FAQs
The Greater Dublin Drainage (GDD) Project is one of the largest and most critical wastewater infrastructure projects in Ireland’s history. It is a once-in-a-generation project that will protect public health, safeguard our environment, and facilitate growth to 2050 and beyond.
It includes a new regional wastewater treatment facility and sludge hub centre on a 30-hectare site at Clonshaugh (Clonshagh) and an underground orbital sewer from Blanchardstown to Clonshaugh including a new pumping station at Abbotstown.
Once operational, the GDD Project will have the capacity to provide wastewater treatment for the equivalent of half a million people living and working in this area,supporting housing delivery for up to approximately 185,000 homes.
This will greatly enhance the housing development potential in Dublin, Meath, Louth and parts of Kildare and Wicklow by providing new infrastructure that will alleviate pressure within the existing wastewater network.
Adequate wastewater collection and treatment capacity in the Greater Dublin Area (GDA) is essential to protect public health, safeguard the environment, and support sustainable social and economic growth - including the delivery of new housing.
The GDA continues to experience rapid population and economic growth. This is driving significant increases in wastewater volumes and placing sustained pressure on existing infrastructure.
Current projections show that wastewater generation in the region is expected to increase by over 50% by 2050, reflecting continued population and employment growth across the area.
The Greater Dublin Drainage Project will provide wastewater capacity for the equivalent of half a million people within the Greater Dublin Area. This will enable the treatment of wastewater arising in Fingal (areas from Blanchardstown to Clonshagh (Clonshaugh) including from the Dublin Airport Zone), from northern parts of Dublin City, from south-east Meath and from north-east Kildare.
The project will also reduce pressure on existing wastewater treatment plants such as Ringsend, releasing critical treatment and network capacity, and helping Ireland meet national and EU environmental standards.
The Greater Dublin Drainage Project includes the construction of a new regional wastewater treatment facility and sludge hub centre on a 30-hectare site at Clonshaugh (Clonshagh) and a 14km underground orbital sewer from Blanchardstown to Clonshaugh including a new pumping station at Abbotstown.
It also involved the construction of a sewer to divert part of the North Fringe Sewer to the new treatment facility, as well as an outfall pipe 11km from the wastewater treatment facility which will discharge the treated water to the Irish Sea.
The Greater Dublin Drainage (GDD) Project is one of the largest and most critical wastewater infrastructure projects in Ireland’s history. This once-in-a-generation project will:
Safeguard public health
The project is part of Uisce Éireann’s work to ensure that the wastewater generated every day in our homes, schools, and workplaces continues to receive the proper treatment – safeguarding public health and enabling our communities to thrive.
Protect our environment
The project is key to unlocking the wastewater capacity constraints within the Greater Dublin Area, helping Ireland meet national and EU environmental standards by protecting our environment and ensuring cleaner water for fish, wildlife, and everyone who uses Dublin Bay.
- Support the demand for new housing
Once operational, the GDD will have the capacity to provide wastewater treatment for the equivalent of half a million people living and working in this area and the capacity to support up to the equivalent of 185,000 homes.
- Meet the needs of key growth areas in the Greater Dublin Area
It will provide the wastewater treatment and network capacity required in the medium and long term in areas including Leixlip, Blanchardstown, Clonee, Dunboyne, Ashbourne, and Ratoath.
- Enable economic growth
Delivery of water and wastewater infrastructure and services underpin Project Ireland 2040 and are the backbone to supporting sustainable development and economic growth.
The Greater Dublin Drainage (GDD) project is a key piece of national infrastructure identified under Project Ireland 2040 and the National Development Plan to support sustainable growth and housing delivery in the Greater Dublin Area. The detailed project business case has been approved by Uisce Éireann and brought before Cabinet by Minister for Department of Housing, Local Government and Heritage James Browne TD, enabling it to proceed to procurement and early delivery.
Preparatory activities on the Greater Dublin Drainage Project are now underway. Construction on the project will commence by the end of 2026, with main construction works starting in 2028 and completion scheduled for 2032.
All works will be carried out in phases to minimise disruption. Uisce Éireann has appointed a dedicated Community Liaison Officer (CLO) who will be engaging directly with impacted communities and stakeholders as this project progresses.
All works will be carried out in phases to minimise disruption. Uisce Éireann has appointed a dedicated Community Liaison Officer (CLO) who will be engaging directly with impacted communities and stakeholders as the project progresses.
Uisce Éireann recently completed a €550 million upgrade of the Ringsend Wastewater Treatment Plant (WWTP), the largest wastewater treatment project ever undertaken in Ireland and a major milestone for the Greater Dublin Area.
This upgrade is a central component of the wastewater strategy for the Greater Dublin Area. As the region continues to expand, the Greater Dublin Drainage (GDD) project will provide additional treatment capacity and network resilience. Together, these investments support:
- Continued housing delivery
- Economic development
- Environmental protection
- A resilient wastewater network
Uisce Éireann is working to ensure that the wastewater generated every day in our homes, schools and workplaces continues to receive the proper treatment - supporting the sustainable growth of our communities and protecting our environment.
The Greater Dublin Drainage Project is the key to unlocking the wastewater capacity constraints within the Greater Dublin Drainage through the transfer of loads from the north and west of the catchment to the new GDD Wastewater Treatment Plant and resultant release of capacity at Ringsend for growth in the remaining areas of the Ringsend catchment.
Meeting wastewater demand and maintaining compliance in the Greater Dublin Area pending the delivery of GDD remains a challenge. We are working to upgrade all of our wastewater treatment plants to their maximum capacities. This includes recently completed the €550 million investment in the upgrade Ringsend WWTP, to provide treatment for the population equivalent of 2.4 million.
Key network upgrades and interventions are also being progressed across the Greater Dublin Area to maximise the capacity of the existing network. Uisce Éireann is investing a further €150 million between 2022 and 2030 to deliver these tactical interventions.
These interventions are necessary to maintain service but will neither provide the resilience needed or cater for economic and population growth in the long term.
The planning application and Further Information, along with other material on the GDD Project, may be viewed or downloaded from www.gddapplication.ie.
Hard copies of the planning application and Further Information are available for inspection free.
An Environmental Impact Assessment Report (EIAR) is an analysis of the likely effects that a proposed development may have on the environment. This includes any likely effects on people, flora, fauna, soil, water, air, landscape and cultural heritage. The EIAR also includes a non-technical summary.
The EIAR is prepared by the project developer, Uisce Éireann in this case, to inform the Environmental Impact Assessment (EIA) process and is submitted to the planning authority for evaluation along with the planning application documents.
Changes to the baseline environment and the requirement for updated surveys have been considered in the Further Information submitted to the Board to ensure the EIAR is up-to-date, accurate and robust.
Amendments to the original EIAR submitted in 2018 can be viewed alongside the Further Information submitted here.
The Environmental Impact Assessment Report can be viewed at www.gddapplication.ie. The planning, statutory and environmental documents are available to view and download from this website.
Yes. A community benefit scheme for the Greater Dublin Drainage project is proposed in order to leverage and maximise benefits for local communities in proximity to the proposed infrastructure. The scheme will deliver benefits under three main themes: Employment, Education and Environment.
The GDD Community Benefits Scheme forms part of the planning documentation at www.gddapplication.ie.
Uisce Éireann submitted a planning application for the Greater Dublin Drainage (GDD) Project to An Bord Pleanála in June 2018 under the Strategic Infrastructure Development Act, accompanied by an Environmental Impact Assessment Report (EIAR), Natura Impact Statement (NIS) and a Compulsory Purchase Order (CPO). Following public consultation and an oral hearing, planning permission was granted and the CPO was confirmed in November 2019.
The planning permission was subsequently quashed by the High Court, and the application was remitted to An Bord Pleanála in July 2021 for a fresh decision. In August 2022, Uisce Éireann was invited to update its environmental assessments where needed. Uisce Éireann reviewed and updated its environmental assessments where appropriate, to reflect changes in the baseline environment, updated surveys, and current planning and environmental guidance.
This Further Information was submitted in October 2023, followed by public consultation in summer 2024. An Coimisiún Pleanála granted planning permission for the project in June 2025. This was subject to a further Judicial review which was settled in December 2025, enabling the project to proceed.
Separately, as part of the overall consenting process, in December 2024 Uisce Éireann applied to the EPA for a wastewater discharge licence for the North Dublin Agglomeration. The licence is a critical requirement to enable delivery of the GDD Project.
A WWDL (or wastewater discharge licence) is required to authorise the discharge of treated wastewater from the new Greater Dublin Drainage wastewater treatment plant into the marine environment.
All wastewater discharges from Uisce Éireann facilities require a wastewater discharge licence (WWDL) from the Environmental Protection Agency (EPA). This licence is necessary to ensure compliance with Irish and EU legislation that regulate for the safe disposal of treated wastewater into the environment. This supports the GDD Project’s aims of protecting public health and safeguarding the environment.
As part of the overall GDD Project consenting process, Uisce Éireann applied to the EPA for a WWDL for the proposed catchment area to be served by the GDD Project. The proposed catchment is called the North Dublin Agglomeration. The WWDL application for the GDD Project covers the discharge of treated effluent at the proposed discharge location, 1 km north-east of Ireland’s Eye, along with assessments of the existing network, including existing stormwater and emergency overflows.
The EPA’s assessment of the WWDL application is separate from and in addition to the planning process.
Given the scale of the GDD Project and its significant catchment area, the application for a WWDL is supported by a full environmental impact assessment report (EIAR).
Preventative design, monitoring and incident response measures have also been embedded into the project design to mitigate against unintended discharges into the environment.
All documentation in respect of the WWDL application is available on the EPA website. Interested parties may submit written observations or submissions in relation to the application for the WWDL licence or the accompanying EIAR to the EPA via its website, or at its headquarters at P.O. Box 3000, Johnstown Castle Estate, Co. Wexford.
Uisce Éireann has reviewed and considered more than 34,500 submissions which have been made to the GDD project team since 2011.
As part of the planning documentation, Uisce Éireann published the GDD Public and Stakeholder Participation Report which documents the previous consultations and engagement and how public feedback has informed the development of the GDD project.
Uisce Éireann wishes to thank the individuals and organisations that have engaged with the GDD project to date. The GDD Public and Stakeholder Participation Report is available to view with the planning documentation and online at www.gddapplication.ie.
We are preparing for the commencement of access works on the project, ahead of preliminary construction works which are set to take place later this year.
These access works will involve carrying out archaeology studies, constructing access and haulage roads, and installing hoarding and fencing. These works will take place over the summer months.
We will also be carrying out marine site investigations at Portmarnock.
Construction on the project will commence by the end of 2026, with main construction works starting in 2028 and completion scheduled for 2032.
All works will be carried out in phases to minimise disruption. Uisce Éireann has appointed a dedicated Community Liaison Officer (CLO) who will be engaging directly with impacted communities and stakeholders as this project progresses.
We would like to thank the community in advance for their cooperation during this critical project. For more information, news and updates please visit the dedicated project page here.
Uisce Éireann is committed to working closely with local communities and stakeholders throughout delivery of the Greater Dublin Drainage Project to minimise disruption and keep people informed.
This engagement will include:
- Early and regular communication with residents, businesses, local representatives and community groups about upcoming works and timelines
- A dedicated Community Liaison Officer (CLO) as a direct point of contact for communities, providing timely information and responding to queries or concerns
- Phased construction planning to reduce disruption, manage traffic impacts and avoid sensitive periods where possible
- Advance notice of works, including details on access, traffic management and working hours
- Ongoing coordination with local authorities and emergency services
- A commitment to leave a positive and lasting legacy, including local employment opportunities and community benefits where feasible
Uisce Éireann recognises that major infrastructure projects can cause disruption and will continue to engage openly with communities to ensure impacts are minimised and managed appropriately throughout construction.
If you have a question or wish to register for updates on the project, please email the project team at greaterdublindrainage@water.ie.
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