Discovering the River Fleet
The River Fleet
One of London’s largest and most famous ‘lost’ subterranean rivers, the Fleet, begins its journey on Hampstead Heath. This is one of only two places it can still be seen above ground.
Thanks to funding from Thames Water’s Community Grant scheme, Heath Hands has been researching the river, leading walks for the public and carrying out conservation work along the watercourse to enhance the habitats and wildlife it supports.
Background
The Fleet is a tributary of the River Thames. Its two headwaters begin as springs either side of Parliament Hill – the Highgate springs to the east near Kenwood House, and the Hampstead springs to the west in the Vale of Health. Each of these tributaties journeys southwards through the Heath’s valleys to form streams that feed into the Highgate and Hampstead pond chains.
A bit of History
The River Fleet was historically called the “Holebourne”, meaning the ‘stream in the hollow’, remembered in the name Holborn.
The Highgate Ponds were probably dug between 1690 and 1710. The ponds supplied drinking water to London for over 150 years into the early 19th Century.
Today the streams of the Fleet don’t have much water, however an anchor has been found in Kentish Town, showing the original navigability.
After a flood in 1826, the Fleet was channelled underground, both tributaries meeting in front of the Lido.
Beyond the Heath
The Fleet exits the ponds via underground pipes (originally made from bored-out elm trunks) which meet to form the River’s headwaters somewhere between Kentish Town and Camden Town. Its six-kilometre journey continues south-east through King’s Cross and Clerkenwell, past St Paul’s Cathedral, and ends at Blackfriars Bridge.
A 13th Century Earl wrote: “…of water, running at London ender Oldebourne bridge and Fleete bridge into the Thames…”.
Conserving the River Fleet
Alongside our Heath wide conservation programme we have been able to carry out more habitat management along the Fleet. This has included:
removal of invasive species such as Himalyan balsam that over time cause degradation of the stream’s banks
working to open up the canopy, letting more light reach the streambed, improving the ecology of the watercourse
installation of leaky dams to retain silt and improve water quality
monitoring of amphibians and reptile populations
The watercourse supports a wide variety of wildlife:
seasonal wet pools contain water plantain, lesser spearwort, great willowherb, yellow flag iris and brooklime.
nesting birds (including tawny owls, great-spotted woodpecker, nuthatch and tree creepers), amphibians, grass snakes and
small mammals such as wood mice, shrews and rabbits
Meeting the Fleet
As part of our River Fleet project we have been running a series of public outreach events.
We’ve run several guided walks down both chains of the river for the public and have taken multiple school groups to ‘Meet the Fleet’.
We’ve also run several wildlife interpretaion drop in sessions for visitors to learn about wetlands and the wildlife found in the Fleet.
We are now developing an information pack to bring together all our research and resources relating to the Fleet. This will be published soon!
In the meantime, do keep an eye on our upcoming activities for our next Fleet-related nature walk!