For years, data center sustainability discussions have centered on power usage effectiveness (PUE). That helped, but PUE alone can mask major water impacts. A site with excellent PUE may still consume large volumes of potable water through cooling towers or rely on a power supply with high indirect water intensity.
Better decision-making requires a broader scorecard: WUE—water usage efficiency! This takes into account: carbon impacts, source-water stress, reuse rates, water quality risk, and community context. Water treatment sits at the center of this broader view because it determines whether water can be cycled longer, reclaimed safely, or substituted with non-potable supplies.
If you haven’t done so already, check out the Water Stewardship Course offered by Toepfer & Associates, PLLC! It’s money well spent, if for nothing else, to gain an appreciation for the pragmatic challenges of progress and achieving ESG goals. Every site has its own unique balance of water footprint, energy consumption, waste minimization, GHG emissions, capital costs, and operational expenses. You can’t take from one without affecting one or more of the others.
References:
Lei, N., Lu, J., Shehabi, A., & Masanet, E. (2025). The water use of data center workloads: A review and assessment of key determinants. Resources, Conservation and Recycling, 219, 108310. https://doi.org/10.1016/j.resconrec.2025.108310
National Renewable Energy Laboratory. (2024). Data center best practices for energy and water performance. NREL. https://www.energy.gov/sites/default/files/2024-07/best-practice-guide-data-center-design_0.pdf
Ristic, B., Madani, K., & Makuch, Z. (2015). The water footprint of data centers. Sustainability, 7(8), 11260–11284. https://doi.org/10.3390/su70811260
Siddik, M. A. B., Shehabi, A., & Marston, L. (2021). The environmental footprint of data centers in the United States. Environmental Research Letters, 16(6), 064017. https://doi.org/10.1088/1748-9326/abfba1
The Green Grid. (2011). WP#35: Water usage effectiveness (WUE): A Green Grid data center sustainability metric. The Green Grid. Retrieved from: WP#35 - Water Usage Effectiveness (WUE): A Green Grid Data Center Sustainability Metric | The Green Grid