Sadiq Khan: what is his plan to clean up London rivers?

The Mayor of London is seeking to restore the capital’s waterways using natural methods, offering a unique opportunity to monitor the outcomes. Jed Thomas 

Sadiq Khan has launched an ambitious plan to clean up London’s rivers, pledging to make them “swimmable” by 2034 in a project that blends environmental restoration with social justice.  

At the heart of the mayor’s ten-year initiative is a focus on improving water quality through better pollution controls and a sweeping program of monitoring and community engagement. 

All of this while holding polluters to account and making the city’s waterways more accessible to all Londoners. 

Targeting runoff pollution 

City Hall has committed over £7 million in funding, alongside support from Transport for London, to prevent road runoff pollution—one of the primary sources of contaminants such as oil, fertilisers, and pesticides from entering rivers and streams. 

This runoff, especially prevalent during heavy rains in urban areas, degrades water quality and endangers aquatic life.  

The money will also fund large-scale rewilding efforts and back community-led projects through the Green Roots Fund, which supports initiatives like the planting of trees and creation of reedbeds that help filter pollutants naturally. 

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Alongside this, Thames Water has announced a £1.8 billion investment over the next five years, aimed at reducing sewage discharges in tributaries including the Roding, Wandle, Lee, and Brent rivers.  

This work builds on the newly completed Thames Tideway Tunnel, which is designed to prevent 95% of sewage overflows into the tidal Thames.  

The company will also provide £20 million in funding for community and environmental groups, to support local monitoring and restoration work.

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What role will monitoring play in Mayor Khan’s plan? 

Monitoring is a central pillar of Khan’s plan. Pollution levels, especially from road runoff and sewage overflows, will be closely tracked using real-time data and site-specific assessments.  

The expansion of sustainable drainage systems and natural filtration methods like reedbeds will be subject to ongoing evaluation, with the goal of identifying the most effective methods for long-term water quality improvements. 

The mayor has convened a coalition of partners—including the Department for Environment, Food and Rural Affairs, Ofwat, the Environment Agency, and NGOs like the London Wildlife Trust—to coordinate efforts, share data, and hold regular summits to assess progress.  

This coalition will also draw on international expertise, with a future roundtable planned to include representatives from cities like Paris and advisors from Bloomberg Associates. 

Khan’s office has also released an Open Water Swimming Guide to inform the public about safe swimming locations, but City Hall has stressed that not all waterways, particularly the tidal Thames, will ever be safe for swimming due to strong currents and other hazards.  

In 2023 alone, 31 people died in the tidal Thames, prompting officials to underscore the importance of clear and responsible messaging.  

The Port of London Authority, a partner in the initiative, has emphasized the need for continued public safety education and proper signage to prevent accidents. 

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Promoting social justice 

Deputy Mayor Mete Coban has pointed to disparities in swimming access and engagement with nature, citing data that shows Black and Asian communities are far less likely to swim or visit natural spaces.  

The plan aims to change that by improving not only water quality but also access to riverside paths, parks, and safe swimming locations, particularly in underserved areas. 

The restoration of wildlife is another major component, with efforts underway to reintroduce species like otters, eels, and beavers to London’s waterways.  

Following the successful reintroduction of beavers in Ealing and Enfield and water voles on the Hogsmill River, the mayor hopes to see a resurgence of native species as river habitats improve. 

Sadiq Khan has framed the clean rivers initiative as a once-in-a-generation opportunity to reverse decades of neglect and pollution.  

“We have made great progress in cleaning our air in London, and I’m committed to doing the same with our rivers,” he told reporters. “Together we can make our rivers something that every Londoner can be proud of as we continue to build a greener, fairer, better London for everyone.” 

With a robust system of monitoring, community participation, and regulatory oversight, Khan’s plan seeks not only to restore the ecological health of London’s rivers but to ensure that the benefits of clean, accessible waterways are shared by all. 

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