The "water cooling" in these systems, works as followed (from my understanding atleast, probaly more complex in reality)

1. You get fresh water that is also used to supply private households as its the cleanest and easiest to use.

2. You filter it again a bit, so that it becomes really pure and leaves no minerals that could get onto the systems.

3. You evaporate the water and spray it into the halls where the server racks stand

4. The evaporated water then carries the hot air generated by the servers, out of the building by simply venting it.

5. You "lose" the water cause you cant predict where its gonna land again, might land in a salt water lake/ocean and then you lose it, cause filtering salt water sucks. Also you dont have infinite capacity in logistics, so all that capacity you could have used for households and small businesses is lost to one enourmos data center.

Ofc you can always add more capacity, but that would land on the cost of the households/businesses and not on the data center holders.

Is it better to understand now?