Southern Water has today confirmed its intention to appeal Ofwat’s Final Determination for 2025-30 on its AMP8 Business Plan to the Competition and Markets Authority.

In the Final Determination, Ofwat set how much water companies could invest in their networks over the next five years – and it specified the level of customer bills to support that work.

Separately, the water company has also announced its intention to raise £900 million of new equity.

Southern Water CEO Lawrence Gosden said:

“After very careful consideration, our board has decided to appeal Ofwat’s Final Determination to the Competition and Markets Authority. The Final Determination would not enable us to deliver the environmental and performance improvements and new infrastructure that our customers and communities rightly expect.

“The next formal step in the process is submission of our statement of case to the CMA. We’re ready to meet the CMA’s timetable. In addition, to continue advancing investment in the improvements and new infrastructure needed, today we’ve also announced our intention to raise £900million of new equity.”

Southern Water is progressing the equity raise with its shareholders and expects to conclude the process by the end of June 2025.

Importantly, the water company said the equity raise is not conditional on the outcome of the CMA process. It will allow Southern Water to continue with planned investments in new infrastructure and performance improvements, maintaining the urgency and pace of change.

Southern Water is pointing out that while supporting its operational and investment process, and its Turnaround Plan, the company’s shareholders have received no dividends since 2017, and have injected £1.65 billion of new equity funding between 2021-24.

The CMA appeal will not affect customer bills for 2025-26 – the utility said the support Southern Water offers to those households in the greatest need has expanded significantly over the last year.

As part of this, over the next five years the firm is increasing the number of homes receiving a discount of 45% or more on their bill to 182,000 homes.

“We appreciate the impact the bill increases from the Final Determination will have for our customers, and stand ready to work with all of our regulators on ways to best manage any further increases that may follow the CMA process,” the company said.