Creating urban wetlands

Working alongside local communities and four London boroughs, Thames21 is helping to create up to four new wetlands treating at least 750 million litres of water, tackling pollution which would otherwise reach the river Lea and its tributaries. 

Focused in the London boroughs of Enfield, Hackney, Haringey and Waltham Forest, the new funding builds on previous projects in the Lea Valley, including Broomfield Park wetland. This was created in 2019 with funding from the Coca-Cola Foundation via a water stewardship partnership between Coca-Cola, Rivers Trust and WWF. This project was delivered in partnership with Enfield Council and is being monitored. Previous projects such as Firs Farm, Pymmes Park and Salmons Brook Healthy River Challenge have proved that these wetlands improve water quality from ‘poor’ to ‘good’ status (for some pollutants). The new wetlands working in combination with the existing ones will take us nearer to the goal of a healthy river Lea, as they intercept and treat pollution before it reaches the river.


Broomfield Park: photo by The Rivers Trust

Apart from intercepting and treating pollution, wetlands have multiple benefits including slowing the flow of flood water thereby helping to protect properties from flooding. By storing water for longer, wetlands can help to mitigate the impact of droughts, as they help channel water to underground water supplies (aquifers) – although more research is needed to evidence this. Wetlands can also boost biodiversity, often transforming nature-poor grassland into thriving green-blue spaces brimming with life.

Previous projects have shown that people value these new blue-green spaces as crucial places to de-stress, connect with nature and other citizens within their community.

Wetlands are so important for treating water pollution sustainably that recently ZSL and Enfield Council produced the Urban Wetland Design Guide, with Thames21’s support. This provides practical device for design and maintenance of constructed wetlands for treating water pollution.

Thames21 will work with local communities and the councils to choose the best locations and co-design the new wetlands. While four additional wetlands will boost river health, more wetlands are needed in order to fundamentally transform the health of the London Lea, one of the most polluted in England. In partnership, Thames21 will continue to build the evidence base and work towards creating more wetlands at a scale that will deliver a truly healthy river Lea.


Broomfield Park: photo by Alison Archer

Our work forms part of a larger project between the Rivers Trust and the Coca Cola Foundation to improve the freshwater environment in London, Kent and Northumbria. South-east England is one of the most water-stressed areas of the country, where the demand for fresh, clean water exceeds the available supply.

The Replenish programme will include six distinct water management and environmental conservation projects to help improve water quality, reduce flood risk, store carbon, enhance habitat and biodiversity and improve the health and well-being of local communities.

If you are interested in finding out more or proposing a site please contact John Bryden