Pengarnddu Service Reservoir, Merthyr Tydfil


Pengarnddu Service Reservoir plays an important part in supplying fresh clean water to people in south Wales. To make sure we continue to provide our customers with a first-class supply of drinking water every time you open the tap, we have recently completed a £9 million investment project to upgrade the water storage at this site.

This investment project involved building a brand new service reservoir on the land adjacent to the existing service reservoir. By doing this, we are now able to store an additional 9 megaliters of treated drinking water – that’s the equivalent to three and a half Olympic swimming pools! This additional water storage and help reduce the chance of loss of supply in Merthyr Tydfil and the surrounding areas.

The work got underway during the Spring 2021 and took around two years to complete. It involved:

  • Constructing a partially buried service reservoir of 61m x 50m within the landscape.
  • New pipework to connect the new reservoir into the existing water supply network.
  • Building a one-storey valve house to provide operational access to supply pipework and valves.
  • Creating footpaths to provide operational access to the new reservoir and surrounding chambers.
  • Extending the site access track.
  • Replacing part of the existing site boundary with new, secure fencing.
  • Constructing a new control centre located inside a kiosk, adjacent to the existing reservoir.
  • Reinstating the land around the new reservoir to mirror the grassland of the existing site.

To ensure the brand-new reservoir blends in with its surrounding, our team will be carrying out some reinstatement work throughout the year.