Side Sewers and Storms

Your home's side sewer runs from the house to the public sewer main in the street. Blockages or flooding of the side sewer can cause sewer backups. Maintaining the side sewer is the owner's responsibility. In preparation for storm season, maintenance is more important than ever.

Stormwater and Groundwater

Winter storms overload the sanitary sewer system in areas where there is excessive stormwater and groundwater through roof gutters, sump pumps, area drains, or cracks or gaps in side sewers.

What you should do with your side sewer before the storm season

  • Know where your side sewer line is, make sure roots or other obstructions aren’t blocking or penetrating it. Remove trees that are planted over or close to your side sewer. Avoid dumping fats, oils and grease down your drains, as they can cause blockages. Instead, dispose of them in a sealed container in your garbage.
  • If you need repairs to your side sewer, look for contractors who provide "Plumbing, Drains and Sewer Cleaning."
  • For more information about side sewers, see Your Property’s Side Sewer.

If you have a backup

  • Turn off all power to eliminate electrical hazards.
  • Keep children and pets away from the area.
  • If sewage backs up through sinks or toilets, call Seattle Public Utilities' sewer and drainage maintenance staff at (206) 386-1800. City workers will check and remove blockages in the main sewer line. If the problem is the result of too much storm water in the system, you may have to wait until the storm has subsided to have the backup resolved.