About three hundred people walked into a compound of data centres on the Indonesian island of Batam carrying empty plastic bottles and jerry cans, shouting one word: "Water!"
They were residents who said their taps had run dry while the machines inside had enough water to keep from overheating.
What the residents say
"Not a single drop has come through our taps for the last three months," Dewi Susanti, one of the protesters, told the BBC. "Our water supply had been reliable until the data centres came."
Her village, Bakau Serip, had been relying on tanker trucks delivering water she described as "dirty, cloudy and smelly".
What the authorities say
Batam's water utility said it was working to improve supply, but did not say whether the disruption was connected to demand from the data centres.
BP Batam, the agency overseeing trade and industry on the island, blamed a prolonged dry spell and denied the residents' allegation that water intended for homes was being diverted to the servers.
This was not the first protest. After demonstrations in August and September, authorities told firms opening data centres in Batam that they must build their own desalination plants rather than draw freshwater from the island's reservoirs — which is, in its way, an answer to the question of whether there was enough to share.
The number nobody has
The most important fact in this story is an absence. It is not known how much water or electricity the data centres in Batam consume.
"Reliable data on data centre water use in Indonesia remains scarce, partly because companies treat it as proprietary information," says Agus Hasan, a professor at the Norwegian University of Science and Technology. He argues they should be built "rationally, transparently, and responsibly" with the numbers disclosed, warning that "those kept in the dark while their taps run dry will push back, and rightly so".
What is known comes from elsewhere. Research in the United States suggests a typical data centre uses around 300,000 gallons of water a day, roughly what 1,000 American households use. A larger 50MW facility could take as much water as 2,200 households and as much electricity as 22,000 homes, according to Malaysia's central bank.
Batam has no natural freshwater sources of its own and routinely faces shortages, worse this year, possibly because of a severe El Niño.
What it means in Bangladesh
Bangladesh is in the early part of the same conversation, which makes Batam worth reading closely rather than filing under foreign news.
The specific lesson is not "data centres are bad". It is that Batam permitted the facilities first and asked about water second, and the desalination requirement arrived only after people had marched twice. Reversing that order costs nothing at the planning stage and is almost impossible afterwards, because by then the buildings exist and the jobs are real.
The disclosure point is the practical one. If a data centre is proposed here — and with the national ambition to host one, it will be — the question to ask before approval is the one Professor Hasan names: how many litres a day, at what cooling design, drawn from where, and published. A developer who will not answer that during permitting will not answer it afterwards.
The energy side of the same argument is in the Scottish grid arithmetic, and the planning fight in the Amazon site by the M25.
Source: BBC reporting from Batam and Singapore.
