Page 119 - Bexley SuDS DESIGN & EVALUATION

9.10.2 The Principles of SuDS planting selection & design

SuDS vegetation choice and design should SuDS planting is often naturalistic in
achieve the following: character, particularly where SuDS are being
applied to a greenfield site. Naturalistic
■ General planting design should connect Detailed Design
planting is usually the most appropriate,
with the SuDS landscape, ideally with providing maximum biodiversity benefits as
grassland, woodland or ornamental
well as being cost effective, resilient and
planting creating linkages for visual most likely to have modest long term
benefit and biodiversity. The design
maintenance requirements.
criteria set out in the Biodiversity section
(9.9) should be followed where In built up areas a more formal and
appropriate. ornamental design style may be required for
raingardens, bio-retention features and green
■ Vegetation should permanently cover the

ground, both in summer and winter, to / blue roof surfaces. Recent research by the
Royal Horticultural Society (RHS) has
prevent erosion of the soil surface.
demonstrated that ornamental plants, close
■ 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
filtering water and encouraging silt to wildlife as native planting but the capital cost
settle out in components like filter strips, and management can be more difficult and
swales and basins. expensive.

■ A vigorous growth of vegetation, Contract arrangements should always allow 114
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.

■ Planting design should avoid fertilizer,

pesticides or herbicides wherever possible
to avoid leaching of chemicals into the
SuDS and groundwater. They should use
careful plant selection and a soil
conditioner such as ‘green waste
compost’ as an alternative to suppress
weed growth and improve soil fertility.

Strutts Centre, Belper.
Brick channels collect roofwater for linear
raingarden with garden style planting.

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