Drainage guide
Who is responsible for drains and sewers in the UK?
You are responsible only for drains inside your property boundary that serve your home alone. Shared drains and lateral drains — the pipe beyond your boundary — became the water company’s responsibility on 1 October 2011, when around 200,000 km of private sewers transferred to public ownership (Ofwat).
What is a lateral drain?
A lateral drain is the length of your drain that runs beyond your property boundary — typically under the pavement or road — before it joins the public sewer. Since 1 October 2011 it has been the water company’s responsibility, not yours (Ofwat).
Private drain: a pipe within your boundary serving your property alone — your responsibility. Lateral drain: the pipe beyond your boundary serving one property — the water company’s. Public sewer: a pipe serving more than one property — the water company’s.
What changed in the 2011 private sewer transfer?
On 1 October 2011, the Water Industry (Schemes for Adoption of Private Sewers) Regulations transferred around 200,000 km of private sewers and lateral drains into public ownership (Ofwat) — the biggest change in sewer ownership since 1989. Private pumping stations followed by October 2016.
Before the transfer, UK Parliament research estimated nearly half of all domestic properties were served by a private sewer or lateral drain (briefing SN01514, 2011).
Who fixes a blockage in the road?
A blockage in a shared drain or public sewer — including the lateral drain beyond your boundary — is the water company’s responsibility to clear, usually free of charge. Report it to your local sewerage company rather than paying a private contractor.
Who pays for a collapsed drain?
If the collapsed section is within your boundary and serves only your home, you pay. If it is a shared or lateral drain beyond the boundary, the water company is responsible. A CCTV survey confirms exactly where the fault sits.
How do I find out which water company serves me?
Your sewerage company depends on your region — Thames Water in London, Severn Trent across the Midlands, United Utilities in the North West, and so on. Water UK and Ofwat both provide postcode checkers that name the company for your address.
UK drainage in numbers
The scale of the problem
Sources: Water UK, Ofwat and the ABI (2024–2025). Figures are UK-wide and rounded.
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