Programme overview
As the national body responsible for the country’s gas network, we are occasionally required to facilitate diversions of the gas pipeline to support major new public and private infrastructure developments, deemed to be of significant economic and/or social value.
In 2025, we completed a diversion of the Cork to Dublin transmission (high pressure) pipeline on behalf of Irish Distillers Limited (IDL). This customer is undertaking a major expansion of their distillery in Midleton Co Cork so that they can increase production capacity.
IDL requested a diversion of the pipeline to facilitate their development, which involved re-routing a section of the national gas pipeline around the perimeter of the development site.
Working with our project partner, Murphy, we decommissioned an existing section of the Dublin to Cork gas pipeline and a new 675m pipeline was constructed around the edge of the site, connecting in at the northern and southern ends.
‘Stopples’ were required at the two new connection points; this is a process where temporary equipment and valves are used to isolate the flowing gas so that modifications can be made to the existing pipeline without shutting down the entire system. This also meant that customers in the area did not have their gas supply interrupted.
Project highlights
Works on the IDL diversion project commenced on site in September 2024 and were completed in April 2025. Project features included:
- 425m of 70 bar (high pressure) Transmission pipeline decommissioned
- 675m of new heavy wall Transmission pipeline installed underground
- Stopple operations completed at northern and southern sections of decommissioned pipe to attach new pipeline without turning off the gas supply
- Testing and commissioning of new equipment
- Reinstatement works following construction
All these works were carried out while also maintaining supply to the downstream network, ensuring citizens and businesses in the area did not suffer interruptions to their gas supply.
Environment and planning
This project – referred to as the “Cork-Dublin Pipeline Diversion - was granted a Section 39A Consent (“Consent”) from the Commission for Regulation of Utilities (CRU) on 12 September 2024 following technical and environmental review. An Appropriate Assessment (AA) Screening Report was completed for the construction of the pipeline diversion to determine whether the proposed works were likely to have significant effects on designated European sites. An Environmental Impact Assessment Screening Report (EIAR) was also completed for the construction of the pipeline diversion to determine whether the proposed works were likely to have significant effects on the environment. The Consent documents including all environmental reports are available to view at: https://www.cru.ie.
What is a Pipeline Diversion?
Transmission pipeline diversion projects are required when a third party needs to complete construction or developmental works over land where gas pipelines are located. This involves Gas Networks Ireland moving or altering the gas pipeline route so that it is safe to proceed with construction.
The requestors can be public or private organisations and this work is key to supporting economic and social progress because the works are generally linked to new national or commercial infrastructure projects such as factories or motorways.
Timelines on these projects are usually critical to avoid delivery delays. These projects are entirely funded by the third party.