Following recent developments in the industry, many Lead Local Flood Authorities are placing a pre-occupation condition in planning consent, requiring the submission and sign-off of a Sustainable Drainage Systems (SuDS) verification report.

Ensuring you and the contractor are aware of the requirements throughout the construction process is imperative to ensuring a successful project. If the correct records are not kept throughout the construction period, you may be unable to discharge the condition, leading to costly delays and, ultimately, the requirement to re-excavate the drainage system to gather the required evidence.

At Paul Basham Associates, our team of expert engineers can advise you on the measures to implement before starting work on-site to ensure a successful sign-off of any SuDS verification conditions.

Each LLFA is different, but in general, you must ensure the following:

  • The report must be prepared by qualified civil engineers with appropriate indemnity insurance and independence (such as our team at Paul Basham Associates).
  • Complete a detailed as-built survey, and survey as you go. To mitigate the risk of digging up the site, ensure the survey captures as much detail as possible. Take care to keep records throughout the build, for example, surveying the line and level of pipes, inverts of soakaways, permeable paving or attenuation crates as they are installed. A survey that shows only chamber lids won't suffice.
  • Capture dates and appropriate records of inspections undertaken by the report author and your site engineer or clerk of works. Make sure to gather photographs and details of components inspected, e.g., excavations, crate installations, sub-base construction, etc.
  • Confirm how key materials were verified, e.g., inspection of goods receipts for key components such as tanks, geomembranes, sub-base materials, flow control devices; inspections and tests of welded membrane joints, etc.
  • Provide CCTV survey video footage (including reports) of pipelines.
  • Provide details and records of any works to ditches and watercourses (don't forget the survey too).

While this incoming change in regulations may seem burdensome, it should drive quality and process improvement through the industry, avoiding costly remedial work and ensuring developers and end clients receive a great product.