Eel Pass Brushes – Environment Agency

For thousands of years, eels have made their annual migrations from the sea, up river and inland to spawning grounds. Unfortunately, these days mankind can often get in the way of traditional migratory pathways. As eels are regarded as an endangered species, it’s important that they can get to their spawning grounds unhindered. The Environment Agency needed an eel pass brush solution that allowed eels to bypass manmade structures such as weirs, as well as ongoing essential river work without becoming trapped.

Because of Cottam’s extensive experience in solving even the knottiest of problems, The Environment Agency approached us to find out if we could help. “The big challenge was that the eels are all different sizes, so it wasn’t a matter of ‘one size fits all’ when it came to developing an eel pass brush,” explains Cottam consultant Nigel Hutchinson. “We were able to offer single brushes or large 1m x 1m sections for bigger area coverage, as well as offering the Agency some ideas and solutions on how to fix the brushes to the riverbed without damaging the delicate ecosystem of the river. We were even able to create brushes that worked in uneven riverbeds and banks so that the eels could follow their traditional courses.”

It may seem strange to think that a simple brush can help to protect an endangered species, but thanks to the eel pass brushes developed by Cottam the eel population in the rivers where the brushes are deployed is now growing. This in turn has led to other customers approaching Cottam, especially building contractors currently working on river management projects.

Andy Don of the Environment Agency explained why the Agency was so happy with the eel pass brushes from Cottam: “We contacted Cottam to design a solution which would provide the same excellent level of performance while adapting to changing environmental and spatial conditions. They developed a solution which is not only effective but can be customised to any installation.”