East City Arterial Water Main Replacement Project

The Merrion Gates to Ringsend Park Trunk Main Rehabilitation project involves the construction of 3.15km of new trunk water main. The new water main will replace the existing main which is unable to function at its design capacity. This trunk water main is a critical supply transfer main enabling transfer of drinking water between the existing reservoirs in Stillorgan, Cookstown and Ballycoolen.

Primary: In its current condition the main is losing approximately 500,000-1,000,000 litres of water a day which is enough to supply the average daily use for 1,450 – 2,900 houses. The trunk main will greatly improve security of supply in the immediate area with a reduced risk of network interruptions and disruption and cost relating to repairs on its completion.

Secondary: This trunk main is the primary supply to new developments in the North Lotts and Grand Canal Dock Strategic Development Zone, and the Poolbeg West Planning Scheme that has planning for between 3,000 and 3,500 units. It is estimated this main will need to deliver supply to up 31,000 residential units when potential inner-city development is realised. Its function is critical to growth and development in the eastern area of Dublin city. Currently, the existing trunk water main cannot function at its design capacity.  The new main will also allow cross transfer to the Anglesea Road area in the case of supply issues elsewhere thus increasing the resilience of the supply in the local area and Dublin city water supply network. 

Rehabilitation works on the East City Arterial Main commenced in early September 2022 and completion of the works is expected in Summer 2023.

As a result of site investigation work and subsequent design it is anticipated that most of the works can be completed by a method known as slip lining. Slip lining involves the insertion of a new pipe into an existing pipe and restores structural stability.  Slip lining is advantageous compared to traditional open cut methods in that it reduces excavation noise with only entrance and exit pits required at several locations on the pipeline route. This construction method will also greatly reduce the project duration and overall cost with reduced excavation, material removal and complex routing requirements.  As the project area is traversed by a high number of services, design, route selection and excavation associated with the pipe rehabilitation would present issues for an entirely open cut installation methodology. 

When compared to traditional open cut (trenching) methods, slip lining is advantageous by requiring less excavation, cutting and removal of debris. Dust and debris are therefore much reduced, and removal of material also reduced lowering the overall project impact, including less truck movements to and from the site.

No major supply interruptions are expected because of the planned works. There is sufficient water network control to allow for only small shutdowns and back feeding of supply from other areas to allow the slip lining method to be used. 

We will be communicating in more detail the phasing of works to the residents in the area as the works progress and traffic management phasing changes.

An entry pit for the slip lining technology and other project works are required at Ringsend Park. In order to undertake this work safely and efficiently the removal of a number of trees is required as the trees are positioned above the existing pipeline. These trees have been assessed by an arborist and we commit to replacing them where possible to mitigate the loss of existing vegetation and this will be in agreement with Dublin City Council Parks department.  Planting and reinstating will be carried out on completion of this section of works.

As with all complex civil engineering contracts of this scale, delivery and completion of certain elements of work are dependent on a variety of factors project wide including temporary traffic management schemes.

Following a full review of latest site conditions and traffic management plans with input from consultees including An Gardai Síochána and Dublin City Council new traffic management measures will now be introduced to deliver the remainder of the project. This will expediate necessary elements of the works and ensure project roads are open at the earliest opportunity, thereby improving traffic flows and reducing congestion on local roads.

Local access will continue to be maintained and for all phases of works a short local diversion for residents of the area requiring access to Beach Road and Strand Road and environs will be in place.

In first week of January 2023 under new traffic management plan , Beach Road and Strand Road will be limited to southbound traffic, with northbound traffic following signposted diversions. There will be no northbound access onto Beach Road and Strand Road from Merrion Gates.

Sandymount strand carparks opening hours and access to the strand will not be affected by the works. Vehicular access will be by the advertised diversion route on approach.

The ECAM project is aligned with Uisce Éireann’s sustainability goals including lowering the carbon footprint and reducing the amount of subsurface material removed and disposed of.

The footprint of the works is drastically reduced as slip lining techniques require entrance and exit pits at intervals rather than one continuous excavation of the works route. Less excavation reduces:

• Excavation requirements
• Construction noise
• Dust
• Waste disposal
• Truck movements required

Any waste/spoil generated will be handled in accordance with the GMC Waste Management Plan. Reducing the leakage currently associated with this main will have secondary environmental benefits.

The project has undergone Appropriate Assessment Screening according to the requirements of the EU Habitats Directive. The screening report indicated that the requirement to progress to Stage II Appropriate Assessment was not required due to:

• Nature and scale of the proposed works
• The works taking place entirely within an existing road footprint and in an already busy urban setting.
• The lack of hydrological connectivity to sensitive ecological receptors within the designated sites.
• The nature of the qualifying interests of the designated sites.

Additionally:

• Pipeline is 3.15km long but has a very narrow footprint
• Works take place outside European sites and no land take within these sites is required (specifically two Natura 2000 sites South Dublin Bay SAC 000210 and South Dublin Bay and River Tolka Estuary SPA 004024)
• The pipeline is bunded by an existing wall separating it from the closest European site
• No abstraction or resource removal from the designated sites is required
• Emissions from the works will be contained within the existing road drainage system
• Any excavations will be within the existing road footprint

There is a requirement to replace the section of main that goes under the rail crossing at Merrion Gates. We are in detailed discussions with Irish Rail to agree the conditions of the rail crossing. This work will be complete under a full road closure in 2023. We will provide detail when all regulatory processes, timelines and methodologies are agreed. 

We have invested over €500 million between 2017 and the end of 2021 to reduce leakage and replace old pipes on the public water network. We are investing a further €250 million every year up to the end of 2030 - fixing leaks and replacing pipes to provide a more reliable water supply.

This project is one example of how we are working in partnership with Local Authorities to reduce leakage and provide a more reliable and sustainable water supply.  We are making progress. In 2018 the rate of leakage nationally was 46%, by the end of 2021 it was 38%. We are on track to achieve a national leakage rate of 25% by the end of 2030.

Should you have any queries you can contact the project team by phone on 0818 462 200 during office hours or e-mail us at ecam@water.ie. Out of hours queries can be directed to the Uisce Éireann helpline on 1800 278 278.