When will we have a truly sustainable drainage infrastructure?

Written By: Market Development Director, Hydro International.

As Defra’s consultation on National Standards for SuDS came to a close, I was prompted to ask the question: how long will it be before they have a measurable impact on our surface water management infrastructure in the UK?

The answer is, surely not for many years.   Set to become law in Autumn 2012 at the earliest, the National Standards will apply only to new developments and redevelopment over one property.    Don’t get me wrong:  the Standards represent a hugely positive step in the right direction.  However, there is still a mountain to climb if we are to apply the visionary principles of sustainability they represent across our towns and cities as a whole.

Retrofit SuDS

CIRIA is preparing important guidance on retrofitting SuDS in urban environments which are eagerly awaited and international drainage experts are rightly getting very excited about a future for integrated water management through the principles of Water Sensitive Urban Design.  Some cities like Melbourne, Seattle and Portland (Oregon), are setting global benchmarks.

Back home, we have once again seen the public-awareness pendulum turn from flooding to drought in the past weeks.   On the day the consultation closed, hosepipe bans were being announced across the South East.  Yet there is little evidence to suggest that people recognise that drainage and water conservation are linked.

Water conservation

Where is that joined-up thinking that Sir Michael Pitt first demanded to truly combine at-source surface water drainage measures with water storage and recycling?   This would, of course, involve much closer involvement still between many agencies only just beginning to engage with SuDS in earnest, including the Water and Sewerage Companies themselves.


From a highways perspective, the new Standards are really just the tip of a very large iceberg, if we are truly to tackle the joint objectives of reducing flood risk and improving surface water quality from our road networks.

The need to upgrade local authority and Highways Agency drainage to the same sustainable standards presents a major challenge.  The Highways Agency, working closely with the Environment Agency, is making important progress.   It has shown an imaginative approach to using SuDS features on new programmes (for example at the A46 in Nottingham).  It’s also starting to work with industry and to consider the need for retrofit on the many thousands of highway drainage outfalls nationwide.

However, in terms of local authority road maintenance programmes, the task of improving highway drainage water quality remains largely on the “to do” list.  What’s more, with budget cuts and lack of ring-fenced funds, many local authorities are involuntarily neglecting to adequately maintain their highway drainage infrastructure.

True, the Standards set out important principles not only for the permissible runoff flows and volumes, but also in terms of treatment levels required to remove pollutants.  It’s also clear that a full toolbox of SuDS components will require both ‘hard’ and ‘soft’ options to deliver effective, site-specific treatment trains in future.  Highway authorities will be responsible for maintaining new SuDS schemes in public roads, although there is some uncertainty at the moment as to how that will be funded.

Treatment of runoff

Removal of sediments and other pollutants from runoff is an important principle of the National Standards.  But the fact remains that the ‘polluter pays’ principle cannot easily be enforced, when surface water is conveyed along a drainage network owned or adopted by many different agencies.  In future, we will need a much more joined-up approach for highways involving water companies, highways authorities, the EA and local authorities if we are to truly achieve authentic SuDS compliance.

For those of us who remain passionate about SuDS, the introduction of National Standards is a major milestone.  But it’s still just a marker on the wayside in a much longer journey.

The consultation on National Standards for SuDS closed on March 13.  You can view the draft standards here.



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