Southern Water, Anglian Water and South East Water began the appeal to Ofwat earlier on Tuesday, before they were joined by Thames Water, Northumbrian Water and Wessex Water, Ofwat confirmed.
Thames Water is among six water firms urging regulators to allow them to charge customers even more than previously granted – after a High Court judge allowed England’s largest water firm to borrow £3 billion to avoid collapse.
David Henderson, chief executive of Water UK, said that although “many water companies can live with Ofwat’s decisions”, the six appellants felt like they had “no choice” but to demand a review in the hopes that Ofwat would amend its conclusions.
He said: “Water companies need to invest billions to strengthen and expand infrastructure to support economic growth, secure our water supplies and end sewage entering our rivers and seas.
In December, sector regulator Ofwat said it would allow water firms to raise bills by an average of £157, or 36%, over the next five years to help finance investment into crumbling infrastructure.
