A new future for Toddbrook Reservoir

This summer, the largest-ever engineering works in our ten-year history begins, to permanently restore Toddbrook Reservoir at Whaley Bridge, in Derbyshire. The huge £15M project will ensure long-lasting protection for the reservoir and the community, whilst helping residents enjoy time by water in a newly landscaped park and play area. Crucially, once the reservoir is back in operation it will also supply one third of the water needed by the Peak Forest and Macclesfield canals.

You may recall that in July 2019, a series of severe rainstorms caused the collapse of several concrete panels on the reservoir’s auxiliary spillway. As a safety precaution around 1,500 residents of Whaley Bridge needed to be evacuated. Over a billion litres of water were pumped out of the reservoir to protect the town. It has stayed almost empty ever since as intermediate works provided additional protection to the crest of the auxiliary spillway. Over the next two years, the main stage of the restoration will be completed as a new replacement spillway is built. Essentially, a spillway does the same job as the overflow in your bath. If the reservoir fills too high, due to heavy rainfall or flooding, a spillway safely allows excess water to escape before it spills over the top. The new spillway being built at Toddbrook will have a weir that’s over 70m wide and will carry water along a channel that’s over 200m long to a ‘stilling basin’ that will slow the water down before it meets the River Goyt below. Its design is in line with the latest requirements in

Emergency repairs to the failed spillway in 2019 Water levels in the reservoir have been kept low until repairs are completed

Artist’s impression

Restored dam

New play park

Artist impression of the restored dam crest, new weir and spillway

reservoir safety and takes into consideration the future impacts of climate change, ensuring it can deal with exceptional rainfalls, like those seen back in 2019. As principal engineer Alistair Lobban says: “The new spillway is ready for the most extreme flooding events we can foresee; it could carry more than double the amount of water as could be expected in a 1 in 10,000 year flood.” Project manager, Tom Greenwood, says the new spillway will fulfil all the necessary reservoir safety requirements, manage longerterm impacts to the local area and, where appropriate, incorporates improvements to the surrounding landscape: “Our design leading into Memorial Park is more open, helping people enjoy the water. It includes features such as stepping-stones, a new footbridge, viewing platforms, plus terracing so people can sit comfortably by the water. There will be a high quality children’s play-ground, new walking routes and a new home for the reservoir’s sailing club. We have worked very closely with our stakeholders to achieve these in the design. We have had to fell some trees in order to start construction, but many more will be planted on completion, so there will be a biodiversity net gain overall.” Working with the local community has been vital, as Tom acknowledges: “It’s challenging working in such a constrained location, so engaging constructively with our neighbours has been key to finding the right solution. We appreciate what people went through in the 2019 incident and we’ve made every effort to be open, transparent and bring people with us.” It’s a view confirmed by Neville Clarke, founder of the Whaley Bridge Canal Group at the nearby Transhipment Warehouse community centre: “My sense is that the town is pleased work is going ahead and is looking forward to the improvements it will bring. Most locals are positive, knowing the town will have a longlasting, safe and attractive reservoir on their doorstep.”

Community groups gather at the newly restored Transhipmrnt Warehouse

Viewing turrets

Spillway and stilling basin