The SuDS Manual update

The CIRIA SuDS Manual was first published in 2007. Since then, understanding has grown in the UK and internationally regarding how sustainable drainage systems (SuDS) should be incorporated into developments to maximise the many benefits that they can provide.

HR Wallingford led an update the Manual to reflect latest research and best practice, so that it would remain as the key reference document for SuDS planning and design in the UK, used by both decision-makers and practitioners.

Although the project started out as an ‘update’, in reality the manual been completely rewritten. A great deal of thought was put into scoping out the document, working closely with the very large and diverse project steering group. The new Manual has a revised structure to maximise clarity, accessibility and legibility for the breadth of the anticipated audience.  No longer is this a document just for drainage engineers. The new Manual is intended to be read by landscape architects, architects, planners, urban designers, developers, environmental regulators, ecologists, drainage approval bodies, highways authorities, sewerage undertakers, contractors and proprietary drainage and other product manufacturers.

The new Manual promotes an integrated SuDS philosophy that helps planners and designers secure the greatest value from surface water, whilst effectively mitigating flooding and pollution risks posed by surface water runoff from developments.

The types of benefits will vary depending on the site, but broadly fit into four categories: water quantity, water quality, amenity and biodiversity. The new Manual has been structured around these four ‘pillars’ of SuDS design, increasing the emphasis on amenity and biodiversity benefits alongside the main drivers for SuDS of controlling water quantity and water quality.

A key message in the new Manual is that SuDS should be considered early and fully integrated into the surface water management and urban design process. This then encourages the design of drainage systems that consider every opportunity for enhancing both natural and built infrastructure and in so doing, deliver value for money to a wide range of stakeholders including local communities.

The project team included CIRIA, the Environmental Protection Group, EcoFutures, Grant Associates and Illman Young.