The real problem, imo, is data centres doing it wrong.
The average internal combustion engine uses a closed-loop cooling system in which the coolant absorbs heat and then exchanges it with air. Most buildings taller than 6 stories do the same.
Yet somehow we think it is okay for data centres to pump fresh, potable water through their cooling systems and dump it into whatever local drainage system.
Make 'em take care of their waste. All of it. Including waste heat.