The Canal and River Trust, which owns the reservoir, said temporary works will be starting on Monday January 6 2020. These will be carried out on the dam’s auxiliary spillway, which was damaged in August, as well as enhancing the resilience of the dam wall.
The works to the dam will be followed later in the year by improvements to the Todd Brook inlet channel at the head of the reservoir. This will provide greater control over how much water flowers from the brook into the reservoir or around the reservoir, via a bypass channel.
This project will include the installation of a new footbridge across the brook to create a safe route for people wishing to walk from one side of the valley to the other - as requested by residents of Whaley Bridge.
The Canal and River Trust is working closely with contractors Kier to keep the reservoir drained as preparations are made for the dam’s long-term repair.
This process is ‘likely to take several years and cost around £10 million’, the trust said.
During the works due to begin in January, a protective, waterproof nib (short wall) will be inserted all along the spillway crest which will reach down into the dam’s clay core. The spillway crest will then be increased by height by just over one metre at either end and concrete waterproof barriers will be installed on the spillway slope to channel any overflowing water into the central undamaged section – which will be lined for extra protection.
The new features set for Toddbrook Reservoir will ‘ensure that the dam is secure in any extreme weather events’ and will remain in place until permanent reconstruction of the dam is undertaken.
The trust has commissioned an independent inquiry into what caused the damage to the auxiliary spillway and is also assisting with an independent review commissioned by the government – both reports are due to be published ‘early 2020’ and will guide the long-term repair of the dam.
Simon Bamford, asset improvement director for the Canal and River Trust, said: “We are keen to hear the findings of the independent inquiries so we can move forward and decide how best to fix the dam for the long term.
“Once we know what caused the damage to the dam we will be able to work out a detailed plan for repairing it, including a precise timetable and costings.
“In the meantime, we will be doing some work to protect the reservoir and further improve its resilience against any extreme weather events.”
Now that temperatures have fallen, the trust have restarted their fish rescues. Teams are currently catching and weighing the fish in preparation to move them as they make their way to their new home in Bittell Reservoir, a part of the Birmingham network of reservoirs.
It is estimated that around 30,000 fish – five tonnes – will be re-homed.
The trust said they are ‘keen to keep residents updated with the latest information’ and a residents’ briefing was held on Tuesday night.
Daniel Greenhalgh, Canal and River Trust’s north west director, said: “We’ve had an amazing response from the community since day one. They have been generally really supportive, but obviously these are frustrating times for the residents.
“Thank you for bearing with us over the last few months – we have been carrying out a range of modelling, investigatory works and other vital engingeering to prepare for the future restoration of Toddbrook Reservoir.”