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 are currently progressing with detailed design on a 1600mm diameter steel pipe 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 are currently progressing with Ecology, Archaeology and Topographical Surveys and Reports. A site Investigations contractor is also on site progressing with Investigation works along the Route.
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. Further repairs are planned for the August Bank Holiday weekend 2026. You can read more about these works here.
Project Benefits
When complete, this project will:
What’s happening now?
We have identified a Route for the 1600mm diameter Steel Pipe and this route was presented to Landowners at our third in-Person Landowner event in January 2026 in Punchestown Racecource, Kildare.
A site investigation Contractor, Priority Geotechnical Limited are currently progressing through site investigation works along the Route and are due for completion in Q3 2026. Further seasonal Ecology Surveys are also progressing along the route.
Further information for Landowners
