It has been a while since our last news update! Partly because we have been busy carrying out all kinds of fishy work and partly because our twitter account has taken over as our regular news bulletin. Please follow us for regular updates of our work: https://twitter.com/fishtekconsult
For the last year or so we have been working closely with Jacksonhyder to deliver the fish passage element of the TWGR (Thames Weir Gate Replacement) project, an Environment Agency project that aims to update weir gates on the River Thames and install best practice fish passes. We reported on the completion of the eel pass at Caversham weir last year, which is a novel eel passage solution designed and fabricated by Fishtek that has been installed alongside the updated sluice structure. Further information about Caversham can be found here: https://www.fishtek.co.uk/news.php?page=CgkIBRihk-Ky0yoQr8HftqXN8pJ1.
The second of three sites has since been complete and our Senior Engineer, Mike Lakin, recently went to view the works. The sluice gates at Cookham weir have all been updated and Larinier fish passes have been installed in place of the gates at either end of the weir. The fish pass on the true left bank also contains vertically mounted eel tiles to allow for the upstream passage of European eel. The fish and eel passes were designed by Fishtek as a series of discrete aluminium units that could be assembled on site and lifted into position. This method negates the need for within channel concrete works and the requirement to transport large objects. The main body of the fish pass is formed from a series of aluminium sheets that have been bolted together using webbing plates. Internal struts have been used to strengthen the structure and flanges have been installed to create water tight seals where required. It is a simple and cost effective solution that significantly improves habitat connectivity for migratory species and resident (non-migratory) fish. Along with other works being undertaken within the Thames catchment, the fish passes at Cookham weir contribute to meeting objectives of the Water Framework Directive and will aid with the recovery of the fishery of the wider Thames catchment.
Combined Larinier fish pass and eel pass on the true left bank (viewed from downstream)
Combined Larinier fish pass and eel pass on the true left bank (viewed from upstream)
Larinier fish pass on the true right bank (viewed from downstream true left bank)