Current status, existent problems, and coping strategy of urban drainage pipeline network in China.

Urban drainage pipeline systems collect and transport domestic sewage, industrial wastewater, and rainwater. They are important components of urban infrastructure. The quality of drainage facilities directly determines the level of urban development and affects the urban landscape and sanitary environment. In recent years, however, the phenomenon of "attaching importance to construction, despising management and maintenance" has prevailed in China's urban drainage pipeline network. The problems such as structural damage, corrosion, and blockage of the sewage pipelines are becoming increasingly prominent in China, causing a lot of operational challenges such as direct discharge of sewage, backward irrigation of river and lake water, infiltration of external water, and overflow pollution. To comprehensively acquire these information about China's urban drainage pipeline network, this paper reviews current status of construction, operation, management and maintenance, existent problems, and coping strategy of the sewage pipelines. Finally, future directions are also discussed in detail for rational construction and maintenance of sewage pipelines.