Sustainable Drainage

What are Sustainable Drainage Systems (SuDS)?

Sustainable Drainage systems (SuDS) are systems that:

  • deal with rainwater as close as possible to where it falls
  • store runoff and release it slowly (attenuation)
  • allow water to soak into the ground (infiltration)
  • slowly transport (convey) water on the surface
  • filter out pollutants
  • allow sediments to settle out by controlling the flow of the water

CIRIA's susdrain project has produced an animation on Sustainable Drainage Systems (SuDS) that provides an easily understandable overview of SuDS.

Sustainable Drainage (SuDS) via planning

On 18 December 2014, the Secretary of State for Communities and Local Government laid a Written Ministerial Statement setting out how Defra will be strengthening existing planning policy so that sustainable drainage system will be provided in new developments wherever this is appropriate.

These changes came into effect on 6 April 2015.

The changes are applied to new major developments where appropriate. The planning practice guidance has since been updated to reflect these changes and non-statutory technical standards for the design, maintenance and operation of sustainable drainage systems have been published.

Major developments are:

  1. Residential Development: 10 dwellings or more or residential development with a site area of 0.5 hectares or more where the number of dwellings is not yet known.
  2. Non Residential Development: Provision of a building or buildings where the total floor space to be created is 1000 square metres or more or where the floor area is not yet known, a site area of 1 hectare or more.

Unless otherwise agreed at the pre-application stage, any major planning application must now be supported with the following:

  • A detailed drainage strategy, including any arrangements for sustainable drainage, with reference to the non-statutory technical standards.
  • A maintenance plan for the lifetime of the development.


As part of the update of the CIRIA SuDS Manual, a series of priority checklists and frameworks on the planning, design, construction and maintenance of SuDS have been produced. We recommend that developers review these documents prior to requesting pre-application advice. In particular:

Brighton & Hove City Council has worked with partner authorities to produce a guide for master planning sustainable drainage into developments (PDF 10.4mb).

If you have any queries, please email