Project Summary
Coffey, working on behalf of Uisce Éireann, successfully delivered the Terryland Intake Works project in Galway City as part of the Galway West Water Supply Scheme. The newly constructed intake facility on the River Corrib will ensure a more secure and reliable water supply for the city’s 80,000 residents, supporting future population growth and demand.
Project Description
The existing intake to the Terryland Water Treatment Plant (WTP) was no longer sufficient to meet demand, and posed risks to continuity of supply. The upgrade was essential to provide resilience, reduce energy usage, and enhance the city’s infrastructure in line with future planning.
Galway City Council, in partnership with Uisce Éireann, is responsible for the public mains network and water quality in the area. The new intake works are located approximately 100m downstream of the Quincentenary Bridge on the east bank of the River Corrib, within a riverside park near Dyke Road.
The completed works now provide a daily capacity of 55 million litres, with provision to increase capacity to 90 million litres per day in the future.
Scope of Works
The contract included:
- Construction of a new underground intake structure divided into chambers, incorporating coarse and fine screening, fish return systems, penstocks, and pump sump provision for future capacity.
- Installation of a floating boom and piles in the river.
- Construction of a control building, power supply connections, and integration with the Terryland WTP SCADA system.
- Ecological mitigation and riverbank/bottom erosion control measures.
- Site development works including fencing, drainage, hardstanding, landscaping, access road, slipway, and parkland reinstatement.
- 315 m of 1,200 mm diameter transfer main to the existing intake location, including 135 m trenchless construction and a crossing under the Terryland River.
- Modifications to the existing intake, including decommissioning of the old facility and construction of a new connection chamber.
- Decommissioning and removal of redundant pipelines, tanks, and fittings.
Technical Highlights
- Complex microtunnelling of a 1,200 mm pipeline under the N6 in challenging ground conditions with significant boulder and groundwater management.
- Installation of fish deterrent systems, automated fish counters, and cameras to protect biodiversity and monitor fish stocks.
- Use of advanced SCADA integration for real-time monitoring and control.
- Construction within the fastest flowing city river in Europe under stringent safety and environmental controls.
Added Value
Coffey introduced several cost-saving and efficiency measures during the project, including:
- Changing fish screen supplier, achieving significant savings.
- Using over-pumping and damming instead of river diversion for pipe installation, reducing complexity and cost.
- Using a 1,200 mm concrete pipe without a 1,500 mm sleeve and cathodic protection, as initially tendered.
- Eliminating a valve chamber and washout sump, streamlining civil works and cofferdam design.
- Reducing the number of cofferdams from two to one, achieving large cost savings.
- Replacing external boom piles with relocated steel channels in a dry working area, saving money.
- Purchasing, rather than hiring, a cofferdam top frame to reduce long-term costs.
- Minor tunnelling savings achieved compared to the tender price.
Environmental and Community Measures
- Implementation of silt curtains, floating booms, settlement lagoons, and double silt fencing to prevent sediment release and protect water quality.
- Weekly ecological monitoring and water sampling, with vibration and structural surveys prior to tunnelling.
- Engagement with stakeholders including Inland Fisheries Ireland, Galway City Council, NPWS, OPW, local rowing clubs, and tourism operators.
- Public liaison and educational engagement through guided site tours for university engineering students.
Interested in learning how we can support your next water infrastructure project? Get in touch with our team today at info@coffeygroup.com or call 091 844356
