CCTV Survey & Investigation
Ferrymans Way
Dorset
Project Overview
Clearline Drainage was commissioned to carry out a CCTV drainage survey of both the foul and surface water networks serving a residential development in Dorset, to assess overall condition and identify the cause of reported drainage issues.
Our Approach
We traced and labelled chambers in line with the site layout and surveyed the network by CCTV to the maximum extent possible, using engineering drawings to confirm the drainage arrangement. Where blockages prevented camera progression, we recorded the extent and likely cause of the obstruction and provided video evidence to support our findings.
What We Found
The 150mm foul main line was completely obstructed by hardened screed/concrete deposits, consistent with construction debris
The blockage had caused foul water to back up into upstream branch lines, preventing a full survey of the foul network
Significant silt deposits in the surface water system prevented completion of that survey
All accessible sections of drainage that could be inspected were structurally satisfactory
Outcome
We recommended a phased approach: JetVac cleansing and re-survey of the silted surface water system, followed by specialist chain-flail cleaning of the obstructed foul main. We were clear with the client about the risks involved in chain flailing hardened deposits — namely that the material might not clear, or that the process could damage the existing pipe — and set out excavation and replacement as the fallback if that occurs. This gave the client a realistic, risk-aware plan rather than a guaranteed fix that might not hold up on site.
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