What is a CCTV Survey

A CCTV survey is a specialised, non-invasive method used to inspect and assess the condition of drainage and sewer systems. Using high-resolution colour cameras mounted on remote-controlled crawlers or push rods, CCTV surveys allow engineers and drainage specialists to conduct detailed visual inspections of pipes, culverts, and underground infrastructure—often in locations that are otherwise inaccessible or hazardous to enter.

CCTV (Closed-Circuit Television) technology has become the industry standard for diagnosing defects, blockages, structural damage, and misalignments within foul, surface water, and combined drainage systems. It plays a central role in maintenance planning, pre- and post-construction evaluations, property condition assessments, and environmental compliance monitoring.

Whether for domestic properties, commercial premises, industrial estates, or municipal sewer networks, a CCTV survey provides critical data without the need for disruptive excavation. For professionals in plumbing, drainage, civil engineering, and facilities management, understanding how CCTV surveys are performed—and what they reveal—is essential to effective system design, maintenance, and asset management.

Purpose and Applications of a CCTV Survey

The principal aim of a CCTV survey is to obtain accurate, real-time visual information about the internal condition of a drain or sewer system. This helps identify current issues, predict future risks, and inform decisions regarding repair, replacement, or cleaning.

CCTV surveys are employed in a wide variety of scenarios, including:

  • Investigating persistent blockages or slow drainage. 
  • Locating and assessing structural defects such as cracks, fractures, or collapsed pipes. 
  • Identifying infiltration and exfiltration, where water enters or leaks from the pipe. 
  • Detecting root intrusion, displaced joints, or debris build-up. 
  • Mapping out unknown or undocumented drainage layouts. 
  • Verifying the quality of new drainage installations before adoption or handover. 
  • Supporting planning applications, especially for brownfield redevelopment or extensions. 
  • Providing evidence for insurance claims, particularly after flooding or subsidence. 
  • Establishing drain ownership boundaries, often in disputes between private owners and water authorities. 

Because CCTV surveys offer a high level of detail with minimal disruption, they are preferred over traditional methods for diagnostic and compliance work.

Equipment Used in CCTV Drainage Surveys

Modern CCTV drainage survey equipment has evolved to offer exceptional image quality, manoeuvrability, and data capture capabilities. The key components of a typical survey system include:

  • Camera head: High-definition, often pan-and-tilt enabled, with integrated LED lighting. Capable of navigating various pipe sizes and materials. 
  • Cabling and control unit: Used to transmit footage back to a monitor, allowing operators to steer the camera and record findings in real time. 
  • Crawler or robotic unit: Remote-controlled platform with wheels or tracks that carries the camera through large-diameter sewers. 
  • Push rod system: Flexible rod with a mounted camera, suitable for small or narrow-bore pipes. 
  • On-screen display (OSD): Shows live information such as distance from entry point, inclination, and defect coding. 
  • Software and data storage: Allows surveys to be recorded, annotated, and compiled into detailed condition reports using industry-standard formats. 

Some systems also include:

  • Sonar profiling: For submerged pipelines where visual inspection isn’t possible. 
  • Laser scanning: To measure pipe dimensions and deformation. 
  • Inclination sensors: To detect pipe slope and identify backfalls or sags. 

These technologies ensure that survey results are not only highly accurate but also easy to share, review, and store for future reference.

The CCTV Survey Process

A professional CCTV survey follows a structured process to ensure comprehensive and reliable results. The typical stages are:

1. Pre-survey planning

  • Review of site plans and access points. 
  • Identification of manholes, inspection chambers, and entry/exit points. 
  • Risk assessments, particularly for confined space or traffic-heavy areas. 
  • Confirmation of pipe sizes, materials, and potential obstructions. 

2. System cleaning (if required)

  • High-pressure water jetting is often carried out before the survey to remove silt, debris, grease, or root matter that would obstruct visibility. 
  • In heavily blocked or sedimented systems, mechanical root cutting or vacuum extraction may be necessary. 

3. Camera deployment

  • The camera is introduced into the pipe from an accessible point such as a manhole or rodding eye. 
  • For small-diameter domestic drains, a push-rod camera is used; for larger sewers or long runs, a crawler unit is employed. 
  • The camera is manoeuvred along the pipe, capturing continuous footage and stopping at points of interest or concern. 

4. Data capture and reporting

  • Survey footage is recorded and supplemented with real-time notes and defect codes. 
  • Defects are categorised according to national classification systems, such as the WRc Manual of Sewer Condition Classification. 
  • A full report is produced, including: 
    • Annotated video or still images. 
    • Pipe condition scores (e.g. structural and service grades). 
    • Recommendations for repairs, cleaning, or further investigation. 
    • Drainage layout maps, sometimes updated from the findings. 

This process allows for detailed understanding of the system’s health without invasive excavation or dismantling.

Common Findings from CCTV Drain Surveys

CCTV surveys can reveal a wide range of issues, from minor blockages to significant structural failures. Some of the most common findings include:

  1. Structural defects 
    • Cracks or fractures in pipe walls. 
    • Deformed or collapsed sections. 
    • Open or displaced joints. 
    • Broken pipe segments. 
  2. Service issues 
    • Silt, grease, or debris accumulation. 
    • Tree root ingress through joints or cracks. 
    • Evidence of vermin activity. 
    • Standing water or signs of backfall. 
    • Ingress of groundwater (infiltration) or escape of foul water (exfiltration). 
  3. Construction and design anomalies 
    • Incorrect pipe gradients. 
    • Poor workmanship in new installations. 
    • Cross-connections (e.g. foul water entering storm drain). 
    • Unmapped junctions or undocumented alterations. 

Accurate identification of these issues allows for informed decision-making and targeted interventions, saving time and resources.

Standards and Best Practice

In the UK, CCTV surveys are conducted in accordance with recognised industry standards and codes of practice, including:

  • WRc Manual of Sewer Condition Classification (5th Edition): Sets out standardised defect coding and grading for structural and service condition. 
  • BS EN 13508-2: European standard for the visual inspection of sewer and drain systems. 
  • Sewerage Sector Guidance (SSG): Published by water companies for sewer adoption and condition reporting. 

Surveys performed to these standards are typically accepted by local authorities, water companies, and insurers for official documentation and remedial planning.

Benefits of CCTV Drain Surveys

CCTV surveys offer a range of benefits that make them indispensable in modern drainage management:

  • Non-destructive testing: No need for excavation or system shutdown. 
  • Accurate diagnosis: Precise identification of faults, allowing for targeted repairs. 
  • Cost efficiency: Reduces unnecessary works by pinpointing problems. 
  • Compliance and documentation: Supports regulatory submissions and legal proceedings. 
  • Preventive maintenance: Helps identify developing issues before they escalate. 

They are particularly valuable in older buildings, commercial premises, or large estates with legacy infrastructure that may not be fully documented.

Limitations and Challenges

While CCTV surveys are powerful tools, there are some limitations:

  • Obstructed access: Heavy blockage or restricted entry points may prevent full inspection. 
  • Limited visibility: Poor lighting, dirty lenses, or turbid water can reduce image quality. 
  • Survey cost: Though cost-effective overall, initial outlay may be a barrier for some domestic users. 
  • Specialist interpretation: Survey data requires expert analysis for accurate diagnosis and repair recommendations. 

Despite these challenges, the benefits of CCTV inspections outweigh the limitations in the majority of drainage investigations.

Conclusion

A CCTV survey is a vital tool in the inspection and maintenance of drainage and sewer systems. By providing detailed, real-time insight into the internal condition of pipework, it enables engineers and property owners to identify and address faults efficiently, without the disruption and cost of exploratory excavation.

For professionals in plumbing, drainage, and infrastructure management, understanding how to commission, interpret, and act upon CCTV survey findings is key to maintaining reliable, compliant, and sustainable drainage systems. As technology continues to improve, the role of CCTV in proactive asset management and environmental protection will only become more central to the industry.