Water water everywhere! Or... not.
Water is a strong presence in this book, but for a weird reason. We notice it because in this world, it hardly seems to exist. Matt's adventures take place in desert climates, where water is often scarce. That lack of water makes for some dangerous places, like the boneyard. Let's read the narrator's description:
It was the strangest thing he'd ever seen. They came up a slight rise and looked out over a deep chasm. It was filled from side to side with bones. (30.14)
Not to mention, we learn that this area used to be a sea, which Matt realizes when he sees old shells scattered about. So the place where Matt almost meets his end is a place where many others, including sea creatures, have met theirs. He's thirsty, and so, we imagine, are all the others who died out there.
Opium, too, is a grave for hundreds and hundreds of eejits, many of whom died of thirst in the fields. Matt sees this firsthand, when the narrator tells us, "The man we saw on the ground probably lagged behind the other workers and didn't hear the foreman tell them to stop. He might have worked all night, getting thirstier and thirstier" (8.72).
While Opium teems with the life of its flowers, it's really a barren wasteland, filled with death. This eejit dies of thirst, but not for a lack of water. After all, in a place where flowers grow, shouldn't water be abundant? Instead, he dies because of a lack of compassion, as no one ordered him to drink. It's a different kind of thirst, but it's a thirst nonetheless, right?
And finally, we can't forget about Matt's oasis – a place that flows freely with water, which makes it a unique place in Opium. It's a safe place, a free place, a hopeful place.