Southern Water has posted a pre-tax loss of £253.6 million in its financial results for the year to end March.
This compares to a pre-tax profit of £202.9 million for the previous year. The company received a tax credit of £20.7 million, lowering its post-tax loss to £232.9 million.
Meanwhile, its operating profit fell from £263.3 million to £117.9 million following a series of regulatory interventions, which cost the firm £138.5 million in total. The figure would otherwise have been £256.4 million.
These costs include the £126 million which Southern Water agreed to pay to customers after a large-scale investigation by Ofwat found the company had failed to properly maintain its wastewater treatment plants, leading to numerous spills which it then attempted to hide from the regulator. Its operating profit was also impacted by the costs associated with its PR19 business plan for 2020-25.
Southern admitted it needs to “work hard” to regain the trust of its regulators and customers.
Acting chairman Paul Sheffield said: “Both I and the board apologise on behalf of Southern Water for the actions that led to the manipulation of wastewater flows through that period and for misreporting data to our regulators.
“Those actions resulted in us being overpaid for the service we delivered and the reparations now being made are intended to put that right.
“We must also now work hard to regain the trust of our regulators and customers. We started the overhauling of our business practices as soon as these failings came to light two years ago. In order to start that process of regaining trust we have agreed that we will provide external independent audit of our processes for the next five years.”
The company also revealed it is under investigation from the Drinking Water Inspectorate (DWI) as well as the Environment Agency for historic issues including misreporting.
Two DWI final enforcement orders are in place – a final asset improvement scheme and water quality sampling and information management.