What Thailand’s Data Centre Board Will Decide on November 27

Thailand’s Data Centre Board, chaired by Deputy Prime Minister and Finance Minister Ekniti Nitithanprapas, will vote on November 27, 2026 on a draft rule that would force every data centre in the country — new or already running — to treat and reuse at least 80% of the water it discharges from its cooling towers every month, according to The Nation Thailand’s October 25, 2026 report, which cited the Thai business outlet Thansettakij. The vote lands almost three months after a diesel leak at an unlicensed backup-power facility in Bangkok triggered a nationwide freeze on data-centre approvals.

The 80% That Counts, and the Water That Doesn’t

The draft is narrower than “recycle most of your water.” It targets one specific waste stream: blowdown, the mineral-concentrated water a cooling tower bleeds off to stop scale and corrosion building up inside the system. Operators would have to collect, treat and reuse at least 80% of that monthly discharge volume as makeup water for the same cooling system.

Three categories don’t count toward the target, according to the draft reported by The Nation Thailand: water already circulating inside the system, water that has already been treated and reused once, and water drawn from other sources to pad the ratio. Whatever isn’t reused has to meet the Ministry of Natural Resources and Environment’s 2024 discharge notification before it can leave the site, or go to a licensed third-party treatment provider. Diluting non-compliant wastewater with clean water to pass a test is explicitly banned, and operators have to install meters and file monthly reports on water balance, water quality and pollution load.

The scope is broad by design: a “data centre” under the draft is any building or structure that uses electronic equipment and at least 0.5 megawatts of electricity to collect, store, process, host or transmit data — a threshold low enough to catch a mid-sized enterprise server room, not just hyperscale campuses.

A One-Year Clock for Facilities Already Running

If the board approves the draft on November 27, the regulation takes effect 180 days after it is published in the Royal Gazette — then every data centre already licensed or operating before that date gets exactly one year to upgrade its fire protection, emergency power and environmental systems to comply, including the wastewater rule.

That is a tight sequence for anything involving cooling-tower retrofits. Installing blowdown treatment and reuse loops means new piping, treatment skids, metering and, in many existing facilities, redesigning how makeup water enters the system in the first place — civil and mechanical work that typically runs on a planning-and-procurement timeline closer to eighteen months than twelve, before a contractor even breaks ground. An operator who waits for the Gazette notice to start designing is already behind the clock the rule hands them.

This is the rule that was always coming after September’s freeze, just not the one most operators were watching for. The freeze itself — which paused 49 data centres under construction and halted approval for 117 more, 166 projects in all, after the diesel incident, according to Bloomberg’s reporting at the time — was framed around power supply and fire safety. The wastewater quota is the first piece of the rebuild to arrive with a specific number and a specific date attached, and it is about water, not electricity.

What a Thai Data-Centre Operator Should Budget for Before the Vote

Three things are worth doing before November 27, regardless of which way the board votes. First, model the facility’s actual blowdown volume against the 80% target now — the gap between current cycles-of-concentration practice and an 80% reuse mandate is a real engineering number, not a rounding error, and it is cheaper to size the required treatment capacity before a compliance deadline is law than after. Second, separate the metering and reporting burden from the capital project: monthly water-balance and pollution-load reports are an administrative cost that starts on day one of enforcement, independent of whatever retrofit timeline a facility is on. Third, treat the 0.5-megawatt threshold as a warning to any commercial building with an on-site server room or colocation suite that assumed data-centre rules were a hyperscale problem — the draft’s language does not exempt smaller operations.

For a building owner or portfolio manager evaluating a data-hall conversion elsewhere in ASEAN, the signal is broader than Thailand: water, not just power, is becoming a named line item in data-centre regulation, and the facilities that treat it as an engineering problem to solve early will spend less than the ones that treat it as a paperwork problem to solve late.

Key takeaways

  • Thailand’s Data Centre Board, chaired by Deputy Prime Minister Ekniti Nitithanprapas, votes on November 27, 2026 on a draft rule requiring data centres to reuse at least 80% of their monthly cooling-tower blowdown water.
  • Recirculated water, already-treated water and water from other sources do not count toward the 80% target, and diluting non-compliant discharge to pass inspection is explicitly banned.
  • If approved, the rule takes effect 180 days after Royal Gazette publication, after which existing data centres get just one year to upgrade fire-protection, power and environmental systems, including wastewater treatment.
  • The rule covers any facility using at least 0.5 megawatts of electricity for data processing or storage, a threshold low enough to include mid-sized enterprise server rooms, not only hyperscale campuses.
  • September’s freeze on 166 data-centre projects was framed around power and fire safety; this is the first specific, dated compliance obligation to arrive that is about water instead.