On: 45°C cooling design cuts data center water use to near zero

[Groxx]

(ab)using fresh water in vast quantities is cheaper.

currently.

and also more energy efficient, because evaporating water away takes a lot of energy with it. you have to raise radiators to a higher temperature to keep up with that, or have much more surface area.

[loeg → Groxx]

There's just a lot of fresh water almost anywhere you'd want to site a DC. In places where water is more expensive, obviously it doesn't make sense.