New equity to fund record AMP8 investment programme

Southern Water has secured additional equity investment to fund its ambitious £6bn investment programme over 5 years.

This investment programme includes, amongst other things,  the complete rebuilding of our 5 largest water treatment plants, new nutrient treatment at 40% of all treatment plants to improve river quality treatment plants, new water supply and resilience measures including the new reservoir being constructed with Portsmouth Water and 5 new water recycling plants, and overflow reductions at 170 sites. 

Overall, this will provide additional capacity and resilience in response to new legislation and regulatory targets and to support forecast population growth, as well as improvement in services for customers.

Funds managed by Macquarie Asset Management have committed a further £245m of equity, taking the equity committed by our shareholder since July 2025 to £900m, and the total invested since its entry in 2021 to £2.55bn. Over that period, no dividend has been paid -- and none will be paid before 2030.

The £900m equity commitment is unconditional and is expected to be fully drawn by 30 June 2026.

Funds managed by Macquarie Asset Management have also reconfirmed their intention to provide up to a further £300m of binding equity commitments by June 2026.

Southern Water CEO, Lawrence Gosden, said: "We are pleased to have confirmation of £245 million of incremental equity support from funds managed by Macquarie Asset Management.

"This support is vital for us to meet the needs of our customers, the environment and meet new legislative requirements. It enables our largest ever investment programme, including more than £6 billion of growth investment in the 2025-30 AMP8 period, to reduce overflows, meet new environmental standards on river quality, re-build aging water plants and provide additional capacity and resilience."

The incremental £245 million equity commitment takes our shareholders’ total investment in the Southern Water group since 2021 to over £2.5 billion.

The full announcement is available here.