Drainage Strategy | Drainage Assessment

The purpose of a Drainage Strategy or Preliminary Drainage Assessment Schedule is to investigate and advise on the most appropriate drainage solutions.

Drainage Strategy | Drainage Assessment
Planning authorities require assurances about the rigour of the drainage strategy – that it incorporates sustainable and practical drainage solutions; mitigates against flooding, and is realistic.

Early consideration of flood risk and drainage strategy in a scheme can provide considerable cost benefits where drainage requirements affect development layout and land use.  Waterco reports on issues of drainage can be used to gain planning permission and additionally, can be used in a preplanning assessment.

The purpose of a Drainage Strategy or Preliminary Drainage Assessment Schedule is to investigate and advise on the most appropriate drainage solutions. This is delivered in a written report which demonstrates to the planning authority that the site drainage can be effectively dealt with.  The report includes:

  • a review of existing drainage records provided by the client
  • advice on location and Building Regulation Part H percolation test method
  • analysis of percolation test results to determine suitability for soakaways
  • assessment of the impermeable areas and peak rates of run-off where soakaways are not suitable
  • calculation of the volume of run-off pre and post development and identification of how the
  • additional volume could be dealt with (by infiltration, rainwater recycling or attenuated discharge)
  • the submission of the Official Developer Enquiry to Sewerage Operator
  • consultation with Environment Agency, Sewerage Operator, Highway Authority, Planning Authority, Building Control and land owners, if appropriate
  • assessment of drainage options for the site
  • provision of suggested solutions for foul sewerage disposal, surface water disposal and access road drainage
  • recommendations regarding the next steps to be taken in the detailed design.

For further information about drainage strategy please contact:

SuDS Approval Body (SAB) Wales

New legislation (with the introduction of Schedule 3 of the Flood & Water Management Act) in Wales requires new development to have SuDS approval in conjunction with the planning process.

This means new development must incorporate Sustainable Drainage Systems (SuDS).

Waterco can advise on the best form of SuDS on a development by development basis.

To find out more about the new legislation, what SuDS options are available, and how Waterco can help, please visit our SuDS website at: https://www.suds.wales