DrainUK topic library

Outside drainage & flooding

Gullies, inspection chambers, soakaways and surface water.

Choose your drainage question

Read the relevant guide to understand the clues, alternatives and what a contractor should investigate.

Debris in a trapped gully or restriction in the connecting pipe can cause water to back up.

Compacted soil, high groundwater, hard paving and blocked drainage routes can all leave standing water.

Soakaways receive surface water and rely on surrounding ground to absorb it.

A blocked rainwater gully may overflow against thresholds or low-level walls during storms.

A cover may sit below paving level or a chamber may surcharge when flows are restricted.

Channel gratings fill with silt and the outlet pipe can become restricted.

Connections vary by property age and local system; inappropriate connections can overload sewers.

Start with the symptom you can see, rather than assuming an underground pipe is broken.