On any site with existing drainage, the first question is what is already in the ground. A CCTV survey answers it: where the runs go, what condition they are in, what connects to what, and whether any of it can be kept. Without that, a drainage design for a redevelopment or an extension is guesswork.
The surveys themselves are carried out by Clear Drain, using NADC-approved surveyors. Onn Point takes the survey output and turns it into a drainage design, a strategy for planning, or the evidence needed to discharge a condition.
What a survey shows
A camera is passed through the drain or sewer and the internal condition recorded along its length. Defects are coded to the industry standard so the report means the same thing to a designer, an adopting authority and a contractor. A survey will typically identify:
- The route and depth of existing runs, and where they connect
- Structural defects — cracks, fractures, deformation, displaced joints
- Service defects — root ingress, silting, scale, debris and blockages
- Whether foul and surface water are genuinely separate, or wrongly connected
- Whether an existing run has the capacity and condition to be reused
When a survey is needed before design
Redevelopment and brownfield sites
Existing drainage on a previously developed site is rarely recorded accurately, and record plans are often decades out of date. A survey establishes what is actually there before a layout is fixed, which is usually cheaper than discovering it during groundworks.
Connecting to an existing sewer
Before a connection is designed or agreed with the water company, the receiving run needs to be shown to be in serviceable condition and correctly identified as foul or surface water. Misconnections are common and expensive to unpick after the fact.
Sewer adoption
Where drainage is being offered for adoption under a Section 104 agreement, the water company will expect a post-construction CCTV survey demonstrating the works have been built correctly and are free of defects before adoption completes.
Diagnosing a problem
Where flooding, slow drainage or repeated blockages are the reason for the work, a survey identifies the cause before anything is designed to fix it — and sometimes shows the fix is a repair rather than a new system.
What happens with the results
A survey on its own is a report. What makes it useful is what follows: an existing drainage plan, a decision on what to retain and what to replace, a connection strategy, and where relevant a drainage design that can be submitted to the local planning authority. That is the part we do.
Frequently asked questions
When do I need a CCTV drainage survey?
Whenever the existing drainage matters to the design — redevelopment sites where the record plans are decades old, connections into an existing sewer, sewer adoption, or where flooding and repeated blockages need a cause before a fix.
What does the survey report show?
The route, depth and connectivity of the existing runs, and any defects coded to the industry standard — cracks, fractures, displaced joints, root ingress, silting — so the same report means the same thing to the designer, the adopting authority and the contractor.
Do I need a survey for sewer adoption?
Yes. Where drainage is being offered for adoption under a Section 104 agreement, the water company will expect a post-construction CCTV survey showing the works have been built correctly and are free of defects before adoption completes.