The City of London has a myriad of waterways that empty into the River Thames. Old maps show a skein of rivers, streams, and brooks that provided “blue corridors” traversing the city for centuries, providing both sources of food and recreation. But as London boomed, these waterways faded from consciousness – encased by walls, turned into polluted backwaters or simply covered over to run unseen beneath busy streets.
However, these “secret” rivers are imprinted on London’s geography. The suburb of Marylebone started life as St Mary by the Bourne (an old name for a watercourse, in this case the River Tyburn); while Bayswater, Knightsbridge, Westbourne and Holborn are all named for the waterways that ran through them. Deptford was the site of a deep ford over the Ravensbourne, while Wandsworth is named after the River Wandle. East Ham and West Ham got their names from an old word for an area between rivers (hamm) – in their case, the Lea and the Roding rivers. And while Britain’s leading newspapers have left Fleet Street, the River Fleet still runs beneath that famous street.
“London should really be one massive wetland – a salt marsh on an estuary,” said Will Oliver, a development manager at Thames21, a charity that is currently helping guide 40-plus river restorations. Thanks to the organisation’s efforts alongside other groups, buried rivers have returned to the light, while others are being “re-wilded” in ways that will improve the lives and environment of millions of people, as well as provide a key boost for nature.
Take the Wildlife Gardeners of Haggerston, who are revitalising the Old Lea River at Hackney Marshes in east London. You arrive here through traffic-swirled streets, then walk across a vast expanse of park, whose principal signs of life were dozens of football pitches. But along one edge, a line of trees conceals an ancient river that feels like a piece of rural England secreted into grim London vistas. Within minutes of arriving, egrets and kingfishers swoop past.
Esther Adelman, co-founder of the Haggerston volunteer group, explained some of the key work they are doing here. “We change the river flow and get rid of invasive habitats,” she said, pointing to fallen trees that have been used to create partial river barriers – called berms – that add beneficial complexity to the water flow. “This creates a variety of habitats, such as areas of gravel where fish spawn,” said Adelman. “We are imitating natural processes – like human beavers.” Gideon Corby, another Old Lea volunteer and habitat manager at the nearby Kingsland Basin Nature Reserve in Hackney, explained how planting reeds cleans the river by drawing pollutants like phosphates and heavy metals into their roots. Adelman added, her voice filled with a mix of hope and quiet confidence: “We hope eventually the Lea will become home to otters.”
Between 2020 and 2022, meanwhile, the South East Rivers Trust (SERT) trained around 100 citizen science volunteers to survey eels during the Thames Catchment Community Eels Project. As well as counting eels on a clutch of London’s secluded backwater rivers known only really to those who live close by – like the Mole, Kennet, Pang Ravensbourne and Brent – the project worked with 22 schools to deliver workshops, plus guided riverbank walks and wades. It even created an eel-based online game for children.
As part of surveying an impressive 107km of river, the SERT volunteers recorded 119 barriers hindering eel movement – 66 previously undocumented. This has helped create strategies to support this iconic but endangered species. Similarly, the River Hogsmill Connectivity Project spurred the removal of 17 out of 18 obstacles on this west London waterway, making it a far easier commuter route for fish.
Another inspiring form of restoration involves physically liberating the myriad of waterways – like the Turkey Brook at Albany Park in north London, which for decades had been constrained to a narrow, ecologically hostile and dirty flow hemmed by concrete walls. “We dug out the whole channel, broke the walls, and basically freed the river,” said Michael Shorey, senior engineer for Enfield Council Watercourses Team. The result is a beautiful new wetland fed by several hundred metres of now gently babbling brook – a mini urban Eden that is home to myriad river creatures, birds, water plants and wildflowers.
Shorey pointed to places where the brook has created new channels and a small gravel beach. “We wanted it to take on its own course, to naturalise,” he said. “But it will move, and we are going to get drone footage in coming years to see how it changes.”
Creating these new wetlands by renovating the myriad of waterways also helps reduce flood risks across London, by providing areas that can naturally hold excess water from extreme rainfall increasingly linked to climate change. A key example is the Firs Farm Wetlands created after the rediscovery of Moore Brooke. Found buried within a wilderness in a little-used park in the north London borough of Enfield, this “lost” tributary of Pymmes Brook – itself a tributary of the Lea – was freed by Enfield’s watercourse team to create a 3,300 sq m wetland area that Shorey said has significantly reduced flood risk for thousands of people in the area. Newly planted reeds, meanwhile, have also slashed water pollution levels, with phosphate levels alone down 70%.
In 2022, the annual London River Week event published an interactive map that highlighted 144 spots across the city ripe for further restoration, building on the 45km of rivers restored since 2000. Projects include the ongoing Rewilding The Rom to reconnect a trio of historic east London rivers – Roding, Beam and Ingrebourne – to recreate something like their former expansive natural floodplain.
I thought this was refreshing, particularly the projects that involve the next generation. It gives you hope for the future of the planet. I also never knew the extent of London’s myriad of waterways.
