The Derwent Connections Project is multifaceted with aims to establish a dynamic landscape with a strong community acting for nature throughout the Derwent River Valley. Some of the key focus areas within the project include woodland creation and natural flood management.

But what exactly is natural flood management? How does it work, and how it has been used within the Derwent Catchment already?

What is flood management?

The main aim of any form of flood management is to reduce the maximum water height of a flood or delay the arrival of flood water downstream by slowing the flow of water across the river catchment. Conventional flood management techniques such as river dredging and building dams, work to deepen the river channel, reduce the maximum water height or with dams, hold back the arrival of flood water and release this water over longer periods. The difference with ‘natural’ flood management is the methods by which we slow the flow and reduce the height of flood waters.

What is natural flood management?

In natural flood management, the ways in which we slow the flow of water are to utilise natural processes, that do not have a significant impact on farming and are typically small in size.

Examples of natural flood management include returning the river to a more natural state, creating more permeable surfaces so that soils can hold more water, leaky dams that mimic the processes of beavers in the environment, and establishing more wetlands .

These natural methods help to slow the flow of water across the landscape, reducing the maximum height of the river during a flooding event.

Hard-engineered flood management measures like dredging, while in some cases dredging can play a role in river maintenance, in the majority of cases, is not the most efficient or sustainable ways of reducing flood risk and may increase flood risk to downstream communities. Natural processes in many rivers mean silt will return and accumulate in the same places very quickly, sometimes only weeks after dredging and desilting is carried out. This is why we are looking to slow the flow and reduce maximum water height across the entire river catchment through natural flood management measures and woodland creation.

In the Derwent River catchment, we are already working on many natural flood management projects and supporting multiple community groups to carry out natural flood management projects in their communities. Along the Hogshaw Brook at Lightwood the Derbyshire Wildlife Trust and Trent Rivers Trust have evaluated that the site has the potential for 22 types of natural flood management and provides opportunities for community engagement. One of the main natural flood management measures that will be utilised on-site includes the use of leaky dams that can be built and maintained by the local community.

However, it is not just large organisations like Trent Rivers Trust and the Derbyshire wildlife trust implementing natural flood management. Friends of Sunnydale Park in Derby is a small volunteer group in Derby city that has set up natural flood management measures in their park to support the local community. Sunnydale is a local nature reserve covering 13.2 hectares, consisting of woodlands and several ponds among other important habitats. In 2021 Sunnydale park undertook work to create new meadows and wetland habitats in order to reduce the risk of flooding to residents. The project has seen the development of cross-track drainage and land reformation to slow the flow of water and divert water into storage ponds established within the park. The creation of these habitats has helped to improve biodiversity with plant species including water mint and yellow flag iris.

Moving forward the Derwent connections Project continues to work with partners, planting trees, and developing a range of natural flood management measures, all of which contribute to slowing the flow of water into communities further downstream. In urban areas, we continue to work local authorities and other partners to make more green spaces with woodland cover and promote the creation of natural flood management measures such as ponds all of which will help to slow the flow of water rather than it flowing quickly into drains and rivers.