The drainage system of residential area is generally divided into domestic sewage drainage system and rainwater drainage system.

The domestic sewage drainage system is to collect the sewage of each household and public area in the building, then transmit it to the municipal sewage pipeline through the sewage pipe network, and then discharge it into the water after being treated by the sewage treatment plant. For the places where the urban sewage treatment and sewage pipe network are not sound, the sewage in the residential area should be discharged into the municipal drainage pipeline or directly into the water after the purification treatment of chemical manure and oil separation.

Rainwater drainage system is used to collect rainwater through various inlets and roof rainwater collection outlets, and then transmit it to the municipal rainwater pipeline through the rainwater pipeline of the residential area, and then discharge it into the water. Those close to the river with geographical advantages can also be directly discharged into the water.