Businesses in England are using 2.6 billion litres of water a day from the public supply as millions of households face hosepipe bans and three-quarters of the country remains in drought, according to an investigation.
Companies account for around 30% of public water supply use, with two-thirds of that consumption occurring in areas already identified as water-stressed, according to Mosl, the organisation that operates England's business water market. Less than 1% of businesses use more water than the daily needs of 10 million people.
Despite the scale of use, tracking industrial water consumption remains difficult. Regulators have said they are hampered by a lack of data and by "commercial secrecy", while the water sector says this prevents effective planning for growth industries such as datacentres and hydrogen production.
The biggest users of public water supply include oil refineries, chemical plants and paper mills, some of which face no requirement to reduce their consumption. Mosl's map of business water supply points, ranked by volume used, identified the site of ExxonMobil's Esso refinery at Fawley, Southampton, as the largest user of public water supply, though the site also includes other operators, including waste, gas, chemicals and energy companies, that draw on the same supply.
Mosl cited the refinery's water use in written evidence to a House of Lords committee as an example of "the high volume of water wastage in industry that is not disincentivised by government or the regulatory framework". The organisation did not name the refinery directly but described its location, which was also identifiable on its supply point map.
ExxonMobil disputed Mosl's figures, saying its water use was commercially confidential. Mosl said it planned to ask the committee to redact parts of its evidence, and it also removed a report and its supply point map from its website during the course of reporting.
The refinery said the "vast majority" of the water it used was drawn from the Solent strait for cooling purposes, while "industrial water" was used for processes that could not easily be reduced without shutting down operating units. It said potable water accounted for less than 1% of its total consumption.
Beyond refineries, major users of public water supply include paper mills and companies in the chemicals and soft drinks industries. However, the overall picture of business water use remains incomplete. One in 10 businesses are not metered, meaning their consumption is neither measured nor reported. Of those that are metered, only 11% have smart meters installed.
Although Mosl collects data on water taken from the public supply, it is not free to share all of it, even with government departments, according to its chief executive, Sarah McMath. She told the House of Lords committee that when the Department for Environment, Food and Rural Affairs (Defra) or the Environment Agency requested data, Mosl had to negotiate a bespoke agreement before sharing it. McMath said Mosl was working with the water regulator Ofwat to change this, so that data could be shared where it would benefit "the environment or society".
The lack of comprehensive data is already affecting national water planning. Gaps in local authority growth plans, combined with what the Environment Agency and Ofwat describe as "commercial secrecy, especially in the energy sector", mean that plans are often based on assumptions rather than verified figures. Both bodies are calling for mandatory reporting of current and projected water use across all sectors to improve water security.
A Mosl spokesperson said: "Our data highlights both the opportunities and regulatory barriers to incentivising businesses to use less water. Rather than focusing on individual users – many of whom are actively seeking to reduce their water demand – we should focus on creating the right conditions to invest in water efficiency and increase water reuse where it is safe and practical."
Current water resources planning assumes business water consumption will fall by 9% by 2038 and 15% by 2050. However, the trade body Water UK has argued this assumption is unrealistic given growing demand from new homes, datacentres, hydrogen production and other developments. The organisation wants water companies to be able to plan for projected demand rather than government reduction targets.
Businesses are not required to report all their water use, and for some, the more water they consume, the cheaper each unit becomes. One operator told Mosl that a single UK datacentre uses 219 million litres a year, and also maintains a tankered-water supply on standby in case its mains connection fails, as well as its own borehole as a backup.
Separately, businesses can take water directly from rivers, lakes, aquifers and the sea through abstraction, which is regulated by the Environment Agency. Some abstraction remains entirely unreported: anyone can take up to 20,000 litres a day from a stream, borehole or spring without a licence. This gap is estimated to cover around 850,000 people and organisations across England, mostly farms and rural premises.
Richard Benwell, chief executive of the NGO coalition Wildlife and Countryside Link, said: "It's surely an injustice that petrochemical and fossil fuel companies most responsible for the climate crisis are also draining … water supplies and drawing more water from our parched environment."
The water campaigner Feargal Sharkey said: "Yet again, regulatory ineptitude is allowed to triumph over the needs of people and the environment. While water supplies run dry, corporate bank accounts are flooded with the proceeds of corporate greed."
Defra said the government was taking "decisive action to secure water supplies", including plans to build nine new reservoirs and investment in infrastructure.
A Water UK spokesperson said: "Supplies are increasingly at risk because England's official forecasts for how much water the country needs rely on flawed assumptions. The water needed by fast-growing datacentres is explicitly excluded from the forecasts. At the same time, lower water bills have been prioritised over building a resilient system, meaning in some places water companies only have 2% of water spare to deal with increased demand."
The Environment Agency said abstraction licences carried strict conditions and were reviewed regularly, and that it was working towards the target 9% reduction in business water use from the public supply. Meanwhile, England's water companies are separately losing an estimated 2.2 billion litres of water a day through leaking pipes.
