26th May 2017

Delivering Healthy Cities – SuDS and True Collaboration

Paul Morris, one of our Directors recently gave a lecture about “Water in the Urban Environment” at the University of Manchester. The focus of the lecture was on the importance of collaboration to deliver functional, sensitive and resilient infrastructure, that helped to mitigate some of the negative impacts from increased urbanisation and the burning of fossil fuels for industry, energy and transport. A key theme within this was the introduction of green infrastructure and SuDS into our urban centres.

At the end of the lecture a poignant question was asked; “Will engineers ever truly embrace SuDS and a collaborative approach to the design of infrastructure?” Here are our thoughts on the answer to this crucial question.

Green infrastructure is key to healthier cities

There is no doubt that green infrastructure is key to creating healthier cities. With our urban centres growing in scale and density, our public space needs to provide the amenity benefits that the urban population demand. Once the need to introduce more green space into our towns and cities is accepted, the obvious next step is to utilise this space to manage surface water. Managing surface water effectively reduces flood risk, manages the pollution entering our watercourses and brings a host of additional social and economic benefits.

We believe that the approach Civic Engineers take to the design of our infrastructure will ultimately become the norm. There is though a process of change to go through in terms of people’s expectations of what they believe and expect their infrastructure to provide and how this can be designed, delivered and valued within the parameters, as set out in policy, guidance and funding mechanisms.

Many engineering practitioners have already embraced SuDS and there are many excellent schemes across the UK. In the relatively short term SuDS will be accepted as a necessary, functional element of our urban landscape.

What is stopping true collaboration?

Achieving true collaboration is an issue that is difficult to resolve, as is the challenge of how high value urban infrastructure can be designed and delivered. The street which responds to its context and encourages people to dwell, spending both time and money, is vastly more valuable to its place than the street which focuses purely on through movement. It is more challenging to design however, relying heavily on close collaboration between engineer, architect, urban designer, landscape architect, artist, local communities, traders and an array of other stakeholders.

Manual for Streets, published in 2007, sought to address this challenge and promote a collaborative approach towards designing streets that become high quality places and ultimately contribute to the creation of sustainable communities.

The approach promoted by Manual for Streets saw a move away from designing to meet a set of rules and instead required design decisions to be taken collaboratively, based on reason. Unfortunately, many practitioners, and engineers in particular, skipped the information on alternative approaches to design. They instead focused on the small section of the document which could be interpreted as establishing new ‘rules’ with regard to areas they felt comfortable with, such as stopping distance and geometry. As a result, the wholesale shift to designing urban streets as places, rather than movement corridors never truly occurred and few still acknowledge the street as being about more than a corridor for movement. Ambition and aspiration was curtailed in order to limit the much needed true collaboration and ensure that one could always refer to the rule book.

How can we embrace SuDS?

There are similarities to be drawn between the approach to streets in general and the design and implementation of green infrastructure and SuDS. As drainage systems now contribute more than just their rudimentary function, they do require an alternative approach to design. As with streets, what is needed is an approach largely based on reason and collaboration, rather than the rules that can be applied to a below ground drainage system.

The ICE recently published an article acknowledging the issues above as preventing SuDS from being the norm when designing infrastructure. It is suggested that SuDS should be simplified to encourage wider use. In reality, this means standardisation and the production of an ‘oven ready’ approach that can be rolled out without true consideration for context and the potential added value SuDS could bring.

There are obvious added benefits in making SuDS easier to deliver, there are also benefits around adoption and maintenance that would be achieved through a standardised approach. It is critical however to ensure that any standardised approach does not stifle the design of site specific, ambitious SuDS schemes which respond to their context and contribute positively in terms of amenity and biodiversity.

Transport for London SuDs Guidance