Why Does My Sewage Backups Get Worse During Rainy Season?

During heavy rainfall, large amounts of stormwater can enter the city's sewer system through cracks or improper connections. This influx exceeds the pipes' designed capacity, causing a pressure backup. The sewage then has nowhere else to go but backwards into residential lines. This is a common cause of widespread backups during major rain events.

The problem may be worse in older neighborhoods where storm and sanitary sewers are combined. In these systems, all rainwater and household waste share the same pipe. A heavy downpour can quickly fill that single pipe, leading to immediate and severe backups into basements and lower-level drains throughout the area.

When the ground becomes fully saturated from prolonged rain, water seeks any entry point. Your home's foundation and the pipes around it are common targets. This isn't just clean water; it often carries soil and debris that can block drainage paths. The result is water intrusion that may mix with or follow the same paths as a sewage backup.

Foundation drain tiles and sump pits are designed to handle groundwater. However, their discharge lines sometimes tie into the home's sewer system or eject to the yard. If the yard is flooded, an ejected line cannot drain, causing the pit to overflow back into the basement. Ensuring these systems are properly separated is crucial.

• A waterlogged yard increases hydrostatic pressure against your foundation.
• This pressure can push groundwater through cracks into your basement or crawlspace.
• Many homes have perimeter drains that channel this water to a sump pit.
• If the sump pump fails or is overwhelmed, that water has nowhere to go.
• In some cases, this groundwater can enter a floor drain connected to the sewer.
• This creates a direct path for backup into your living space.

Prevention focuses on managing water outside and securing your lateral line. A backwater valve is a mechanical device installed in your sewer line that only allows flow out of the home. If the city sewer backs up, the valve's flapper closes to block sewage from entering. This is a key defense, but it requires regular testing and maintenance to function.

Also, manage rainwater around your property. Ensure gutters are clean and downspouts direct water away from the foundation. Reducing the amount of water that pools near your home lowers the risk of soil saturation and infiltration into your pipes or basement.

• Install a backwater valve on your main sewer line to prevent reverse flow.
• Have a plumber perform a video inspection of your lateral line for defects.
• Ensure your sump pump is working and has a battery backup for power outages.
• Disconnect any downspouts or yard drains from the sanitary sewer system.
• Redirect downspouts to discharge at least five feet away from your foundation.
• Consider replacing old clay or Orangeburg lateral pipes with modern PVC.