Screw data centers, I want to see desalination combined with nuclear power plants. They literally generate power by boiling water, it's a match made in heaven.
We just need a few more advances in technology to remove impurities from brine and we'd also corner the table salt market.
Not to mention a much higher carbon footprint.
The reason evaporative coolers are cheap is because they use a fraction of the electricity that chillers do.
And note that the majority of data center water usage is indirect via power generation, so using less water on site but more indirectly by consuming more power is both more expensive and less efficient.
Unfortunately, evaporative coolers are the best way to go, for now.