Patrick J. Campbell, Rachel Schwaab
December 2, 2025
How to use water wisely in data centres
Data centres are the backbone of our global information infrastructure but can pose environmental challenges. We explore how data centres can use our precious water resources with care, ensuring operational resilience and positive impacts on local water resources.
Data centres form the backbone of our global information infrastructure, enhancing productivity, efficiency, connectivity, and driving economic growth. However, in some regions, they rely on substantial amounts of water to satisfy their cooling needs, which can have profound impacts on local water resources and communities. Achieving responsible water usage is critical for the long-term resilience and environmental sustainability of data centres.
Understanding water usage in data centres
Water usage in data centres primarily stems from cooling processes. Traditional cooling methods, such as evaporative cooling, use large amounts of water to lower temperatures and maintain optimal operating conditions for IT equipment. Although effective at reducing power usage effectiveness (PUE), these methods can significantly impact water resources, particularly in water-scarce areas.
PUE and water usage effectiveness (WUE) are critical metrics for assessing the efficiency of data centres. PUE measures the ratio of the total building energy usage to the energy consumed by IT equipment, with lower values indicating more efficient energy use. WUE quantifies the amount of water used for cooling annually relative to the energy consumed, expressed as litres per kilowatt-hour (L/kWh). Lower WUE values represent better water efficiency.
Balancing PUE and WUE often involves trade-offs. For instance, improving PUE by adopting water-based cooling systems can lead to higher water consumption, thus affecting WUE. Conversely, enhancing WUE by minimising water usage can result in higher energy consumption, impacting PUE. Therefore, an integrated approach that considers both metrics is essential for sustainable and resilient data centre operations.
Strategies for achieving wise water use and water-neutral designs
To achieve responsible use of water in data centres and develop water-neutral designs, effective strategies must be implemented.
Here are some strategic steps for data centre managers to consider:
- Optimising cooling systems: Data centres can adopt water-efficient cooling technologies to mitigate water usage. Alternatives like adiabatic cooling and hybrid systems offer substantial water savings. Additionally, direct-to-chip and immersion liquid cooling are emerging as powerful solutions to enhance efficiency while reducing water dependency.
- Utilising recycled and alternate water sources: Adding recycled wastewater and harvested rainwater to the water supply mix can significantly reduce the reliance on traditional water sources. This water reuse approach not only conserves potable water but also enhances local water security.
- Implementing efficient water treatment: Enhanced water treatment processes that minimise chemical usage can contribute to sustainability. Efficient water treatment ensures that the water can be reused in multiple cycles without degrading quality, thereby reducing overall usage.
- Incorporating constructed wetlands and cooling tower blowdown: Utilise constructed wetlands to treat and discharge cooling tower blowdown water, providing co-benefits. Treating and reusing spent cooling tower blowdown, aiming for zero liquid discharge, can significantly reduce water waste and enhance sustainability.
- Enhancing monitoring systems: Implement advanced monitoring to track water usage and adjust practices accordingly.
- Conducting water audits: Balance water usage against operational power usage – both PUE and WUE are important and trade off against each other. Assess the total water consumption and identify areas for improvement.
Community collaboration is key to sustainable water usage
Collaborating with local communities and water utilities through public-private partnerships can align data centre operations with community goals. These partnerships promote the use of reclaimed municipal wastewater and other non-traditional sources, creating sustainable outcomes for the data centre, community, and environment.
By prioritising reclaimed municipal wastewater effluent and other alternative sources in the water supply, these partnerships create mutually beneficial outcomes: reducing pressure on traditional water sources, enhancing local water security and delivering the infrastructure needed for reliable operations.
Driving water stewardship in data centres
Achieving sustainable water usage in data centres is not just about reducing water consumption – it’s about adopting a holistic approach to sustainable resource management. By integrating innovative cooling technologies, utilising recycled water, and fostering community partnerships, data centres can lead the way in responsible water stewardship. Embracing these practices ensures resilient operations, environmental compliance, and sustained community support.
How Ramboll can help
Ramboll is leveraging its expertise in engineering, architecture, and consultancy to support data centres in achieving sustainable water use. Our team of specialists provides comprehensive services tailored to the unique needs of each data centre project.
Here’s how we can assist:
- Water audits and analysis: Ramboll conducts detailed water audits to identify usage patterns and opportunities for improvement. Our experts develop water use – and water reuse – strategies that optimise water efficiency across data centre operations.
- Waterwise cooling solutions: We advise on the adoption of advanced cooling technologies that reduce water consumption while maintaining optimal performance. Our solutions include both innovative systems and retrofit options for existing facilities.
- Integrated water management: Ramboll supports data centres in utilising recycled and alternative water sources. We engineer systems that, for instance, integrate rainwater harvesting, reuse greywater, and/or reclaimed municipal wastewater.
- Stakeholder collaboration: We foster collaboration between data centre operators and local communities through public-private partnerships. Our approach aligns operational needs with community goals, creating mutually beneficial outcomes.
- Regulatory compliance and reporting: Navigating regulatory landscapes can be challenging. Ramboll ensures data centres adhere to environmental compliance standards and helps with reporting requirements, supporting a license to operate.
Want to know more?
Patrick J. Campbell
Director for Water & Wastewater Treatment Americas
+1 615-277-7555
Rachel Schwaab
Project Manager
+1 443-845-7614
