Page 37 - SuDS Design & Evaluation Guide-Newham V4 Spreads

P. 37

Concept Design 7.4.2 Building the Management Train ■ Source Controls: green and blue roofs, 7.4.3 Collection of runoff from hard surfaces Concept Design

Surface collection in channels, gutters and
The way that runoff is collected from roofs,
A successful management train begins with
permeable surfaces, filter strips, protected
source control, and uses surface conveyance,
roads, car parks and other hard surfaces is a
permeable pavements, or as sheet flow onto
filter drains, together with some swales
grass surfaces, keeps runoff at or near the
wherever possible, to link subsequent SuDS
critical consideration in any SuDS design.
and basins, provide the first stage of
components in series. Integration of the
surface, enabling cost-effective and visually
Conventional drainage techniques such as
legible design.
management train should be considered from
treatment, intercepting primary pollution
gully pots and pipes, promote the
the Concept Design stage and throughout
and reducing runoff flow rates.
Collection of runoff at or near the surface
concentration of flows and mobilisation of
the design process.
for simple removal of blockages.
be preceded by source controls, and meet
The management train provides potential for
so that management of runoff at or near the
remaining storage requirements.
‘interception losses’ along its whole length, as ■ Site Controls: these features will normally pollutants, forcing runoff deep underground, also reduces maintenance costs, and allows
surface is difficult to achieve.
well as through soakage into the ground, Permeable surfaces will often store the
evaporation, and transpiration through the whole attenuation volume. Where the is Highway runoff is intercepted using a chute
leaves of vegetation. It also reduces the rate insufficient storage at source, additional gully and taken into a conveyance swale at this
at which runoff flows through the site, and open conveyance and storage structures, retrofit SuDS project. Devonshire Hill, Haringey.
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 32
space or other parts of a development to
contribute to open space amenity.
Flow Controls can be incorporated in green Permeable paving and planted open channels
roofs to manage volumes and provide source collect runoff from hard surfaces at Bewdley
control, transforming them into ‘blue roofs’.
School, Worcestershire.

32 33 34 35 36 37 38 39 40 41 42