To make fire extinguishment possible by utilizing the sewage stored in rainwater sewer pipes or the seawater stored therein even if the fire hydrants of water works are not available near the site of a fire.

This system consists of sewer conduits 1 which discharge household and industrial waste water or rainwater to water sources, such as seas, rivers or lakes, at least one water gates 7 installed freely openably and closably near the water sources of these sewer conduits 1, conduits 16 which are inserted into the sewer conduits 1 and have excellent durability and backflow pumps 12 installed near the water sources of the conduits 16. The water forcibly fed into the conduits 16 from the water sources via these backflow pumps 12 is utilized as the water source for the fire extingushment.