internal assessment reaches the same shape: negligible at national scale, material locally in Spata and Thessaly (ΥΠΕΝ report, Jun 2026). Whether that allocation of responsibility is the right one is a policy question; this page records how it works.

Legal instruments — ΚΥΑ 146896/2014, water-use permits: ΦΕΚ Β' 2878/2014 ↗, consolidated ↗ · Ν. 4014/2011, environmental licensing (ΠΠΔ vs ΑΕΠΟ): ΦΕΚ Α' 209/2011, consolidated ↗ · ΚΥΑ ΥΠΕΝ/ΔΙΠΑ/82255/5190, standard terms for 2–20 MW data centres: ΦΕΚ Β' 4095/2025 ↗ · Ν. 4608/2019, strategic investments (ΕΣΧΑΣΕ): ΦΕΚ Α' 66/2019, official PDF ↗, consolidated ↗. Official texts: National Printing Office (et.gr); consolidated versions: e-nomothesia.gr. Facility examples link to the Diavgeia act.

Where the grid wants them — and where the water isn't

PwC mapped how much new data-centre load each region's grid could carry by 2034. Set that against each basin's Water Exploitation Index (EEA WEI+ — the share of renewable water already withdrawn): the biggest grid headroom sits in Thessaly and the north, the most over-drawn basins in the country.

The collision. 4 of the 9 regions with grid room are already water-stressed or severe — including Thessaly (605 MW of headroom, WEI+ 69.7%, the most over-drawn basin in Greece) and Attica, which is both severely stressed and already holds most of the connected load. The grid's spare capacity and the country's spare water are in different places.

Grid headroom: PwC for the Greek government, 'Grid Capacity for DCs — KtP Stream II' (confidential, presented 13 Mar 2026; obtained and published by Solomon, DocumentCloud 28651462). MW available for data-centre connection in 2034 assuming the operators' planned works complete; regional figures are not summable; max single site per region. PwC / Solomon ↗. Water stress: EEA WEI+ (annual) by river-basin district. Regional MW are not summable; each is a max single-site figure.

Model a specific site

IT load × 8,760 h × 90 % × WUE, cross-referenced to the municipality's verified drought record.

No ΔΕΥΑ matched to this municipality by name in the utility layer — supply may be run by the municipality itself or by ΕΥΔΑΠ / ΕΥΑΘ. Counts are floors of what Diavgeia holds. Method and national picture: Where Greece's water goes.

Download the data

All of it, free, no sign-up. Every row carries its source; nothing is inferred from absence. Reuse with attribution: Greek Water Reports · waterintel.eu, compiled from Diavgeia decisions and named public registers.

• datacentres.json ↓

  Everything: 50 facilities with acts, sources, coordinates; market figures; regulatory trail; WUE references; method.

• datacentres-sites.csv ↓

  One row per facility — operator, entity, location, status, MW, investment, cooling, water, coordinates.

• datacentres-acts.csv ↓

  One row per Diavgeia act — facility, date, ΑΔΑ, what it is, link.

• datacentres-sources.csv ↓

  One row per cited source — facility, title, publisher, date, URL.

• datacentres-eprm.csv ↓

  The data-centre decisions in the ΥΠΕΝ environmental register (ΗΠΜ), identifiers only.

Third-party inputs are linked, not redistributed: Solomon's site dataset at wearesolomon.com/datacenters-gr ↗; the ΗΠΜ register at eprm.ypen.gr ↗. Compiled from Diavgeia acts, the ΗΠΜ register, Solomon, Data Center Map, the PwC siting study and dated reports.