University of Portsmouth team work to standardise sustainable drainage
A new housing development which includes sustainable drainage in the form of a detention basin
A guide which could eventually lead to fewer UK homes being flooded is being developed by engineers and surveyors at the University of Portsmouth.
The team are working on developing guidance to increase the use of sustainable drainage — abbreviated to SuDs — to reduce the downstream flood risk caused by new developments.
Sustainable drainage slows the flow of flood water by storing it in wetlands and ponds or through infiltration. Such environmentally-friendly infrastructure is also thought to make urban areas more pleasant, whilst also cleaning polluted run-off water.
However, the economic case for sustainable drainage and the specifics of who pays for the benefits is more difficult to identify in contrast to piped drainage — a common hurdle to their implementation.
Dr John Williams, an expert in environmental technology, and colleagues from the School of Civil Engineering and Surveying at Portsmouth, are developing a toolkit for measuring a range of costs and benefits of incorporating sustainable drainage in new housing developments.
The toolkit will help council planners, engineers, surveyors, water companies, and house buyers clear guidance on how to value environmental sustainability being included in new developments.
Dr Williams was awarded £100,000 in funding by the Natural Environment Research Council (NERC) for the two-year project.
He said: “Recent flooding has seen many calls for the impacts of new developments on downstream flood risk to be managed through the use of sustainable drainage.
“There is no clear professional guidance available on valuing sustainable drainage systems. Ponds, wetlands, and grass ditches slow the flow of water compared to pipes; they create a better urban environment, better habitats and cleaner rivers.”
“How do we put a price on these environmental improvements or having more green open space in developments. Will people be prepared to pay more for a house in a development where some land has been given over to a pond or wetland?
“There is a therefore a great deal of economic uncertainty in the construction and maintenance of sustainable drainage and the government has recently withdrawn legislation introduced after the 2007 floods, aimed at making the adoption process clearer.”
Experts in the School of Civil Engineering and Surveying will be working with project partners including the Royal Institution of Chartered Surveyors, Hampshire County Council, Southern Water, First Wessex, Atkins Global, the Environment Agency, and the Department for Environment, Food, and Rural Affairs.
Together, they will assess the capital and life costs of sustainable drainage systems, and the benefits to the environment, buyers, water companies, and developers. They aim to produce a guide allowing planners and developers to estimate the costs to individuals and the environment of incorporating sustainable drainage in developments in a standardised way.