Our urban environments face unprecedented challenges from climate change and increasing population. Our environment is becoming fragmented and our children are not enjoying the access to the natural environment they need. Making our cities greener and bluer can help our cities face these challenges and make their local places more resilient. One way we can do this is through sustainable drainage systems (SuDS).
Sustainable drainage systems can, if designed appropriately, benefit us in a wide variety of ways. For example, they reduce the risk of surface water flooding by slowing and reducing the flow of water, which runs off hard impermeable surfaces before it reaches the sewer. They can also improve the quality of that run off, removing polluting particles in the water as well as from the air, improving air quality. They can store carbon, provide habitat for wildlife and increase people’s health and well-being.
So why aren’t they everywhere?
Well, these benefits aren’t really seen as pounds and pence and they don’t accrue to any one person, business or even sector. They are societal benefits that diffuse across communities and as such there are limited drivers to install or retrofit SuDS into our urban spaces. There is also no current Government policy or driver around fitting SuDS into existing developments despite the many advantages.
We want to change this. There are real benefits to retrofitting SuDS. Today WWT and Business in the Community (BITC) launch a report that highlights these benefits and suggests one possible way forward.
WWT have been working with BITC and others, including Arup and MWH to produce this publication. Using the CIRIA Benefits of SuDS Tool (BeST) we indicate what the scale of a roll out of SuDS across Greater Manchester could look like.
We report that a roll out of SuDS across Greater Manchester should be cost beneficial and of good value. Societal and environmental benefits under our test case range from £4 million to around £50 million depending on the scale of the roll out. The greatest benefits accrue around mental well-being and education. However, important benefits, including flood risk reduction and water quality improvements, could not be quantified at this high level as they are so site dependent.
Together with BITC, we propose a pilot roll out of SuDS retrofit across Greater Manchester. A pilot would provide much-needed demonstration sites for schools, NHS sites and businesses in the North West. Societal and environmental benefits will accrue to communities and businesses across the roll out area. A pilot roll out would demonstrate the opportunities for flood risk mitigation in the urban environment and could aim to optimise other societal and environmental benefits. This should be led as a joint venture between government, the private and third sector, working through the Manchester Urban Pioneer. Alongside practical demonstration sites, the pilot should consider prospective sustainable funding options for such natural capital investment.
The Government promised to leave the environment in a better state than it found it. This doesn’t just mean the rural environment. Let’s make our urban spaces rich in bird song, buzzing bees, flowers, ponds and trees which everyone can enjoy. Let’s start making the connection and build SuDS for schools, for flood reduction, for healthier rivers, for communities, for cities, for the future.
Hannah Freeman, Senior Government Affairs Officer
Wildfowl & Wetlands Trust