Global data centres are growing rapidly as AI spreads. The United States led expansion after 2023 by building more than 100 data centres, but the burden on water supply was larger in Chile and Belgium.

On Oct. 6 (local time), IT outlet TechRadar reported that an analysis of 143 countries by Comparitech showed registered data centres in the United States rose by 127, to 5,427 this year from 5,300 in 2023. Russia rose 44 percent, to 251 from 174, and the UK increased 12 percent, to 523 from 465. The figures reflect changes in data centre listings and may not exactly match actual new construction.

On the environmental front, expanding data centres in water-scarce areas was cited as a problem. On the World Resources Institute's water-stress index by country, Chile scored 4.5 out of 5 and Belgium 4.4. The United States scored 2.6 and the UK 1.3. Scores of 4 to 5 mean "extremely high water stress," with more than 80 percent of total renewable water supply withdrawn for agriculture, industry and household use.

Chile's registered data centres increased by 13, to 59 from 46 after 2023. Large data centres in Quilicura, north of Santiago, were reported to use about 1.5 billion litres of water a year. Belgium also rose over the period, to 81 from 69. Water stress itself cannot be seen as a direct result of the increase in data centres.

Water use by data centres also varies widely by facility. Comparitech explained that large facilities can use up to about 5 million gallons (18,927,059 litres) a day, but that is a general upper-bound example for large data centres, not actual use at a specific facility in Belgium.

Security risks are also coming into focus. In March, an Iranian attack damaged AWS facilities in the United Arab Emirates and Bahrain, and data centres in Ukraine were also hit by Russian attacks. Concentrations of data centres improve power and network efficiency, but an analysis said they can also increase risks including pressure on local resources, single points of failure and concentration of military targets.