Increasing connectivity and resilience to provide Greater Dublin with a reliable and sustainable water supply

Leixlip and Saggart Strategic Watermain Link - Concept to Handover Services

With this strategic watermain link between Leixlip and Saggart, Uisce Éireann aimed to increase connectivity, improve resilience, and provide a reliable and sustainable water supply to water users in Greater Dublin.

Our services included initial concept and feasibility studies, through to handover of the commissioned assets including approximately seven kilometres (four miles) of 1.2-metre (3.9-foot) diameter pipeline and pumping capacity of 40 megalitres per day (11 million gallons per day). We also provided comprehensive site management, supervision, and stakeholder consultation services for the duration of the project.

One of our greatest civil design challenges involved the crossing of the N7 road at a location with six live carriageways. Following an extensive assessment of the crossing point options, we identified an optimum crossing location that required installation by means of micro-tunnelling under the N7 and adjacent properties. We developed micro-tunnelling slurry recycling measures to reduce the environmental impacts of the process and set out requirements and constraints during construction for the disposal of surplus excavated materials off-site.

Accompanying works for this project included design for scouring of the pipeline since no discharge to the environment along the pipeline route was permitted. Our design solution for this constraint provided the additional benefit of greater flexibility, allowing the pipeline to also supply in the reverse direction, thereby increasing the utility of the infrastructure installed.

The project was completed six months ahead of schedule and with no impact on water supply to over one million customers. Today it results in Greater Dublin benefitting from increased connectivity, improved resilience, and a reliable and sustainable water supply.