Welsh Water Pontsticill Reservoir

  • Client: Welsh Water
  • Date: Monday, 01 September 2014
  • Info: Water supply reservoir

Welsh Water Pontsticill Reservoir, Wales. Welsh Water installs first ResMix 5000cc Source Management System at the Pontsticill Reservoir to improve water quality prior to treatment works.


Gurney Environmental accomplished an additional “First” for the WEARS Australia ResMix “Source Management” System with the first Northern Hemisphere installation of the 5000cc for Welsh Water, the first ResMix system for the Water Company.

This is the first application of the ResMix 5000cc in the Northern Hemisphere. The ResMix 5000cc is a sustainable, low energy system for reservoir “Source Management” providing water quality improvements and maintenance, but using only 10 kW of energy to influence very large water bodies.

The ResMix 5000cc consists of two counter rotating, surface-mounted, large axial mixers, each with 5 m diameter impellers. The units are able to transfer 20 tonnes of water from the surface to the bottom of a reservoir every second. This significant transfer of surface water not only evens out water temperature, preventing thermal stratification, but also increases net dissolved oxygen levels throughout the water column of the reservoir, thereby addressing many water quality issues.

This is also the first ResMix system for Welsh Water, having been selected after a 4 year evaluation of options for reservoir management by Welsh Water and their consultants, Black and Veatch. Welsh Water now join a growing list of ResMix users Worldwide.


  • Pontsticill reservoir, located in the Brecon Beacons, north of Merthyr Tydfil
  • Holds more than 15 billion litres of water
  • Serves 106,000-plus customers in the Merthyr area and other parts of the south Wales valleys.


Welsh Water’s capital delivery manager for south-east Wales said: “We are very pleased to be using this innovative management system in the reservoir at Pontsticill. This investment will improve the water quality for customers in the area and ensure they continue to receive a top quality supply of drinking water long into the future.”

The project was fast tracked for installation in August 2014. Gurney Environmental, WEARS Australia and Welsh Water worked together to streamline the procurement and delivery process so that this could be achieved.

For further information on this project or the WEARS systems, please CONTACT US.




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Video of Helicopter Installation of Units


Welsh Water Feature Story and Video on Their Website

Welsh Water is featuring a web article with video on the 2014 installation of the ResMix 5000cc Source Management system by Gurney Environmental at the Pontsticill Reservoir in Wales.

From the story, "At Pontsticill reservoir a new ‘res mix’ solution has been introduced to improve water quality – the first time this solution has been used outside of Australia. Using low energy the system moves 20,000 litres of water a second and has been very successful. This is all part of the £1.5m investment in the reservoir to protect customers water supply."

Read the story and view the video here: WELSH WATER WEB STORY