Sustainable Urban Drainage Systems (SUDS)

NO ONE can deny that intense periods of heavy rainfall are placing new challenges on our country’s drainage infrastructure.  Two thirds of the devastating 2007 Summer floods were the result of surface water flooding - urban deluges which flooded over 44,600 homes with a total bill in the region of £3 billion. It’s been a “wake up call” for policymakers and for the wider construction industry.

THE House of Commons EFRA committee has made strongest call yet for a more ‘joined up’ approach to tackling what it calls the ‘confused and chaotic’ management of surface water drainage in the UK.   

EFRACOM’s (Environment, Food and Rural Affairs Committee) enquiry into flooding, reported in early June 2008, strongly echoes the initial conclusions of Sir Michael Pitt’s enquiry into last year’s devastating flooding, and the current industry consultation by Defra as part of their Future Water strategy.

EFRACOM has highlighted the urgent need to establish new Local Authority-based drainage authorities to own, co-ordinate and connect surface drainage systems more effectively within the entire water infrastructure.

This is an extremely welcome move forward.   There are currently too many bodies responsible for surface water management in the UK.  With the Environment Agency in an over-arching role, a new kind of agency based within local authorities would bring the necessary focus.

This new framework would also bring the UK into line with other major European countries and keep us on track for the ‘source to sea’ philosophy embedded in the European Water Framework Directive. However we will need to work hard to develop the necessary engineering skills to make these authorities a long-term success.

Sustainable Urban Drainage Systems (SUDS)

EFRACOM has also shown its strong support for much more widespread use of sustainable drainage systems (SUDS).  

To achieve this will mean tackling the serious misperceptions which are still deeply embedded about SUDS.  One of the guiding principals of Sustainable Drainage is to replicate the pre-developed site runoff hydrograph and deal with surface water as close as possible to the point of falling (the source) using the most appropriate means and technologies.
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However, in trying to achieve the required amenity value, many planners, developers and even some water companies tend to interpret SUDS as ‘natural’ above-ground solutions such as swales or ponds.   But, these natural solutions can have economic limitations for developers in terms of space required, and can often lead to health and safety concerns whether real or perceived.

For SUDS principles to be truly adopted requires a ‘best management’ approach using the full SUDS ‘toolbox’ of techniques to use the most appropriate for both new and retrofit applications, selected from both natural methods and proprietary technologies, including underground infiltration, storage and attenuation devices.    Full account also needs to be taken of effective control and removal of sediments and pollutants – again at the earliest stage in the process.  

“It’s 15 years since Hydro International published ‘Urban Drainage – The Natural Way’ highlighting the importance of Source Control and Sustainable Drainage (SUDS).  Those principles still apply today – and we hope that the measures taken to tackle surface water drainage will go back to those first principles. In short, the three key tenets of Sustainable Drainage of quantity, quality and amenity remain authentic and valid.”

By Alex Stephenson, Director Stormwater Division, Hydro International.

SUDS Solutions

Hydro International’s SUDS products are available from the Burdens depot network. We are stockists of Stormcell and Stormbloc which can be used for attenuation and infiltration systems.

Water Treatment & Flow Control

Burdens are suppliers of a range of Hydro International’s bespoke products designed based on specific project requirements. The Hydro-Brake Flow Control Units work in conjunction with attenuation tanks to regulate water flow from mains drainage into underground storage tanks. Be-spoke water treatment products are also available in the form of the Downstream Defender and Up Flow Filter.