What are SuDS?

December 2015 was the wettest month on UK record and saw over 16,000 homes flooded, highlighting the fact that our towns and cities aren’t well equipped for high levels of water and prompting the question – ‘How can the UK be better prepared for such extreme weather conditions?’

One of the ways in which the risk of flooding can be reduced is through the use of SuDS (Sustainable Drainage Systems). We’re often contacted for more information about SuDS, so we sat down with Martin Lambley, Product Manager for Foul, Utilities and Water Management to answer some of your FAQS.

What is SuDS drainage?

In their latest SuDS manual, CIRIA offers the following definition: ‘’Sustainable drainage systems (SuDS) are designed to maximise the opportunities and benefits we can secure from surface water management.’’

Fundamentally, SuDS mimic mother nature in urban environments where there tends to be less permeable ground for infiltration. When rain falls on impermeable surfaces like pavements and car parks, the risks of flooding and erosion are increased because water has nowhere to runoff and be drained away, so SuDS can be installed to manage rainwater where it falls.

What types of SuDS are available?

SuDS can take many forms and operate both above and below ground – some involve the use of landscaping whereas others include manufactured products such as our AquaCell units.

The type of SuDS chosen for a project depend on a range of factors. Traditional ‘SuDS thinking’ divided SuDS into two different types: soft (green) and engineered (grey).

Soft SuDS uses green landscaping to manage water within the site whereas engineered SuDS makes use of civil engineering structures such as culverts and underground tanks to manage water. However, recent changes in thinking now means many schemes incorporate elements of both soft and engineered SuDS within one holistic scheme.

The difference between these two types of SuDS was explored in our webinar with Building Magazine which you can listen to here.

Who maintains SuDS?

As with all drainage systems there is a requirement for SuDS systems to be inspected and maintained. A defined maintenance program will ensure that the SuDS scheme operates effectively through the life cycle of the development.

The issue of who is responsible for SuDS maintenance remains a complex one. Current planning legislation, whilst defining the requirement for a SuDS scheme, provides no guidance on where the responsibility for maintenance lies.

Susdrain suggest that, in the absence of legislation, funding for the SuDS adopter to provide the necessary maintenance needs resolving at the start of a project to ensure the local authority, maintenance-company, water-company or residents have the resources to maintain the scheme in the long-term.

For more information on SuDS or to download a digital version of CIRIA’s SuDS Manual, please visit www.susdrain.org