by Ruth Slavid
As droughts and floods become more frequent, so does the importance of planning and designing with a new respect for water. The principles are now broadly understood, but landscape professionals need to learn more about detail and to spread the word. The following series of articles should help.
When Sue Illman took over as president of the Landscape Institute last summer, she announced that she would make water one of her key concerns.
This chimed with much of the work that her own practice, Illman Young, has been doing in the realm both of SuDS (sustainable urban drainage solutions) and of WSUD (water-sensitive urban design). But it was also timely, which was why she laid such emphasis on it.
We have reached a stage at which we can no longer ignore the problems of flooding and of water shortages. Flooding has always caused enormous misery as well as loss of life. Government estimates the cost of flooding in England as more than £2bn annually. And, according to Defra, an estimated 2.7 million properties in England and Wales lie in areas that are at risk of flooding. The 2012 floods caused the biggest insurance industry losses since 2007, with customers filing for £3bn in water damage claims.
We know this is likely to get worse, since climate change is going to make weather more unreliable, and are going to result in a greater number of extreme events. Already we hear fairly regularly of ‘one in a hundred year’ storms returning in less than a decade.
While major interventions such as barriers are needed to prevent the most catastrophic floods, there are far more intelligent ways of dealing with water on both the everyday scale and at the unusual but not cataclysmic scale that can still cause so many problems.
The solution can come from two areas, with two approaches which sound similar but are, although complementary, different. The first, and better known, is SuDS. This is a way of dealing with run-off that does not just stick it in a pipe in the ground.
Instead, it mimics natural drainage with features such as swales, ponds and wetlands, to slow down the flow of water, preventing flooding and also the burden on sewerage. In contrast to pipes, which are simply a cost with no amenity value, SuDS can provide interest and amenity in the form of green infrastructure.
The newer, more holistic, approach, is WSUD. This looks at the entire role of water in the environment. As well as reducing flooding, it should cut down demand for potable water by allowing grey water to be filtered and re-used for non-potable applications.
SuDS and WSUD already make sense in environmental and social terms. But they need a push if they are to be adopted more widely. That is why one of the Landscape Institute’s recommendations is for full implementation of the Flood and Water Management Act, which will ensure the implementation of SuDS on all new developments in the UK. Schedule 3, the relevant element, has still not been introduced despite the act passing in 2010. The latest estimate is that it will be brought in in April 2014, but there is some scepticism.
Other recommendations from the Institute include:
• Removal of the ‘un-economic cost’ get-out in Defra’s draft National Standards for Sustainable Drainage System unless exceptional circumstances exist (with ‘exceptional’ being defined)
• A commitment to consider soft options first
• Adoption of water sensitive urban design policies
in every Local Plan
• A comprehensive programme of retrofitting SuDS alongside larger water catchment management programmes and flood defence programmes.
The institute has also supported the publication of Water Sensitive Urban Design by CIRIA (the Construction Industry Research and Information Association), which is aimed at the general public.
‘The big message,’ said Paul Shaffer, an associate at CIRIA, ‘is that the best schemes are water sensitive, and that with early consultation and innovation, SuDS can be delivered on any site.’
CIRIA has set up an entire website, called SusDrain, which has the aim of disseminating information about SuDS, by pulling together guidance and case studies. ‘I would say people understand it as a concept, but there are still quite a lot of myths,’ Shaffer said. ‘The challenge is not that it is more difficult but that it is different.’
Illman believes that the landscape profession is in a similar state, that people grasp the importance, but that there is a hunger to really understand how to apply the approaches in detail and, crucially, to convince clients that they can work.
A new film, released in August, demonstrates that by creating ‘water sensitive cities’ it is possible to address the major challenges of water shortage, flooding and pollution. The film, commissioned by the Landscape Institute and based on work by CIRIA, Arup and AECOM, explains the concept
of water sensitive urban design (WSUD) and argues the case for designing ‘with’ water when planning any new development.
The film is available to watch on the LI’s YouTube channel. Search for landscapeinstituteuk.