Stuart Crisp, UK manager of Advanced Drainage Systems (ADS), looks at looming legislation which will mandate Sustainable Drainage Systems and explains why their adoption will require new skills for specifiers and developers.
In January 2023, the Government announced plans to finally implement Schedule 3 of the Flood and Water Management Act 2010, which will make the adoption of Sustainable Drainage Systems (SuDS) mandatory in England, as it has been in Wales since 2019. In Scotland, Schedule 3 has not been implemented, but SuDS is generally a requirement within planning legislation.
“Schedule 3 is a game changer for the drainage industry”
Subject to consultation, the implementation of Schedule 3, which includes SuDS approval and adoption, is expected in late 2024. That means there is less than a year for specifiers and developers to get up to speed with the range and implications of possible solutions, both above and below ground.
While developers currently have the right to connect drainage systems into sewers, that is unlikely to be the case anymore without prior justification and consent. Instead, they will have to show that they have included SuDS in their schemes and demonstrate how that SuDS system can be maintained over the lifetime of a development.
Designers and specifiers will have to think about more than just hydraulic design, and consider whole-life maintenance and treatment to deal with water quality issues and specific pollutants. There will probably be a transition period as Schedule 3 comes in, but it makes sense to upskill now in order to future-proof the design and specification of systems that are being planned now.
Currently, SuDS can be adopted by water companies as long as systems comply with the Design and Construction Guidance (DCG), which sets out how SuDS should be delivered. However, it is not compulsory to jump through the adoption hoops. The end result of this is that some assets do meet prescribed and consistent standards of quality and performance, may not be properly maintained and, consequently, there are problems down the line.
The DCG was updated last year to include arch-shaped belowground attenuation structures. One such system offers a flexible and cost-effective alternative to other below-ground attenuation structures such as crates or large-diameter pipes, with the benifit of built-in stormwater quality management, reducing the extent of additional treatment required elsewhere in the SuDS system.
It is expected that Schedule 3 will change the assessment and adoption of SuDS to become SuDS approving bodies (SABs), which will be within unitary councils or county councils. And new statutory guidance will be introduced, taking over from DCG to cover design, construction and operation over an asset’s lifetime.
The statutory requirements in England may be more onerous than both the DCG and the current non-statutory standards in terms of what will be acceptable for planning approval and adoption after construction. SuDS adoption becoming mandatory, with few exceptions, will raise the bar.
Happily, poor quality products and poorly executed designs are likely to be challenged and disappear from the market. For anyone looking to start the upskilling process now, training and CPDs are already available from some manufacturers and should include information on legislation, best practice and comparable systems.
