Fish Pass Brush – Bailey Contracts Ltd
Bailey Contracts Ltd are a Civil Engineering Contractor specialising in working within and around water courses including Fish Passes, Hydroelectric Plants, Bridges and retaining structures.
Bailey Contracts were contracted by Severn Rivers Trust to build a fish pass system near Fromebridge Mill in Whitminster, Gloucestershire. Fishtek Consulting, who designed the system, are regular customers of Cottam and recommended that Bailey approach us to discuss the project and their requirements.
This fish pass system is part of a wider Salmon to Salmon Springs project run by Severn Rivers Trust. The weir at Fromebridge Mill is approximately 14.7m wide, with an approximate head height of 2m, and is one of several barriers to fish migration on the River Frome. By building a multi-species fish passage, this allows fish to move upstream beyond the weir, and tackles larger issues surrounding access and habitat quality.
Many fish species migrate during their lifetime for a variety of reasons, including feeding, seeking shelter, finding a mate, or avoiding predators.
When infrastructure such as watermills were built during the industrial revolution, rivers were usually diverted around them. This, along with other manmade structures (such as weirs) cause barriers to fish migration, leading to decreasing populations. Where it isn’t possible to remove these barriers (for heritage reasons, for example), fish pass structures can be installed to assist migration.
Based on the size and scale of the fish pass project, as well as the water flows, it was determined that a Fish solution needed to be constructed with 70 brushes being required. These brushes are an integral part of the system as they guide the fish as they swim through the system.
Bailey Contracts sent details of the fish pass, as well as plans of the surrounding area as part of their quote request stage. Cottam’s engineers used these plans to recommend the best bristle filaments and manufacturing method, as well as provide a detailed quote for the brushes, which was approved.
The fish pass system was successfully installed in April. Over the next 12 months, breeding numbers will be monitored to track the impact the pass has had on fish populations, but early indications are that this was a successful project.
