The artificial intelligence boom means the Environment Agency has no idea how much water England will be short of in future decades, as datacentres do not have to report how much they are using to cool their servers.

England’s public water supply could be short by 5bn litres a day by 2055 without urgent action to future-proof resources, the government environment regulator has warned, with a shortfall of a further 1bn litres a day for farming, energy generation and powering emerging technologies.

However, EA sources told the Guardian that this figure of 1bn for industry did not include the amounts of water to be used by datacentres, because that figure was unknown. This means the shortage could be much higher, as datacentres often use vast amounts of water.

Every five years, the EA puts out its water deficit projections, but it was difficult to do this year, the sources said, because of the growth in AI, which is one of the most significant changes to projected usage in recent years. The regulator added that the majority of datacentres were using the public water supply rather than alternative sources and that they did not want this to stop or transparency over their figures.

At the moment, the EA does not have sufficient data to be able to understand both these centres current use and their needs.

Datacentres for AI are a pivotal part of the government’s growth strategy, and Keir Starmer announced this year that he would hugely increase AI capacity and reduce planning restrictions on companies that wanted to build datacentres by setting up “growth zones” with fewer constraints.

AI datacentres use a large amount of water to prevent their servers overheating and shutting down. The centres have cooling towers and outside air systems, both of which need clean, fresh water. AI consumes between 1.8 and 12 litres of water for each kilowatt hour of energy usage across Microsoft’s global datacentres. One study estimates that global AI could account for up to 6.6bn cubic metres of water use by 2027 – the equivalent of nearly two-thirds of England’s annual consumption.

The EA chair, Alan Lovell, said: “The nation’s water resources are under huge and steadily increasing pressure. This deficit threatens not only the water from your tap but also economic growth and food production.

“Taking water unsustainably from the environment will have a disastrous impact on our rivers and wildlife. We need to tackle these challenges head-on and strengthen work on coordinated action to preserve this precious resource and our current way of life.”

Plans to increase supply, submitted by water companies, include nine desalination schemes, 10 reservoirs and seven water recycling schemes by 2050. Water bills for customers have risen, and will continue to rise, to pay for this infrastructure.

The government also plans to monitor individual household water use by rolling out smart meters, which charge based on the amount used and allow water companies and other agencies to track usage.

Climate breakdown will further squeeze water supplies, the EA said, as hotter drier summers become more probable. Areas that rely mostly on surface water will therefore be more susceptible to drought, and it may not rain consistently enough for groundwater to recharge.

Thames Water on Tuesday opened a statutory public consultation on a controversial drought scheme to pump millions more litres of treated sewage into the River Thames every day. Under the £300m project, Thames would extract 75m litres of water a day from the river in south-west London during drought and replacing it with treated sewage from one of Europe’s largest treatment plants at Mogden.

The plan has drawn objections from thousands of people, including the Liberal Democrat MP Munira Wilson, over concerns about the effect on river water quality, the impact of forever chemicals, and the adverse effect on the ecology. The EA has said Thames Water has failed to show that the scheme is “feasible or environmentally acceptable”. Thames Water loses about 570m litres a day from leaks on its network, the most of all the privatised water companies.

Ofwat’s chief executive, David Black, said: “Boosting supply through building critical water infrastructure is essential to safeguard supplies of drinking water. The way is now clear for the water industry to build on the success of the recently opened £5bn Thames Tideway project by stepping forward to deliver an expanded pipeline of 30 major projects we need in England and Wales.”