Sonde Locating & Drain Tracing

When you're dealing with a drainage issue, knowing exactly where the pipe runs, where a blockage sits, or where a defect is under the surface saves time and avoids unnecessary digging. Sonde locating, also called drain tracing, is a fast, accurate way to map underground drainage and pinpoint problem areas.

ICE Drainage provides sonde locating and drain tracing across the UK for commercial, industrial, and domestic sites. We locate underground pipes, identify the position and depth of defects, and support targeted repairs, CCTV surveys, and planned maintenance.

A sonde is a small transmitter that's inserted into a drain or pipe, usually through a rodding point, manhole, or during a CCTV survey. A receiver above ground then picks up its signal, which lets us:

Trace the route of underground drainage runs
Pinpoint the location of a blockage or defect
Work out depth to support safe excavation planning
Confirm where a pipe connects or changes direction

Sonde locating is commonly used alongside CCTV drainage surveys, jetting, and repair work.

Sonde locating vs CCTV surveys

These two services work best together, but they do different jobs. A CCTV survey shows the internal condition of the pipe and identifies defects. Sonde locating shows where that defect is on the surface and how deep it sits.

If a CCTV survey has told you what the problem is but not where it is on site, sonde locating fills that gap.

When you might need drain tracing

Sonde locating is useful in a wide range of situations, including:

Recurring blockages where you need to locate the exact point of restriction
Suspected collapsed drains or displaced joints
Unknown drainage routes on older sites or estates
Pre-construction or refurbishment planning, to avoid striking services
Locating connections between buildings, yards, and outfalls
Confirming line routes before excavation, lining, or patch repairs
Tracing pipes under car parks, roads, slabs, and landscaped areas

For commercial sites, accurate locating reduces downtime and avoids unnecessary disruption.

Key benefits include:

More targeted repairs with less excavation
Less disruption to operations, access routes, and customers
Faster fault finding during drainage incidents
Better planning for contractors and facilities teams
Less risk of repeat work caused by inaccurate assumptions
Clearer documentation for managing agents, insurers, and third parties

Our sonde locating process

We follow a structured approach designed to be accurate and safe on site.

1) Site assessment and access planning

We confirm access points, likely drainage routes, and any site controls such as permits, restricted hours, or traffic management.

2) Sonde insertion

We insert the sonde into the drainage line. Depending on the job, this might mean attaching it to rods and pushing it through the line, using it alongside CCTV equipment during a survey, or using it to locate a specific point of interest, such as a blockage.

3) Surface tracing and pinpointing

Using a receiver, we trace the sonde's signal from above ground to map the route and locate key points.

4) Depth estimation and marking

Where needed, we provide depth information and mark the location on the surface to support safe excavation planning.

5) Findings and next steps

We explain what we've found and recommend the next step, which might be jetting and clearance, a CCTV survey for internal condition evidence, localised repair or lining, or excavation planning if a collapse or major defect is confirmed.

Sonde locating for commercial and industrial sites

We support sonde locating and drain tracing for facilities management and managing agents, warehouses, depots, and logistics sites, retail parks and mixed-use estates, construction and refurbishment projects, public sector and education estates, and industrial sites with complex drainage networks.

If your organisation needs contractor governance, RAMS, permits, or audit-ready reporting, we can support those requirements.

Reporting and documentation

Where needed, we can support your internal documentation with clear written findings, marked locations and practical access notes, evidence to support repair scopes and approvals, and recommendations for planned maintenance or further surveys.

If you also need a written report with video footage, we can combine services to give you a complete evidence pack.