> you just use less overall cooling water.

yeah... that's the point right?

Hybrid systems keep the primary process fluid in a closed loop, they spray water on pads to cool the coils during the hotter parts. Basically a stop gap when air cooling is not enough.

There's also close loop systems that lose none, it's just more expensive to build. They are already being deployed in areas with scarce water. Microsoft and a quite a few others already built a few.