Eleven water companies will be forced to cut tens of millions from their customers’ bills after missing targets on supply interruptions, pollution incidents and internal sewer flooding.

These targets, called performance commitments, are a combination of shared targets across the sector and individual targets on a wide range of issues.

The water regulator said the poorest performers, Southern Water and Thames Water, will have to return nearly £80 million to their customers.

Ofwat noted that these two companies missed targets on water treatment works compliance, pollution incidents and internal sewer flooding.

David Black, Ofwat Chief Executive Officer, said: “When it comes to delivering for their customers, too many water companies are falling short, and we require them to return around £150 million to their customers.

“We expect companies to improve their performance every year; where they fail to do so, we will hold them to account.”