Lough Mask Water Supply Scheme Extension

Water Supply Project

This €10 million project delivered an extension of the Lough Mask Water Supply Scheme to Ballinlough/ Loughglynn and Williamstown.

This project represented an investment of €10 million to ensure a clean and secure supply of drinking water for the 5,000 consumers on the two supplies. It was also responsible for the removal of the long-standing boil water notice in Ballinlough affecting 3,600 of those consumers.

€10 million


  • A long term solution to Ballinlough/Loughglynn enabling 3,600 consumers to be taken off a boil water notice
  • A long term solution to 1,400 consumers at Williamstown who had been on a boil water notice up until 2016 by safeguarding the drinking water supply
  • Ensures compliance with requirements set out in the European Union Drinking Water Directive and National Drinking Water Regulations


  • Decommissioning of the existing Ballinlough/ Loughglynn and Williamstown water treatment plants
  • Construction of a pumping station at the Ballyhaunis Reservoir, enabling the transfer of water to Ballinlough/Loughglynn and Williamstown
  • Construction of a 2,800m³ ground reservoir and new control building at the site of the existing Garranlahan Water Tower
  • A separate upgrade project at the Lough Mask Water Treatment plant, ensuring the availability of water to extend supply to these areas