Features

Restoring the Roding

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Environmental charity Thames21 is making improvements to the River Roding adjacent to Wanstead Park. River Restoration Support Officer Tyler Randall invites you to get your hands dirty (and wet)

Throughout history, rivers have undergone extensive modifications to align with human needs. The River Roding, the third-largest river to traverse London, flowing through Wanstead Park, presents a rewarding area of intervention for Thames21. In this wide and deep stretch, where banks rise to heights exceeding 2m, the river has carved a profound trench in the landscape due to its rapid flow.

Prior to human intervention, the Roding’s shape and the landscape were in constant flux, the lines between river and land far less defined than now. However, to build cities and civilisations, controls were implemented, and certain banks in this Wanstead stretch are concreted, particularly where houses border the river or where erosion tends to occur.

These types of interventions have led to many rivers lacking character, particularly in urban settings: fallen trees are removed to prevent flooding and rivers are straightened in areas to simplify the landscape. Rivers have been dredged and banks raised, separating rivers from their floodplain. All of these actions ultimately remove habitats and make rivers less diverse and more ecologically simple.But nature is inherently messy and thrives on complexity. So, in this section of the Roding, Thames21 is installing large wood debris into the river, otherwise known as deflectors.

This intervention aims to mimic the natural process of trees falling into the river. Ash trees that were suppressed or dying from ‘Ash dieback’ (a fungal disease afflicting many Ash trees across Europe) were felled and cut to the correct size. We then positioned these deflectors in the river and pinned the trees to the bank and riverbed with stakes and wire to stop them from moving.

Deflectors influence the river in many ways: slowing water around the banks and accelerating water in the centre, creating turbulence and complex flow patterns which oxygenate the water, providing food and habitat for invertebrates, fish and bird species, creating varied sediment types which, in turn, promote plant growth and cleaning gravels for fish spawning. It also acts as a place for biofilms and algae to grow, which purify water and reduce the impact of pollution. Prior to our interventions, this complexity was notably absent in this stretch of the Roding. This is a fairly simple intervention, but it can have a profound effect on the biodiversity within a section of the river. Imagine a whole catchment, a whole city.

Volunteers have been playing a crucial role in completing this work. If you are available and eager to contribute to the work Thames21 does, improving the health of London’s rivers with community support, please get in touch.


Volunteer sessions will take place on 4, 7, 12 and 18 March from 10am to 2.30pm. For more information and to take part, visit wnstd.com/restoreroding or email tyler.randall@thames21.org.uk