£12m restoration plan for Toddbrook Reservoir
The Canal & River Trust has announced its permanent repair plan for restoring Toddbrook Reservoir in Whaley Bridge.
The trust plans to build a new side channel weir, ‘tumble bay’, spillway channel and stilling basin on the northern side of the dam, at an estimated cost of between £12 – £16m. The auxiliary spillway, damaged in summer 2019, will be de-commissioned and the dam slope grassed. Subject to planning permission, work is likely to start at the end of 2021 and take around two years to complete.
The reservoir, which supplies water to the Peak Forest and Macclesfield canals, has been out of action and near empty of water since the spillway was damaged. Ahead of the permanent repair, the trust, and contractors Kier, have carried out a major project to make safe the damaged spillway and add a protective waterproof nib to the dam crest.
The long-term repair design was informed by feedback from residents who took part in the public consultation last September.
Working with engineering design consultants Arup, the trust says its project team has carried out extensive technical investigations and design work, listened to all feedback and tried to accommodate the best engineering option within the landscape.
A second public consultation will happen later this spring in advance of a planning application to High Peak Borough Council this summer.
“Repairing the reservoir is a huge engineering challenge and public safety is our top priority,” says Daniel Greenhalgh from the trust. “The permanent repair design has been shaped by local feedback and guided by modern engineering best practice.
“The new spillway will unfortunately require the relocation of the sailing club’s clubhouse and slipway. We appreciate this will have a substantial impact on the club but we are committed to working with them to ensure we provide suitable replacement buildings, boat storage and slipway to support their continued use and enjoyment of the reservoir once the project is complete.
“The use of a side channel weir allows us to connect the existing reservoir bywash into the top of the tumble bay, which will mean water flows down the spillway at all times. We were guided in this design modification by public feedback indicating that a continuous flow of water down the spillway was preferable to having a predominantly dry channel.”
The 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.
Subject to planning permission, the Canal & River Trust is hoping to start work on site at the end 2021 and for the reservoir to be re-opened to the public in early 2024. High volume pumps will remain in the reservoir to manage water levels until the end of the restoration project.
