The Royal Naval College

Comprehensive CCTV Drainage Survey and Maintenance Planning

A large commercial site approached our call centre to request information on annual planned maintenance options and emergency call-out support. During our initial discussions, it became clear that the client did not have recent or reliable information about the current condition of their drainage system. To ensure any maintenance plan would be meaningful and cost-effective, we proposed a full assessment of the underground drainage network and arranged a site visit.

Phase 1: Initial Survey and Preparation

Phase 1 involved a fully comprehensive CCTV survey carried out over eight days. Before the inspection could begin, a specialist tanker service was deployed for two days to remove accumulated debris and blockages from the drainage lines. Clearing the pipework was essential, as it allowed the cameras to enter the system unobstructed and ensured that the footage obtained would be accurate and usable.

The footage from Phase 1 provided a valuable overview but also revealed several areas that required deeper inspection. Some drainage routes were partially inaccessible, while other sections showed indications of structural deterioration, hidden debris and restricted flow points. Based on this information, the client authorised a second phase of works to complete the analysis.

Phase 2 : Advanced Survey and Specialist Access

Phase 2 involved a further eleven days of CCTV survey work. This extended inspection was required to reach complex sections of the system, including deeper drainage runs and junctions. An additional three days of tanker support were also necessary to manage more significant deposits and to create clear access pathways for the survey equipment.

Because certain areas of the drainage network posed higher safety risks, confined space entry procedures were implemented. Our team utilised the appropriate safety equipment and followed all regulatory guidance to enter these areas safely. This allowed us to document and assess manholes, enclosed chambers and other difficult-to-reach drainage structures that could not be inspected during Phase 1.

Outcomes and Client Benefits

By the end of the project, the client received a complete and detailed overview of the drainage system. The findings highlighted:

• Areas affected by debris build-up and reduced flow.

• Structural defects and potential weak points within the network.

• High-risk locations where preventative maintenance would be more cost-effective than reactive repairs.

The combined work over both phases provided the client with actionable insights needed to plan future maintenance and avoid unexpected drainage failures.