Sustainable drainage for major planning applications

Sustainable urban drainage systems (SuDS) are a planning requirement for major developments, including, for example, developments of 10 dwellings or more and commercial developments of over 1,000 sq.m.

Previously, the National Planning Policy Framework (NPPF) only required SuDS to be prioritised for new developments in areas at risk of flooding. However, from 6 April 2015, sustainable drainage became a planning requirement, and all decisions on planning applications are now expected to make sure that SuDS are in place for the management of run-off.

To make sure that arrangements are in place for ongoing SuDS maintenance over the lifetime of the development, conditions are now added to planning decisions, or developers are expected to enter into a legal agreement under S106 of the Town and County Planning Act 1990 (as amended).

All major applications need to be supported by the following information. Applications will not be made valid without this information:

  1. Detailed site layout at an identified scale.
  2. Topographical survey of the site.
  3. Plans, drawings and specification of SuDS proposed. This should include detail of hard construction, soft landscaping and planting.
  4. Calculations of discharge and run-off rates, water storage capacity of the proposals, and demonstration that they meet the requirements of the site.
  5. Details of any offsite works required, together with necessary consents.
  6. Management and maintenance plan for all SuDS.

Please email for further information on SuDS and the above requirements.