What is Inflow and Infiltration?

What is I&I?

🌧️🚫 Why Inflow & Infiltration (I&I) Matters on Tybee

When rainwater or groundwater enters the sewer system, it can overload pipes and treatment facilities. This is called I&I — and it can cause sewer backups, overflows, and increased maintenance costs for our community.

Inflow = stormwater getting into the sewer
This can happen through:
• Roof downspouts tied to sewer lines
• Yard/driveway drains connected to sewer
• Sump pumps going into sewer pipes
• Leaky manhole covers

Usually during heavy rain or storms 🌧️

Infiltration = groundwater seeping in
This happens when groundwater enters through:
• Cracked pipes
• Loose joints
• Aging sewer lines
• Damaged manholes

Often during periods of high groundwater 💧

💡 Why this matters:
Our sewer system is designed for wastewater — not stormwater. Too much extra water can strain our system, cause backups, and impact our waterways.

We all play a part in keeping Tybee’s system healthy and resilient.