Water is local: generalities do not apply

Water use has become a benchmark metric for data center operational efficiency and sustainability, as well as a frequent target of community criticism. Operators should track and optimize their water use to protect the environment and secure the facility cooling’s autonomy when its capacity relies on water. However, water use does not fit into a standard template — each data center location has a distinct water signature. Despite this, studies often generalize and flatten several important factors that contribute to the variation in daily and annual water use.

Legacy facilities, except those in arid climates or constrained urban environments, often consume large quantities of water by using open evaporative cooling towers to produce low-temperature chilled water. Conversely, new data centers can use little to no water for cooling by deploying state-of-the-art water-efficient, waterless and hybrid heat rejection systems, as detailed in this report. An accurate assessment of a data center's water use — and its effects on communities and the environment — must examine local restrictions on water use, competition for water, the watershed’s safe withdrawal rate, the cooling system type, and climatic conditions at a given location.