Page 118 - Newham SuDS DESIGN & EVALUATION GUIDE
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Detailed Design  9.10 Planting design for SuDS                                                                         9.10.2 The Principles of SuDS planting selection & design                                                    Detailed Design


           The choice of vegetation cover and plant
                                                                                                                                                                                    SuDS planting is often naturalistic in
                                                                                                                             SuDS vegetation choice and design should
           species is an important aspect of designing
                                                                                                                             achieve the following:
                                                                                                                                                                                    character, particularly where SuDS are being
           SuDS systems and features.  Vegetation is an
                                                                                                                                                                                    applied to a greenfield site. Naturalistic
                                                                                                                                ■
                                                                                                                                 General planting design should connect
           inherent functional part of any soft-landscape
                                                                                                                                                                                    planting is usually the most appropriate,
                                                                                                                                 with the SuDS landscape, ideally with
           SuDS feature as well as being about
                                                                                                                                                                                    providing maximum biodiversity benefits as
                                                                                                                                 grassland, woodland or ornamental
           aesthetics, usability and wildlife benefits.
                                                                                                                                                                                    well as being cost effective, resilient and
           Vegetation type and species selection can
                                                                                                                                 benefit and biodiversity. The design
                                                                                                                                                                                    maintenance requirements.
           significantly affect hydraulic and pollution
                                                                                                                                 criteria set out in the Biodiversity section
           control functionality as well as the                                                                                  planting creating linkages for visual              most likely to have modest long term
                                                                                                                                 (9.9) should be followed where                     In built up areas a more formal and
           contribution to amenity and biodiversity.
                                                                                                                                 appropriate.                                       ornamental design style may be required for
           The SuDS plant palette will often vary from                                                                          ■                                                   raingardens, bio-retention features and green
           conventional landscape design for reasons of                                                                          Vegetation should permanently cover the            / blue roof surfaces. Recent research by the
                                                                                                                                 ground, both in summer and winter, to
           SuDS functionality, different ground                                                                                                                                     Royal Horticultural Society (RHS) has
           conditions and to protect the wider                                                                                   prevent erosion of the soil surface.               demonstrated that ornamental plants, close
           environment from chemical contamination.                                                                             ■  The matrix of roots, stems and leaves of         to the wild type, especially from the northern
                                                                                                                                 vegetation slows the flow of runoff,               hemisphere can provide similar benefits to
                                      Strutts Centre, Belper.
               Contemporary ‘prarie’ planting in raingarden                                                                      filtering water and encouraging silt to            wildlife as native planting but the capital cost
              collecting roof runoff and access road runoff.                                                                     settle out in components like filter strips,       and management can be more difficult and
                                                                                                                                 swales and basins.                                 expensive.

  113                                                                                                                           ■  A vigorous growth of vegetation,                 Contract arrangements should always allow             114
           9.10.1 Objectives of planting design for SuDS                                                                         particularly when forming an extensive             for additional or remedial works to ensure the
                                                                                                                                 root mat, encourages natural losses into           integrity of vegetation surfaces that perform
                                                                                                                                 the ground throughout rainfall events.             a SuDS function.
           SuDS planting design should satisfy general               ■  augmenting biodiversity by structure,
           planting design criteria and relies on an                 species richness and careful management                    ■  Planting design should avoid fertilizer,
           awareness of the landscape maintenance                    (refer to the Biodiversity section 9.9)                     pesticides or herbicides wherever possible
           requirements. In addition, planting should                ■  creating attractive surroundings and                     to avoid leaching of chemicals into the
           fulfill specific SuDS functions, such as:                                                                             SuDS and groundwater. They should use
                                                                     community amenity                                           careful plant selection and a soil
              ■  preventing soil erosion
                                                                     ■  protection of the environment by avoiding                conditioner such as ‘green waste
              ■  trapping silt and pollution from runoff             the need for herbicides, pesticides or                      compost’ as an alternative to suppress
                                                                     fertilizer treatment.                                       weed growth and improve soil fertility.
              ■  encouraging interception (evaporation,
               infiltration and transpiration)

              ■  enabling long term infiltration by opening
               soil profiles through the root growth cycle
                                                                                                                                                        Strutts Centre, Belper.
                                                                                                                                    Brick channels collect roofwater for linear
                                                                                                                                       raingarden with garden style planting.


           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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