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Concept Design  7.4.2  Building the Management Train           ■  Source Controls: green and blue roofs,

           A successful management train begins with
           source control, and uses surface conveyance,
                                                                     permeable surfaces, filter strips, protected
                                                                     filter drains, together with some swales
           wherever possible, to link subsequent SuDS
                                                                     and basins, provide the first stage of
           components in series. Integration of the
           management train should be considered from
                                                                     treatment, intercepting primary pollution
           the Concept Design stage and throughout
                                                                     and reducing runoff flow rates.
           the design process.


                                                                     be preceded by source controls, and meet
           The management train provides potential for
                                                                     remaining storage requirements.
           ‘interception losses’ along its whole length, as          ■  Site Controls: these features will normally
           well as through soakage into the ground,                  Permeable surfaces will often store the
           evaporation, and transpiration through the                whole attenuation volume. Where the is
           leaves of vegetation. It also reduces the rate            insufficient storage at source, additional
           at which runoff flows through the site, and               open conveyance and storage structures,
           provides treatment of runoff as it passes                 such as basins and protected wetlands or
           through each SuDS component.                              ponds, will manage remaining runoff
                                                                     volumes on most sites.
           Selecting SuDS components within the
           management train:                                         ■  Regional Controls: where it is difficult to
                                                                     store all the runoff within a development
                                                                     boundary, clean water can be conveyed to

  31                                                                 open storage features within public open
                                                                     space or other parts of a development to
                                                                     contribute to open space amenity.
           Flow Controls can be incorporated in green
           roofs to manage volumes and provide source
           control, transforming them into ‘blue roofs’.






























           London Borough of Bexley SuDS D & E Guide                                                        © 2018 McCloy Consulting & Robert Bray Associates
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