Your lateral, the city's sewer
The pipe that carries wastewater from your house to the public sewer is the lateral. The city's Blueprint Columbus lateral lining brochure says homeowners are responsible for maintaining their laterals and the city for its own portion. In older homes, laterals are usually clay pipe, which can crack or fill with roots over time.
A clue to where the problem is: if only your house backs up, especially in dry weather, suspect your own line and call a plumber. If neighbors back up too during heavy rain, the public sewer may be surcharging, which is what Project Dry Basement is for.

