Page 69 - Updated SuDS Design & Evaluation Guide-Newham V3 Spreads

P. 69

Outline Design 8.6 Affordability more expensive but avoids extensive pipe 8.8 Outline information required for SuDS evaluation Outline Design

The design of SuDS is influenced by the type
8.8.1
of development and how important each
work, gullies, manhole, dedicated SuDS
The Outline SuDS Design will show what the
The information required at Outline Design
component is to the appearance and
storage and in some situations oil
stage will depend on whether a Concept
scheme will look like, how it will function and
functionality of the scheme.
interceptors. The open graded sub-base
confirm any additional information provided
Design has been provided and the level of
provides 30% void storage which is
An urban renewal project in the city will
since Concept Design Stage.
information included at that stage.
require a different approach to the visual
of maintenance into the future.
quality than a simple SuDS design for a
plan form, confirming site layout and SuDS
suburban layout. confirmed by a flow control and a low level The design information should be provided in
Completing a cost comparison for permeable
infrastructure together with a SuDS Design
pavement demonstrates the wider
SuDS components are cost effective when Statement presenting all information that
considerations of drainage, surfacing and
compared to conventional drainage but cost cannot be conveyed on plan.
savings are only realised through good SuDS engineering profiles that have to be
considered.
design.
8.8.2 Outline Design – information checklist
A good example of cost effective SuDS Evidence for the cost effectiveness of
design is the use of permeable pavement as Information recommended in the ASA Practical
SuDS can be found here: http://www.
a replacement for impermeable surfaces. The susdrain.org/resources/evidence.html Guidance
cost of the profile construction is marginally
■ Flood Risk Assessment (FRA) – a review ■ ground investigation review
of critical elements
■ evidence of third party agreement for
63 8.7 Management of the SuDS resource ■ Outline Design Strategy Statement consent to discharge or agreement in 64
principle.
The future maintenance of SuDS is influenced In other locations a SuDS feature can ■ Outline Design Plan – layout
by design. Wherever possible the idea of contribute to landscape infrastructure e.g.
‘passive maintenance’ should be considered the ‘rain garden’ or ‘bio retention’ element in ■ the plan will incorporate preliminary
landscape proposals
with SuDS components integrated into the design.
everyday management.
Wherever possible maintenance should be
Additional information to inform evaluation of the scheme:
Although there will be situations where allocated to site care rather than SuDS
dedicated SuDS components are appropriate management.

e.g. a pond or wetland, many SuDS features This reduced dedicated maintenance ■ topographical information and flow route ■ sensitive receptors for runoff where
can be incorporated into multifunctional analysis appropriate e.g. SSSIs
obligation can sometimes be reduced to just
space e.g. courtyards, play basins and checking inlets, outlets and control ■ destination and discharge route of rainfall ■ offsite works that may be required
recreational space. via infiltration or runoff
structures. ■ general maintenance principles

Design Note : ■ infiltration investigation results where ■ design life of any products used and
appropriate
Well designed SuDS are not ‘land hungry’ in that they can be integrated into both hard and requirements for potential replacement.
soft landspace spaces which are available within development. Making SuDS cost effective ■ existing utilities plan confirming existing
reinforces the requirement to consider SuDS layout at Concept Design stage. watercourses or sewer locations

64 65 66 67 68 69 70 71 72 73 74