Plans lodged for Welsh Water’s biggest-ever project

Plans have gone in for Welsh Water’s £600m overhaul of water treatment infrastructure serving more than 400,000 properties across south Wales.

The Cwm Taf scheme is the biggest infrastructure project in the company’s history and will 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 starting 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, alongside 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.

Together, the projects will allow the existing Pontsticill and Cantref treatment works to be retired as maintenance becomes increasingly difficult and costly.

Planning applications have been submitted to Merthyr Tydfil County Borough Council and Bannau Brycheiniog National Park Authority.

Welsh Water is also calling suppliers to a major engagement event at ICC Wales in Newport on 10 November to explore work opportunities with delivery partners and the wider supply chain.

Earlier market engagement outlined a 25-year contract for a competitively appointed provider, with a delivery partner appointment targeted for August 2028. That timetable envisaged regulatory completion in March 2032 followed by 12 months of testing.

The latest announcement describes the investment as £600m, against the £667m figure used at the earlier market engagement stage.

Welsh Water chief executive Roch Cheroux said: “As a company we need to deliver this critically important infrastructure for the benefit of our customers. The effects of climate change are already being realised in Wales, with extreme weather bringing more frequent storms and heatwaves, all increasing the pressure on our ageing water treatment assets.”

The revised plans follow community consultation and include green roofs, habitat improvements and greater use of previously developed land at existing sites.

Plans lodged for Welsh Water’s biggest-ever project | Construction Enquirer News