Gravity drains are designed to run partly full. When inflow exceeds capacity — a downstream blockage, or a storm overwhelming the sewer — the pipe pressurises and water rises up every available opening. That is when overflow relief gullies earn their keep.
Wet-weather surcharge of public sewers is a network problem; surcharge in dry weather almost always means a blockage downstream of the affected point.
Describes the pressurised, over-capacity state of a drainage system.
Any drain downstream of a blockage, and public sewers during major rain events.
A CCTV drain inspection is the standard way to confirm whether this is what's happening in your pipes: the camera shows the condition on screen, a locator pinpoints the exact position and depth, and you get a recorded report before any repair decisions are made.
A CCTV drain inspection shows exactly what's happening inside your pipes — no guesswork.