Dŵr Cymru Welsh Water has announced the next stage of its Cwm Taf Water Supply Strategy signalling intent to push forward the largest infrastructure investment in the firm’s history.

The major investment of over £500M will modernise drinking water services across South Wales by replacing ageing water treatment facilities, increasing water storage capacity and strengthening the resilience of supplies.

As the project is now being progressed to the next stage, Welsh Water has invited infrastructure investors, lenders and engineering partners to help shape the commercial and procurement approach before formal procurement begins.

As part of the strategy, proposals include:

The market engagement programme, managed by Efficio Consulting, will take place in two phases.

Its first stage will involve targeted discussions with investors and lenders to test the project’s affordability.

The second phase will broaden engagement to include Tier 1 delivery partners to validate the proposed commercial and procurement models.

Welsh Water believes the engagement will help refine the procurement approach before key governance decisions are taken and ahead of procurement commencing in early 2027.

Following statutory pre-application consultation undertaken in 2025, Welsh Water expects to submit planning applications for the projects under the programme later this year.

This new market engagement programme will help ensure the project benefits from the “strongest possible commercial arrangements, attracts world-class expertise and delivers long-term value for customers, communities and the environment,” Welsh Water said.

Welsh Water interim chief asset officer Ruud Haket said: “The Cwm Taf Water Supply Strategy is a once-in-a-generation investment that will secure resilient drinking water supplies for South Wales for decades to come.

“We’re looking to work with organisations that share our ambition to deliver high-quality infrastructure that benefits our customers, supports our communities and protects the environment.”

He added: “This market engagement is an important first step in building those partnerships and ensuring we develop a delivery model that attracts the very best expertise and investment available.”

The Cwm Taf Water Supply Strategy was identified through Welsh Water’s Water Resources Management Plan.

When formal procurement for partners in the programme begins, it will be done under Ofwat’s Direct Procurement for Customers (DPC) model.

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