Thames Water will have to hand £51m back to their customers for failing to meet targets related to internal sewer flooding and customer experience, if plans are approved.

Ofwat called Thames Water one of its ‘poorest performers’ in an annual performance review, with the company receiving the lowest satisfaction rating from customers among the 17 organisations subject to the regulator.

The draft Ofwat decision is in consultation stage, which closes on October 21, and if upheld will see Thames Water customers returned the money in the form of discounts on their future bills.

David Black, Ofwat CEO, said: “When it comes to delivering for their customers, too many water companies are falling short, and we are requiring them to return around £150m to their customers.

READ MORE: Body of woman in her twenties found in Reading address

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

“The poorest performers, Southern Water and Thames Water, will have to return almost £80m to their customers.

“All water companies need to earn back the trust of customers and the public and we will continue to challenge the sector to improve.”

Warren Buckley, customer experience director at Thames Water, said there was a “significant reduction” in complaints to the business following improvements last year.

READ MORE: New bakery and cafe set to open in Broad Street tomorrow

He said there was a 39 per cent reduction in supply interruptions in the last two years.

“We’re determined to do better, and while we’re heading in the right direction, we know there is a long way to go,” said Mr Buckley.

 “Our aim is to always deliver brilliant customer service. It’s one of the biggest priorities of our plan to turn around our performance and our shareholders have recently approved an additional £2billion into the business so we can improve outcomes for customers, leakage and river health.

He continued: “We know we have more work to do to improve customer experiences across our services and we’re already accelerating the customer elements of our turnaround plan to improve our position.”

Overall, 11 companies will knock £150m off customer bills in 2023-4 if Ofwat plans go ahead.