The Tatenhill Brook is a small tributary to the River Trent. We have been making improvements for wildlife in a section just South of Burton-on-Trent, near to Branston Leas, with the Environment Agency who have funded the work through their Burton-upon-Trent Flood Risk Management Scheme

Through this work, we will improve the river channel habitat by adding a mixture of gravel, brushwood, and larger wood berms that will create a variety of habitats for the fish and aquatic invertebrates inhabiting the brook. The flow in this brook is rather sluggish, as it has a lot of vegetation, so the work will also improve the flow to be a bit more dynamic. This in turn will help add more oxygen to the water; making the quality of air in the water better for wildlife that lives there.

What is a berm?

“Berm” is a general term used by conservationists to describe materials which are placed to form a shelf at the bottom of the river bank. They tend to be placed in areas with less flow, often on the outside of a river bend. There are several different ways they can take form.

They can start as a Bar, an area where deposited gravels collect and form a natural shelf at the bottom of a river bank. Over time, these bars can stabilise when vegetation starts to grow on them. This then becomes a characteristic Berm. Eventually, berms may collect more vegetation, becoming sturdier and turning into what is known as a Bench.

The force of the water moving through rivers constantly shifts gravels and silt in a cycle of river bank erosion and sediment deposition. Berms are features influenced by the flow of the water and will change location and form as the river adjusts its course through the landscape over time. They are indicative of a healthy and dynamic water flow within a river. Using conservation techniques, we can make berms where we know they would benefit flow and wildlife.

Why are berms important?

Berms can create pools behind them and these areas provide better habitat for fish to spawn and invertebrates to thrive in slower currents. These areas can also encourage the growth of more plant life, attracting a variety of birds and mammals such as otter.

Over time, berms can also influence a more natural, meandering channel. This helps slow the overall flow of water by deflecting or absorbing some of the momentum of the water. During a flood event, they can help reduce the peak flow of water in undesirable areas where it might affect people and businesses. Conversely, where appropriate, they can also create a narrower channel in locations where to flow of water is too slow.

Berms support the natural erosion and deposition cycle in rivers, encouraging other river features to form; shallow gravel riffles - areas where water has a swift current in the shallows, and rocks and pebbles breaking the water surface causing the water to become turbulent. This provides valuable oxygen to the water making it healthier for water loving wildlife to breathe.

Why do we need to re-instate berms?

Nature very rarely forms straight lines, so when you see a river that is straight and is of uniform depth over a reasonable distance, it is likely that the river has been heavily modified by people. Historically, this has been done for a number of reasons. For example, to support the growth of industry, increase the availability of farmland, or to limit water movement within a channel.

Unfortunately, this has an impact on the natural functionality of our rivers and floodplains. They are less able to support a variety of wildlife, but also the natural services they could provide people. For example, healthy floodplain habitats can provide better natural flood defence than a floodplain habitat in poor condition.

Biodiversity is in a vulnerable state due to a range of pressures including climate change, but one way we can improve nature’s resilience is by working in our rivers and floodplains to restore them across a larger area; creating a nature recovery network along our rivers. There are added benefits for communities and businesses, like better controlling erosion, improving water quality, storing more carbon, and having a cleaner safer environment for recreational activities.