Collaboration and innovation drive Irish water sector climate change impacts project

This Insight piece first appeared in iagua magazine on 25 May, 2026, and was authored by Amphos21 Project Director (Climate Change and Water Resources) Álvaro Sáinz García and Water Research Centre (WRc) Technical Director Andrew McArthur.

Climate change impacts are an inescapable reality, a simultaneously challenging and unifying factor across all sectors, creating greater opportunities, and impetus, for real collaboration. Without exception, we require reliable intelligence to inform long-term asset management, including, of course, capital and operational expenditure planning. Climate science has come a long way and is increasingly empowered by innovations in predictive analysis. This is of paramount importance when your organisation exists to ensure secure, safe and sustainable water services for an entire country.

This is the responsibility that rests with Uisce Éireann (Irish Water), the national regulated water utility serving the people of Ireland. The organisation manages more than 1750 water and wastewater treatment plants and over 90,000 kilometres of networks, serving over 4 million people. With increasing variability in rainfall, temperature and extreme events directly impacting the availability and demand for clean water, the treatment of wastewater and urban drainage performance, the Climate Change Risk and Resilience Assessment (CCRRA) project was born. Its purpose was clear: to support Uisce Éireann in forming robust, evidence-based plans for climate change adaptation across 50 priority water and wastewater assets.

Given the complexity and interdisciplinary nature of the project, the team was composed of professionals from five RSK Group companies. RSK is a global leader in the delivery of environmental and engineering solutions, employing more than 17,000 people in over 200 businesses in 40 countries. For the Uisce Éireann project, RSK drew on a distinct set of skills across five group businesses. Water Research Centre (WRc), with support from ADAS, took responsibility for project management, risk assessment and adaptation; Nicholas O’Dwyer was tasked with data aggregation, client communication, quality control and stakeholder engagement; Amphos 21 carried out climate modelling; and wastewater modelling was provided by Richard Allitt Associates (RAA).

Climate change risks to Ireland’s water infrastructure

Observations show that Ireland’s climate is changing at a scale and rate consistent with regional and global trends associated with human-induced climate change. Temperature rise, increased likelihood of drought, sea level rise and increased storminess, as well as more frequent and intense precipitation events, will make it increasingly challenging for Uisce Éireann to maintain sustainable service levels. The changes in climate will, on one side, affect the availability of drinking water and the efficiency of wastewater treatment, while on the other side, they might lead to a shift in water consumption patterns, such as increased consumption during drought periods.

Applying ISO 14091 to climate risk assessment

The project is based on the requirements of ISO 14091, ‘Adaptation to climate change – Guidelines on vulnerability, impacts and risk assessment’. This standard establishes the methodology to evaluate climate change risk as a combination of climate hazard and the exposure and vulnerability of the receptor.

Conducting a climate risk assessment for a system as extensive and critical as a water treatment plant and the overall water supply network required a deep understanding of the infrastructure, the local environmental context and the operational dynamics. High-resolution climate projections are required to ensure meaningful analysis at the relevant spatial and temporal scales. To respond to this challenge, the project team closely collaborated with Uisce Éireann throughout all project phases. All relevant stakeholders were actively engaged to ensure technical alignment and contextual understanding.

Using high-resolution climate data for water sector planning

A close collaboration with the Irish Meteorological Service – Met Éireann – was also developed to access the most accurate and high-resolution climate data available, i.e., the TRANSLATE project output. This model data was used to feed both the initial climate risk assessment and the detailed network modelling.

The Met Éireann TRANSLATE initiative follows international best practice to provide robust, high-resolution and standardised future climate projections for Ireland. These bias-corrected, standardised data sets help decision-makers across Ireland plan for the future. TRANSLATE provides regionalised data sets with:

• a spatial resolution of 1.5 km by 1.5 km, enabling local, site-specific climate projections
• three climate ‘warming’ scenarios based on Representative Concentration Pathways (RCP) 2.6 (‘stringent’), 4.5 (‘intermediate’) and 8.5 (‘worst case’)
• future time periods: 2021–2050, 2041–2070 and 2071– 2100.

Uisce Éireann was one of the first organisations to use the data since it was produced in July 2023.

Climate modelling and resilience testing across 50 assets

The phased approach to the project included the following steps.

• Data aggregation: A comprehensive compilation of data sets was undertaken, combining observed and projected climate variables with asset-level operational data. This included hydrological records, rainfall and temperature series, river flow and groundwater data, and flood risk maps.
• Climate statistics and modelling: In a first phase, an initial assessment was carried out across 50 assets (25 water and 25 wastewater treatment plants) to build a consistent evidence base on how climate hazards could affect operations. Using the TRANSLATE data sets, the team assessed key climate variables and derived a set of climate statistics to quantify the frequency and intensity of relevant hazards, with a particular focus on rainfall-driven pressures. This approach provided a comparable basis for decision-making across a geographically diverse portfolio of sites and allowed the project team to distinguish where climate hazards were likely to translate into operational risk, rather than remaining as purely meteorological signals.In addition, for10 wastewater networks, detailed flow modelling and resilience testing was carried out. A key enabler of this step was the development of the TRANSLATE2Red tool, created specifically for this project to translate Ireland’s national climate projections into rainfall inputs suitable for wastewater network models. Building on the approach of the RED-UP tool developed by UK Water Industry Research (UKWIR, 2017) for the UK, TRANSLATE2Red was tailored to Irish conditions and to the TRANSLATE data sets, ensuring methodological consistency and traceability from climate projections to operational modelling.Using TRANSLATE2Red, the team generated climate change rainfall time series by adapting historical sub-daily rainfall records, including five-minute resolution series, to reflect projected future rainfall patterns across relevant scenarios and time horizons. This provided model-ready inputs for stress-testing wastewater network performance under more intense rainfall conditions, enabling a realistic assessment of system sensitivity to short-duration, high-intensity events, which are often the critical drivers of surcharge, flooding and operational disruption in wastewater systems.
• Climate change risk and resilience assessment: Assets were evaluated for their exposure, vulnerability and capacity to adapt to the impacts derived from climate change hazards (adaptive capacity). This identified the key current and future climate risks to the systems and infrastructure, including, for example, flood damage to low-lying facilities, reduced dilution capacity in receiving waters during droughts and increased energy demand for water treatment under higher temperatures. Short- (up to 2050), medium- (to 2070) and long-term (to 2100) risk scores were provided for each site based on three climate warming scenarios – RCP 2.6, RCP 4.5 and RCP 8.5. The project looked at 50 sites in total – 25 water and 25 wastewater sites.
• Adaptation options assessment: Potential adaptation options were developed and assessed through a multi-criteria analysis, with criteria including effectiveness, feasibility, cost, co-benefits and alignment with existing investment programmes. The participatory approach ensured that the proposed measures were realistic and aligned with operational needs, ranging from flood protection upgrades, to improved process management for future climate scenarios.

Turning climate risk into practical adaptation plans

For each site, these risk-based adaptation options were presented within Adaptation Pathways to support the development of an adaptive plan. Effective adaptation results in enhanced adaptive capacity, strengthening resilience and reducing vulnerability to extreme weather. It does this by supporting effective decision-making where uncertainty exists around which ‘future’ may be realised, feeding into and enabling risk-based and optimised investments.

Building long-term resilience across Ireland’s water sector

The CCRRA project provided Uisce Éireann with a clear understanding of where and how climate change poses the greatest risks to its operations and where resilience measures can deliver the highest value. By combining climate science, engineering knowledge and stakeholder input, the study created a solid evidence base for strategic adaptation planning.

The project has also demonstrated how a utility-wide assessment can bridge the gap between high-level climate policy and day-to-day operational decisions. The use of ISO 14091 ensured methodological consistency, while the engagement process built capacity across the organisation and strengthened awareness of climate risks within the wider water sector.

In the long term, this initiative supports Ireland’s broader climate objectives under the Climate Action and Low Carbon Development (Amendment) Act 2021 and contributes to national efforts to safeguard essential services under changing climatic conditions. It also provides a replicable model for other utilities seeking to embed climate resilience into infrastructure management and investment planning.

In a sector where continuity of service is critical, understanding and anticipating climate risks is no longer optional – it is a prerequisite for sustainable water management. The collaboration here illustrates how science-based risk assessment can be translated into practical adaptation strategies, ensuring that Ireland’s water systems remain reliable, efficient and resilient in the face of an uncertain climate future.

From Uisce Éireann’s perspective, the project has proved to be highly valuable. The different forms of climate change impacts on both water and wastewater treatment assets have been identified and categorised to make more manageable. Impacts have been graded by severity for a range of future timescales and an extensive series of potential adaptative measures has been collated. The project has significantly increased the level of understanding of the range of climate change impacts and associated adaptation measures to mitigate the same. In addition, the scale of impacts of projected changes to rainfall and storm overflows on wastewater networks have been quantified. These impacts are now more fully understood and this knowledge is used in wastewater network modelling to inform designs going forward.