Plumbing & water
Outside drain blocked? Whose problem is it?
Before you pay a drainage firm, answer one question: is this drain even yours? Since October 2011, in England and Wales, shared drains and everything beyond your boundary belong to the water company, and their unblocking visit costs you nothing.
By the Tickover team · Published 19 January 2026 · 4 min read
How urgent is this?
This week, before it backs up
A gurgling, slow outside drain gives you a few days of warning. Sewage rising toward the house, or into it, is an act-now problem.
The 2011 rule, in plain English
In October 2011, most private sewers and lateral drains in England and Wales transferred to the water companies. The working definitions: a drain serves one property; a sewer serves more than one; a lateral drain is the stretch of your drain that lies beyond your property boundary. You keep responsibility only for the first of these.
| The pipe | Whose job | Who pays |
|---|---|---|
| Drain inside your boundary, serving only your home | Yours | You |
| Lateral drain beyond your boundary | Water company | Free to you |
| Shared drain or sewer, even under your garden | Water company | Free to you |
| Public sewer under the road | Water company | Free to you |
The practical upshot: if next door’s plugholes are gurgling at the same time as yours, the blockage almost certainly sits in a shared section, so ring the water company before anyone with a van and a card machine. Semi-detached and terraced homes share drains far more often than their owners assume.
Whose blockage is it?
Reading the inspection chamber
Your best diagnostic tool is the inspection chamber, the round or rectangular cover in the garden or drive. Prise the lid with a flat spade or bolster (gloves on, lift with your legs, mind fingers on the way down). A chamber standing full of water means the blockage is downstream of it, toward the boundary. A dry chamber means the problem is upstream, between the chamber and the house.
If the blockage is yours, a set of drain rods with a plunger head will clear most of them. Feed the rods in, apply steady pressure rather than stabbing, and turn them clockwise only: anticlockwise unscrews the joints and donates a rod to the drain, converting a £15 problem into a £300 one.
Rods, jetting and cameras
When rodding fails, drainage firms escalate to high-pressure jetting, which strips fat and debris off the pipe walls rather than punching a hole through the middle. If the same drain blocks repeatedly, pay for a CCTV survey once instead of a third jetting: roots, a displaced joint or a bellied pipe will keep recreating the blockage until someone actually looks.
Typical drainage prices
Unblock an outside drain
High-pressure jetting
CCTV drain survey
Typical UK ranges, mid-2026, as a guide only. Your home, your area and the job itself all move the number — always compare real quotes.
Not sure what you’re dealing with?
Describe what is backing up where and Self-Diagnose will help place the blockage, tell you if the water company should attend free, and brief a vetted drainage firm if the job is yours.
Stop it happening again
Foul drains block on wipes and fat, so the fix starts at the kitchen sink and the bathroom bin. Surface-water gullies block on leaves and silt: clear the grilles when you do the gutters, and give both a check in the autumn round. Five minutes with a glove beats an afternoon with the rods.
For how drains connect to everything upstream of them, traps, stacks and stopcocks included, the home plumbing guide has the full map.
Quick answers
Who is responsible for a blocked drain outside my house?
It depends where the blockage sits. Pipes inside your boundary serving only your home are yours. Shared pipework and anything beyond the boundary transferred to the water companies in England and Wales in October 2011, and they unblock those free. If neighbours are affected at the same time, call the water company first.
How do I tell where the blockage is?
Lift the inspection chamber cover. A chamber full of standing water means the blockage is downstream of it; a dry chamber means it is upstream, nearer the house. One slow plughole points indoors to that fixture’s trap, while several slow fixtures plus a full chamber point to the drain run itself.
Can I unblock an outside drain myself?
Often, yes. A set of drain rods with a plunger head clears most blockages within your boundary. Wear gloves, work with steady pressure, and only ever twist the rods clockwise, because anticlockwise unscrews the joints and leaves a rod in the drain. If two attempts fail, hand over to a drainage firm with a jetter.
How much does it cost to unblock an outside drain?
As a guide, £100–£180 for a standard unblocking visit, £150–£350 for high-pressure jetting, and a similar range for a CCTV survey if the drain keeps refilling with trouble. If the blocked section is shared or beyond your boundary, the water company attends at no charge, so establish whose pipe it is first.
This guide is general information for UK homes, not advice about your specific property. Anything involving gas must be done by a Gas Safe registered engineer, and notifiable electrical work by a qualified electrician. If you smell gas, call the National Gas Emergency line on 0800 111 999. If you’re ever unsure, stop and get a professional in — that’s exactly what Tickover is for.
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