Dŵr Cymru Welsh Water lodged planning applications in late October 2026 for its £600 million Cwm Taf Water Supply Strategy, and expects to start procurement in early 2027. The cost is down from the £667 million used at the earlier market engagement stage.
What is being built
The scheme centres on a new water treatment works at Dan-y-Castell near Merthyr Tydfil and an upgrade of the Llwyn-onn works in the Bannau Brycheiniog National Park, with treated-water storage and pipelines. It is planned to replace the Pontsticill and Cantref works and to serve more than 400,000 properties in south Wales. Applications went to Merthyr Tydfil County Borough Council and the Bannau Brycheiniog National Park Authority.
A competitive, long-term contract
The project is to be procured under Ofwat's Direct Procurement for Customers model. Earlier market engagement envisaged a 25-year contract with a competitively appointed provider, a delivery partner appointment targeted for August 2028, and regulatory completion in March 2032 followed by 12 months of testing. Those dates have not been reconfirmed since the cost was revised.
Why the timing matters
The scheme arrives while the company is under pressure to deliver. Ofwat said in August 2026 that Dŵr Cymru Welsh Water had not shown it remains on track for its 2025-30 commitments, and the company met 6 of 23 Ofwat performance targets in 2025-26. Its 2025-30 settlement includes a £6.0 billion total expenditure allowance, and the company plans £4.2 billion of capital investment over the period.
Which AMP8 frameworks already hold the company's capital and network work, how it buys outside them, and which other schemes suppliers should target first are covered in the full brief. The full report, Dŵr Cymru Welsh Water: Utility Account Brief, is available for USD 499. For a free overview, read the Dŵr Cymru Welsh Water Utility Snapshot.