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

Project update - 6 May 2020

Temporary works to reinforce the dam’s auxiliary spillway have continued during April, with social distancing being strictly enforced on site in accordance with the government’s current guidelines.

On the football club side of the dam wall, a small temporary wooden bridge over the large pumping pipes has been replaced with a much sturdier reinforced concrete bridge. This will help to speed up construction of the raised weir superstructure on the dam wall crest by enabling direct access for larger, heavier vehicles.

Over the next few weeks, there will be an ongoing programme of grouting, plus preparation of the existing structure for the construction of the new weir superstructure on the crest apron and chute down the sloping spillway. A new harness and safety line system is being installed to enable contractors to abseil across the steep slope as they create the new concrete barriers.

The damaged drystone wall next to Reservoir Road has now been rebuilt and the orange barriers removed.

Please note that Toddbrook Reservoir is still an active construction site and is not open to the public. Our site staff have had to deal with several disruptive break-ins in recent weeks. On one occasion, the police had to be called after one trespasser put his and other lives in danger by trying to walk on the deep silt reservoir floor. For your own safety, please keep away from the construction site, including the dam wall and the bypass channel.

Update on temporary repair project – 30 March 2020

Work continues on the important temporary repair project to enhance the resilience of Toddbrook Dam’s auxiliary spillway. Stringent working conditions have been introduced to protect staff against coronavirus, including the use of extra protective equipment and ‘social distancing’ rules.

The effectiveness of the dam’s waterproof clay core has been improved by the installation of a concrete ‘cut off beam’, completed at the end of March. This will be further enhanced by the installation of a crest wall in late April. Sturdy concrete waterproof barriers will be constructed on the spillway slope to channel any overflowing water into the central undamaged section.

The new features will ensure that the spillway is secure in any extreme weather events. They will remain in place until permanent reconstruction of the auxiliary spillway is undertaken – a project which is likely to take several years and cost around £10 million.

The record rainfall totals in February provided a severe test for the pumping system. Everything worked as it should. Our 11 high volume pumps were highly efficient in keeping water levels very low and the reservoir almost drained.

Work to install the clay core ‘cut off beam’. A rail and bogey system has been introduced to reduce manual handling

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

Coming up:

Over the next few weeks we will be repairing boundary walls and clearing vegetation.

In late spring, the temporary works to the dam will be followed by improvements to the Todd Brook inlet structures 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. During normal weather conditions, while the reservoir remains drained, all flow is sent down the bypass channel ie, none into the reservoir.

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 new structure, potentially incorporating a footbridge, to provide a greater degree of control over water flows.

The Trust will continue to monitor the bypass channel closely. 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 (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?

Our weekly surgeries, held every Wednesday at the Transhipment Warehouse by the canal basin, have been suspended until further notice due to the coronavirus.

However, you can still 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: 6 May 2020