Uisce Éireann has completed deep cleaning works at 13 treated water reservoirs across Louth as part of a major maintenance programme aimed at protecting drinking water quality and improving the resilience of the county’s water supply. Work is continuing at a further 17 reservoirs, with the full programme expected to be completed by October.
This complex work is underpinned by detailed planning and a phased delivery approach that ensures customers continue to receive a continuous water supply throughout the works rather than taking reservoirs offline abruptly. Treated reservoir levels are carefully reduced through normal customer usage before specialist crews carry out intensive cleaning, inspection and disinfection works
Peter Liggett, Project Manager with Uisce Éireann, highlighted the precision and coordination involved. “Our customers are at the forefront of this programme, and a phased approach has been carefully planned throughout the eight-month delivery period. Significant planning is required for each reservoir, including carefully sequencing activities, scheduling works during off-peak demand, and managing network flows to allow supply to be supported from alternative zones where needed. In instances where interruptions are unavoidable, works are carried out at night to minimise impact on customers.”
A standout example of this approach in action is the recent deep clean of the Donore treated water reservoir. Although located across the border in Meath, it is a critical asset supplying Drogheda. This twin-cell treated reservoir plays a vital role in meeting the area’s high-water demand, supplying approximately 65,000 litres per hour. Each reservoir measures 32.2 metres in diameter and 6.5 metres in height. Together, they have a combined capacity exceeding two Olympic-sized swimming pools.
The first treated reservoir was gradually drawn down through normal customer demand, enabling specialist crews to remove naturally occurring sediment using advanced jet‑vac equipment. Cleaning, inspection and disinfection were completed within four hours, while the second reservoir remained fully operational—ensuring uninterrupted supply to customers.
Once complete, the cleaned reservoir was carefully refilled over a controlled period before the team switched focus to the second reservoir, repeating the same efficient process.
The treated water reservoirs at Ardee–Blakestown and Tullyallen have both recently been cleaned as part of this programme.
James O’Hagan, Water Network Operations Manager said: “While reservoir cleaning works are progressing at pace, customers may experience occasional short-term discolouration as network conditions adjust. This is temporary and typically resolves once normal network flows stabilise.”
Delivering this programme at scale requires careful coordination—balancing supply, timing and system recovery—while ensuring each reservoir is returned to service safely and effectively. Safety remains central to all operations. Reservoir cleaning involves confined space entry and is carried out under strict health, safety and environmental protocols, ensuring crews can carry out this essential work safely and responsibly.
Looking ahead, the Reservoir Cleaning Programme continues to gather pace. Throughout July, works will focus on multiple tanks and reservoirs within the Cavanhill Water Treatment Plant. Upon completion of these works, the programme will move to the reservoirs serving Termonfeckin and Clogherhead before progressing north to all active reservoirs across the Collon, Ardee and Cooley water supply networks.
The programme is scheduled for completion by late October 2026 and will ensure that all active reservoirs across the county have been cleaned and inspected. This phased approach will support the continued delivery of high-quality drinking water while maintaining the highest standards of water quality, operational resilience and regulatory compliance. As the programme advances, Uisce Éireann is delivering a step-change in how reservoirs are maintained—taking proactive action to protect water quality, strengthen network resilience and support growing communities now and into the future.
Uisce Éireann is responsible for delivering public drinking water and wastewater services for the people of Ireland. We are committed to enabling communities to thrive by continuously upgrading and developing critical infrastructure to support sustainable growth and development, providing safe drinking water, and enhancing the environment.
To find out more, visit www.water.ie.
