Vartry Water Supply Scheme, Monitoring, Ireland

Project summary

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. A British Pathé archive film shows the opening of the second upper reservoir from 1923. 

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.

Uisce Éireann invested €150 million in the Vartry Water Supply Scheme Upgrade project, to improve the scheme and ensure that water provided complies with water quality standards set out in the European Union Drinking Water Directive and the current, national Drinking Water Regulations.

In 2018, Uisce Éireann completed the new pipeline from Vartry to Callowhill. This pipeline replaced a four-kilometre-long rock lined tunnel that was at risk of collapse.

The four-kilometre-long tunnel was part of the original Vartry Water Supply Scheme and had been chiselled by hand through hard, dense “greywacke” rock. Treated water flowed through the unlined rock over its 150-year service life, gradually eroding it towards risk of collapse. A pipeline connection was required to replace the tunnel and secure the water supply to over 200,000 people in Wicklow and Dublin. This work got underway in February 2017 and was completed in December 2018 and included 4km of pipelines from Vartry to Callowhill as well as a pumping station and related infrastructure.

The new pipeline secures and safeguards the water supply for more than 200,000 people in north Wicklow and south Dublin, one of the most densely populated areas in the country.