Ofwat accepts Severn Trent’s preemptive enforcement package

(by Verity Mitchell)

Ofwat has formally accepted a package of undertakings from Severn Trent Water to ensure that the company returns to wastewater compliance.

Ofwat’s investigation found that Severn Trent Water breached its duties, not only failing to provide drainage and deal with the contents of its sewers, but also not having adequate processes and systems to meet those duties.

But Ofwat commended Severn Trent Water for proactively identifying and beginning to address problems in its network before an enforcement case was opened in July 2024. The company’s shareholders have already invested £98m in direct infrastructure improvements.

Ofwat also said that from the outset of the investigation, Severn Trent cooperated fully and was able to evidence both its failures and the concrete steps it had taken and will continue to take to address them.

The £98m of shareholder-funded investment has included additional capacity at 65 wastewater treatment sites, Flow to Full Treatment and storm tank enhancements, increased storage at storm overflows, and £26m of nature-based solutions in the Mansfield area. This forms part of what Ofwat called an ambitious spills reduction programme, launched in 2024, which will take Severn Trent beyond current licence requirements.

The company achieved a 41% year-on-year reduction in spills per storm overflow in 2025, despite experiencing heavier rainfall than some other regions, and has been a consistent above-average performer on this measure throughout the investigation period.

This is the eighth wastewater investigation case Ofwat has closed. The outcomes of each case so far are shown in the table below.