Source control SUDS delivery on a global scale and in Scotland including approach by responsible organisations and professional groups

Background to research
The Sustainable Urban Drainage Scottish Working Party via CREW commissioned this work on the implementation of source control for SUDS in Scotland. The project is being carried out by researchers based at Abertay University Dundee involves three phases. These are presented in separate reports; this report covers phase 2 of that work. Source control sustainable urban drainage systems (SUDS) are an established technique in many parts of the world. Source control SUDS are a key component of what is termed the stormwater treatment train. Source controls manage the more frequent but smaller polluting rainfall events as close to the source as possible (where the rain falls). Site and regional control SUDS are larger downstream structures which manage the longer term rainfall events and provide additional treatment when required. One of the key advantages of managing the more frequent rainfall events at source is that downstream site and regional SUDS will have longer life spans resulting in overall cost efficiencies. Scotland is regarded as a frontrunner in the UK regarding implementation of SUDS with site and regional drainage structures now considered ‘business as usual’. However the uptake of source control is less routine than would be expected.

Objectives of research
Phase one of this research looked at the background to the evolution of source control in Scotland to provide an insight into the enabling factors and obstacles for uptake of the systems since. Phase two(this report) appraises delivery of the systems in seven countries and case studies are developed to understand why source control was implemented and how it was achieved. The current delivery by responsible organisations and professional groups which encourage and influence the source control agenda in Scotland is also appraised. Using these findings, the transition pathway from traditional drainage to source control SUDS are reconstructed and mapped out to highlight the historical and current enabling (and disabling) factors to realise the transition to date. A transition framework is used to highlight the transition strengths developed by responsible organisations over the last two decades which had assisted in accelerating the transition.

Key findings and recommendations
Key outcomes of this research include:
* In Scotland the source control vision and agenda is fragmented due to different stakeholder drivers and funding mechanisms.
* There are examples of the use of incentives in Scotland (i.e. legislative, regulatory, financial,social and environmental) to drive integrated agendas. However these have not been successfully showcased to provide the evidence base for encouraging replication and up-scaling of the methodologies and techniques.
* There are limited frontier source control SUDS ‘niches’ to nurture innovative techniques such as raingardens – a learning by doing concept. A more focused research agenda to validate these systems as viable sustainable solutions for Scotland would assist in accelerating uptake.
* Lack of sector engagement, particularly with the public is a disabling factor for uptake.

A final observation from this phase of the study is that requests from various interested parties for CREW / SUDS Working Party to share outputs indicates the need for this research.