Since the first drainage infrastructure designed in the seventeenth century, wastewater in Mexico City has been discharged towards the Tula Valley to finally be expelled into the Gulf of Mexico. Through the general understanding of the system, six objects belonging to three landscapes of different characteristics are detected: the city, the space in-between and the valley. Each of these objects not only describe the relationship between the material scale and the territorial scale, but also illustrate six urgent dilemmas related to the drainage management in Mexico City.