Complaints to water firms have spiked in the last year and Thames Water was the most complained about company, an annual report reveals.

The number of complaints escalated to the Consumer Council for Water (CCW) by households in England and Wales who failed to get a resolution from their supplier rose by 29 per cent in 2023-24 – the highest level for nearly a decade.

CCW rated Thames Water, the supplier in Swindon, as poor and it was the worst-performing water company overall, receiving more direct complaints and complaints made to the CCW than any other provider.

Concerns about the environmental performance of water firms and issues with water meters had fuelled the increase in complaints and there were 222,956 complaints made directly to water companies in England and Wales.

Complaints regarding water meters rose by 30 per cent with common issues being concerns about how often they were being read and whether they were working properly.

David Bird, retail director at Thames Water, said: “We are committed to improving the experience of our customers and have been working closely alongside CCW to address these issues. CCW has recognised the collaborative approach we have taken and that the improvements we are making are showing promise. However, we recognise we have more to do.

“Our turnaround plan is focused on resolving customer complaints and improving the quality of their interaction with our business, from first contact through to resolution.

“Furthermore, we have proposed an ambitious business plan for 2025-2030 based on customers’ feedback and insight. Our customers told us to focus on delivering safe and resilient water supplies, address concerns over our overall performance including on customer service, and deal more effectively with wastewater. If approved, it will deliver the improvements customers are looking for.”

Sewage spills into rivers and seas more than doubled in 2023 and according to the Environment Agency, there were 3.6 million hours of spills last year, compared with 1.75 million hours in 2022.

Earlier this year, Ofwat revealed £168 million of proposed fines for three of England’s biggest water companies for failing to manage sewage spills – including a £104 million penalty for Thames Water.

In July, Ofwat proposed that water firms should be allowed to increase bills by a third less than they had requested on average and in response, Thames Water proposed raising average yearly water bills to £666.50 per customer by 2030 – a 52 per cent increase.