Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Revision of Draft National Standards on Sustainable Drainage Systems (SuDS) - Implementation of Schedule 3 of Flood and Water Management Act 2010. - WT0982

This project is to collate and assess recent science, guidance and evidence from both the UK and international sources, in order to robustly and comprehensively update the SuDS Manual and in so doing support the delivery of legislation, local policies, guidance and ultimately good surface water management schemes. Sustainable Drainage Systems (SuDS) are an approach to more naturally managing rainfall where it falls proving opportunities to manage the risks from flooding and diffuse water pollution as well as improving biodiversity, amenity and the quality of our places.
The relevance of updating the SuDS Manual to key policy is outlined below:

•Delivering more for less – The economic benefits of SuDS in managing and treating runoff as well as reducing runoff entering the sewage system are increasingly being recognised. Furthermore, opportunities for climate change adaptation and the delivery of multiple benefits (green infrastructure and ecosystem services) make SuDS even more attractive and essential within our built environment. Equally, there is also a need to ensure that guidance supports the delivery of affordable SuDS solutions that meet set criteria whilst making efficient use of space and reducing potential liabilities.

•Regulatory change – Since the publication of the SuDS manual the planning and regulatory framework has evolved to strengthen and in some case mandate the delivery of SuDS. The updated SuDS manual will support these regulatory changes by providing the comprehensive detail that will be required by the professionals planning, designing, approving, constructing and maintaining SuDS schemes. This is will be particularly the case with the development of the National Standards for SuDS, associated guidance (both nationally and locally).

•Local delivery, national certainty - The regulatory context is focussing on local delivery with local authorities in England and Wales having a critical role as SuDS Approval Bodies. Many LAs and some sewerage undertakers are developing their own local standards and guidance documents and it will be essential that there is nationally accepted good practice for consistent reference, thereby reducing uncertainty. Updated guidance will also support this new role for local government, helping them effectively and competently manage the costs, risks and liabilities associated with their new responsibilities.
•SuDS components – It’s accepted that on some sites (particularly high density and retrofit sites) that subsurface or hard engineered SuDS components may be the appropriate choice, particularly where storage is required and there is limited public open space. It is important that the updated Manual recognises this and provides improved guidance on generic proprietary products and their integration within the broader SuDS scheme and site.

•Water quality – Greater focus on the effective management of diffuse pollution and design of SuDS schemes to reduce pollution to acceptable levels requires further guidance. The Manual needs to be updated to exploit the latest science and evidence in this area from around the world (ie UK, Europe, USA, Australia).

No final report was produced for this project. The outputs are the revised national standards.
The specific objectives of the project are to:

• undertake a systematic review of guidance requirements of UK surface water management stakeholders (through effective engagement processes) in order to best support the widespread implementation of best practice sustainable drainage systems;
• undertake a thorough review of the national and international literature and evidence base to ensure that the Manual recommends up to date and cutting edge best practice, grounded in the latest relevant evidence, science and analysis;
• update the manual with respect to the current regulatory and legislative position across the UK relating to surface water management;
• update and improve the technical guidance within the SuDS Manual and ensure it is underpinned by evidence and good practice;
• widen the scope of the manual to include frameworks and checklists to better support SuDS approval and adoption;
• widen the scope of the manual to address the design and implementation of SuDS in specific situations e.g. urban SuDS, SuDS on contaminated sites, SuDS on sloping sites, SuDS for roads and highways, (and potentially rural SuDS)
• provide the specific guidance that is required to support statutory and non-statutory regulation and Standards;
• effectively link this document with other key publications to ensure that surface water management stakeholders are aware of and have access to the latest complementary guidance (on SuDS and related disciplines);
• improve case study material – with strong links to the objectives of delivering compliance to published Standards and delivering multiple benefits from multi-functional systems;
• disseminate the project findings widely across industry and government bodies, and to organisations with specific needs so that these can be targeted specifically.
Time-Scale and Cost
From: 2013

To: 2013

Cost: £63,999
Contractor / Funded Organisations
Water Quality