I was an irrigation tech at a 27 hole golf course a while back. We had the reclaim system you're talking about and a retention lake that we would pull from. During the winter (Florida) it was pretty close to a stable system. There wasn't much loss to evaporation and our lake didn't need to be refilled. During the summer and especially in droughts, more than half our water was city water supplementing our lake. We would pump about 1 million gallons of water per night normally. In the summer and drought seasons it could be closer to 2 million per night and half of that was city water. We were a smaller course too, some of the PGA 36 hole courses could easily double those numbers. Golf courses are a blight on the land and a giant waste of all kinds of resources.