WORKS to lower the water level of the upper pond at Cannop began this week as part of further investigation into the condition of the dams and spillways.

Forestry England (FE) announced last month that ground investigation works, which will include drilling into the dams to take samples, would be carried out over two weeks in June.

Equipment being used to pump out water from the top pond arrived on site on Monday (June 12), with the aim of lowering the water level so that the spillway can be cleaned and properly inspected.

The area surrounding the top pond is now laden with safety signage, several lengths of hose and two sizeable yellow pumps, along with a remote-controlled security 'tower' to deter people from tampering with the equipment.

Locals, including supporters of the Save Cannop Ponds campaign, expressed concerns about seeing large-scale works being carried out at the site amid the row over what the future holds for the ponds.

Some questioned whether dropping the water level was the right thing to do given the current weather conditions, which they said could be "detrimental" to the wildlife there.

FE says the work will help them learn more about the condition of the dams, and establish what mitigation will be needed when draining the ponds.

It comes with a decision on the future of the ponds yet to be made, with FE having held a public consultation event on the options being considered back in March.

A statement says disruption to the public during the works will be kept "to a minimum".

It says the investigation is being undertaken to gather “critical information” which will help inform their final decision.

It reads: “This work will help us understand the geological make-up of Upper and Lower Cannop dams, and the immediate surrounding area.”

It explains the works will involve taking “core samples” through the dam wall and down to the bedrock underneath.

“These bore holes will be small, approximately six inches wide, and will be filled in afterwards so as not to affect the integrity of the existing dams.

“The samples will then be taken away to be studied by expert engineers and geologists.

“These tests will tell us what kind of ground is underneath the dams, and where the original ground level would have been.

“It will also tell us exactly what materials were used to construct the dams and will provide more evidence on their current condition.”

That work is being carried out by Gloucester-based firm Geotechnical Engineering Ltd.

At the same time, silt samples will be collected from both ponds using a floating pontoon.

This will help establish the depth of the silt and what it is made of, including any possible contamination.

The statement adds: “As all options for the future of Cannop Ponds will require water levels to be lowered at some stage, the results of this work will help determine what kinds of mitigation will be needed to prevent the spread of this silt and ensure any historical industrial pollution is not disturbed.”

Kevin Stannard, Deputy Surveyor for FE in the Forest of Dean, said: “We know that drilling works at Cannop Ponds may be worrying for some people, but this work is essential for us to gain a better understanding of the dam structures.

“Our current knowledge is based on visual inspections and historic information.

“This work gives us the opportunity to test our assumptions and increase our knowledge.

“The engineers now need to move beyond assumptions and visual assessment of the historic dams, to work with firm data of what the dams are sitting on, what the dams are made of, as well as the depth and make-up of the silt layers in the Ponds themselves.

“This information will be vital to inform the decision as to which option is taken forward; and the final design of that option.”

The uncertainty surrounding Cannop Ponds stems back to investigations last year which found that the ageing dams would not be able to withstand a 150-year flooding event, the chances of which occurring are becoming increasingly likely according to climate change modelling.

FE is now exploring four options for the future of the ponds, which range from replacing the dams with much larger structures built to modern specifications, to draining the ponds and restoring the Cannop Valley to its original state, as it was before the ponds were created for industry in the 1800s.

At the public consultation earlier this year, Mr Stannard said with action needing to be taken for reasons of safety, “it’s got to be sensible“ to explore options to do what is best for the forest and for wildlife, while retaining the site’s value for people.

But many simply want to see the dams repaired and ponds retained, not least the Save Cannop Ponds campaigners, who launched a petition that was signed by 50,000 people following FE’s initial announcement last summer.

During this month’s works, the car park will remain open, though there are “short, temporary” closures to the road planned while the drill is brought on and off site.

Additionally, public rights of way across the dams will be closed temporarily.

As the materials will be sent off to a lab, results are not expected for a few months.