Water consumption and localized atmospheric heating have been cited elsewhere as drawbacks. There have been some articles citing noise/vibration pollution (subsonic?) but I'm not completely convinced on that front. Personally, I would add electric grid load to the list.
In the worst case, if your local municipality sides with business over the little guy, that means potential brownouts and water shortages for you.
In the worst case, if your local municipality sides with business over the little guy, that means potential brownouts and water shortages for you.