The restoration of Toddbrook Reservoir in Whaley Bridge takes a major step forward this month with submission of a planning application for its permanent repair by the Canal & River Trust charity.
The Trust, which cares for the reservoir and 2,000 miles of waterways across England and Wales, has applied to High Peak Borough Council for permission to replace the 1970s-built spillway, damaged following torrential rain in summer 2019, with a new overflow structure to the north of the dam which will funnel away excess water when the reservoir is full.
The application for the new structure includes building a new overflow side channel weir, ‘tumble bay’, spillway channel and stilling basin which links to the existing bypass channel before flowing into the River Goyt in the town’s Memorial Park.
The planning application also includes a proposal to replace the current sailing club facilities, which will be impacted by the new spillway. Plans feature a new clubhouse, boat storage, slipway and car park, located on a site behind the proposed tumble bay.
The repair project is estimated to cost in the region of £12 million – £16 million. Subject to planning permission, work is due to start in spring 2022 and is expected to take about two years to complete, with the reservoir re-opening to the public in summer 2024.
Feedback from two public consultations influenced several design features to reduce the visual impact of the new concrete structures. These include the addition of natural stone cladding to most exterior side walls above ground level and ensuring wall heights are kept as low as possible. There was also a public wish to see water constantly flowing down the spillway channel instead of it being predominantly dry and this has been achieved by connecting the top of the tumble bay into the existing reservoir bypass channel.
The 1970s overflow spillway overlooking the park, which was damaged in summer 2019, will be de-commissioned, the concrete panels removed and the dam slope grassed over. The original 1840s spillway, near the existing sailing club, will also be removed and some of the stone reclaimed and re-used as cladding on the exterior walls of the new structures.
Daniel Greenhalgh, Canal & River Trust North West director, said: “We are very grateful to everyone who has given feedback or attended our public consultations in September 2020 and June this year. We have also had extensive discussions with local residents, particularly those nearest the site, and have tried to adapt our plans and designs to cause the least disruption and inconvenience.
“We recognise the repair work will cause disruption for some residents, particularly those living nearby, and we will do our very best to mitigate noise and inconvenience as far as we are able. We thank everyone for their patience and support over the last two years. Plans for the permanent repair design have been guided by modern engineering best practice and shaped by local feedback. Public safety is our top priority.
“Restoring Toddbrook is vital to ensure the long term viability of the Peak Forest and Macclesfield canals. We look forward to completing this challenging engineering project so we can again rely on its essential water supply and for the beautiful reservoir to be re-instated for the benefit of everyone in Whaley Bridge.”
The Trust has been working closely with engineering and consultancy firm Arup to prepare the detailed plans after carrying out extensive technical investigations and design work. The construction project will be delivered by the Trust’s main contractor Kier.
Temporary site compound in the Memorial Park
In order to carry out the essential repairs, the Trust will set up a temporary site compound at the northern end of the Memorial Park, next to the dam. Following feedback from local residents, a footpath will be retained across the park, connecting Wharf Road along the river to the Memorial Park Bridge, providing a viewing point for the construction site.
During the works the playground will unfortunately have to be removed but will be replaced with temporary alternative play equipment at the top of the dam next to Whaley Bridge Athletic Football Club. A new playground, similar to the existing one, will be rebuilt at the same location in the Memorial Park at the end of the project in 2024. The park will be re-landscaped, with extra footpaths and a new footbridge over the bypass channel.
Access for construction vehicles into the site compound will be along Reservoir Road. There will be no temporary traffic lights at weekends or evenings and the Trust will arrange for weekday construction traffic to be managed by having staff on duty with ‘stop’ and ‘go’ signs and radios to provide a more personal and interactive traffic management service.
A number of trees will need to be felled to make way for the construction of the new spillway but the Trust has worked closely with the council to discuss replacement planting and habitat creation, which is predicted to achieve a net biodiversity gain of more than 10%.
Toddbrook Reservoir, which supplies water to the Peak Forest and Macclesfield canals, has been out of action and almost empty of water since the spillway was damaged after excessive rainfall in July 2019. Last summer, ahead of the permanent repair, the Trust and its contractors Kier carried out works to make safe the damaged spillway and add a protective waterproof nib to the dam crest.
The major construction project on the dam will be followed by works to the inlet cascade, at the far end of the reservoir, to increase its resilience to high flows from the Todd Brook stream. High volume pumps will remain in the reservoir to manage water levels until the end of the restoration project.
The planning application will be available for view on the High Peak Borough Council website, once uploaded: http://planning.highpeak.gov.uk/portal/servlets/ApplicationSearchServlet
For more information about restoring Toddbrook Reservoir, please go to the Canal & River Trust website: https://canalrivertrust.org.uk/restoring-toddbrook-reservoir