The Cwm Taf Scheme will be split across two sites and will be delivered using the new design, build and finance route agreed by the water regulator.

The plan involves a new water treatment works at Dan-y-Castell Farm near Merthyr with a raw water pumping station at Pontsticill worth around £362m, and a £194m upgrade of the existing Llwyn-onn water treatment works in the Bannau Brycheiniog National Park.

Proposed Dan-y-Castell water treatment works

The scheme will be procured through a competitively appointed provider under a 25-year contract term.

Welsh Water is aiming to appoint a delivery partner in August 2028, with regulatory completion expected in March 2032 followed by 12 months of testing.

The utility is seeking responses from contractors, designers, engineers and infrastructure investors to help shape procurement, risk allocation, and financing. Engagement runs until 22 September.

More details on the projects can be found here.

To register and participate in the market engagement process email Welsh Water.