Welsh Water has lodged plans for the Cwm Taf scheme, which the company says is the biggest infrastructure project in its history. The programme is intended to replace ageing treatment assets that have served the region for more than a century.
Contractors and investors are already being sounded out ahead of procurement, which is due to start in early 2027 under Ofwat’s Direct Procurement for Customers model.
The main construction package centres on a new water treatment works at Dan-y-Castell Farm near Merthyr Tydfil. It also covers treated water storage, a new pumping station at Pontsticill and connecting pipelines.
A second project will upgrade Llwyn-onn Water Treatment Works in the Bannau Brycheiniog National Park, adding water storage and pipeline connections.
Two linked workstreams
The proposals therefore cover both new-build treatment infrastructure near Merthyr Tydfil and an upgrade to an existing treatment site in the national park. Across the two elements, the scope includes treatment works, storage, pumping and pipeline connections.
The Cwm Taf scheme is being positioned as a replacement for long-serving assets, with market engagement taking place before the procurement process begins. The plans mark the latest stage in preparing the programme for delivery.