Where Rivers Run Wild Again: The Art of River Restoration

Introduction to River Restoration

River restoration is a process that seeks to return rivers and streams to a more natural and functional state, addressing the damage caused by centuries of human activity. Many rivers in the UK have been straightened, polluted, or obstructed, leading to issues such as increased flooding, reduced water quality, and a loss of biodiversity. In response, a variety of restoration strategies are employed to improve these vital ecosystems.

These strategies include removing artificial barriers, reintroducing natural meanders, and enhancing habitats for wildlife. While it’s often not possible to fully restore rivers to their original condition due to irreversible changes in the landscape and human dependence on water resources, rivers are resilient and capable of recovery when given the right support. Restoration efforts focus on aiding this recovery by addressing hydrological, morphological, biological, chemical, and societal challenges within the catchment area.

The aim is not only to improve ecological health but also to create more resilient landscapes and cleaner water systems. Restoring features such as migration routes for fish such as salmon or reintroducing native vegetation along riverbanks which enhances biodiversity and helps to restore natural river processes. River restoration goes beyond ecology—it is about preserving the beauty, function, and sustainability of our waterways, ensuring they can thrive for future generations.

Re-meandering and Brash Dams: Reviving Natural River Dynamics

One of the most effective techniques in river restoration is re-meandering, which involves reintroducing the natural curves and bends that rivers often lose due to human intervention. Straightened rivers may seem more efficient, but they disrupt the flow dynamics, increase erosion, and reduce habitats for aquatic and riparian species. By restoring these meanders, rivers slow down, allowing sediment to settle naturally, reducing flood risks downstream, and creating varied habitats for fish, insects, and plants.

Natural Flood Management (NFM)

NFM is an innovative approach that uses the power of nature to reduce the risk of flooding and improve the resilience of landscapes. Also referred to as Natural Water Retention Measures (NWRM) or Nature-based Catchment Management (NbCM), NFM focuses on restoring or mimicking the natural processes that once governed rivers, floodplains, and the surrounding environment. By allowing rivers to function more like they did before human interventions, NFM helps slow the flow of water, which can significantly reduce flood risk downstream. But it does more than that—by enhancing the ability of the landscape to retain water, it also helps to make land more resilient to drought conditions by releasing water more slowly over time.

NFM involves a variety of techniques designed to work with nature, rather than against it. For example, leaky dams—constructed from wood, stone, or other natural materials—are placed in streams to slow water down and allow it to spread out, reducing the speed and volume of water downstream. Swales, which are shallow, vegetated ditches, can be used to capture rainwater and direct it away from vulnerable areas, while offline ponds hold water temporarily during heavy rainfall, preventing it from overwhelming the river. Remeandering rivers helps restore natural curves, allowing water to slow down and spread out rather than rushing in a straight line. In addition, land management practices such as controlled grazing, reforesting, and planting cover crops improve soil health, making it more absorbent and reducing surface runoff. Soil management also plays a key role by improving infiltration and reducing erosion. Finally, the reintroduction of beavers can play a vital part in flood management, as their dam-building activities naturally slow water and create wetland habitats, which help retain water and reduce flood peaks.

Alongside re-meandering, smaller interventions like brash dams play a crucial role. These simple structures, made from natural materials like branches and twigs, are placed across the river or its tributaries. Brash dams mimic natural woody debris, slowing water flow, trapping sediment, and creating pools and riffles. These features are vital for aquatic life, offering spawning grounds for fish and habitats for invertebrates.

Stourhead Estate and Panford Beck

In our recent projects at Stourhead Estate in Wiltshire and along Panford Beck in Norfolk, we've successfully implemented some of these techniques to restore natural river dynamics.

Stourhead Estate Masterplan

At Stourhead Estate, renowned for its 18th-century landscape gardens, the original design included the creation of a large artificial lake by damming the River Stour. Over time, sediment accumulation and changes in water flow necessitated restoration efforts to maintain the lake's health and aesthetic appeal. By reintroducing techniques as above, we've helped to enhance water quality, reduced sediment build-up, and revitalised habitats for local wildlife.

Similarly, at Panford Beck, a tributary of the River Wensum in Norfolk, we've applied these restoration techniques to great effect. These interventions have also contributed to better flood management, helping the return of native species and increased resilience of the local ecosystem.

These projects demonstrate how combining traditional landscape aesthetics with modern ecological restoration techniques can yield benefits for both heritage sites and natural environments.

What is Stage 0 Restoration?

Stage 0 restoration is a cutting-edge approach to river restoration that aims to reset a waterway to its most natural, undisturbed state. Unlike traditional restoration methods, which often involve specific interventions such as remeandering or installing brash dams, Stage 0 focuses on reconnecting a river with its original floodplain and allowing it to flow freely across the landscape. This process often involves removing artificial barriers, drainage ditches, and embankments, essentially giving the river permission to behave as it would have before human interference.

A prime example of Stage 0 restoration in the UK is the National Trust’s Holnicote Estate project on Exmoor. This groundbreaking initiative has transformed the waterways of the estate by completely rewilding sections of the river. Instead of following a straightened course or even a carefully engineered meander, the rivers at Holnicote are now allowed to spread, braid, and create their own paths across the floodplain.

The results have been remarkable. Flood risks downstream have decreased as water is naturally slowed and absorbed across the landscape. Sediments are deposited where they would have been historically, improving soil health and reducing silting in downstream rivers. Wildlife has flourished too, with wetland habitats returning to support species like otters, water voles, and wading birds. The benefits aren’t just ecological; local communities benefit from improved water quality, reduced flooding, and a restored landscape that’s more resilient to climate change.

Stream evolution model (Cluer and Thorne 2013). Stage descriptions are provided in Table 5. Dashed arrows indicate "short circuits" in the normal progression.

A Ripple Effect

Whether it’s through re-meandering, brash dams, or Stage 0 restoration, river restoration projects across the UK are proving that working with nature, rather than against it, can deliver lasting benefits for both wildlife and people. Projects like those at Stourhead Estate, Panford Beck, and Holnicote Estate demonstrate the power of these techniques to transform our waterways and landscapes.

By restoring rivers to their natural state, we’re not only repairing the damage of the past but also creating resilient ecosystems that can thrive for generations to come.