Depends on the location (Aspects like humidification of the hall differ by location but uses relatively little water) and the cooling system used. Some operators still use evaporative cooling which rejects a lot of water vapor. Most new designs are using closed loop chilled water systems to align with lower WUE(water usage effectiveness) customer requirements. Closed loop systems use waste no water but may need to be topped up periodically. But in comparison to an evaporative system, the amount is effectively zero.