Plug pulled on Forest plan to remove historic ponds
By Simon Hacker | 24th October 2023
A threat to the existence of historic Cannop Ponds – two picturesque 19th century reservoirs in the heart of the Forest of Dean – has been lifted.
Forestry England (FE) announced today (Tuesday October 24th) that it is no longer considering the removal of the scenic ponds, which were built in the 1820s to supply water to Parkend Ironworks.
Earlier this year, the authority revealed that the Ponds are at risk of collapsing and flooding the Cannop Valley, near Cinderford.
Forestry England put forward four possible solutions for public consulation – one of which was renaturalisation of the Valley and the total removal of the Ponds.
Today, however, the authority says it has concluded that re-naturalisation of Cannop Brook is "no longer viable and will not be progressed further".
A spokesperson said: "The renaturalisation option restored the original watercourse, similar to how it would have been before the construction of the reservoirs.
"The biodiversity results show that this option would deliver habitat improvements, that would in turn benefit wildlife. However, the flood modelling results show a potential increase in future flood risk.
"Forestry England has previously committed to deliver a project which will not cause any worsening of future flood risk. The aim is to ideally improve future risk, and so this option has been discounted. "
Three options remain and are under consideration: a spillway and dam upgrade, storm water storage and a cascade of ponds.
"Storm water storage through the removal of the upper reservoir spillway and creation of a cascade of ponds through the removal of both spillways have also been shown to deliver an increase in biodiversity, as they would both create more complex habitats," said the spokesperson.
"The flood modelling indicates that option two would also deliver a tangible downstream flood risk benefit to people and properties.
"Spillway and dam upgrade for both ponds is still being considered, although it would likely deliver a loss in wildlife habitat as larger, concrete spillways would need to be built in place of the existing structures.
All options will now move forwards to be assessed, says FE, alongside other key criteria, to confirm a preferred option early next year."
Josh Howe, Director of Engineering for Forestry England said: "The results of these two studies will play an important role in the decision-making process for this project and have already helped us narrow down the options.
"We are facing a changing climate and a biodiversity crisis and so delivering a project that will mitigate against future flood risk whilst supporting habitats and species is vital.
"Both these factors are crucial, and we need to strike a careful balance between them.
"Our next steps will be to combine this information with the other data being gathered in order to put forward a preferred option early next year."
Created as reservoirs in the 19th century, Cannop Ponds have become a popular picnicking, leisure and beauty spot as well as a focal point for the Forest. Forestry England says it is concerned about the ageing dams and the resilience of the area to the changing climate. If the dams fail, they say there is a flood risk to neigbouring villages.
Both Upper and Lower Cannop Ponds hold more than 25,000m3 of water each and are defined as 'reservoirs' under the Reservoirs Act 1975. As a result, they are subject to regular inspection by independent reservoir engineers.
A spokesman added: "Following recent inspections, significant engineering issues were identified, which include the need to make provision for managing future increased water volumes from more intense storms and increasing flood events.
"In the unlikely event that either dam wall was to be breached, it could have a significant impact on the communities downstream. Flood risk mapping highlights Parkend, Whitecroft and Lydney as vulnerable to flooding should either or both dams fail.
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