Hackers have launched five cyberattacks against Britain's drinking water suppliers since the beginning of last year, according to reports filed with the drinking water watchdog and partially disclosed to Recorded Future News under freedom of information laws.

None of the attacks impacted the safe supply of drinking water itself, but instead affected the organizations behind those supplies. The incidents, a record number in any two-year period, highlight what British intelligence warns is an increasing threat posed by malicious cyber actors to the country’s critical infrastructure.

The data shared by the Drinking Water Inspectorate (DWI) showed the watchdog received 15 reports from suppliers between January 1, 2024, and October 20, 2025. These were sent under the NIS Regulations, which is just one part of the extensive legal framework governing the security of drinking water systems in Britain.

Of these reports, five regarded cybersecurity incidents affecting what the DWI called “out-of-NIS-scope systems” with the others being non-cyber operational issues. Further details of the 15 reports were not shared with Recorded Future News..

Currently, the NIS Regulations limit formally reportable cyber incidents to those that actually result in disruption to an essential service. If British infrastructure suppliers were impacted by hacks such as the pre-positioning campaign tracked as Volt Typhoon, suppliers would not have a legal duty to disclose them.

DWI said the five incidents that were disclosed to the watchdog were shared for information purposes because they were considered to be “related to water supply resilience risks.”

British officials are expected to try to amend this high bar for reporting when the government updates those laws through the much-delayed Cyber Security and Resilience Bill, when it is finally introduced to Parliament later this year.

A government spokesperson said: “The Cyber threats we face are sophisticated, relentless and costly. Our Cyber Security and Resilience Bill will be introduced to Parliament this year and is designed to strengthen our cyber defences — protecting the services the public rely on so they can go about their normal lives.”

Five reports better than none

That the reports were made despite not being required by the NIS Regulations was a positive sign, said Don Smith, vice president threat research at Sophos.

“Critical infrastructure providers, like any modern connected enterprise, are subject to attacks from criminal actors daily. It is no surprise that security incidents do occur within these enterprises, despite the compliance regimes that they’re subjected to,” Smith told Recorded Future News when asked about the data.

“I think we should be encouraged that these reports were shared outside of the scope of the NIS Regulations. It is very useful for critical infrastructure operators to understand the nature of these attacks, both in the case of commodity threats and if there’s an advanced adversary operating, and a culture of information sharing helps widen everyone’s aperture.”

Although there have been ransomware attacks against the IT office systems used by water companies — including on South Staffs Water in the U.K. and Aigües de Mataró in Spain — it is extremely rare for cyberattacks on water suppliers to actually disrupt supplies.

In one rare case of a successful attack on an OT (operational technology) component, residents of a remote area on Ireland’s west coast were left without water for several days in December 2023 when a pro-Iran hacking group indiscriminately targeted facilities using a piece of equipment the hackers complained was made in Israel.

The U.S. federal government had issued a warning about the exploitation of Unitronics programmable logic controllers (PLCs) used by many organizations in the water sector. Attacks on PLCs, core technology components in a lot of industrial control systems, are one of the main concerns of critical infrastructure defenders.

Initiatives to improve the security of water systems in the United States faltered under the Biden administration when water industry groups partnered with Republican lawmakers to put a halt to the federal efforts, despite significant increases in the number of ransomware attacks and state-sponsored intrusions.

Last week, Canadian authorities warned of an incident in which hacktivists changed the water pressure at one local utility among a spate of attacks interfering with industrial control systems.

Britain's National Cyber Security Centre encourages critical infrastructure providers to ensure they have properly segmented their business IT systems and their OT systems to reduce the impact of any cyber intrusion. In August, the agency released a new Cyber Assessments Framework to help organizations improve their resilience.

“Commodity rather than targeted attacks remain the most likely threat to impact critical infrastructure providers. The messaging I pass to CISOs and the people managing risk in these organizations is to worry about defending from the everyday as opposed to defending from the exotic,” said Smith.

“They’re expected to do both, but the much bigger risk is that we end up with a major piece of our CNI knocked offline because of a ransomware attack. I worry about people thinking about investing huge amounts in monitoring esoteric systems when they’re actually not protecting themselves from the basics.”