humans are hypersensitive to the smell of fresh water, hence why we can smell storms coming. It's so sensitive that we can smell water better than most dogs -- Anon Guest
The Human origin world, Earth to some, Terra to most, has a surface that is over seventy percent water. Thus, it is surprising to most that Humans can detect it. With land in such relative scarcity, most Galactic Citizens assume that finding good soil would be a better priority.
It's a logical assumption, until one learns that most of the water on Terra is not potable. Humans excel at finding fresh water. They can smell it coming in the weather. They can scent it on the air even though it is in a cavern far, far underground. They can find rivers and streams in the time it takes to take a deep breath. Literally.
This one fact has saved many lives.