Sun is continuously running a very nice distillation cycle the size of the world that makes fairly clean water just fall out of the sky. It's only a question of where does it fall, and how much. If you want it even cleaner, wait a couple centuries for it to filter down underground, and get it from there - besides maybe a bit high mineral contents, that can easily be removed, it's essentially free, clean water. The only question is how much it's replenished in the area you're taking it from.

There's plenty of areas where there's more rainfall, than there is outflow/evaporation, with water continuously replenishing deep groundwater. "Saving water" in such areas is of little concern besides the basic, economic one of well maintenance - each one can only pull so much, and more usage means more wells, and more upkeep.