Sustainable Drainage Systems

The Council requires the use of Sustainable Urban Drainage Systems (SuDS) to manage surface water in a sustainable way.

SuDS in new developments

From April 2015 sustainable drainage is a material consideration in planning decisions. To reduce the risk of surface water and sewer flooding, all development proposals in the borough that could lead to changes to, and have impacts on, surface water run-off are required to follow the London Plan drainage hierarchy.

The Council requires that SuDS are used in all development proposals.

From Monday 1 April 2019, applicants are required to complete a London Sustainable Drainage Proforma for all planning applications.

Applicants will have to demonstrate that their proposal complies with the following:

  1. A reduction in surface water discharge to greenfield run-off rates wherever feasible
  2. Where greenfield run-off rates are not feasible, this will need to be demonstrated by the applicant, and in such instances, the minimum requirement is to achieve at least a 50% attenuation of the site's surface water runoff at peak times based on the levels existing prior to the development

The Council will:

  • Ensure that the minimum standards of operation proposed by the applicant are appropriate
  • Ensure through the use of planning conditions or planning obligations that there are clear arrangements in place for ongoing maintenance of the SuDS scheme over the lifetime of the development

In all applications for development, developers or applicants must include a statement outlining the proposed Sustainable Drainage System to be incorporated in the development, along with details for their long term management and maintenance. 

The SuDS guidance document(pdf, 1364KB) provides advice to developers, applicants, designers, householders and others on how to incorporate SUDS within new developments of all types and sizes.

For further information please see Lead Local Flood Authority (LLFA).

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Updated: 15 March 2019