Public or mainline storm sewer backups can be caused by a number of factors. Heavy or intense rainfall events can overwhelm the storm sewer system. The majority of storm sewers in Shaker Heights were designed and installed between 1910 and 1920. They are designed to handle a 5-year or 10-year rain storm event. For rainstorm events greater than a 10-year storm, the storm sewers will overflow.
A blockage in the main sewer line may be caused by breaks in the pipe, an intrusion of tree roots, or downstream restrictions. Grass clippings, leaves, branches, newspapers and trash that enter the storm drain can also cause blockage. Shaker Heights Codified Ordinance prohibits any person from putting paper, wood, stone, or other foreign objects into the storm sewer system. The primary source of the foreign objects is the street catch basins.