A new “fish highway” at Langsett Reservoir on the edge of the Peak District, will allow trout to swim upstream to breeding waters at the top of the Little Don River, for the first time in more than a century.
A weir, installed to trap gravel, had previously prevented the trout getting to calmer spots where they could breed. But a fish pass, installed at Stockbridge in Barnsley by Yorkshire Water and the Environment Agency, will help to increase their populations.
It was opened yesterday – the eve of World Fish Migration Day – by the local MP, Angela Smith.
Dr Ben Gillespie of Yorkshire Water, said the fish pass would allow trout to scale the weir by giving them a gently-sloping channel, with low water velocities and enough depth to let them climb.
“We wanted to maintain the heritage value of the weir and decided that the best option was to build a ‘Larinier’ type fish pass,” Dr Gillespie said.
Dr Jerome Masters, fisheries technical specialist at the Environment Agency, said: “Weirs used to be built without any consideration for wildlife.
“Young trout can be washed downstream from the Little Don into the reservoir during high flows. Until now, these fish would have been stuck in the reservoir, where there are no suitable spawning grounds. Although the trout can survive there, we know they try to swim back into feeder streams to spawn. The new fish pass now gives them the opportunity to do just that.”
The project is one of 14 similar schemes in the region, with others on the River Aire for salmon, and on the rivers Don, Wharfe and Hull.
Part of the Little Don has been designated a site of special scientific interest. Nine years ago, a rare species of newt not usually found in Yorkshire set up home near Langsett, and last year, Yorkshire Water announced a £20m improvement scheme at the reservoir, which supplies 200,000 people in Sheffield and Barnsley.