Proceedings

There occasionally arrives a point in time where a paradigm change is necessary to realise the true
potential of a much hyped concept. This hypothesis is often demonstrated by some of the great
entrepreneurs, with Sir James Dyson (who recently championed the role of the engineer) being a perfect
example. Described as “as man who likes to make things work better” there must have been a significant
paradigm change for Dyson to develop an improved way to clean carpets than merely “Hoover” them,
while still utilising a familiar appliance silhouette.

Are we standing at a similar crossroads with regards to contemporary sustainable drainage? Arguably
yes, if we genuinely want the concept to realise its full potential and authentically contribute to the
notion of sustainable development, itself defined so impeccably by the Brundtland Definition;
“Sustainable development is development that meets the needs of the present without compromising the
ability of future generations to meet their own needs.”

The widespread implementation of sustainable drainage (also known as “SUDS”) best management
practices (BMPs) should be integral to any contemporary development’s surface water management
strategy. This will provide the platform to mimic the response of the existing catchment and its surfaces
post development, preferably with some betterment, while negating any residual on or off-site flood risk.
However, there has been a growing belief by some that the term “SUDS” is confusing, misrepresenting
the concept and possibly redundant. It has sometimes conjured up a misplaced belief that “sustainable”
must equate to a natural drainage technique and this simply isn’t accurate. Similar to Dyson, we may
benefit from moving on from the acronym that is “SUDS” by advocating a paradigm change towards a
“sustainable drainage” concept and here’s why.

The contemporary balance for a sustainable surface water management train must unquestionably lie in
the “toolbox” of drainage techniques, including both natural and proprietary best management practices.
This should also integrate traditional and lateral (such as public engagement) techniques where
appropriate. The three established sustainable drainage key tenets of quantity, quality and amenity
remain authentic and valid. Each of the three need not be deployed in equal measures and in certain
instances, not at all dependent on the required system performance and development type. That being
said, no-one can deny the many advantages of natural drainage techniques such as infiltration, when and
where they can be appropriately implemented as authentic sustainable drainage components.

However, it is also clear that the optimum selection of contemporary sustainable drainage techniques
goes beyond quantity, quality and amenity. This is particularly pertinent given emerging challenges for
sustainable drainage including The Water Framework Directive (stronger emphasis on water quality),
climate change and flood risk management. My own wide ranging experience with Arup of implementing
sustainable drainage across a wide range of development types has underscored the importance of
construction and maintenance issues for genuine longevity and there is an overriding need to understand the whole life requirements of sustainable drainage selection for the UK water industry to meet these challenges. Determination of this ideology will confirm that a proprietary system can be designed and implemented as sustainable drainage when dictated by development constraints. However, a contemporary methodology must replace historical conventional thinking (i.e. a flow controlled and
attenuating contemporary system replacing a freely discharging conventional system).