Drain Mapping & Tracing
Find out where your drains run, where they connect and how deep they are. Ask for an accurate drainage plan you can share.
What is drain mapping and tracing?
Drain mapping and tracing finds hidden pipe runs and shows where they go. A small radio sender called a sonde travels the pipe, while a locator above ground follows it. Together they plot the route, depth and connections, and the result becomes a drainage plan.
Drain tracing finds hidden pipe runs and shows where they connect. That matters before building work, when nobody knows the connections, or when a fault is out of reach. A sonde on the camera and a locator above ground follow the route and depth.
You should end up with an accurate drainage map. It shows pipe runs, chambers, the way the water flows, and where pipes connect. Builders and planners can then see what lies underground before work starts.
For more detail, read who is responsible for a blocked drain and whether you need a drain survey when buying.
When you need drain mapping and tracing
- You are planning an extension, new build or major landscaping
- You do not know where your drains run or what they connect to
- You need a build-over or build-near sewer agreement
- There is a question over shared drainage responsibility
- A pipe needs work but cannot be located from the surface
Why it matters
Know what is underground
You can avoid hitting drains during an extension, landscaping or any dig. Since the engineer marks the route on site, everyone knows where not to dig.
Confirm connections
A trace shows whether the drains run to the public sewer, a soakaway or a private system. This matters for build-over agreements and shared drains alike.
Accurate plans
Ask for a clear map for builders, architects, surveyors or planning. Quotes and plans can then rest on fact, not guesswork.
What it usually includes
Ask the engineer to confirm what their quote covers, since this varies.
- Tracing of the pipe route, marked out on site
- Depth and position of pipe runs and connection points
- Confirmation of flow direction and what each run connects to
- A clear drainage plan you can share with builders or planning
How it works
- 01
Insert sonde
First, the sonde travels the pipe while the engineer follows its signal from above. The signal shows the route, so nobody has to dig.
- 02
Trace route & depth
Next, the engineer marks the run, its depth and its connections above ground. They also note anything that could affect the work you have planned.
- 03
Produce the map
Finally, ask for the findings as a clear drainage plan. You can then share it with builders, architects or the local council.
How much does drain mapping and tracing cost?
The cost of drain tracing and mapping depends on the size of the site and how many runs need tracing. A larger site, or a trace with a full CCTV survey, gets a price based on the scope. Send us the details, and ask for a written quote before any work starts.
What affects the price
- The size of the site and number of runs to trace
- Depth and accessibility of the pipework
- Whether you need a formal drainage plan for planning
- Whether a full CCTV survey is carried out at the same time
Each job gets its own price. Send us the details, with no obligation. Ask for a written quote before any work starts.
Request a no-obligation quote →Drain Mapping & Tracing — your questions answered
How much does drain tracing cost?
It depends on the size of the site and how many runs need tracing. A larger site, or a trace with a CCTV survey, gets a price based on the scope. Ask for a written quote before any work starts.
Why would I need drain tracing?
Most often, people need it before an extension or new build. It confirms connections, settles shared-drain questions, or finds a pipe nobody can otherwise reach. When the route is unknown, a trace saves guesswork and damage.
Can a trace confirm if my drain connects to the public sewer?
Yes, because a trace shows where a run goes and what it joins. That can give you the evidence a build-over agreement needs.
Do I need this for a build-over agreement?
Often, yes. Water companies usually want to know where any public sewer near your build runs, and how deep it is. A trace can show that.
Further reading
Get a drain mapping and tracing quote
Tell us what you need and where you are, and we'll pass your request on straight away. There's no obligation. Ask for a written quote, then decide.