Photo credit: Darren Tolley

Severn Trent Water has been found in breach of its wastewater obligations, though Ofwat has decided against a financial penalty. The regulator concluded the company failed in its duties to provide drainage and manage the contents of its sewers, and had historically breached licence requirements to maintain adequate processes and systems. Instead of a fine, Ofwat has accepted an enforceable package of undertakings committing the company to fix outstanding problems.

Why no penalty

The decision turns on timing. Severn Trent identified problems in its own network and began addressing them before Ofwat opened an enforcement case against it in July 2024, a sequence that sets this case apart from the seven that preceded it. Shareholders have since funded £98 million of infrastructure work, including extra capacity at 65 wastewater treatment sites, storm tank and Flow to Full Treatment upgrades, increased storage at storm overflows, and £26 million of nature-based schemes around Mansfield.

Ofwat pointed to the results. Average spills from storm overflows fell by 41 per cent year on year in 2025. The regulator noted that Severn Trent had consistently outperformed other wastewater companies on that measure across the investigation period, despite its region receiving heavier rainfall than some others. Lynn Parker, Ofwat’s senior director for enforcement, called the breaches “serious and unacceptable” and said the company accepts that finding, but that its response set a standard the regulator expects of others: spotting the fault, funding the remedy, and dealing openly with the regulator. She said Ofwat would be as willing to state publicly when a company does the right thing as when it fails.

The wider investigation

The case is the eighth to conclude in Ofwat’s sector-wide wastewater investigation, opened in 2021, which has so far produced enforcement packages and fines exceeding £300 million. Two cases remain open.

Severn Trent, which serves around eight million people, committed in 2023 to spend £450 million by 2030 under a spills reduction programme, targeting an average of fewer than 14 spills per storm overflow by that date. Chief executive James Jesic said the company accepted Ofwat’s findings on issues it had proactively identified, and that early monitoring and investment were now delivering benefits, while acknowledging further work remained.