In A Long Walk to Water, water works as a symbol. A symbol in literature is something—be it a person, an object, an action, or an event—that is representative of something other than its literal physical properties. Water is the most significant symbol in the novel: it represents survival. Salva and the other refugees are in dire need of it (Salva sees many men who die of thirst), and Nya is also desperate for water: every day she has to walk miles in order to reach a pond so that she can bring back unclean water for her family:
Nya filled the container all the way to the top. Then she tied the gourd back in place and took the padded cloth doughnut from her pocket. The doughnut went on her head first, followed by the heavy container of water, which she would hold in place with one hand.
Finally, Salva brings clean water to Sudan after he creates his "Water for South Sudan" non-profit organization.