Page 56 - Newham SuDS DESIGN & EVALUATION GUIDE
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Concept Design  7.5.3  Preliminary water quality considerations                                                        7.5.4  Preliminary amenity considerations                                                                    Concept Design

                                                                                                                             Amenity relates both to the usefulness and
           At the Concept Design stage it is necessary
                                                                                                                             the appearance of SuDS features. Ideally
           to show how water quality is managed:
                                                                                                                             SuDS features should be integrated into the
                                                                                                                             landscape, to minimise dedicated land take
                                                                                                                             and management obligations.
              ■
                                                                 The design will also consider:
               A simple assessment of risk using the
                                                                                                                             Key amenity elements to consider when
               ‘treatment stage’ approach is acceptable
               on low and medium risk development. If
                                                                     groundwater.
                                                                                                                                ■
                                                                                                                                 Legibility – can the design be understood
               the risk screening (SuDS Manual p571)                 ■  Sensitivity of the receiving watercourse or          designing SuDS features include:                          ■  Multi-functionality – all parts of the SuDS
               demonstrates that  the ‘simple index                  ■  Environmental and technical constraints                  by users and managers?                                landscape should be available for use by
               approach’ is appropriate, then the                    such as contamination, protected                           ■  Accessibility – can all parts of the SuDS           people when not performing a SuDS
               ‘treatment stage’ is acceptable.                      landscapes, SSSI, SAC, AONB, Ancient                                                                              function.
                                                                                                                                 scheme be easily reached, both for
                                                                     Woodland and existing biodiversity
              ■  All sites should demonstrate source                                                                             recreation and maintenance? All parts of              ■  Visual character – all elements of the
               control to remove silt, heavy metals and              features.                                                   the scheme must be safe by design. It is              SuDS design must be attractive (or at
               hydrocarbon pollution at the beginning of             ■  The LPA and LLFA will not accept the                     not usually appropriate to fence SuDS                 least visually neutral, e.g. inlets, outlets
               the management train.                                 gully pot as a method of treatment. Table                   features for safety reasons (except                   and control structures) and safe.
                                                                     26.15 of the CIRIA SuDS Manual denotes                      toddler fences where young children may
              ■  Unless permeable pavement is used to
                                                                     that conventional gully and pipe drainage                   not be fully supervised).
               collect runoff, where the pavement                    provide zero treatment.
               provides high water quality treatment,
  51           there will usually be a second feature to                                                                                                                                                                                  52
               manage additional volumes and provide
               additional treatment.                                                                                         7.5.5  Preliminary biodiversity considerations
                                                                                                                             There are key biodiversity requirements that
                                                                                                                             should be demonstrated at the Concept
                                                                                                                             Design stage:

                                                        Design Note:                                                             ■  Clean water – ‘a controlled flow of clean          ■  Topographical diversity – variation in

                       Where there is a high risk of pollution, a formal risk assessment is required.                            water’ is provided by the use of source               vertical and horizontal structure allows for
                                                                                                                                 control at the beginning of the                       complex habitat development. This is
                                                   High-risk development:
                                                                                                                                 management train. Subsequent surface                  implicit in SuDS design, e.g. swales, basins,
              Trunk roads and highways – follow the guidance and risk assessment process set out in HA                           conveyance and open SuDS features will
                                                           (2009)                                                                                                                      ponds and wetlands.
                                                                                                                                 ensure connectivity and habitat
             Haulage yards, lorry parks, highly frequented lorry approaches to industrial estates and waste                      opportunities.                                        ■  Ecological design - the creation of
                sites, sites where chemicals and fuels (other than domestic fuel oil) are to be delivered,                                                                             habitats within the development.
                 handled, stored, used or manufactured and industrial sites. Discharges may require an                           ■  Connectivity - habitat connections                 ■  Sympathetic management – through
                 environmental licence or permit obtain pre-permitting advice from the environmental                             outside and within the development                    considered management, a mosaic of
                                    regulator. Risk assessment is likely to be required.                                         ensure that plants and animals can travel             habitat types can be created, ensuring

                                               CIRIA The SuDS Manual 2015                                                        between habitat areas.                                maximum ecological value.



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