New dam overflow spillway structure constructed in Whaley Bridge
We have completed a major phase of its project to restore Toddbrook Reservoir, near Whaley Bridge, with the construction of a new dam overflow spillway structure.
Final weir block is craned into place
After Christmas, further work will continue to connect the new structure to the River Goyt, refill the reservoir and return the construction site to community use again.
The new spillway
The creation of a new dam spillway is key to making the reservoir operational again, after the former auxiliary spillway on the dam wall was damaged in the summer of 2019, following excessive rainfall.
Over the last four years, our contractor Kier has created a new waterside weir, tumble bay, stepped spillway channel and stilling basin, providing a new route for excess water to reach the River Goyt. The total cost of responding to the whole incident is expected to be around £50 million.
Artist impression aerial view of turrets
During spring and summer 2026, the town’s Memorial Park and land around the dam works, will gradually be re-levelled and re-landscaped with hundreds of new shrubs, mature trees and spring bulbs. A new playground will be installed, replacement sailing club constructed, and the football field returned to Whaley Bridge Athletic Football Club.
After the removal of scrub vegetation from the reservoir basin, Toddbrook Reservoir will be allowed to re-fill naturally over the spring and summer in carefully monitored stages, before returning to its primary function of supplying water to the Peak Forest and Macclesfield canals. It will then be restocked with fish towards the end of 2026, after the new reservoir has been thoroughly tested.
The redundant concrete panels on the dam wall are currently being removed, and the entire slope will be grassed over. A popular former walkway across the dam crest is also being replaced and should be available to the public again soon.
Kier site cabins and equipment will gradually be removed over the next few months, with a final withdrawal date of autumn 2026.
Grateful to local residents
Dilwyn Parry, our Toddbrook project manager, said: “We are very grateful to all the local residents for their continuing patience with the construction project. The end is now in sight and by the seventh anniversary of the incident, we should be well on our way to having a beautiful, working reservoir again for everyone to enjoy.
“In advance of re-filling Toddbrook Reservoir, our contractors will remove scrub vegetation which has sprung up below the usual waterline of the reservoir. As this is a Site of Special Scientific Interest due to the presence of a rare dwarf bladder moss, we are working closely with Natural England on a plan to clear trees, weeds and shrubs before the start of the 2026 bird nesting season.
“The reservoir will then be allowed to re-fill naturally over spring and summer 2026 in carefully managed stages. Safety is paramount and the gradual rise in water level will be a phased 16-week, monitored process. The effectiveness of the reservoir will be thoroughly tested to ensure the integrity of the new structure, as levels are held at different heights during the re-filling process.
“The speed of the re-fill will be influenced by the prevailing weather conditions in early 2026, so if we experience a dry spring, the process will be slightly slower than if rainfall is plentiful.”
The section of the bypass channel behind the spillway structureis no longer needed and is being filled in and landscaped
What next?
Planning permission is in place to build a new sailing clubhouse on the edge of the reservoir near the newly constructed weir. Building work is expected to start in spring/summer 2026 and will include a new carpark and launch slipway for boats. The clubhouse is likely to be operational by next winter. The former reservoir keeper’s lodge, which was at one stage considered as an alternative clubhouse, will be put up for sale.
During spring and summer 2026, over a thousand mature trees, shrubs, perennials and ornamental grasses will be planted in the Memorial Park around the playground and on land currently occupied by the construction site.
The planting list includes over 40 mature trees like maple, birch, oak, elm and hornbeam, and 678 shrubs, such as hazel, sweet briar, guilder roses, woolly willow, blackthorn and elder. Over 340 new daffodil bulbs will adorn the park in the spring, supplemented by dozens of other perennials – yarrow, cornflowers, rosemary, sage, sweet woodruff and ornamental grasses.
