Restoring Toddbrook Reservoir

Toddbrook Reservoir, near Whaley Bridge in the Peak District, supplies water to the Peak Forest and Macclesfield canals. These waterways are hugely popular for boating, angling, walking and cycling, and form part of the Cheshire Cruising Ring.

Toddbrook Reservoir autumn 2019 Toddbrook Reservoir autumn 2019. High volume pumps help to keep the reservoir drained for repairs

Update on repair project – temporary work started in January 2020

We're currently working to enhance the resilience of the Toddbrook dam wall and spillway following damage caused in August 2019 after heavy rainfall. 

The temporary works to the dam will be followed by improvements to the Todd Brook inlet channel at the head of the reservoir. This will provide greater control over how much water flows from the brook into the reservoir or around it via a bypass channel. The project includes installing a new footbridge across the inlet weir.

As the charity that cares for Toddbrook Reservoir and 2,000 miles of waterways across England and Wales, we're working closely with contractors Kier to keep the reservoir drained as preparations are made for its longterm repair – a process that is likely to take several years and cost around £10 million.

Works to the dam wall and auxiliary spillway

From Monday 6 January 2020, temporary works will be carried out on the dam’s auxiliary spillway, which was damaged in the summer of 2019. 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 be increased in height by just over one metre at either end and sturdy 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 will ensure that the dam is secure in any extreme weather events. They will remain in place until permanent reconstruction of the dam is undertaken.

Toddbrook Reservoir 2020 diagram 1 Toddbrook Reservoir 2020 diagram 1
Toddbrook Reservoir 2020 diagram 2 Toddbrook Reservoir 2020 diagram 2

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 north west 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. In 2020, these will be replaced by a footbridge incorporating sluice gates, to provide a higher degree of control over water flows.

The Trust will continue to monitor the bypass channel closely, with expert hydrologists having carried out extensive modelling to assess the topography and the maximum capacity at all points along its course. During normal weather conditions, while the reservoir remains drained, all flow is sent down the bypass channel ie, none into the reservoir.

Toddbrook inlet and bypass channel Toddbrook inlet and bypass channel

Long term plan and inquiry update

The Trust has commissioned an independent inquiry into what caused the damage to the dam’s auxiliary spillway. It is also assisting with an independent review commissioned by government. Both these reports are due to be published early in 2020 and will guide the long-term repair of the dam.

Simon Bamford, our asset improvement director, explains: “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're doing some work to protect the reservoir and further improve its resilience against any extreme weather events.

Following intense heavy rainfall at the end of July 2019, several concrete panels on the Toddbrook dam spillway became dislodged. Around 1,500 residents of Whaley Bridge were evacuated from their homes for 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.

Get regular updates on Toddbrook

Gillian Renshaw is the Trust’s dedicated local community engagement manager during the project. Come and meet her at one of the weekly drop-in surgeries.

Where: Transhipment Warehouse, Whaley Bridge

When: Wednesdays, 10.00pm-3.00pm

She'll be supported by specialists from the Trust on the following dates:

  • 15 January 2020: local volunteering opportunities
  • 22 January: local environment and ecology
  • 29 January: repair project manager

If you need to get in touch, please email:

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: 13 January 2020