Project Background

The Vartry Water Supply Scheme provides drinking water for a supply area stretching from Roundwood, through north Wicklow up to south Dublin and serves over 200,000 people. It was developed by Dublin Corporation in the 1860s and includes two reservoirs, a water treatment plant, a 4km tunnel under Callowhill and 40km of trunk mains that deliver water to storage reservoirs at Stillorgan in Dublin. The scheme was a significant engineering feat, with much of the ground and building works being carried out and completed by men using only picks, shovels, horses and carts. At the time, the scheme greatly improved sanitation in Dublin City and helped reduce outbreaks of cholera, typhus and other diseases associated with contaminated water. The original Vartry Water Supply Scheme still provides drinking water to around 15% of the Greater Dublin Area.

Project Overview

Irish Water is making a significant investment in the Vartry Water Supply Scheme to ensure a safe and sustainable water supply for the north Wicklow and south Dublin areas. This investment will ensure that water provided complies with water quality standards set out in the European Union Drinking Water Directive (1) and the current, national Drinking Water Regulations (2).

(1) Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption.
(2) European Union (Drinking Water) Regulations 2014.

Irish Water is the national water utility responsible for providing and developing water services throughout Ireland.

Aerial View of the Vartry Water Treatment Plant

Established in July 2013, Irish Water brings the water and wastewater services of 31 Local Authorities together under one national service provider. This includes the transfer of responsibility for the Vartry Water Supply Scheme from Dublin City Council. Dublin City Council continues to have responsibility for the day-to-day operation of the scheme.

What is involved in this project?

The Vartry Water Supply Scheme project will involve:

  • Constructing a new Water Treatment Plant on the site of the existing plant at Vartry.
  • Constructing a 4km pipeline to secure the transfer of treated water from Vartry to Callowhill pumping station.
  • Decommissioning the existing Water Treatment Plant.
  • Decommissioning the Vartry tunnel to allow for remediation works to be carried out.
  • Replacing ageing pipes and fittings within the dam of the Vartry Reservoir.
  • Improvements to the Vartry dam spillway to allow for more intense rainfall events resulting in larger spills from the reservoir to ensure public safety.

It is important to note that the works are focused on securing the existing supply for customers, no additional water will be abstracted from the Vartry reservoirs or catchment area.

Irish Water has also committed to release sustainable freshwater flows to the River Vartry downstream from the new Water Treatment Plant.  This protection is especially important at times of drought. The freshwater flows will come directly from the existing Vartry reservoir and is in addition to the natural flows from groundwater, other tributaries in the catchment and from the reservoir itself when the water levels are high.

This will be the first time in the 150 year operation of the Vartry Water Treatment Plant that such a guarantee will be used to safeguard the ecology of the river.  Further details are available in the FAQs.

This project is closely linked to the Stillorgan Reservoir Upgrade Project which will provide covered water storage in Stillorgan and associated pipeline modifications that will improve the protection of the water supply to the network.

News and Updates

Planning permission for the upgrade works to the Water Treatment Plant was granted, subject to six planning conditions, by Wicklow County Council in November 2016. The details are available on the Wicklow County Council website. This planning permission was appealed by third parties to An Bord Pleanála in December 2016 and the appeal is presently under consideration. As part of the planning deliberations An Bord Pleanála have indicated they will hold an oral hearing; a date has yet to be confirmed. Details of the appeal are available on the An Bord Pleanála website.

Irish Water submitted a planning application for the pipeline from Vartry to Callowhill to Wicklow County Council on the 3 October 2016.  Planning permission was granted, subject to seven conditions, by Wicklow County Council in January 2017.  The works are expected to commence on site in 2018 and will take approximately two years to complete.

View our Project Roadmap for further details.

Contact Us

Please contact us with any questions or queries about this project.

  • Telephone: 1890 815661
  • Email:
  • Postal enquiries: F.A.O. Vartry Water Supply Project, Colvill House, 24-26 Talbot Street, Dublin 1

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