Ballymore Eustace Water Treatment Plant to Saggart Reservoir Resilience Project
Background
Ballymore Eustace (BME) is the largest water treatment plant (WTP) in Ireland and produces drinking water for about half the people living in the Greater Dublin Area (GDA), including parts of Kildare and Wicklow. This treated water is delivered through two pipelines to Saggart Reservoir.
These two pipelines are gravity trunk mains. The first was constructed in 1940 and is 24km long and 1.27m in diameter, supplying 60 million litres of water water per day. The second pipeline was constructed in 1982 and is 26km long and 1.6m in diameter, supplying 220 million litres of water per day.
The GDA Water Resource Zone (WRZ) supplies approximately 600 million litres of clean drinking water per day to 1.7 million customers.
Almost half of the water required for the GDA WRZ is supplied from Ballymore Eustace Water Treatment Plant through the two pipelines to Saggart Reservoir.
Project Overview
Uisce Éireann is designing and planning solutions to address the issues along the two pipelines connecting Ballymore Eustace Water Treatment Plant to Saggart Reservoir.
It is a complex project as both pipelines supply water across the Greater Dublin Area including to homes, businesses, hospitals, schools and farms. Taking either pipeline out of service to carry out remedial works would significantly impact the drinking water supply to 1.7 million people across Dublin, Kildare and Wicklow.
Uisce Éireann will commence site surveys in the coming months. We expect to be in a position to share our shortlist of options with landowners and the public towards the end of 2025.
Study Area
Why is this project needed?
The two pipelines are at high risk of unplanned water outages and bursts. If either pipeline was to fail it would likely result in water supply interruptions for up to 814,000 customers for 3 to 7 days.
Critical repairs were carried out on the 1.6m diameter pipeline in August 2024 and August 2025. You can read more about these works here.
Project Benefits
When complete, this project will:
What’s happening now?
We have selected the study area and are currently assessing the different options for this project. As part of this process, we held an in-person landowner engagement event in February 2025 in Punchestown Racecourse Kildare.
We have appointed a contractor to carry out site investigation works. Priority Geotechnical Limited will be working on our behalf. Works are due to commence in late October 2025 and all landowners are being notified.
Further information for Landowners
