Flood Resilience for Residential Properties
Rain, snowmelt, and ground water enter the wastewater treatment system in two primary ways:
- Inflow:
- When rain gutter downspouts, weeping tiles and sump pumps are connected directly to sewers. During a heavy rainfall, all this water flowing directly into the sewer can be more than the sewer can handle, leading to basement flooding and discharge into the environment.
- Infiltration:
- When groundwater enters the sewer system through broken or cracked sewer pipes and manholes
All of this water is called "storm water”.
Why Reducing Inflow and Infiltration Matters
While individual connections may seem small, excess rainwater and groundwater entering the sanitary sewer system can have significant system-wide impacts, especially during heavy rainfall or snowmelt.
Sanitary sewers and wastewater treatment facilities are designed to handle wastewater, not large volumes of clean stormwater. When inflow and infiltration are added to the system, sewer capacity is reduced and the system becomes more vulnerable during weather events.
Reducing inflow and infiltration helps to:
- Preserve sewer system capacity during storms
- Reduce stress on pipes, pumping stations, and treatment facilities
- Lower energy use and operational costs
- Reduce the risk of sewer backups and basement flooding
- Protect the environment by limiting overflows and bypass events
Addressing sources of inflow and infiltration on private property is an important part of maintaining a reliable and resilient wastewater system for the entire community. Check out the Stormwater Matters Guide to learn more about stormwater and how to properly manage it.
