UK's largest fish pass opens in Nottinghamshire

Construction of the Colwick Fish Pass, at a price of £12m, has opened up the River Trent and its tributaries for coarse and migratory fish, including salmon and trout, as well as eels, making more habitat accessible for fish.

After two years in construction, fish are now able to reach their spawning and feeding grounds.

The structure was officially opened last week by Alan Lovell, chair of the Environment Agency.

Steve Lawrie, area environment manager at the Environment Agency, said: “The fish pass provides a significant step in restoring the River Trent catchment to its former glory for salmon and other coarse and migratory fish.  It also includes an eel pass to help support the critically endangered European eel.

“ We also have a public viewing platform above the water, with highly visual interpretation boards. They inform and advise visitors about the local wildlife in and around the river, including the fish that are expected to use the pass.”

The Colwick fish pass is 200 metres long, six metres deep and 6.5 metres wide. It includes a two-metre-high automated radial gate that constantly monitors the water levels and flow rates in the River Trent. The pass then opens and closes based on the differing water levels throughout the year.

The pass is divided into 20 ascending chambers into which water flows through narrow slots. Fish of all species can swim upstream to lay their eggs in the gravel riverbeds of the Trent tributaries such as the River Dove and the River Derwent. They will be able to pass through these slots and rest in the chamber above before continuing.

The decline of migratory fish in the Trent catchment dates back to the Industrial Revolution, when large weirs were built to open up the river for trade. While some fish were able to overcome these barriers not all of them could.

The Environment Agency has a statutory duty to maintain, improve and develop migratory and freshwater fisheries as set out in the Environment Act 1995.

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