Thames Water given one-star rating in latest assessment of English water firms

Thames Water has been given a one star rating in the latest assessment of the performance of England's water and sewerage companies.

This week, the Environment Agency’s (EA) latest Environmental Performance Assessment (EPA) was released and revealed the lowest ratings since the process was started in 2011.

The EPA provides an independent comparison of environmental performance across the sector.

Since 2011, the EA has used the EPA to provide a rating for each company in England from one star to four stars, to showcase where improvement in water company performance is needed.

In 2024, the nine companies collectively achieved 19 stars out of a possible 36 – which is the lowest number of overall stars since the beginning of the EPA process.

Thames Water, which serves part of the Thames Valley area, has been given a one star rating for 2024, meaning it is a ‘poor performing company’.

The troubled water and sewerage company was given a record fine of £123million earlier this year for failures with its sewage pollution control and for paying out big dividends.

It has been given up to five years to pay off as part of a payment plan.

In the EPA report, company performance in each of the categories is given either a red, amber, green status, depending on whether it is ‘significantly below’, below or has achieved the target or bettered it for each EPA metric.

The results showed that there were 470 pollution incidents from Thames Water sewerage assets in 2024.

This has received a red status, meaning it is ‘significantly below’ target.

Thames Water saw 43 sewerage pollution incidents per 10,000km of sewer, rating this as red.

However, this performance was better than the sector which saw 47 sewerage incidents per 10,000km of sewer.

The company was given another red status for having 33 serious pollution incidents from its sewerage assets in 2024.

Thames Water was the ‘worst performing company’ for self-reporting of all pollution incidents in 2024, the report said.

The company reported 75 per cent of all incidents, but this is below the sector’s performance of 85 per cent.

A Thames Water spokesperson, said: “In 2024-25 Thames Water made a record capital investment of £2.225 billion.

“We know we need to further improve for our customers, communities and the environment, and that is why we have embarked on the largest ever investment programme, delivering the biggest upgrade to our network in 150 years. 

“Transforming Thames is a major programme of work that will take time; it will take at least a decade to achieve the scale of change required.” 

Thames Water stated that its number of recorded pollution incidents were ‘adversely impacted’ by high groundwater levels and rainfall.

But the company stated it has made progress in addressing ‘many of the underlying causes’ of its poor performance.

This includes being ‘more proactive in sewer cleaning’.

This year, the company expects to achieve the stretch target of cleaning circa 1,550km of sewers.

The newly-complete Thames Tideway Tunnel, which runs from west to east London, will ‘reduce the volume of discharges entering the tidal Thames in a typical year by 95 per cent’, the company said.

Environment Agency Chair Alan Lovell said: “This year’s results are poor and must serve as a clear and urgent signal for change. 

“What is needed now from every water company is bold leadership, a shift in mindset, and a relentless focus on delivery. 

“We will support them however we can but will continue to robustly challenge them when they fall short.”

View the EPA report at: https://www.gov.uk/government/publications/water-and-sewerage-companies-in-england-environmental-performance-report-2024