The human version (we wrote this, not the council)
This section adds detail on how sustainable drainage systems should be designed. SuDS must be planned as an integral part of the site layout, favouring above-ground and dispersed features rather than reliance on one large storage feature. They should deliver several benefits at once: reducing flood risk, cleaning water through a four-stage treatment train, boosting wildlife, providing attractive amenity space and helping to cool urban areas. Drainage features should also become part of the wider ecological network.
An unofficial plain English summary. The official wording below is
what counts at examination; check it before you rely on anything here.
The text below is extracted automatically from the official PDF and may
contain artefacts; the PDF is authoritative.
th.
Policy ID.12
Multifunctional Sustainable Urban Drainage Systems
High-quality, multi-functional Sustainable Drainage Systems
(SuDS) must be implemented proportionately across the whole site
to manage surface water runoff, reduce flood risk and deliver wider
environmental benefits.
A. Drainage Strategy
Development proposals must demonstrate, through a Drainage Strategy, that:
1. surface water runoff will be managed as close to source as possible;
2. there will be no flooding of properties from all sources up to and including the
1% Annual Exceedance Probability (AEP) event, plus appropriate allowance for
climate change; and
3. development will not increase flood risk on-site or to the surrounding areas
Proposals must give early consideration to overland flow routing when designing site
layouts. Development should be sympathetic to existing watercourses and surface
water flow paths. Blue-green corridors should be retained and enhanced to reduce
flood risk, improve water quality, support biodiversity and provide amenity space, and
aligned with the Local Nature Recovery Strategy priorities. Development proposals
must protect and improve the quality of water bodies.
On brownfield sites, development must be disconnected from surface water and
highway drainage from combined sewers wherever feasible.
B. Sustainable Urban Drainage Systems (SuDS)
SuDS must be designed as an integral part of the site layout and should:
1. prioritise above-ground, source-control and dispersed SuDS features rather
than reliance on single large storage features;
2. provide multiple benefits, including flood risk reduction, water quality
improvement meeting the four stage SuDs treatment train, biodiversity
enhancement with features designed as habitat assets amenity and landscape
integration, including accessible GBI and urban heat island mitigation
3. become integral components of the wider ecological network and be in line
with the Loc