I've never really understood where this water "goes". A kilogram of cotton can contain no more than 1 kg of water, so the rest of the water must somehow be invo

I've never really understood where this water "goes". A kilogram of cotton can contain no more than 1 kg of water, so the rest of the water must somehow be involved in growing and processing the cotton. However, suppose I use 10,000 L of water to irrigate my cotton plot. A lot of this water is lost to evaporation and transpiration. A little bit is bound up in the non-harvest-able parts of the plant too. However, none of this water seems like it's really "lost"--it eventually comes back as rain or snow, right? If we're not spending tons of energy moving the water around, this doesn't seem too awful. The worst possible outcome seems like it would involve the water evaporating and then returning as rain over the sea, which would make it more expensive to reuse as fresh water. On the flip side, I can imagine that some water is also contaminated by the processing in a way that makes it expensive or impossible to reuse. That seems much worse.