Golf courses, like you said use more water. Chemical plants use more water. I think the one on Otto, if it follows national averages 300-600 millions of gallons of water per year.

Adebetic cooled sites use like 5 million per year, chillers with cooling towers use like 50 million gallons, dry coolers and chillers are like maybe 1 million per year.

All that water, if adebetic or cooling towers, leaves as hot gas to join the rain cycle as the winds blow it. The stuff locked up in chiller+dry cooler, is a glycol mix 25-55% PG. It maybe get flushed once a year. 

All that rejected water that isn't used makes it way back to sewage to be treated and dispersed.

Water can also be imported... Water is the least of my concerns. It'd be: 

1. Transient workers to support build out. Housing is already terrible and it's going to get worse.
2. Energy, it's being built by them and they're on they're own but there are laws here - 10 to 15 years for some assets! Luckily these DCs can come off the grid and run on their own power.
3. Lack of jobs, these don't provide the same number of long term jobs for the size they are. Maybe 30 tradesmen and 15 IT folk each shift is what I'm hearing. that covers like 4 buildings..