The future of Cannop Ponds

Updated 2nd August 2022

The future of Cannop Ponds is being reviewed following concerns about the condition of its ageing dams, and its resilience to our changing climate.

Find out more about what's happening below or go straight to our frequently asked questions here.  

Background  

Cannop Ponds, in the Forest of Dean, consists of Upper and Lower Pond, each of which has its own man-made dam. These dams are almost 200 years old and were originally built for industrial works at Parkend in the 1820s.  

The ponds are classed as ‘reservoirs’ under the Reservoirs Act 1975. As a result, they are subject to regular inspection by independent reservoir engineers.  

The age of the dams means they do not meet modern engineering standards and recent inspections have identified significant engineering issues. Decisions must now be made about the future of the ponds. 

Considerations 

Our climate is changing with more intense storms and frequent flood events putting pressure on Cannop Brook and the ageing dams. In the unlikely event that either dam wall was to be breached as a result of the increased volume of water, it could have a major impact on the communities downstream. Flood risk mapping shows that Parkend, Whitecroft and Lydney would be vulnerable to flooding.  

Whilst this is extremely unlikely at present, it is something that needs to be thought about for future generations. Since the inspections were carried out, we have completed initial repair work to make the reservoirs safe. However, a long-term solution is required. Doing nothing is not an option. 

Forestry England has a duty to safeguard the future of the Forest and address any threats it faces.  

Options  

The significant issues identified mean that the dam at Lower Cannop Ponds requires extensive works, including the construction of a new spillway and other substantial interventions to prevent it from failing. It is not known what further repairs would be required in the future, and how often these would need to be carried out. 

Upper Cannop Ponds was inspected in May 2022 and we speculate further enforceable action to be required as a result of this inspection. 

An option which is being considered as an alternative is the removal of both dams. This would return the valley back to its natural state. The reservoirs were created to supply water to Parkend Ironworks - before this it was a natural valley.  

Case studies from around the world show that re-naturalising reservoirs can bring benefits to the river ecosystem and surrounding wildlife. According to the Nature Conservancy more than 4,500 dams, weirs and other river barriers have been removed across Europe over the last 25 years.  

The selective removal of dams can help to restore natural river processes and improve habitats. These habitats could include a series of smaller ponds, reed beds, areas of wet grassland and wet woodland. It is believed that wildlife would naturally colonise in these newly created habitats, populating them and creating a thriving ecosystem. 

Whilst restoring the Cannop valley and removing the existing reservoirs is not a decision to be taken lightly, it could provide opportunities as we face up to the biodiversity crisis. We do not yet know exactly what the site would look like if the dams were removed. This vision would be developed as the project progresses if this decision is made.  

Our Shared Forest 

Key to the decision making is the Forest of Dean’s land management plan Our Shared Forest, published following extensive public consultation in 2019. Our Shared Forest has a vision that the decisions we take are “to be guided by the natural potential of the land, as well as the varied influences of our ever-changing world”.   

Our Shared Forest sets out an agreed, understood and supported direction for what the Forest will look like, feel like and be like in 100 years’ time. It considers the impact on all aspects of the Forest, from cultural and environmental, to the trees, water, geology, soils and wildlife.  

The plan states that water in the Forest should “no longer require anything but the most minor interventions for natural processes to function and for a healthy water environment to prevail", further reinforcing the case for Cannop Ponds to be returned to its natural state in the valley.  

What happens next 

During the summer, Forestry England will work with design engineering consultants, Arup, to talk to professional stakeholders and industry experts. This will confirm if a re-naturalising of the site would be both viable and supported.  

Following this, information will be shared with the public. If removal of the dams is seen to be the best option, we will speak with Forest of Dean residents and their representatives to gather thoughts on how the site could look and function in the future.  

We are committed to providing spaces that bring people and forests closer together, and any future vision for Cannop Ponds would continue to welcome people, encouraging them to explore and enjoy the site. 

Have a question?

Please visit our frequently asked questions page.

We will keep this page up to date with information as the project progresses, or you can follow us on Facebook for more news. 

For anything else, please email us: cannopponds@forestryengland.uk