If this can be translated as either I wish to drink water or I want to drink water, what's the difference between "deseo" and "quiero"?
"deseo" = "wish" and (in this case) "quiero" = "want". That's the difference, though in Spanish the two words are used a bit more interchangeably than in English.
why is desire left out of translation
ah hola amigo mi deseo beber amigos
in English "hi friend I want to drink friends"