SE was described as “lagging behind” in Ofwat’s latest performance report, with the regulator demanding a service commitment plan be published by the company before the end of this month to address its underperformance.
In the report, the company, which only supplies water rather than providing wastewater disposal, ranked as the worst performer on water supply interruptions in England and Wales.
According to Ofwat, there was an average 3 hours, 2 minutes and 21 seconds lost per property compared with its performance commitment level of 5 minutes and 45 seconds in the period covering 2022 to 2023.
It also had ‘poor’ performance on customer satisfaction, leakage, per capita consumption reduction, and mains repairs.
SE was ranked as having ‘satisfactory’ performance on priority services and drinking water quality.
Ofwat chief executive David Black said: “Providing reliable water supplies is at the heart of a water company's responsibilities. Too many customers have been failed too often by SE.”
Black said the regulator has been clear that water companies need to do more to regain public trust.
“Where this does not happen, we will use all of our powers to ensure the sector delivers better value for both customers and the environment,” he continued.
A SE spokesperson said: “We acknowledge the decision by Ofwat to open this investigation. Resilience forms a major focus for SE both now, and as a significant part of our PR24 business plan which has been submitted to Ofwat.
“We intend to fully cooperate with Ofwat on this matter.”
The news comes after the Drinking Water Inspectorate (DWI) informed SE just last month that it is considering taking enforcement action against it in order to secure improvements to its supply system.
Ofwat has said it will be working closely with the DWI and not discuss the specifics of the case until the investigation has concluded.