Sustainable urban drainage systems are increasingly being seen as the way forward in water and flood management. There are some great examples of these systems in practice across Europe and Northern America, and the Flood Management Act 2010 encouraged the adoption of sustainable urban drainage systems in England and Wales, making the installation of these systems compulsory for most new developments.
So, what are sustainable urban drainage systems and why do we need them in our cities?
The aim is to replicate natural systems, using cost effective solutions that have a minimal impact on the environment. SUDS can take many forms, including living walls, green roofs, wetland areas, filter strips and permeable surfaces such as block paving or gravel.
Reduce flood risk
One key benefit of SUDS is their potential to manage and reduce the risk of flooding in urban areas. Around one in six homes in the UK is at risk of flooding and this is set to get worse in light of climate change and the extreme weather conditions that accompany it. With this in mind it is imperative that we have effective drainage systems in place for our towns and cities.
The very nature of urban areas makes them susceptible to flooding. Large areas of concrete, and paving and the subsequent loss of permeable surfaces, mean that there is less soil for water to sink into. Instead, rain water is rapidly channelled into gullies and drains, increasing the risk of flash flooding.
To avoid this we need a more sensible approach to water management and SUDS offer an alternative solution – slowing down the flow of water, providing areas for water storage and allowing evapotranspiration from surface water and vegetation. By replicating natural systems, SUDS enables surface water to be drained effectively and sustainably.
Improve the environment
A key tenet of SUDS is their ability to reduce pollution and benefit the environment. In more conventional drainage methods, pollutants such as oil, litter, animal waste and silt can be washed into water courses, contaminating ground water sources and polluting the environment.
Heavy and prolonged rainfall can also put added pressure on our sewer systems, causing them to overflow and leading to untreated waste water entering our rivers and seas.
In contrast, SUDS can filter out pollutants, for example through the use of natural vegetation, before they reach our water ways, leading to improved water quality and a healthier environment.
Benefits for people and wildlife
Aside from the environmental benefits listed above, implementing SUDS in urban areas can have significant advantages for residents and wildlife alike. The best examples of SUDS include a range of habitats that are not just good for water management but are also beneficial to wildlife.
These spaces can also provide a focus for community life, with people coming together to maintain or create projects such as seeding a meadow or planting a living wall, or simply to enjoy some leisure time in pleasant surroundings.
In these times of reduced public spending, local authorities are facing ever more squeezed budgets, and funding for flood management initiatives appears to be limited.
However, as SUDS are often less expensive to build and maintain than more conventional drainage methods, they enable councils to implement systems that are cost effective and yield multiple benefits, both for the environment and for residents. They also have the added advantage of providing longer term savings as the risk of devastating flooding is reduced.
It is clear to see that with careful and intelligent planning, sustainable urban drainage systems offer an array of benefits, both the local environment and the people who inhabit it. In short they have the potential to improve our cities, making them cleaner, happier and safer places to live.
Fraser Ruthven is the Marketing Associate for London’s leading drainage company- London Drainage Facilities. Fraser feels that people irresponsibly disposing of fats and oils is because an enormous issue that needs to be addressed as soon as possible.