Water sector regulator Ofwat has today welcomed wastewater companies' plans to address storm overflows and river quality – but warned that some companies have shown “limited ambition” to act before 2025.

Wastewater companies have set out how they are going to cut the harm they cause to rivers, following calls from the regulator and concerns from the public.

Ofwat has today posted a statement welcoming the immediate commitments to tackle these issues alongside areas for improvement.

The regulator said it is pleased to see some companies have committed to make immediate progress on the issue.

Anglian Water, Severn Trent, South West Water and Northumbrian Water have all committed to achieve an average of 20 storm overflow spills per year by 2025 and to ensure company operations are not responsible for water bodies not achieving Good Ecological Status by 2030. United Utilities and Wessex Water have also made commitments to reduce use of overflows by 2025.

However, Ofwat is warning that there are also companies that have shown limited ambition to act before 2025 beyond pre-existing plans set three years ago. The regulator has emphasised the importance for all companies to make their plans public and accessible, to increase trust with the public on river health.

Ofwat said that storm overflows that are regularly spilling due to unresolved operational problems, including asset configuration, pump failures and power failures, are “within companies' gift to resolve now.” All companies are expected to address the issues as a priority in line with their legal duties to effectually deal with the contents of sewers.

The regulator also expects that the commitments made by leading companies will help to set performance benchmarks on storm overflows at PR24, warning that companies that fail to act now to reduce overflows “may well face more challenging improvement targets at PR24.”

David Black, Ofwat CEO, commented:

"Wastewater companies know that the current situation regarding pollution in rivers is unacceptable and has to change. I am pleased to see the firm commitments to take action within some of the plans, which sets the pace for others to follow. These commitments need to be turned to actions which can and must start now.

"Companies that are lagging behind need to catch up with the leading companies. Where companies are failing to meet their legal obligations, we will not hesitate to take action. All wastewater companies are still subject to our ongoing investigation on how they manage their sewage treatment works."

All wastewater companies are still being scrutinised as part of the investigations by Ofwat and the Environment Agency into sewage treatment works. The commitments made by leading companies are expected to help to set performance benchmarks on storm overflows at PR24, and companies that fail to act now to reduce overflows may well face more challenging improvement targets at PR24.

As part of PR24, Ofwat will also consider how to incentivise and enable companies to further reduce harm caused by overflows to achieve targets set by Defra in its Storm Overflow Discharge Reduction Plan, along with their new storm overflow duties introduced by the Environment Act 2021, once in force.

Responding to Ofwat’s announcement, Emma Clancy, Chief Executive of the Consumer Council for Water (CCW), said:

“The whole industry should be united behind the same level of ambition to reduce the harm caused by storm overflows, at a time when two-thirds of people have told us they want to see planned improvements to ensure rivers are a healthy habitat for wildlife.”

“We’ll be working alongside Ofwat to challenge all wastewater companies to take the action needed to rebuild trust with their communities where it has been damaged.”

Environment Minister Rebecca Pow added:

“Through our Environment Act, we are the first government to instruct water companies to reduce the harm caused by storm overflows. Water companies have been allowed to get away with it for too long, and they must step up.

“We will be monitoring the progress of water companies, and where they do not deliver we will not hesitate to take further robust action.”