Policy information sourced from Enfield Development Managament Document (DMD)

DMD 61 Managing Surface Water

A Drainage Strategy will be required for all developments to demonstrate how proposed measures manage surface water as close to its source as possible and follow the drainage hierarchy in the London Plan. All developments must maximise the use of and, where possible, retrofit Sustainable Drainage Systems (SuDS) which meet the following requirements:

  • Suitability
    • SuDS measure(s) should be appropriate having regard to the proposed use of site, site conditions/context (including proximity to Source Protection Zones and potential for contamination) and geology.
  • Quantity
    • All major developments must achieve greenfield run off rates (for 1 in 1 year and 1 in 100 year events).
    • All other development should seek to achieve greenfield run off and must maximise the use of SuDS, including at least one ‘at source’ SuDS measure resulting in a net improvement in water quantity or quality discharging to sewer in-line with any SuDS guidance or requirements.
  • Quality
    • Major developments must have regard to best practice and where appropriate follow the SuDS management train by providing a number of treatment phases corresponding to their pollution potential and the environmental sensitivities of the locality.
    • Measures should be incorporated to maximise opportunities for sustainable development, improve water quality, biodiversity, local amenity and recreation value.
  • Functionality
    • The system must be designed to allow for flows that exceed the design capacity to be stored on site or conveyed off-site with minimum impact.
    • Clear ownership, management and maintenance arrangements must be established.
  • Other
    • Where appropriate, developments must incorporate relevant measures identified in the Surface Water Management Plan.

The criteria above must be demonstrated through the submission of a site specific FRA, where one is required, or a Sustainable Design and Construction Statement.

This Policy should be read in conjunction with Core Strategy Policy 28.

For more information please see the Development Managament Document (DMD)