Restoring Toddbrook Reservoir

We are currently working on a major project to restore Toddbrook Reservoir after the dam auxiliary spillway was damaged in August 2019 after a period of intense rainfall.

Work is ongoing at Toddbrook Reservoir Work is ongoing at Toddbrook Reservoir

Update 5.30pm, 20 January 2021

Members of our team are on site, and will remain on site overnight, actively monitoring the water levels at Toddbrook Reservoir as Storm Christoph passes over. We are following our agreed water management plan, using the array of high capacity pumps we have on site to keep water levels down and ensure the reservoir remains safe.

During this time we are in close contact with key partners, including the Environment Agency, to support them in responding to the storm event, whilst we meet our responsibilities for managing water levels in the reservoir.

If you have concerns about flooding in the area, you can find information and advice in the government's flood warning for Whaley Bridge.

Update 7 December

Work continues with our design consultants Arup to develop our plans for the permanent repair of Toddbrook Reservoir. The public consultation provided us with invaluable feedback which is now helping to guide the development of the preferred options for a new spillway and we are also liaising closely with High Peak Borough Council. We have also found it necessary to carry out further investigation works within the natural ground at the base of the dam which will continue on site into the new year. This will  inform the slope stability analysis and ground model development. 

We are expecting to be able to share the preferred spillway replacement option later in the winter. This will be accompanied by a series of briefings and discussions with local people and key stakeholders, followed by a further public consultation once the proposed design has been developed.

Update 6 November 2020

Thank you once again to everyone who took part in our public consultation in September. Over 1,000 people visited our virtual consultation room online, 151 attended one of our drop-in events in Whaley Bridge on 18 and 19 September, and we received 325 responses across our digital, feedback form and email channels.

Your comments matter to us and we appreciate the strong response that you took the time to share. We are now taking the time to carefully consider all feedback received.

An initial summary of consultation feedback received is now available here. We wanted to share these early findings as we continue to consider this feedback in detail to inform the development of a preferred solution for repairing the reservoir.

During the consultation we presented two possible options for restoring the reservoir:

  • 60% of people told us they preferred Option A (A new ‘bathtub’ weir and spillway channel on the left hand end of dam)
  • 30% preferred Option B; (A new ‘tumblebay’ weir and spillway on the right hand end of dam)
  • and 10% of responses had no preference.

We also asked what local benefits you would like to see from the restoration:

  • 59% of people supported keeping the new spillway open and transforming this into a water feature where it passes through the park;
  • the most popular suggestion for other community enhancements was for a circular walking route around the reservoir using the new inlet footbridge, which 30% of responses preferred;
  • 21% of people told us they had a preference for tree planting and more flowers;
  • 19% of responses wanted to see a woodland walk with improved footpaths and information boards on ecology, with 16% of people also preferring improved footpath surfaces;
  • the most popular artistic interpretation to be included as part of the new footbridge was for information on environmental features such as reservoir wildlife (29%);
  • and other popular suggestions for information boards included local reservoir/canal history (22%), or the story of the 2019 incident (21%).

This feedback is now being carefully considered alongside a range of environmental and technical criteria, such as how best to ensure reservoir safety and manage potential local impacts, as we work to develop a preferred repair option. As part of this, you may notice members of our team and machinery undertaking ground investigations around the site as we gather more information to develop our proposal.

Once this process has been completed, we will publish further information to explain the progress we have made in developing a solution. This will include our response to your feedback and how this has helped shape the preferred option.   

In the meantime, we committed to provide detailed information on how the two options we consulted on were selected from the long list of possible options we initially considered. We have now published our full Options Report. This details the process undertaken to identify the long list of options for the restoration, the criteria used to assess these, and the reasons other options were discounted. 

We look forward to continuing the conversation on this project in the coming months. In the meantime, please don’t hesitate to get in touch if you have any questions regarding the information in our Option report or Initial Consultation summary; the repair project, or our ongoing management of Toddbrook Reservoir. See below for contact details. 

About the project

The Canal & River Trust has commissioned expert engineering design consultants Arup to come up with a design solution for repairing the dam and Kier to deliver the construction project.

Work will start on site, initially at the Todd Brook inlet, in spring 2021. This major project is likely to take about three years to complete. The high-volume pumps will remain in situ and water levels kept very low until the repair project is finished in 2023.

Why do we need to restore Toddbrook Reservoir?

Toddbrook Reservoir normally provides just over a third of the water supply needed to keep the beautiful Peak Forest and Macclesfield canals operational. It is essential we repair the reservoir to secure the long term future of the canal network in High Peak and East Cheshire.

Waterside footpath reopened temporarily

The footpath along the northern side of the reservoir, next to the bywash channel, has been opened to the public again over winter. No construction work will take place until spring, allowing this part of the site to be de-restricted. Due to safety concerns, it will be necessary to keep the footpath over the dam bridge closed throughout the project until the reservoir restoration is completed in 2023.

June 2020: waterside path along bypass channel and reservoir June 2020: waterside path along bypass channel and reservoir

Auxiliary spillway - resilience repair project completed

As part of the first phase of restoring Toddbrook Reservoir, an important repair project to the dam’s damaged auxiliary spillway was completed in late summer 2020, greatly increasing its resilience against extreme weather events.

A protective, waterproof nib or short wall has been added to the crest of the dam wall above the damaged spillway. This reaches down to create a seal with the dam’s clay core and ensures no water from inside the reservoir can penetrate beneath the concrete slabs at the top of the spillway.

The spillway crest has also been increased in height by just over one metre with the installation of a sturdy waterproof concrete wall. Engineers completed the job with the installation of new pressure relief holes and joint repairs on the spillway.

Summer 2020: Works to increase the resilience of the dam wall were completed. Summer 2020: Works to increase the resilience of the dam wall were completed.

Improving the Todd Brook inlet and bypass channel

Toddbrook Reservoir is fed by a stream, Todd Brook, which is diverted at the head of the reservoir to either feed into the reservoir or along a bypass channel. The bypass channel runs along the northwest edge of the reservoir before feeding directly into the River Goyt.

After the emergency in August 2019, the masonry weir at the inlet channel was raised with the installation of mesh baskets filled with sandbags.

Starting in spring 2021, the plan is to replace these with a new structure, incorporating a footbridge, to provide a greater degree of control over how much water flows from the brook into the reservoir or around it via the bypass channel.

During normal weather conditions, while the reservoir remains drained, all flow is sent down the bypass channel ie. none into the reservoir. Expert hydrologists are constantly monitoring localised weather forecasts and water levels in the reservoir and bypass channel via a series of remote sensors. They can then alert colleagues if the on-site pumps need to be activated or sluice gates opened.

Toddbrook inlet and bypass channel Toddbrook inlet (left) and bypass channel (right)

About the emergency

Following intense heavy rainfall at the end of July 2019, several concrete panels on the Toddbrook dam spillway collapsed. Around 1,500 residents of Whaley Bridge were evacuated from their homes for up to six nights as a safety precaution. Trust staff and volunteers worked around the clock with the local emergency services, including Derbyshire Fire & Rescue, Derbyshire Police and the Environment Agency, to stabilise the dam wall.

Over a billion litres of water were pumped from the reservoir during this emergency phase and water levels continue to remain nearly empty while the dam is repaired. This is likely to take several years.

Want to get in touch or need more information on Toddbrook?

You can contact the Trust or get in touch with our Whaley Bridge community liaison manager, Gillian Renshaw, by emailing:

Gill Renshaw at Whaley Bridge Gill Renshaw at Whaley Bridge

Toddbrook Reservoir fast facts

  • Construction: Built in 1830s. Opened in 1840 as a feeder for the Peak Forest and Macclesfield canals
  • Length: 1.1km
  • Volume: 1,238 megalitres – equivalent to 495 Olympic-sized swimming pools
  • Dam wall height: 23.8m
  • Environmental status: Site of Special Scientific Interest (SSSI) 

Last date edited: 20 January 2021