And they don't even need to waste it, there are plenty of ways to cool them that doesn't result in the water being used up.
Best one is the Google datacenter in Hamina, Finland, they have the cooling loop connected to the city central heating system, so not only is no water used, the excess heat is useful as well. And the datacenter is powered by solar, so it's renewable heat as well.
IRL we aren't anywhere near the point where the laws of robotics can be used as they require an AI intelligent enough to understand them first.
Just the first law: "A robot may not injure a human being or, through inaction, allow a human being to come to harm" requires something that can process the difference between a robot and a human, the concept of causality, what actions or events may or may not harm a human, and use those to actively decide of it should do something or not.