Ofwat's investigation found that Severn Trent, which serves millions of customers across England and Wales, had failed to establish adequate systems and processes for managing its drainage and sewage network, representing what the regulator termed serious and unacceptable breaches of duty. However, unlike seven other water companies that faced fines ranging from £11m to £104m in concurrent cases, Severn Trent received no financial penalty.

The company avoided fines because it had independently identified the operational failures and begun implementing solutions before the formal case opened in July 2024. Following a £98m shareholder investment programme, Severn Trent reported a 41% reduction in storm overflow spills between 2024 and 2025, despite experiencing higher rainfall in its region. The regulator's approach in this case emphasised rewarding genuine accountability and reform, distinguishing it from the enforcement actions taken against other water companies in the sector-wide investigation.