I believe this is something that already happens in certain countries with Coca-Cola bottling plants, where when local droughts happen, the plant is protected over the local population.
It's usually agriculture (and industry) that's the big consumer. Alas, not many places have functional markets for water, so people can't buy out the farmers' water rights. And it's often use-it-or-lose-it for the farmers.
See eg https://en.wikipedia.org/wiki/Water_trading#Australia for what could be done.