Customers are expected to receive a rebate of less than £7 each from Thames Water next year despite the supplier’s worsening sewage failings.
Thames Water was the hardest hit by financial penalties handed out by regulator Ofwat on Monday, which ordered the UK’s largest supplier to return £100m to billpayers following a “deterioration” in its river pollution.
This was by far the largest individual fine, as Ofwat said underperforming suppliers must return £114m due to failings on sewage, leaks and customer satisfaction.
The money will be returned through customer bills.
Ofwat’s latest annual performance report revealed that Thames Water recorded a 22pc increase in pollution incidents last year, as it was one of the “worst performers” for customer satisfaction.
Yet, Thames Water’s £100m rebate will offer little respite to customers, who are likely to receive an average of £6.70 off their annual bills from April, according to Telegraph calculations. Thames Water declined to comment on the figure.
The rebate comes two months after the UK’s largest supplier was handed a £750m lifeline from shareholders in its battle to avoid nationalisation, with bosses admitting it will need a further £2.5bn by 2030.
A Thames Water spokesman said: “Our customers expect a great service from us every time, and we’re sorry when we fail to deliver at the first opportunity.”
However, they said that its turnaround plan is having an impact: “Our complaints fell by 28pc, the second consecutive significant year-on-year reduction and we have seen improvements in several key performance commitments including a reduction in sewage discharges, internal sewer flooding, and sewer blockages.”
In Monday’s report, Ofwat did not rank a single one of Britain’s water firms in its highest “leading” category.
Instead, it said 10 firms were “average” and seven were “lagging”.
The worst performers were Anglian Water, Dŵr Cymru, Southern Water, Thames Water, Yorkshire Water, Bristol Water and South East Water.
Southern Water was the second-worst performing firm and was ordered to pay back £43m.
The net industry rebate of £114m was offset by some companies being rewarded cash, such as Severn Trent receiving £88m and United Utilities £25m.
Ofwat judges the performance of water companies in England and Wales each year against targets set in 2019 for a five-year period until 2025.
Ofwat chief executive David Black said: “The targets we set for companies were designed to be stretching – to drive improvements for customers and the environment.
“However, our latest report shows they are falling short, leading to £114m being returned to customers through bill reductions. While that may be welcome to billpayers, it is very disappointing news for all who want to see the sector do better.”