My mind immediately goes to "schemes for water harvest". Does rain ever fall on your balcony? If so, where? Can you capture it creatively? You mentioned a nearly constant wind from the east. Does this lead to rain falling on the western side of the balcony more often? You might want to make a shaded rock pile to harvest humidity through condensation, which could than run down to the top of the pyramid bed. the less humidity you have, the less well it will work, though.