Outside drains: gullies, rodding eyes, manholes and who owns what

Most of the waste water from a house leaves through pipes you never see. The parts you can see outside are the access points: a grid at the bottom of a downpipe, a small round cap set in a path, a square cover in the driveway. Knowing what each one is makes a blocked drain far less mysterious, and helps you work out whose problem it is.

The fittings you can see

Yard gully. A trapped opening at ground level, usually with a square grid on top. The kitchen waste pipe, a downpipe, or both, often discharge into it. Like a sink trap, a gully holds water to stop drain smells coming back up. Leaves, food fat and silt collect in it.

Hopper or back-inlet gully. A gully with a raised collar or a side inlet so a waste pipe can enter below the grid. It keeps splashes and leaves out and stops the waste pipe being blocked by debris sitting on the grate.

Rodding eye. A small capped access point, often round, set at ground level on a pipe run. It lets drain rods go straight down the pipe without lifting a manhole cover.

Inspection chamber or manhole. A cover over a chamber where drain pipes meet or change direction. Lifting it lets you see whether water is flowing through or standing. Older chambers may be brick with heavy iron covers. Newer ones are often plastic.

Soil stack and downpipes. The soil stack takes toilet waste down the outside or inside of the house. Downpipes take rainwater from the gutters. Depending on the age and location of the house, rainwater may go to the same drain as the foul water or to a separate surface water drain or soakaway.

If the outside tap drips into a gully, a slow leak can keep the gully wet and slimy all year. Our outdoor tap guide covers the tap side of that.

Your drain or the public sewer?

The consumer body CCW explains the split on its page who is responsible for my drains or sewers? In summary:

• A drain is a pipe that serves one property. CCW says homeowners are responsible for repairs to drains that serve their property and lie beneath the property, garden or driveway.
• A main sewer carries waste from many drains. Wastewater companies are responsible for the large sewers normally found under the road or pavement.
• Where shared pipework connects several properties to a public sewer, CCW says the wastewater company is also responsible for maintaining it.

That page has a diagram that makes the boundary much clearer than words. If you are not sure whose pipe is blocked, CCW suggests contacting your sewerage provider and keeping a record of the contact, in case you are told the blockage is private and it later turns out not to be.

A quick test: lift your own inspection chamber cover. If it is full, and the next chamber downstream (or a neighbour's) is also full, the blockage is probably further along and may be in a shared or public pipe. If yours is full and the next one down is empty, the blockage is probably between them, on your side. These rules are for England and Wales. Scotland and Northern Ireland have different arrangements, so check with your water and sewerage provider there.

What you can reasonably clear at a gully

A blocked yard gully is one of the few drain jobs most people can sort out themselves.

1. Wear rubber gloves and eye protection. Drain water carries bacteria. Keep children and pets away.
2. Lift the grid and scoop out leaves, silt and fat by hand or with a small trowel into a bucket lined with a bag.
3. Run water from a hose or bucket and watch whether it drains away.
4. If it is still slow, a plunger or a short rod worked gently into the outlet can shift a soft blockage.
5. Clean the grid, put it back, and wash your gloves and tools.

If the gully is slow because the drain beyond it is blocked, a set of screw-together drain rods worked from a rodding eye or an inspection chamber may clear it. Turn the rods in the direction the maker says, so they do not unscrew and get left in the pipe.

When to stop

Stop and call a drainage contractor or your sewerage company if:

• the blockage is beyond your boundary or in a shared pipe;
• sewage is coming up inside the house, or toilets downstairs are filling up;
• a manhole cover is too heavy, rusted in, or damaged, or the chamber is deep;
• rods meet something hard, or you think a pipe is broken, collapsed or full of roots;
• the same drain keeps blocking.

Do not climb into a manhole or lean right into a deep chamber. Drain gases and poor air can build up in them.

CCW's blocked drain tips say that if flushing is difficult, or water drains slowly or bubbles come up in the toilet, you should not keep flushing, because it could cause flooding inside. It suggests seeking advice from your sewerage company. If sewage does come into the house, CCW's sewer flooding page puts safety first, then contacting the water company and your insurer.

For blockages that start inside, see blocked sink and blocked toilet.

Keeping outside drains clear

• Keep fat, oil and food scraps out of the kitchen sink. They cool and set in gullies.
• Only pee, poo and toilet paper go down the toilet.
• Sweep leaves away from gully grids in autumn.
• Keep gutters clear, so less grit reaches the drains.
• Do not cover inspection chamber lids with paving or decking. You will need them one day.

Drain rods at Wickes

We haven't tested this. Figures are as the maker states them (checked 13 November 2026).

Who do I call about a blocked drain outside?

If it is your own drain, a plumber or drainage contractor. If it is a shared pipe or the public sewer, your sewerage company. If you are not sure, contact the sewerage company first and keep a note of what they say.

Is it safe to lift a manhole cover?

A light plastic cover in a garden path is usually fine to lift carefully. Heavy, rusted or deep covers are another matter: use proper lifting keys or leave it to a contractor. Never leave an open chamber unattended.

Why does my outside gully smell?

Usually because the water seal has dried out, or because the gully is full of decaying debris. Clear it and pour in water. If the smell persists, the drain may be blocked further down.