> use copious amounts of water.

If you're in Europe and/or using completely closed loop systems, then yes. Your only water use is humidifiers, and maybe the sprayers you use on drycoolers in the summer months.

On the other hand, if you use water spraying into air as heat absorption system or use open loop external circuits, you're using literally tons of water.

Source: Writing this comment from a direct liquid cooled data center.