South East Rivers Trust (& the Wandle Trust)

Nature Based solutions to man-made problems


The Urban Wetland Design Guide

There is no doubt that we are going through a massive and positive paradigm shift. It is finally hitting home that human activities thoroughly depend on the health of the natural environment and the sustainability of the many services it provides. The natural environment has rapidly moved from the periphery to the very centre of conversations, with action on fundamental issues from our own well-being to agriculture and the economy. 

Humans are an increasingly urban species, although a major consequence of the COVID-19 pandemic is how we have come to realise the importance on being in contact with Nature, and how Nature can provide us with many solutions to the problems we create.

One of those problems is road runoff.  Most of us are highly dependent upon cars or other vehicles and the massive road network carved into our catchments, to get us or the goods we buy from one place to another.

Contaminants from combustion, oil spills, and the wear and tear of tyres and car components combine with dust and dirt along our road networks. After heavy rainfall, surface water drains are often overwhelmed, resulting in a deadly mix of these contaminants [zinc, cadmium, copper, lead, micro plastics and hydrocarbons], that are chemically bound to suspended solids, being washed into river systems.

There is increasing public awareness of road runoff impact on river ecosystems and public health. Road runoff can destroy the ecological, amenity and leisure value of rivers. Acute impacts are often witnessed during summer storms after prolonged periods of dry weather and low flows, including highly toxic ‘first flushes’ that can devastate local watercourses.

Constructed wetlands are a Nature Based Solution that can be used to stop road runoff from reaching rivers – especially urban rivers – by slowing the flow and trapping contaminated sediments around pollution-tolerant aquatic and semi-aquatic plants. These wetlands also bring other benefits: they can be great amenity spaces for local communities, and valuable biodiversity hotspots – especially for plants, insects, bats and birds. In short, wetlands are pretty fantastic!

Do you want to know more about the many benefits of wetlands? How to identify opportunities in the urban landscape and understand wetland design concepts? Then look no further!

SERT has been working in a partnership programme with Thames21, Middlesex University, ZSL, GLA, Environment Agency and Transport for London to address the problem of waterborne pollutants from road runoff. We’ve also collaborated, together with these organisations and Enfield Borough Council, in the publication of the “Urban Wetland Design Guide”. You can download it HERE and – who knows – you might start on the path to building one for your local community and river! 

Don’t hesitate to contact us at SERT if you want to know more about wetlands. We are more than happy to talk about them all day long!