Ofwat has opened an investigation into South East Water on whether it has failed to develop and maintain an efficient water supply system.

Ofwat explained that South East Water is the worst performer for water supply interruptions in England and Wales; in 2022-23 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.

The regulator categorised the company as ‘lagging behind’ in its recent Water Company Performance Report, and Ofwat has required it to publish a service commitment plan by the end of November to address several areas of underperformance, including supply interruptions.

South East Water said it would fully cooperate with the investigation.