Uisce Éireann says its county-wide Reservoir Cleaning Programme is gathering pace, delivering works designed to safeguard safe, clean drinking water and improve the resilience of the network. The plan covers 30 treated reservoirs of different sizes, from large strategic assets to smaller local tanks. To date, 13 have been completed, with the remaining 17 due to finish by October under a tightly managed timetable.

The utility is prioritising sediment removal, contamination prevention and continued compliance with drinking water standards. To avoid abrupt shutdowns, reservoir levels are eased down through normal customer use before specialist teams undertake intensive cleaning, inspection and disinfection. The phased approach is intended to maintain a continuous supply throughout.

Peter Liggett, Project Manager with Uisce Éireann, said: "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."

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A recent deep clean at the Donore treated water reservoir illustrates the approach. Although sited in County Meath, it is a key asset for Drogheda, supplying roughly 65,000 litres per hour. The twin-cell facility comprises two reservoirs, each 32.2 metres in diameter and 6.5 metres high, together holding more than two Olympic swimming pools' worth of water. One cell was gradually drawn down via everyday demand, allowing crews to remove naturally occurring sediment with advanced jet vac equipment. Cleaning, inspection and disinfection were completed within four hours while the second cell stayed online, keeping customers in supply. The cleaned cell was then carefully refilled before the team repeated the process on the second. The treated water reservoirs at Ardee–Blakestown and Tullyallen have also been cleaned under the programme.

Delivering the works at this scale requires careful sequencing, supply balancing and system recovery, with safety central to every step. Reservoir cleaning involves confined space entry and is conducted under strict health, safety and environmental protocols. Through July, activity will concentrate on multiple tanks and reservoirs at the Cavanhill Water Treatment Plant. The schedule will then move to the reservoirs serving Termonfeckin and Clogherhead, before progressing north across all active reservoirs in the Collon, Ardee and Cooley water supply networks.

The programme is expected to conclude by late October 2026, ensuring every active reservoir in the county is cleaned and inspected. The phased delivery is intended to uphold high-quality drinking water, strengthen operational resilience and maintain regulatory compliance. Uisce Éireann says the initiative marks a step-change in reservoir maintenance—taking proactive measures to protect water quality, bolster the network and support growing communities now and into the future.

Uisce Éireann provides public drinking water and wastewater services for Ireland. The organisation says it is committed to enabling communities to thrive by continually upgrading and expanding critical infrastructure to support sustainable growth, deliver safe drinking water and enhance the environment.