A highway drain survey is a CCTV inspection and condition assessment of drainage located in the public highway, typically required where works are proposed under section 50 of the New Roads and Street Works Act 1991. The survey establishes a baseline of drainage condition before excavation and allows comparison with a follow-up inspection after the works are complete, supporting agreement with the local authority highways team. In Greater London the survey is commonly used by Thames Water adoption schemes, utility connections, basement conversions involving the public footway and new connections to the surface water and foul sewer network. Engineers carry out the work to BS EN 13508-2, grading defects against the WRc Manual of Sewer Condition Classification. The output supports the section 50 licence application and any subsequent reinstatement under BS EN 1610.
Highway drain survey (s.50)
Survey of drainage affected by highway works, typically required under section 50 licensing.
