ABSTRACT Drainage systems are important facilities for the maintenance of a city’s normal operation. Whilst they directly affect the internal urban environment, they are also a key link between a city and the world outside. The traditional drainage mode of Chinese cities was challenged by modern technologies that changed the relationship between cities and nature. Tianjin had developed rapidly into an important port in northern China, from a basis constructed during its days as a treaty port. The old drainage system changed significantly due to urban expansion and the appearance of modern health facilities such as sewer pipes. This reduced the commercial flow of sewage and ditch mud as rural fertilizers, gradually weakening the connection between the city and the surrounding environment. However, although the creation of a modern drainage system improved the urban landscape and people’s living conditions, it also affected the traditional urban wastewater disposal and sewage recycling. The resulting reduction in material exchange with the countryside caused metabolism rift, as discussed by Karl Marx. The ecological consequences and lasting influence of this change are worth our attention.