Sheffield Abbeydale Industrial Hamlet dam: Potential for risk of collapse as leaks cause problems

Sheffield City Council has agreed to spend almost £670k on Abbeydale Dam at Abbeydale Industrial Hamlet. Work is also going to take place to fix leaks at popular city beauty spot Forge Dam.

At a meeting of the council’s finance committee (February 19), it was agreed to use £668.9k of capital receipts funding to deliver an interim solution to address the leaks at Abbeydale Dam. The four-acre dam, off Abbeydale Road, once powered water mills.

The hamlet is an industrial museum that preserves the historic steelworking site. It is closed until spring for National Lottery-funded improvement work.

A report to the committee said that the water in the dam has had to be lowered temporarily to help stop the leaks. It warned: “Should the need for repair not be addressed, further deterioration could lead to collapse of the dam.”

Leaks are affecting some of the nearby historic buildings, the report said.

Coun Bryan Lodge said: “From memory, this must be about the third time that we have done work on the dam. I just hope we’re going to get to the bottom of it because we seem to have been spending large amounts of money over the last few years, trying to resolve it.”

A recently rediscovered mechanism at Forge Dam in the Porter Valley that was found to be causing leaks could actually have several benefits.

The committee (February 19) agreed to spend £46.3k on works needed to fix the sluicegate at Forge Dam. It was originally a mill pond, part of the water power system that operated a forge built by 18th-century industrialist Thomas Boulsover for his son-in-law, Joseph Mitchell.

At that time 20 water mills and ponds operated in the Porter Valley alone as Sheffield took advantage of its place at the confluence of five rivers to use water power to drive its early industrial revolution.

The dam is now part of Forge Dam Park, which is a well-known spot for families and walkers to visit.

The sluicegate, which was buried five metres down in the dam spillway, was only rediscovered during the desilting works that took place in 2021-22. It was originally installed to allow water to flow into the Porter Brook to clear out the mill pond when it silted up.

The plan had been to block it up to prevent water leaking from the dam but, following 18 months of monitoring the impact on the pond and downstream environment, the plan is now to install a mechanism called a penstock to operate the sluicegate. The £46.3k agreed will fund the first part of the works needed.

A report to the committee said this decision would have multiple benefits.

It would help to protect the nationally endangered white claw crayfish which breed in the pool at the bottom of the spillway.

It would also support biodiversity in the nearby Wire Mill Dam, also built by Boulsover, where the Environment Agency and fire service have in the past had to intervene when fish became distressed during dry weather. The sluicegate could also potentially be used as part of local flood management in the Porter Valley.

A local group is interested in developing an educational hydroelectric generation scheme in the millrace at Forge Dam, but that can only go ahead once the leak in the spillway is under control, which will allow sufficient water flow.