Operator terms · Wastewater
What is a sewer manhole?
A manhole is an access point into a sewer line, usually where pipes join, change direction, or change slope. It lets operators inspect, clean, and maintain the collection system, and its cover and frame must seal well to keep storm water and debris out.
Last reviewed 2026-08-03
Why they exist
Sewers need access for cleaning and inspection. Manholes are placed at junctions, bends, and grade changes so crews can reach the line to clear blockages, run cameras, and check flow.
How they affect I&I
A cracked manhole or a leaky cover lets groundwater and storm water pour into the sewer as inflow. Keeping manholes sealed and sound is part of controlling infiltration and inflow.
Common questions
- What is a manhole for?
- Access to inspect, clean, and maintain a sewer line.
- Where are manholes placed?
- Where pipes join, change direction, or change slope.
- How do manholes relate to I&I?
- Cracks or leaky covers let storm water in as inflow.