Thames Water repairs crisis leaves supply 'on knife-edge'

Thames Water has £23bn of assets in urgent need of repair and the supply of water to its 16 million customers is "on a knife-edge", a Guardian investigation can reveal.

- Anna Isaac

Britain's biggest water company has failed to adequately tackle serious safety concerns, not upgraded essential IT systems and tolerated a culture of intimidation among staff, according to company insiders and an analysis of documents. The investigation suggests the company is in a worse financial state than previously admitted, and neither its managers nor regulators appear to have grasped the perilous state of some of its reservoirs and pipes.

The Guardian has also discovered that key data is still managed on obsolete software that dates to 1989. Sources claimed the company had been subject to cyber-attacks from groups affiliated with hostile states, including Russia.

A spokesperson for Thames Water said: "The wellbeing and safety of our colleagues and customers is our highest priority."

Regarding cyber-attacks, Thames declined to comment on the record, but a source at the company said it had "not experienced any cyber-attacks full stop".

The Guardian has spent several months investigating the finances and culture of Britain's biggest water company as it struggles for survival.

Sources described how concerns about Thames's governance and operations have been raised at the highest levels of management. Yet they claimed the issues had not been tackled, suggesting the scale of the turnaround required at Thames may have been underestimated.

"Operations have been hollowed out and cut to the bone," one senior source at Thames said. "We're putting the public at risk by failing to invest in the most basic needs."

They added that, in their view, management had not moved quickly enough to address problems such as weakening explosive infrastructure - including containers holding the gas produced by sewage and cracks in reservoirs.

They said Thames's management and the regulator, Ofwat, had both been slow to address these issues, allowing them to escalate.